light metal systems. part 1: selected systems from ag-al-cu to al-cu-er

Landolt-BörnsteinNumerical Data and Functional Relationships in Science and TechnologyNew Series / Editor in Chief: W. Martienssen

Group IV: Physical ChemistryVolume 11

Ternary Alloy SystemsPhase Diagrams, Crystallographic and Thermodynamic Data

critically evaluated by MSIT®

Subvolume ALight Metal Systems

Part 1Selected Systems from Ag-Al-Cu to Al-Cu-Er

EditorsG. Effenberg and S. Ilyenko

AuthorsMaterials Science International Team, MSIT®

ISSN 1615-2018 (Physical Chemistry)

ISBN 3-540-20190-4 Springer-Verlag Berlin Heidelberg New York

Library of Congress Cataloging in Publication Data

Zahlenwerte und Funktionen aus Naturwissenschaften und Technik, Neue Serie

Editor in Chief: W. Martienssen

Vol. IV/11A1: Editors: G. Effenberg and S. Ilyenko

At head of title: Landolt-Börnstein. Added t.p.: Numerical data and functional relationships in science and technology.

Tables chiefly in English.

Intended to supersede the Physikalisch-chemische Tabellen by H. Landolt and R. Börnstein of which the 6th ed. began

publication in 1950 under title: Zahlenwerte und Funktionen aus Physik, Chemie, Astronomie, Geophysik und Technik.

Vols. published after v. 1 of group I have imprint: Berlin, New York, Springer-Verlag

Includes bibliographies.

1. Physics--Tables. 2. Chemistry--Tables. 3. Engineering--Tables.

I. Börnstein, R. (Richard), 1852-1913. II. Landolt, H. (Hans), 1831-1910.

III. Physikalisch-chemische Tabellen. IV. Title: Numerical data and functional relationships in science and technology.

QC61.23 02'.12 62-53136

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Editor: G. Effenberg

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Materials Science International Services GmbHPostfach 800749, D-70507, Stuttgart, Germanyhttp://www.matport.com

Author: Materials Science International Team, MSIT®

The present series of books results from collaborative evaluation programs authored by MSIT® in whichdata and knowledge are contributed by many individuals and accumulated over almost twenty years.Authors for the evaluations in this volume are:

Ibrahim Ansara†, Grenoble, France

Oger Arkens, Leuven, Belgium

Laura Arrighi, Genova, Italy

Nataliya Bochvar, Moscow, Russia

Oksana Bodak, L’viv, Ukraine

Anatoliy Bondar, Kyiv, Ukraine

Yong Du, Changsha, China

Günter Effenberg, Stuttgart, Germany

Riccardo Ferro, Genova, Italy

Gautam Ghosh, Evanston, USA

Bernd Grieb, Tübingen, Germany

Joachim Gröbner, Clausthal-Zellerfeld, Germany

Andriy Grytsiv, Wien, Austria

Leonid Guzei, Moscow, Russia

Fred Hayes, Manchester, UK

Ernst-Theo Henig, Stuttgart, Germany

Kiyohito Ishida, Sendai, Japan

Kazuhiro Ishikawa, Sendai, Japan

Volodymyr Ivanchenko, Kyiv, Ukraine

Ryosuke Kainuma, Sendai, Japan

Kostyantyn Kornienko, Kyiv, Ukraine

Ortrud Kubaschewski, Aachen, Germany

K.C. Hari Kumar, Chennai, India

Viktor Kuznetsov, Moscow, Russia

Hans Leo Lukas, Stuttgart, Germany

Pierre Perrot, Lille, France

Alexander Pisch, Grenoble, France

Qingsheng Ran, Stuttgart, Germany

Paola Riani, Genova, Italy

Peter Rogl, Wien, Austria

Lazar L. Rokhlin, Moscow, Russia

Eberhard E. Schmid, Frankfurt, Germany

Rainer Schmid-Fetzer, Clausthal-Zellerfeld, Germany

Gerhard Schneider, Stuttgart, Germany

Hans J. Seifert, Stuttgart, Germany

Vladislav Sidorko, Kyiv, Ukraine

Sibylle Stiltz, Stuttgart, Germany

Vasyl Tomashik, Kyiv, Ukraine

Tamara Velikanova, Kyiv, Ukraine

Yuriy Voroshilov, Uzhorod, Ukraine

Andy Watson, Leeds, UK

Patric Wollants, Leuven, Belgium

Institutions

The content of this volume is produced by Materials Science International Services GmbH and its international team of materials scientists, MSIT®. Contributions to this volume have ben made from the following institutions:

The Baikov Institute of Metallurgy, Academy of

Sciences Moscow, Russia

Central South University, Research Institute of

Powder Metallurgy, State Key Laboratory for

Powder Metallurgy, Changsha, China

ENSEEG, Laboratoire de Thermodynamique et

Physico-Chimie Metallurgiques, Domaine

Universitaire Saint Martin d’Heres, Cedex, France

I.M. Frantsevich Institute for Problems of

Materials Science, National Academy of Sciences,

Kyiv, Ukraine

Indian Institute of Technology Madras, Department of Metallurgical Engineering, Chennai, India

Institute for Semiconductor Physics, National

Academy of Sciences, Kyiv, Ukraine

Katholieke Universiteit Leuven, Department

Metaalkunde en Toegepaste Materiaalkunde,

Heverlee, Belgium

G.V. Kurdyumov Institute for Metal Physics,

National Academy of Sciences, Kyiv, Ukraine

Magnequench Europe, Tübingen, Germany

Materials Science International Services GmbH,

Stuttgart, Germany

Max-Planck-Institut für Metallforschung,

Institut für Werkstoffwissenschaft,

Pulvermetallurgisches Laboratorium, Stuttgart,

Germany

Moscow State University, Chemical Faculty,

Moscow, Russia

National University of L’viv, Kathedra of

Inorganic Chemistry, L’viv, Ukraine

Northwestern University, Department of Materials

Science and Engineering, Evanston, USA

Technische Universität Clausthal, Metallurgisches

Zentrum, Clausthal-Zellerfeld, Germany

Tohoku University, Department of Materials,

Science Graduate School of Engineering, Sendai,

Japan

Universita di Genova, Dipartimento di Chimica,

Genova, Italy

Universite de Lille I, Laboratoire de Métallurgie Physique, Villeneuve d’ASCQ, Cedex, France

Universität Wien, Institut für Physikalische

Chemie, Wien, Austria

University of Leeds, Department of Materials,

School of Process, Environmental and Materials

Engineering, Leeds, UK

Uzhgorod State University, Uzhgorod, Ukraine

Preface

The sub-series Ternary Alloy Systems of the Landolt-Börnstein New Series provides reliable andcomprehensive descriptions of the materials constitution, based on critical intellectual evaluations of alldata available at the time. The first four volumes contain evaluation reports on selected ternary systems ofimportance to industrial light alloy development and systems which gained in the recent years otherwisescientific interest in the area of light metal systems. In a ternary materials system, however, one may findalloys for various applications, not only light alloys, depending on the chosen composition.

Reliable phase diagrams provide scientists and engineers with basic information of eminent importancefor fundamental research and for the development and optimization of materials. So collections of suchdiagrams are extremely useful, if the data on which they are based have been subjected to critical evaluation,like in these volumes. Critical evaluation means: there where contradictory information is published dataand conclusions are being analyzed, broken down to the firm facts and re-interpreted in the light of allpresent knowledge. Depending on the information available this can be a very difficult task to achieve.Critical evaluations establish descriptions of reliably known phase configurations and related data.

The evaluations are performed by MSIT®, Materials Science International Team, a group which workstogether since almost 20 years, now. Within this team skilled expertise is available for a broad range ofmethods, materials and applications. This joint competence is employed in the critical evaluation of theoften conflicting literature data. Particularly helpful in this are targeted thermodynamic calculations forindividual equilibria, driving forces or complete phase diagram sections.

Insight in materials constitution and phase reactions is gained from many distinctly different types ofexperiments, calculation and observations. Intellectual evaluations which interpret all data simultaneouslyreveal the chemistry of a materials system best. The conclusions on the phase equilibria may be drawn fromdirect observations e.g. by microscope, from monitoring caloric or thermal effects or measuring propertiessuch as electric resistivity, electro-magnetic or mechanical properties. Other examples of useful methods inmaterials chemistry are mass-spectrometry, thermo-gravimetry, measurement of electro-motive forces, X-ray and microprobe analyses. In each published case the applicability of the chosen method has to bevalidated, the way of actually performing the experiment or computer modeling has to be validated and theinterpretation of the results with regard to the material’s chemistry has to be verified.

An additional degree of complexity is introduced by the material itself, as the state of the material undertest depends heavily on its history, in particular on the way of homogenization, thermal and mechanicaltreatments. All this is taken into account in an MSIT expert evaluation.

To include binary data in the ternary evaluation is mandatory. Each of the three-dimensional ternaryphase diagrams has edge binary systems as boundary planes; their data have to match the ternary datasmoothly. At the same time each of the edge binary systems A-B is a boundary plane for many ternary A-B-X systems. Therefore combining systematically binary and ternary evaluations can lead to a new level ofconfidence and reliability in both ternary and binary phase diagrams. This has started systematically for thefirst time here, by the MSIT® Evaluation Programs applied to the Landolt-Börnstein New Series.

The multitude of correlated or inter-dependant data requires special care. Within MSIT® an evaluationroutine has been established that proceeds knowledge driven and applies both, human based expertise andelectronically formatted data and software tools. MSIT® internal discussions take place in almost allevaluations and on many different specific questions, adding the competence of a team to the work ofindividual authors. In some cases the authors of earlier published work contributed to the knowledge baseby making their original data records available for re-interpretation. All evaluation reports published herehave undergone a thorough review process in which the reviewers had access to all the original data.

In publishing we have adopted a standard format that presents the reader with the data for each ternarysystem in a concise and consistent manner. Special features of the compendium and the standard format areexplained in the Introduction to the volumes.

In spite of the skill and labor that have been put into this volume, it will not be faultless. All criticismsand suggestions that can help us to improve our work are very welcome. Please contact us [email protected]. We hope that this volume will prove to be an as useful tool for the materialsscientist and engineer as the other volumes of Landolt-Börnstein New Series and the previous works ofMSIT® have been. We hope that the Landolt Börnstein Sub-series, Ternary Alloy Systems will be wellreceived by our colleagues in research and industry.

On behalf of the participating authors I want to thank all those who contributed their comments andinsight during the evaluation process. In particular we thank the reviewers. Their names are as follows:Pierre Perrot, Hans Leo Lukas, Hans Stadelmaier, Tamara Velikanova, Gabriele Cacciamani, AlexanderPisch, Oksana Bodak, Hari Kumar, Rainer Schmid-Fetzer, Peter Rogl, Benjamin Grushko, Andy Watson,Lazar Rokhlin, Nathalie Lebrun.

We all gratefully acknowledge the skilled scientific and technical coordination by Dr. Svitlana Ilyenkoand the editorial team: Dr. Larisa Plashnitsa, Dr. Oleksandra Berezhnytska, Dr. Oleksandr Dovbenko, Ms.Natalya Bronska.

Dr. G. Effenberg Stuttgart, October 2003

Contents

IV/11A1 Ternary Alloy SystemsPhase Diagrams, Crystallographic and Thermodynamic Data

Subvolume A Light Metal Systems

Part 1 Selected Systems from Ag-Al-Cu to Al-Cu-Er

IntroductionData Covered . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . XIGeneral . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . XIStructure of a System Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . XI

Literature Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . XIBinary Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . XISolid Phases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . XIIPseudobinary Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .XIIIInvariant Equilibria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .XIIILiquidus, Solidus, Solvus Surfaces. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .XIIIIsothermal Sections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .XIIITemperature – Composition Sections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .XIIIThermodynamics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .XIIINotes on Materials Properties and Applications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .XIIIMiscellaneous . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .XIIIReferences. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .XVI

General References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . XVII

Ternary SystemsAg–Al–Cu (Silver – Aluminium – Copper) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Ag–Al–Mg (Silver – Aluminium – Magnesium) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8Ag–Al–Ti (Silver – Aluminium – Titanium) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16Ag–Cu–Mg (Silver – Copper – Magnesium) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23Al–B–C (Aluminium – Boron – Carbon) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29Al–B–Mg (Aluminium – Boron – Magnesium) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52Al–B–N (Aluminium – Boron – Nitrogen). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56Al–B–Ni (Aluminium – Boron – Nickel) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67Al–B–Ti (Aluminium – Boron – Titanium) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80Al–Be–Cu (Aluminium – Beryllium – Copper) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102Al–Be–Mg (Aluminium – Beryllium – Magnesium) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115Al–C–Fe (Aluminium – Carbon – Iron) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123Al–C–Si (Aluminium – Carbon – Silicon) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139Al–Ca–Li (Aluminium – Calcium – Lithium) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146Al–Ca–Si (Aluminium – Calcium – Silicon) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150Al–Cd–Cu (Aluminium – Cadmium – Copper) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159Al–Cd–Mg (Aluminium – Cadmium – Magnesium) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168

Al–Ce–Co (Aluminium – Cerium – Cobalt). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174Al–Ce–Cu (Aluminium – Cerium – Copper) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181Al–Ce–Fe (Aluminium – Cerium – Iron) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196Al–Co–Fe (Aluminium – Cobalt – Iron) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206Al–Co–Gd (Aluminium – Cobalt – Gadolinium) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217Al–Co–Hf (Aluminium – Cobalt – Hafnium). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224Al–Co–Mn (Aluminium – Cobalt – Manganese) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229Al–Co–Ni (Aluminium – Cobalt – Nickel) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246Al–Co–Ti (Aluminium – Cobalt – Titanium). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289Al–Co–Y (Aluminium – Cobalt – Yttrium) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303Al–Cr–Cu (Aluminium – Chromium – Copper). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310Al–Cr–Fe (Aluminium – Chromium – Iron) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320Al–Cr–Mg (Aluminium – Chromium – Magnesium). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 351Al–Cr–Nb (Aluminium – Chromium – Niobium) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 360Al–Cr–Ni (Aluminium – Chromium – Nickel) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 371Al–Cr–Si (Aluminium – Chromium – Silicon) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 411Al–Cr–Zr (Aluminium – Chromium – Zirconium) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 421Al–Cu–Dy (Aluminium – Copper – Dysprosium) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 431Al–Cu–Er (Aluminium – Copper – Erbium) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 439

CD-ROM providing interactive access to the system reports of this volume

Survey of Volume IV/11A1

Ternary Alloy SystemsPhase Diagrams, Crystallographic andThermodynamic Data

critically evaluated by MSIT®

Light Metal Systems Subvolume A

Selected Systems from Ag-Al-Cu to Al-Cu-Er Part 1

Selected Systems from Al-Cu-Fe to Al-Fe-Ti Part 2

Selected Systems from Al-Fe-V to Al-Ni-Zr (tentative) Part 3

Selected Systems from Al-Si-Ti to N-Ti-V (tentative) Part 4

Noble Metal Systems Subvolume B

Non-Ferrous Metal Systems Subvolume C

Iron Systems Subvolume D

Refractory Metal Systems Subvolume E

XI

Landolt-BörnsteinNew Series IV/11A1

MSIT®

Introduction

Introduction

Data Covered

The series focuses on light metal ternary systems and includes phase equilibria of importance for alloydevelopment, processing or application, reporting on selected ternary systems of importance to industriallight alloy development and systems which gained otherwise scientific interest in the recent years.

General

The series provides consistent phase diagram descriptions for individual ternary systems. Therepresentation of the equilibria of ternary systems as a function of temperature results in spacial diagramswhose sections and projections are generally published in the literature. Phase equilibria are described interms of liquidus, solidus and solvus projections, isothermal and pseudobinary sections; data on invariantequilibria are generally given in the form of tables.

The world literature is thoroughly and systematically searched back to the year 1900. Then, thepublished data are critically evaluated by experts in materials science and reviewed. Conflicting informationis commented upon and errors and inconsistencies removed wherever possible. It considers those, and onlythose data, which are firmly established, comments on questionable findings and justifies re-interpretationsmade by the authors of the evaluation reports.

In general, the approach used to discuss the phase relationships is to consider changes in state and phasereactions which occur with decreasing temperature. This has influenced the terminology employed and isreflected in the tables and the reaction schemes presented.

The system reports present concise descriptions and hence do not repeat in the text facts which canclearly be read from the diagrams. For most purposes the use of the compendium is expected to be self-sufficient. However, a detailed bibliography of all cited references is given to enable original sources ofinformation to be studied if required.

Structure of a System Report

The constitutional description of an alloy system consists of text and a table/diagram section which areseparated by the bibliography referring to the original literature (see Fig. 1). The tables and diagrams carrythe essential constitutional information and are commented on in the text if necessary.

Where published data allow, the following sections are provided in each report:

Literature Data

The opening text reviews briefly the status of knowledge published on the system and outlines theexperimental methods that have been applied. Furthermore, attention may be drawn to questions which arestill open or to cases where conclusions from the evaluation work modified the published phase diagram.

Binary Systems

Where binary systems are accepted from standard compilations reference is made to these compilations.In other cases the accepted binary phase diagrams are reproduced for the convenience of the reader. Theselection of the binary systems used as a basis for the evaluation of the ternary system was at the discretionof the assessor.

XII


MSIT®

Introduction

Solid Phases

The tabular listing of solid phases incorporates knowledge of the phases which is necessary or helpfulfor understanding the text and diagrams. Throughout a system report a unique phase name and abbreviationis allocated to each phase.

Phases with the same formulae but different space lattices (e.g. allotropic transformation) aredistinguished by:

– small letters (h), high temperature modification (h2 > h1)(r), room temperature modification(1), low temperature modification (l1 > l2)

– Greek letters, e.g., , '– Roman numerals, e.g., (I) and (II) for different pressure modifications.In the table “Solid Phases” ternary phases are denoted by * and different phases are separated by

horizontal lines.

Heading

Literature Data

Binary Systems

Solid Phases

Pseudobinary Systems

Invariant Equilibria

Liquidus, Solidus, Solvus Surfaces

Isothermal Sections

Miscellaneous

Miscellaneous

Isothermal Sections




Solid Phases

Binary Systems

Text

References

Tables anddiagrams

Temperature-Composition Sections


Thermodynamics

Materials Properties and Applications

Thermodynamics

Materials Properties and Applications

Fig. 1: Structure of a system report

XIII


MSIT®

Introduction


Pseudobinary sections describe equilibria and can be read in the same way as binary diagrams. The notationused in pseudobinary systems is the same as that of vertical sections, which are reported under“Temperature-Composition Sections”.


The invariant equilibria of a system are listed in the table “Invariant Equilibria” and, where possible, aredescribed by a constitutional “Reaction Scheme” (Fig. 2).

The sequential numbering of invariant equilibria increases with decreasing temperature, one numberingfor all binaries together and one for the ternary system.

Equilibria notations are used to indicate the reactions by which phases will be– decomposed (e- and E-type reactions)– formed (p- and P-type reactions)– transformed (U-type reactions)For transition reactions the letter U (Übergangsreaktion) is used in order to reserve the letter T to denote

temperature. The letters d and D indicate degenerate equilibria which do not allow a distinction accordingto the above classes.


The phase equilibria are commonly shown in triangular coordinates which allow a reading of theconcentration of the constituents in at.%. In some cases mass% scaling is used for better data readability(see Figs. 3 and 4).

In the polythermal projection of the liquidus surface, monovariant liquidus grooves separate phaseregions of primary crystallization and, where available, isothermal lines contour the liquidus surface (seeFig. 3).

Isothermal Sections

Phase equilibria at constant temperatures are plotted in the form of isothermal sections (see Fig. 4).

Temperature – Composition Sections

Non-pseudobinary T-x sections (or vertical sections, isopleths, polythermal sections) show the phasefields where generally the tie lines are not in the same plane as the section. The notation employed for thelatter (see Fig. 5) is the same as that used for binary and pseudobinary phase diagrams.

Thermodynamics

Experimental ternary data are reported in some system reports and reference to thermodynamicmodelling is made.

Notes on Materials Properties and Applications

Noteworthy physical and chemical materials properties and application areas are briefly reported if theywere given in the original constitutional and phase diagram literature.

Miscellaneous

In this section noteworthy features are reported which are not described in preceding paragraphs. Theseinclude graphical data not covered by the general report format, such as lattice spacing – composition data,p-T-x diagrams, etc.

XIV


MSIT®

Introduction

Fig

. 2:

T

ypic

alre

acti

on s

chem

e

Ag-T

lT

l-B

iB

i-A

gA

g-T

l-B

i

(Tl)

(h)

(T

l)(r

),(A

g)

23

4d

1l

(A

g)

+ (

Bi)

26

1e 5

(Ag

) +

(T

l)(h

) +

Tl 3

Bi

L +

Tl 3

Bi

(A

g)

+ (

Tl)

(h)

28

9U

1

l (

Ag

)+(T

l)(h

)

29

1e 3

l (

Tl)

(h)+

Tl 3

Bi

30

3e 1

l (

Bi)

+T

l 2B

i 3

20

2e 7

l T

l 3B

i+T

l 2B

i 3

19

2e 8

(Tl)

(h)

Tl 3

Bi+

(Tl)

(r)

14

4e 9

L (

Ag

) +

Tl 3

Bi

29

4e 2

(max

)

L (

Ag

) +

(T

l)(h

)

28

9e 4

(min

)

L (

Ag

) +

Tl 2

Bi 3

20

7e 6

(max

)

(Ag

)+(B

i)+

Tl 2

Bi 3

L (

Ag)+

(Bi)

+T

l 2B

i 31

97

E1

(Ag

)+(T

l)(r

)+T

l 3B

i

(Tl)

(h)

Tl 3

Bi

+ (

Tl)

(r),

(Ag

)1

44

D1

(Ag

)+T

l 3B

i+T

l 2B

i 3

L (

Ag

)+T

l 3B

i+T

l 2B

i 31

88

E2

seco

nd b

inar

y

eute

ctic

rea

ctio

nfi

rst

bin

ary e

ute

ctic

rea

ctio

n

(hig

hes

t te

mper

ature

)te

rnar

y m

axim

um

reac

tion

tem

per

ature

of

26

1°C

mo

no

var

iant

equil

ibri

um

sta

ble

do

wn

to

lo

w

tem

per

ature

s

seco

nd

tern

ary

eute

ctic

reac

tion

equat

ion o

f eu

tect

oid

reac

tion a

t 144°C

XV


MSIT®

Introduction

20

40

60

80

20 40 60 80

20

40

60

80

A B

C Data / Grid: at.%

Axes: at.%

δ700

p1

500

400

400°C

γ

300

U e1

700

500

β(h)

400

300

E

300

α400

e2

500°C isotherm, temperature is usualy in °C

liquidus groove to decreasing temperatures

estimated 400°C isotherm

limit of known region

ternary invariantreaction

binary invariantreaction

primary γ-crystallization

20

40

60

80

20 40 60 80

20

40

60

80

A B

C Data / Grid: mass%

Axes: mass%

L+γ

γ+β(h)

L+γ+β(h)

β(h)

L+β(h)

L

L+α

α

phase field notation

estimated phase boundary

tie line

three phase field (partially estimated)

experimental points(occasionally reported)

limit of known region

phase boundary

γ

Fig. 3: Hypothetical liquidus surface showing notation employed

Fig. 4: Hypothetical isothermal section showing notation employed

XVI


MSIT®

Introduction

References

The publications which form the bases of the assessments are listed in the following manner:[1974Hay] Hayashi, M., Azakami, T., Kamed, M., “Effects of Third Elements on the Activity of Lead

in Liquid Copper Base Alloys” (in Japanese), Nippon Kogyo Kaishi, 90, 51-56 (1974) (Experimental,Thermodyn., 16)

This paper, for example, whose title is given in English, is actually written in Japanese. It was publishedin 1974 on pages 51- 56, volume 90 of Nippon Kogyo Kaishi, the Journal of the Mining and MetallurgicalInstitute of Japan. It reports on experimental work that leads to thermodynamic data and it refers to 16 cross-references.

Additional conventions used in citing are:# to indicate the source of accepted phase diagrams* to indicate key papers that significantly contributed to the understanding of the system.Standard reference works given in the list “General References” are cited using their abbreviations and

are not included in the reference list of each individual system.

60 40 200

250

500

750

A 80.00B 0.00C 20.00

A 0.00B 80.00C 20.00Al, at.%

Tem

pera

ture

, °C

L

32.5L+β(h)

β(r) - room temperature

β(r)

L+α+β(h)

α+β(h)

α

L+α

phase field notation

concentration ofabscissa element

alloy compositionin at.%

β(h)

modification

β(h) - high temperaturemodification188

temperature, °C

Fig. 5: Hypothetical vertical section showing notation employed

XVII


MSIT®

Introduction

General References

[E] Elliott, R.P., Constitution of Binary Alloys, First Supplement, McGraw-Hill, New York(1965)

[G] Gmelin Handbook of Inorganic Chemistry, 8th ed., Springer-Verlag, Berlin [H] Hansen, M. and Anderko, K., Constitution of Binary Alloys, McGraw-Hill, New York

(1958) [L-B] Landolt-Boernstein, Numerical Data and Functional Relationships in Science and

Technology (New Series). Group 3 (Crystal and Solid State Physics), Vol. 6, Eckerlin, P.,Kandler, H. and Stegherr, A., Structure Data of Elements and Intermetallic Phases (1971);Vol. 7, Pies, W. and Weiss, A., Crystal Structure of Inorganic Compounds, Part c, KeyElements: N, P, As, Sb, Bi, C (1979); Group 4: Macroscopic and Technical Properties of

Matter, Vol. 5, Predel, B., Phase Equilibria, Crystallographic and Thermodynamic Data of

Binary Alloys, Subvol. a Ac-Au ... Au-Zr (1991); Springer-Verlag, Berlin. [Mas] Massalski, T.B. (Ed.), Binary Alloy Phase Diagrams, ASM, Metals Park, Ohio (1986) [Mas2] Massalski, T.B. (Ed.), Binary Alloy Phase Diagrams, 2nd edition, ASM International,

Metals Park, Ohio (1990) [P] Pearson, W.B., A Handbook of Lattice Spacings and Structures of Metals and Alloys,

Pergamon Press, New York, Vol. 1 (1958), Vol. 2 (1967) [S] Shunk, F.A., Constitution of Binary Alloys, Second Supplement, McGraw-Hill, New York

(1969) [V-C] Villars, P. and Calvert, L.D., Pearson's Handbook of Crystallographic Data for

Intermetallic Phases, ASM, Metals Park, Ohio (1985) [V-C2] Villars, P. and Calvert, L.D., Pearson's Handbook of Crystallographic Data for

Intermetallic Phases, 2nd edition, ASM, Metals Park, Ohio (1991)

1


MSIT®

Ag–Al–Cu

Silver – Aluminium – Copper

K.C. Hari Kumar and Oger Arkens

Literature Data

The liquidus surface and isotherms were investigated by [1930Uen]. In a review article by [1977Cha] these

data were corrected in order to be consistent with then accepted binary phase diagrams, especially along the

Al-Cu edge. The first evaluation within the ongoing MSIT Evaluation Programs was made by [1990Ark],

which is updated by the present work. Employing metallographic technique [1961Pan] determined phase

equilibria near the Cu-rich corner at 500 and 700°C. Using optical microscopy, X-ray diffraction and

electron microprobe analysis [1973Mas] determined phase relationships in the temperature range 575 to

625°C along the Ag-Cu side of the ternary systems. Their results are generally not in agreement with that

of [1961Pan]. They also concluded that small additions of Cu to Ag3Al(h) phase stabilizes it well below the

temperature of existence in the binary. Liquidus in the region Al-Al2Cu-Ag2Al was investigated by

[1983Liu] using thermal analysis. They identified a ternary eutectic reaction at 500°C and claimed that the

section Al2Cu-Ag2Al is pseudobinary, with a monovariant maximum at 527°C. [1989Ado1, 1989Ado2]

established isothermal phase relationships along the Ag-Cu edge of the ternary at 500, 650 and 850°C by

analyzing samples prepared from high purity starting materials, employing X-ray diffraction,

metallography, thermal analysis and electron microprobe analysis. Their results are in agreement with that

of [1973Mas], except that they could not observe any extended stability for the Ag3Al(h) phase. The

isothermal section at 850°C should be treated as metastable since the fcc miscibility gap originating from

Ag-Cu system is still present in the section. Moreover, this section is above the eutectic temperature of the

Ag-Cu system and therefore liquid phase also should be present. [2000Fla] measured the partial enthalpies

of components in the liquid phase and thereby integral enthalpies of mixing of liquid alloys at 873°C using

a drop-calorimeter. Measurements were performed starting from pure Al to about 40 at.% Al along three

sections with Ag:Cu ratios of about 1:3, 1:1 and 3:1. The partial enthalpies of mixing of the components of

liquid alloys at 979°C were determined using a high-temperature isoperibolic calorimeter [2002Wit].

Measurements were performed starting from both pure Al and from binary liquid Ag-Cu alloys along

sections with constant Ag:Cu ratios 1:3, 1:1, and 3:1. The integral enthalpies of mixing of these ternary

alloys are calculated from the partial enthalpies of mixing using different methods. It was found that the

partial enthalpy of Cu reported by [2000Fla] for all sections from are about 8 kJ·mol-1 more negative in

comparison with data of [2002Wit].

[1997Lim] modelled the Gibbs energy functions of the stable phases in the ternary system using the Calphad

approach. They calculated the isothermal section at 575°C and the liquidus projection pertaining to the

Al-corner.

Binary Systems

The binary systems used in the present evaluations are: Al-Cu [2003Gro], Ag-Al [1995Lim] and Ag-Cu

[2003Van].

Solid Phases

The known binary phases are listed in Table 1. No ternary phase is formed in the Al-rich corner up to Ag2Al

and to CuAl2, and not at the Ag-Cu-side up to 37 at.% Al, 63 at.% Cu and 50 at.% Ag, 50 at.% Al.


The existence of a pseudobinary section Ag2Al-Al2Cu is reported by [1983Liu]. Only the monovariant

eutectic maximum (e6, L + ) is reported using DTA measurements: 527°C at the composition

21.8Ag-55.8Al-22.4Cu (at.%).

2


MSIT®

Ag–Al–Cu


Certain plausible invariant equilibria in the system were discussed by [1925Got, 1976Mon, 1977Cha]. A

ternary eutectic reaction L (Al)+ + occurring at 500°C is reported by [1983Liu]. Composition of the

liquid phase is given in Table 2.

Liquidus Surface

Figure 1 shows the liquidus projection along with few isotherms for the region Al-Al2Cu-Ag2Al as

investigated by [1983Liu]. Liquidus data reported by [1930Uen] is not used here due to inconsistencies with

binary systems. It should be noted that [1930Uen] determined the liquidus projection at a time when little

was known about the binary systems and even the liquidus projection proposed by [1977Cha] ignores many

reactions originating from the binaries Al-Cu and Ag-Al.

Isothermal Sections

The isothermal section at 625°C in the 0 to 40 at.% Al region is shown in Fig. 2. It is adapted from

[1973Mas]. [1973Mas] also reports the 575°C isotherm, which is essentially similar to Fig. 3, except for a

small three-phase region (Ag)+ 2+ appearing just inside the Ag-Al binary line at about 2.7 at.% Ag. Figure

3 depicts isothermal section at 500°C. It is based on the data from [1989Ado1, 1989Ado2].

Thermodynamics

The evaluated integral enthalpy of mixing of liquid alloys demonstrates that the minimum for the Ag-Al-Cu

is at -17.1 kJ·mol-1 corresponding to the binary composition Al4Cu6. Figure 4 is taken from [2002Wit], that

depicts isoenthalpy contours calculated using fitted equations.

References

[1925Got] Goto, S., Tokushicki, M., “On some Aluminium Alloys, 2nd Report” (in Japanese), J. Min.

Metall. Inst. Japan, 1-17 (1925) (Experimental, Equi. Diagram, 2)

[1930Uen] Ueno, S., “On the Ternary Silver Alloys IV Mechanical Properties of some Ternary Silver

Alloys”, Kyoto Imp. Univ., 57, 78-83 (1930) (Equi. Diagram, Experimental, 2)

[1931Pre] Preston, G.D., “An X-Ray Investigation of some Copper-Aluminium Alloys”, Philos. Mag.,

12, 980-993 (1931) (Crys. Structure, Experimental, 11)

[1961Pan] Panseri, C, Leoni, M., “The Constitution of Ternary Alloys of Cu, Al and Ag Containing

High Percentages of Cu” (in Italian), Allumino, 30, 289-298 (1961) (Equi. Diagram,

Experimental, 8)

[1973Mas] Massalski, T.B., Perepezko, J.H., “Constitution and Phase Relationships in

Copper-Silver-Aluminium Ternary System”, Z. Metallkd., 64, 176-181 (1973)

(Experimental, Equi. Diagram, *, 17)

[1976Mon] Mondolfo, L.F., “Aluminium Alloys - Structure and Properties”, Butterworth, 420-421

(1976) (Review, Crys. Structure, Phys. Prop., 13)

[1977Cha] Chang, Y.A., Goldberg, D., Neumann, J.P., “Phase Diagrams and Thermodynamic

Properties of Ternary Copper-Silver Systems”, J. Phys. Chem. Ref. Data, 6, 621-673 (1977)

(Review, Equi. Diagram, Crys. Structure, Thermodyn., #, 3)

[1983Liu] Liu-Shuqi, Zhao-Shimin, Zhang-Qiyun, “Phase Diagram of the Aluminium-Copper-Silver

Alloy System” (in Chinese), Acta Metall. Sin., 19, 70-73 (1983) (Experimental, Equi.

Diagram, 9)

[1985Mur] Murray, J.L., “The Aluminium-Copper System”, Int. Met. Rev., 30, 211-233 (1985) (Equi.

Diagram, Review, #, 230)

[1989Ado1] Adorno, A.T., Cilense, M., Garlipp, W., “Phase Relationships in the

Copper-Silver-Aluminum Ternary System, near the Copper-Rich Corner”, J. Mater. Sci.

Lett., 8(11), 1294-1297 (1989) (Experimental, Equi. Diagram, 4)

3


MSIT®

Ag–Al–Cu

[1989Ado2] Adorno, A.T., Cilense, M., Garlipp, W., “Phase Relationships in the

Copper-Silver-Aluminum Ternary System, Near the Copper-Rich Corner”, J. Mater. Sci.

Lett., 8(3), 281-284 (1989) (Experimental, Equi. Diagram, 4)

[1989Mee] Meetsma, A., de Boer, J.L., van Smaalen, S., “Refinement of the Crystal Structure of

Tetragonal Aluminum-Copper (Al2Cu)”, J. Solid State Chem., 83(2), 370-372 (1989) (Crys.

Structure, Experimental, 17)

[1990Ark] Arkens, O., “Silver - Aluminium - Copper”, MSIT Ternary Evaluation Program, in MSIT

Workplace, Effenberg, G. (Ed.), MSI, Materials Science International Services GmbH,

Stuttgart; Document ID: 10.11841.1.20, (1990) (Crys. Structure, Equi. Diagram,

Assessment, 7)

[1994Mur] Murray, J.L., “Al-Cu (Aluminium-Copper)”, in “Phase Diagrams of Binary Copper

Alloys”, Subramanian, P.R., Chakrabarti, D.J., Laughlin, D.E., (Eds.), ASM International,

Materials Park, OH, 18-42 (1994) (Equi. Diagram, Crys. Structure, Thermodyn., Review, #,

*, 226); similar to [1985Mur]

[1995Lim] Lim, M.S.S., Rossiter, P.L., Tibballs, J.E., “Assesment of the Al-Ag Phase Diagram”,

Calphad, 19(2), 131-141 (1995) (Assessment, Equi. Diagram, Theory, Thermodyn., 27)

[1997Lim] Lim, M.S.S., Tibballs, J.E., Rossiter, P.L., “An Assesment of Thermodynamic Equilibria in

the Ag-Al-Cu-Mg Quaternary System in Relation to Precipitation Reactions”, Z. Metallkd.,

88(3), 236-245 (1997) (Assessment, Equi. Diagram, Theory, Thermodyn., 40)

[1998Liu] Liu, X.J., Ohnuma, I., Kainuma, R., Ishida, K., “Phase Equilibria in the Cu-rich Portion of

the Cu-Al Binary System”, J. Alloys Compd., 264, 201-208 (1998) (Equi. Diagram,

Experimental, #, *, 25)

[2000Fla] Flandorfer, H., Hayer, E., “Partial and Integral Enthalpy of Molten Ag-Al-Cu Alloys”,

J. Alloys Compd., 296, 112-118 (2000) (Experimental, Thermodyn., 6)

[2002Gul] Gulay, L.D, Harbrecht, B., “The Crystal Structures of the 1 and 2 Phases in the Al-Cu

System”, Abstr. VIII Int. Conf. “Crystal Chemistry of Intermetallic Compounds”,

September 2002, Lviv, P139, 73 (2002) (Crys. Structure, Experimental, 5)

[2002Wit] Witusiewicz, V.T., Hecht, U., Rex, S., Sommer, F., “Partial and Integral Enthalpies of

Mixing of Liquid Ag-Al-Cu and Ag-Cu-Zn Alloys”, J. Alloys Compd., 337, 189-201 (2002)

(Experimental, Thermodyn., 30)

[2003Gro] Groebner, J., “Al-Cu (Aluminium - Copper)”, MSIT Binary Evaluation Program, in MSIT


Stuttgart; to be published, (2003) (Equi. Diagram, Crys. Structure, Assessment, 68)

[2003Van] van Rompaey, T., Rogl, P., “Ag-Cu (Silver - Copper)”, MSIT Binary Evaluation Program,

in MSIT Workplace, Effenberg, G. (Ed.), MSI, Materials Science International Services

GmbH, Stuttgart, Document ID: 20.14511.1.20, (2003) (Equi. Diagram, Crys. Structure,

Assessment, 28)

Table 1: Crystallographic Data of Solid Phases

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

(Ag)

< 961.93

cF4

Fm3m

Cu

a = 408.57 pure Ag at 25°C

[Mas2]

(Al)

< 660.452

cF4

Fm3m

Cu

a = 404.96 at 25°C [Mas2]

4


MSIT®

Ag–Al–Cu

(Cu)

< 1084.62

cF4

Fm3m

Cu

a = 361.46 at 25°C [Mas2]

melting point [1994Mur]

2, Ag3Al(h)

600-778

cI2

Im3m

W

a = 324

[Mas2]

[V-C2], 700°C

, Ag3Al(r)

< 450

cP20

P4132

Mn

a = 694.2

[Mas2]

[V-C2]

, Ag2Al

< 726

hP2

P63/mmc

Mg

a = 287.79

c = 462.25

22.9-41.9 at.% Al [Mas2]

[V-C2] 25°C

, Cu3Al

1049-559

cI2

Im3m

W a = 295.64

70.6 to 82 at.% Cu [1985Mur] [1998Liu]

at 672°C in + (Cu) alloy

2, Cu1-xAlx< 363

~TiAl3long period

superlattice

a = 366.8

c = 368.0

0.22 x 0.235 [Mas, 1985Mur]

at 76.4 at.% Cu

(subcell only)

0, Cu1-xAlx1037-800

cI52

I43m

Cu5Zn8

- 0.31 x 0.40 [Mas2]

0.32 x 0.38[1998Liu]

1, Cu9Al4< 890

cP52

P43m

Cu9Al4

a = 870.68

a = 871.32

at 33.8 at.% Al [V-C] from single crystal

[V-C]

, Cu1-xAlx< 686

hR*

R3m

a = 1226

c = 1511

0.381 x 0.407

[Mas2, 1985Mur]

at x = 38.9 [V-C]

1, Cu1-xAlx958-848

c**? - 0.379 x 0.406

[Mas2, 1985Mur]

2, Cu2-xAl

850-560

hP6

P63/mmc

Ni2In

a = 414.6

c = 506.3

0.47 x 0.78

55.0 to 61.1 at.% Cu

[Mas, 1985Mur, V-C2]

NiAs in [Mas2, 1994Mur]

1, Cu47.8Al35.5(h)

590-530

oF88 - 4.7

Fmm2

Cu47.8Al35.5

a = 812

b = 1419.85

c = 999.28

55.2 to 59.8 at.% Cu [Mas2, 1994Mur]

structure: [2002Gul]

2, Cu11.5Al9(r)

< 570

oI24 - 3.5

Imm2

Cu11.5Al9

a = 409.72

b = 703.13

c = 997.93

55.2 to 56.3 at.% Cu [Mas2, 1985Mur]


1, CuAl(h)

624-560

o*32 a = 408.7

b = 1200

c = 863.5

49.8 to 52.4 at.% Cu

[V-C2, Mas2, 1985Mur]

Pearson symbol: [1931Pre]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

5


MSIT®

Ag–Al–Cu

Table 2: Invariant Equilibria

2, CuAl(r)

< 569

mC20

C2/m

CuAl(r)

a = 1206.6

b = 410.5

c = 691.3

= 55.04°

49.8 to 52.4 at.% Cu

[V-C2]

, CuAl2< 591

tI12

I4/mcm

CuAl2

a = 606.3

c = 487.2

31.9 to 33.0 at.% Cu [1994Mur]

Single crystal

[V-C2, 1989Mee]

Reaction T [°C] Type Phase Composition (at.%)

Ag Cu Al

L (Al) + + 500 E L 17.5 14.0 68.5

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

20

40

60

80

20 40 60 80

20

40

60

80

Cu Ag

Al Data / Grid: at.%

Axes: at.%

550

550

575

600

700

650

575

600

e1

p1

e2

e3

525

625

675

p2

p5p6

e5

p4

p3

575

e4

e6

E

p7

(Al)

θ ζ

Fig. 1: Ag-Al-Cu.

Liquidus surface

6


MSIT®

Ag–Al–Cu

20

40

60

80

20 40 60 80

20

40

60

80

Cu Ag


Axes: at.%

γ1

β

(Cu)

(Cu)+(Ag)

γ1+β2

γ1+(Ag)

ζ

β2

(Ag)

Fig. 2: Ag-Al-Cu.

Isothermal section at

625°C

20

40

60

80

20 40 60 80

20

40

60

80

Cu Ag


Axes: at.%

γ1

(Cu)

(Cu)+(Ag)

γ1+(Ag)

ζ

(Ag)

Fig. 3: Ag-Al-Cu.


500°C

7


MSIT®

Ag–Al–Cu

20

40

60

80

20 40 60 80

20

40

60

80

Cu Ag


Axes: at.%

0

-4

-2

-16 -14 -12-10

-8

-6

-4

-20

2

Fig. 4: Ag-Al-Cu.

Isoenthalpy contours

for integral enthalpy

of mixing of liquid

alloys at 979°C

8


MSIT®

Ag–Al–Mg

Silver – Aluminium – Magnesium

Qingsheng Ran, updated by Ibrahim Ansara†, K.C. Hari Kumar, Patric Wollants and Yong Du

Literature Data

The Al-AgMg section of the system was studied by [1933Ota] using thermal analysis, metallography and

electrical resistance measurements on twenty alloys. The materials used were of 99.9 (Ag), 99.8 (Al) and

99.8 (Mg) mass% purity. [1933Ota] proposed the section to be a pseudobinary system, which was also

mentioned by [1959Zam] and [1961Fri]. [1957Kus], however, disputed this on the basis of X-ray diffraction

studies of the precipitates occurring in a Al-1.98 mole% AgMg and a Al-2.22 mole% AgMg alloy.

The Mg-rich corner was investigated by thermal and metallographic analysis ([1938Nis], 37 alloys;

[1939Hau], 69 alloys; [1939Saw], 54 alloys; [1945Kus1], 52 alloys and [1945Kus2], 15 alloys) and X-ray

diffraction [1945Kus1, 1945Kus2]. All the authors used metals with a purity better than 99.8 mass%.

The Al-rich corner was studied by metallography ([1959Zam], 38 alloys; [1961Fri], 38 alloys and [1969Ito],

10 alloys), thermal analysis (DTA) [1961Fri, 1969Ito], X-ray diffraction ([1972Wil], 22 alloys),

microhardness [1961Fri] and electrical resistivity measurements [1969Ito]. The Al had a purity of 99.98

mass% or better. [1986Cou] studied the stable and metastable precipitates of three alloys in the Al-rich

corner at 120, 183 and 235°C, and determined the precipitated phases and their structures using X-ray

diffraction.

Alloys containing 99.99% pure Al and Ag and > 99.8% Mg were examined by [1986Sch]. The 400, 300

and 200°C sections in the Mg-rich corner were investigated based on ten samples. The equilibrium

composition of the phases in two- and three-phase equilibria was determined by electron beam

microanalysis and metallography.

The agreement between different experiments for the Mg-rich and the Al-rich corner is generally good,

except for the concentrations of the liquid and the Mg solid solution at the invariant equilibrium. Values

from [1939Saw] strongly differ from the other reported values. [1956Gla] reported the mutual solubilities

of AgMg and Ag3Al based on X-ray and microstructural investigation, without details of the experimental

procedures. [1933Ota] mentioned the existence of the ternary compound AgMgAl and its equilibria with

other phases. [1957Kus] determined its structure. Another ternary compound T, with a composition near

8.92 Ag - 52.87 Al - 38.21 Mg at.%, was proposed by [1965Whe]. Using TEM, he found this phase to be

body-centered cubic. This phase was confirmed at a slightly different composition by [1966Aul] using

X-ray diffraction. Both ternary phases, AgMgAl and T, were confirmed by XRD [1972Wil, 1986Cou].

A metastable phase (T') with the same composition as T was detected by [1976Aul] and confirmed by

[1986Cou] by means of X-ray precession camera photographs. The unit cell was determined.

The present evaluation was published in the MSIT Evaluation Program earlier and reflects today’s state of

knowledge.

Binary Systems

The binary Ag-Al system from [Mas2], the Ag-Mg system from [Mas2] and the Al-Mg system from

[1998Lia] are accepted.

Solid Phases

The structure of phase T was suggested by [1966Aul] to be the same as that of Mg32(Al,Zn)49 [1957Ber]

with the composition of (Ag,Al)49Mg32, Ag:Al = 1:6. The solid elements, the ternary compounds and the

phases appearing in the phase diagrams presented are listed in Table 1.

9


MSIT®

Ag–Al–Mg

Pseudobinary Sections

[1933Ota] reported the pseudobinary section Al-AgMg with the ternary compound AgMgAl and two

invariant equilibria. [1959Zam] and [1961Fri] mentioned this and measured the solubility limit of AgMgAl

in Al and the temperature at which this limit was achieved. The temperature agrees well with that reported

by [1933Ota]. However, the measured solubility was 1.98 and 2.62 mole% AgMg, whereas that determined

by [1933Ota] was 3.37 mole%. [1957Kus] reported that X-ray diffraction lines of a second precipitate

appeared in some of their Al+2.22 mole% AgMg samples, in addition to the lines of AgMg which were

always present. Therefore they disagreed that this section was a pseudobinary one. The conclusion of

[1957Kus] is quite doubtful, since AgAlMg is a stable phase, and a Al - 1.98 mole% AgMg sample of

[1957Kus] did not show diffraction lines of this phase. [1972Wil] also suggested that the section Al-AgMg

should not be pseudobinary at 200 C. The pseudobinary section based on [1933Ota] is presented in Fig. 1.


A ternary eutectic was reported between 403 and 405°C [1938Nis, 1939Hau, 1939Saw, 1945Kus1,

1945Kus2]. Concerning the liquid concentrations, four authors agree fairly well in the amounts of Ag and

Mg whereas [1939Saw] gave the values with 7.6 at.% Ag and 13.5 at.% Mg. Other reported invariant

equilibria are the peritectic and eutectic in the pseudobinary system Al-AgMg. The invariant equilibria are

listed in Table 2.

Liquidus Surface

[1939Hau] proposed a liquidus surface of the partial system with more than 50 mass% Mg. The

contributions of [1938Nis, 1939Saw] and [1945Kus1] are in good agreement.

Isothermal Sections

Isothermal sections of the Mg-rich region are shown in Fig. 3. With decreasing temperature the solubilities

of Ag and Al go down to 1 mass% Ag and 3 mass% Al at 200°C. Isothermal sections of the Al-corner at

500 and 200°C are presented in Figs. 4 and 5.

Thermodynamics

A thermodynamic calculation for the Ag-Al-Mg system has been performed by [1997Lim] who modelled

the ternary compounds AgMgAl and T as Ag1Mg1Al1 and (Ag,Al)49Mg32, respectively. The agreement

between the measured and calculated invariant reactions is good. Also for the Al-AgMg pseudobinary

system this is the case. However, some discrepancies between the calculated and experimentally determined

isothermal sections remain.

References

[1933Ota] Otani, B., “An Investigation of the Ternary Alloy of Al-Ag-Mg, “Silver Duralumin” (in

Japanese), Kinzoku no Kenkyu, 10, 262-276 (1933) (Equi. Diagram, Experimental, #, 1)

[1938Nis] Nishimura, H., Sawamoto, H., “On the Investigations of Magnesium-Rich Mg-Al-Ag

System” (in Japanese), Suiyokwai-Shi, 9, 645-653 (1938) (Equi. Diagram, Experimental,

13)

[1939Hau] Haughton, J.L., “Alloys of Magnesium, Part IX: The Constitution of the Magnesium Rich

Alloys of Magnesium, Aluminium and Silver”, J. Inst. Metals, 65, 447-456 (1939) (Equi.

Diagram, Experimental, #, 10)

10


MSIT®

Ag–Al–Mg

[1939Saw] Sawamoto, H., “Age-hardening of Mg-rich Mg-Al-Ag Alloys” (in Japanese),

Suiyokwai-Shi, 9, 821-829 (1939) (Equi. Diagram, Experimental, 0)

[1945Kus1] Kusnetsov V.G., Guseva, L.N., “Magnesium-rich Alloys of Magnesium with Aluminium

and Silver, I: Equilibrium Diagram of System Mg-Mg3Ag-Mg4Al3” (in Russian), Bull.

Acad. Sci. USSR, Classe Sci. Chim., 297-307 (1945) (Equi. Diagram, Experimental, 13)

[1945Kus2] Kusnetsov, V.G., “X-Ray Investigations of Solid Solutions of Aluminium and Silver in

Magnesium” (in Russian), Bull. Acad. Sci. USSR, Classe Sci. Chim., 420-430 (1945) (Equi.

Diagram, Experimental, 13)

[1956Gla] Gladyshevskii, E.I., Cherkashin, E.E., “Solid Solutions on the Bases of Metallic

Compounds” (in Russian), J. Inorg. Chem., 1, 1394-1401 (1956) (Equi. Diagram,

Experimental, 4)

[1957Ber] Bergman, G., Waugh, J.L.T., Pauling, L., “The Crystal Structure of the Metallic Phase

Mg32(AlZn)49”, Acta Crystallogr., 10, 254-259 (1957) (Crys. Structure, Experimental, 20)

[1957Kus] Kusumoto, K., Ohta, M., Konishi, N., “X-Ray Studies on the Precipitation Process of

Al-AgMg Alloys” (in Japanese), Nippon Kinzoku Gakkai Shi, 21, 561-565 (1957) (Crys.

Structure, Equi. Diagram, Experimental, 5)

[1959Zam] Zamotorin, M.I., “The Simultaneous Solubility of Magnesium and Silver in Aluminium in

the Solid State” (in Russian), Tr. Leningrad. Polithekhn. Inst., No.202, 28-29 (1959) (Equi.


[1961Fri] Fridlyander, I.N., Zakharov, A.M., “Phase Diagram and Mechanical Properties of

Al-AlAgMg Alloys” (in Russian), Deformation Alluminium Alloys, Sb. Statei, Moskow,

17-23 (1961) (Equi. Diagram, Experimental, Mechan. Prop., 5)

[1965Whe] Wheeler, M.J., Blankenburgs, G., Staddon, R.W., “Evidence for a Ternary Phase in the

Aluminium-Magnesium-Silver System”, Nature, 207, 746-767 (1965) (Crys. Structure,

Experimental, 3)

[1966Aul] Auld, J.H., Williams, B.E., “X-ray Powder Data of T Phases Composed of Aluminium and

Magnesium with Silver, Copper or Zinc”, Acta Crystallogr., 21, 830-831 (1966) (Crys.


[1969Ito] Ito, T., Furuya, T., Matsuura, K., Watanabe, K., “The Solid Solubility of the -Phase in an

Al-Mg Alloy Containing 0.5 mass% Ag and the Aging Phenomena” (in Japanese), J. Jpn.

Inst. Met., 33, 1232-1238 (1969) (Equi. Diagram, Experimental, 16)

[1972Wil] Williams, B.E., “The Aluminium-rich Corner of the Al-Ag-Mg Phase Diagrams”,

J. Australian Inst. Metals, 17, 171-174 (1972) (Equi. Diagram, Crys. Structure,

Experimental, #, 9)

[1976Aul] Auld, J.H., Cousland, S., “The Metastable T' Phase in Al-Zn-Mg and Al-Ag-Mg Alloys”,

Met. Sci., 445-448 (1976) (Crys. Structure, Experimental, 10)

[1986Cou] Cousland, S.M., Tate, G.R., “Structural Changes Associated with Solid-State Reactions in

Al-Ag-Mg Alloys”, J. Appl. Crystallogr., 19, 174-180 (1986) (Crys. Structure, Equi.


[1986Sch] Schürmann, E., Engel, R., “Investigation of the Phase Equilibria of Magnesium rich Alloys

in the Quaternary System Magnesium-Silver-Aluminium-Lithium at 400, 300, and 200 C

with Respect to the Solid Solubility of the -Magnesium Solid Solution in Equilibrium with

the , , and Phases. Part 1: Experimental Conditions for Melting and Annealing as well

as Results of the Determination of Solid State Phase Equilibria of Magnesium Rich Alloys

of the Binary and Ternary Systems” (in German), Giessereiforschung, 38, 58-66 (1986)

(Equi. Diagram, Experimental, #, 25)

[1997Lim] Lim, M.S.-S., Tibballs, J.E., Rossiter, P.L., “An Assessment of Thermodynamic Equilibria

in the Ag-Al-Cu-Mg Quaternary System in Relation to Precipitation Reactions”,

Z. Metallkd., 88, 236-245 (1997) (Assessment, Thermodyn., Experimental, Theory, Equi.

Diagram, 40)

11


MSIT®

Ag–Al–Mg

[1997Su] Su, H.-L., Harmelin, M., Donnadieu, P., Baetzner, C., Seifert, H. J., Lukas, H. L., Effenberg,

G., Aldinger, F., “Experimental Investigation of the Mg-Al Phase Diagram from 47-63 at.%

Al”, J. Alloys Compd., 247, 57-65 (1997) (Equi. Diagram, Experimental, #, 20)

[1998Lia] Liang, P., Su, H.-L., Donnadieu, P., Harmelin, M.G., Quivy, A., Ochin, P., Effenberg, G.,

Seifert, H.J., Lukas, H.L., Aldinger, F., “Experimental Investigation and Thermodynamic

Calculation of the Central Part of the Mg-Al Phase Diagram”, Z. Metallkd. 89, 536-540

(1998) (Equi. Diagram, Thermodyn., Experimental, 33)

[2003Luk] Lukas, H.L.,“Al-Mg (Aluminium-Magnesium)”, MSIT Binary Evaluation Program, in

MSIT Workplace, Effenberg, G. (Ed.), MSI, Materials Science International Services

GmbH, Stuttgart; to be published, (2003) (Crys. Structure, Equi. Diagram, Assessment, 49)


Phase /

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments

(Ag) cF4

Fm3m

Cu

a = 408.61 25°C

pure, [V-C2]

(Al)

< 660.452

cF4

Fm3m

Cu

a = 404.95 23°C

pure, [V-C2]

(Mg)

< 650

hP2

P63/mmc

Mg

a = 320.944

c = 521.076

25°C

pure, [V-C2]

Ag2Al

< 726

hP2

P63/mmc

Mg

a = 287.79

c = 462.25

[V-C2]

25°C

AgMg

< 820

cP2

Pm3m

CsCl

a = 331.14 [V-C2]

AgMg4

< 465

hP? [Mas2]

AgMg3

< 484

cF? [Mas2]

Mg2Al3< 452

cF1168

Fd3m

Mg2Al3

a = 2823.9 1168 atoms on 1704 sites per unit cell

[2003Luk])

60-62 at.% Al [1997Su]

Mg17Al12

< 458

cI58

I43m

Mn

a = 1048.11

a = 1053.05

a = 1057.91

52.58 at.% Mg [L-B]

56.55 at.% Mg [L-B]

60.49 at.% Mg [L-B]

designated as Mg4Al3 in some

publications

AgMgAl hP12

P63/mmc

MgZn2

a = 538

c = 874

[1972Wil]

12


MSIT®

Ag–Al–Mg


* T, (Ag,Al)49Mg32 cI162

Mg32(AlZn)49

a = 1452±1 [1966Aul]

prototype suggested but not proved,

Ag:Al 1:6

* T', (Ag,Al)49Mg32 hP* a = 1411

c = 2804

[1976Aul] metastable


Ag Al Mg

L + AgMg AgAlMg 570 p (min) L

AgMg

AgMgAl

31.01

47.05

33.33

37.98

5.90

33.33

31.01

47.05

33.33

L Al + AgAlMg 538 e (max) L

Al

AgMgAl

21.03

2.52

33.33

57.94

94.96

33.33

21.03

2.52

33.33

L Mg + Al12Mg17 + AgMg3 404 E L

(Mg)

Mg17Al12

AgMg3

8.26

1.43

~3

25

22.39

7.62

~37

0.4

69.35

90.95

~60

74.6

10 20 30 40400

500

600

700

800

900

Al Mg 50.00Ag 50.00Al 0.00Mg, at.%

Tem

pera

ture

, °C

(Al)

AgMg

AlAgMg

L

570

538

Fig. 1: Ag-Al-Mg.

The pseudobinary

system Al - AgMg

13


MSIT®

Ag–Al–Mg

60

70

80

90

10 20 30 40

10

20

30

40

Mg Mg 50.00Ag 50.00Al 0.00

Mg 50.00Ag 0.00Al 50.00 Data / Grid: at.%

Axes: at.%

e1(472°C)

e2(436°C)

E(404°C)

Mg17Al12

AgMg3

(Mg)

625 600

575 55

0 525

500

475

450

425

450

Fig. 2: Ag-Al-Mg.

Liquidus surface of

the Mg-corner

60

70

80

90

10 20 30 40

10

20

30

40

Mg Mg 50.00Ag 50.00Al 0.00


Axes: at.%

(Mg)+AgMg4

(Mg)

(Mg)+Al12Mg17

(Mg)+AgMg4+Al12Mg17

60

70

80

90

10 20 30 40

10

20

30

40

Mg Mg 50.00Ag 50.00Al 0.00


Axes: at.%

(Mg)+AgMg4

(Mg)

(Mg)+Al12Mg17

(Mg)+AgMg4+Al12Mg17

Fig. 3a: Ag-Al-Mg.

Partial isothermal

section at 400°C

14


MSIT®

Ag–Al–Mg

60

70

80

90

10 20 30 40

10

20

30

40

Mg Mg 50.00Ag 50.00Al 0.00


Axes: at.%

(Mg)+AgMg4

(Mg)+AgMg4+Al12Mg17

(Mg)+Al12Mg17

(Mg)

Fig. 3b: Ag-Al-Mg.

Partial isothermal

section at 300°C

60

70

80

90

10 20 30 40

10

20

30

40

Mg Mg 50.00Ag 50.00Al 0.00


Axes: at.%

(Mg)(Mg)+AgMg4

(Mg)+AgMg4+Al12Mg17

(Mg)+Al12Mg17

Fig. 3c: Ag-Al-Mg.

Partial isothermal

section at 200°C

15


MSIT®

Ag–Al–Mg

Mg 10.00Ag 0.00Al 90.00

Mg 0.00Ag 10.00Al 90.00

Data / Grid: at.%

Axes: at.%

(Al)

(Al)+AgAlMg

(Al)+T

(Al)+T+AgAlMg

Al

Fig. 4: Ag-Al-Mg.

500°C isothermal

section of the Al-cor-

ner

Mg 10.00Ag 0.00Al 90.00

Mg 0.00Ag 10.00Al 90.00

Data / Grid: at.%

Axes: at.%

(Al)+T

(Al)

+T

+A

gAlM

g

(Al)

+A

gMg+

AgA

lMg

(Al)+A

gMg+A

g2 A

l

(Al)

+A

gAlM

g

(Al)+AgMg

(Al)

(Al)+Ag2Al

(Al)+Al3Mg2

(Al)+Al3Mg2+T

Al

Fig. 5: Ag-Al-Mg.

200°C isothermal

section of the

Al-corner

16


MSIT®

Ag–Al–Ti

Silver – Aluminium – Titanium

Hans Leo Lukas

Literature Data

Köster and Sampaio [1957Koe] investigated ternary isothermal sections at 800°C, 1000°C and 1100°C by

X-ray and metallographic analyses (xTi > 25 at.% and xAg < 42 at.%). At these temperatures they found the

binary Al-Ti phases in equilibrium with an Ag-rich melt or with the silver solid solution, (Ag).

Hashimoto et al. [1983Has] determined the 800°C isothermal section (xAl < 75 at.%) and a vertical section

from Ti+51 at.% Al to Ag+7.5 at.% Al by electron microprobe, X-ray diffraction, scanning electron

microscopy and DTA. These authors analyzed also the ternary solubilities of the (Ag) solid solution at

800°C.

Mabuchi et al. [1990Mab] detected a ternary phase Ti(Al1-xAgx)3 of the AuCu3 type (L12) with 0.1<x<0.25.

This phase has also a considerable homogeneity range with respect to the ratio Ti:(Al+Ag), 25-30 at.% Ti

at 1000°C. [1957Koe] did not investigate the area of this phase and [1986Has] investigated one alloy in this

area (65 at.% Al+10 at.% Ag), reported it as single phase at 800°C, but interpreted it as a solid solution of

the TiAl3 phase.

Several papers [1991Dur, 1992Dur, 1993Nak, 1999Yam] compare L12 phases Ti(Al1-xXx)3 with different

elements X (Ag, Co, Cr, Cu, Fe, Mn, Ni, Pd, Zn) but similar compositions of X. Yamamoto et al.

[1999Yam] reported the homogeneity range of the L12 phase at 1177°C. Tian and Nemeto [2002Tia]

studied the precipitation of TiAl and TiAl2 from the L12 phase, homogenized at 1000°C, as well as that of

L12 from TiAl during annealing at lower temperatures (700-900°C). The present evaluation updates that of

[1990Luk].

Binary Systems

The three binary systems are accepted from the SGTE assessments in Landolt-Börnstein [2002LB]. For

Ag-Ti [2002Li] and Al-Ti [2003Sch] the MSIT Workplace provides assessments with nearly equivalent

contents. For Al-Ti the [2003Sch] evaluation states, that there is still some uncertainty, especially on the

area between TiAl and TiAl3.

The Ag-Ti system used by [1957Koe] assumed a much higher temperature of peritectic formation of the

Ti2Ag phase (1280°C) than [2002LB] (940°C).

All three [2002LB] diagrams are based on thermodynamic calculations, two of them published before:

Ag-Al [1995Lim], Al-Ti [1998Sau].

Solid Phases

A single ternary phase, , of the AuCu3 (L12) type was found near TiAl3. Like TiAl3, TiAl2, Ti5Al11, TiAl

and Ti3Al it is an ordered form of a close packed crystal structure [1991Dur, 1992Dur]. Some more binary

Al-Ti phases between TiAl and TiAl3 were not considered as stable phases in the accepted binary Al-Ti

system. All solid phases regarded to be stable in the Landolt-Börnstein evaluations are summarized in

Table 1.


A tentative reaction scheme was given by [1957Koe]. Due to the discrepancies between the binary systems

used by [1957Koe] and those accepted here, it needs modification. Using the approximate thermodynamic

description given below in section “Thermodynamics” a tentative reaction scheme above 800°C can be

calculated. Figure 1 shows the result. The temperatures and phase compositions of the ternary invariant

reactions must be taken as tentative only, therefore no table of invariant reactions is given. Below 800°C

the system is nearly degenerate and the reaction scheme is equal to the binary Ag-Al system with either the

phase or TiAl3 being in equilibrium with the Ag-Al phases, but not taking part in the reactions.

17


MSIT®

Ag–Al–Ti

After the calculation the Ag solubility in the (Ti)(r) phase decreases very rapidly above 1000°C and thus

there appears twice a four phase reaction between liquid, (Ti)(r), (Ti)(h) and Ti3Al (at 1280 and 1033°C).

This may be an artefact, although the three phase field liquid+(Ti)(h)+Ti3Al between these two

temperatures is supported by the 1100°C isothermal section reported by [1957Koe].

Isothermal Sections

The sections at 1100, 1000 and 800°C, (Fig. 2, Fig. 3 and Fig. 4), are drawn from thermodynamic

calculations using the description given in the next section. The homogeneity range of the phase as well

as the (Ti)(r)+(Ti)(h)+liquid equilibrium at 1000°C are modified to fit to the reported measured points of

[1957Koe, 1986Has, 1990Mab]. The sections differ from those of [1957Koe] due to the differences in the

accepted binary systems and due to the consideration of the phase. In Köster’s diagrams Ti2Ag appears

as stable above 1100°C and all phases between Ti3Al and TiAl were not yet known. The 800°C section of

[1983Has] differs from that given by [1957Koe] for the same temperature mainly by the equilibria

containing the Ag-Ti phases TiAg and Ti2Ag. The calculation strongly supports the equilibria given by

[1983Has]. The Ti solubility measurements in liquid and solid Ag reported by [1983Has] gave significantly

lower values than compatible with the Ag-Ti system of [2002LB]. Also [1983Has] did not consider the

TiAl2 phase between TiAl and TiAl3 and they did not distinguish from TiAl3. The Ag solubilities in Ti3Al,

TiAl and TiAl3 are accepted from [1957Koe].

Thermodynamics

The thermodynamic data sets as used in [2002LB] allow approximate calculation of the ternary system.

Without the introduction of ternary parameters, however, the homogeneity ranges of the (Ti)(h) and (Ti)(r))

solid solutions in this calculation disagree significantly with [1957Koe] and [1986Has]. For phases with

only small ternary solubilities the calculated equilibria agree fairly well with those reported by [1957Koe]

and [1986Has].

Using the thermodynamic descriptions of the binary systems [2002LB] with additional ternary terms of

+120000 xAgxAlxTi J·mol-1 for Gbcc and (+80000 12T)xAgxAlxTi J·mol-1 for Ghcp the ternary system can be

approximately calculated. The ternary phase can be roughly approximated by a stoichiometric phase

Ti0.27Ag0.12Al0.61 with the Gibbs energy of formation G -0.27-GhcpTi-0.12Gfcc

Ag-0.61

GfccAl= 36500+7T J·mol-1.

References

[1957Koe] Köster, W., Sampaio, A., “The Ternary System Titanium-Silver-Aluminium” (in German),

Z. Metallkd., 48, 331-334 (1957) (Equi. Diagram, Experimental, #, *, 12)

[1962Poe] Pötzschke, M., Schubert, K., “On the Constitution of some T4-B3 Systems or Quasi-T4-B3

Systems” (in German), Z. Metallkd., 53, 548-561 (1962) (Crys. Structure, Experimental, 44)

[1965Ram] Raman, A., Schubert, K., “On the Constitution of some Alloy Series Related to TiAl3 II” (in

German), Z. Metallkd., 56, 44-52 (1965) (Crys. Structure, Equi. Diagram, Experimental, 13)

[1965Sch] Schubert, K., “On the Constitution of the Systems Titanium-Copper and Titanium-Silver”

(in German), Z. Metallkd., 56, 197-199 (1965) (Crys. Structure, Experimental, 14)

[1983Has] Hashimoto, K., Doi, H., Tsujimoto, T., “Experimental Study on Phase Diagrams of the

Ternary Ti-Al-Ag System”, (in Japanese), J. Jpn. Inst. Met., 47, 1036-1041 (1983), English

translation published in: Trans. Jpn. Inst. Met., 27, 94-101 (1986) (Equi. Diagram,

Experimental, #, 13)

[1986Has] Hashimoto, K., Doi, H., Tsujimoto, T., “Experimental Study on the Phase Diagram of the

Ternary Ti-Al-Ag System”, Trans. Jpn. Inst. Met., 27(2), 94-101 (1986) (Equi. Diagram,

Experimental, 13)

[1990Luk] Lukas H.L., “Silver-Aluminium-Titanium”, MSIT Ternary Evaluation Program, in MSIT


18


MSIT®

Ag–Al–Ti

Stuttgart; Document ID: 10.21188.1.20 (1990) (Crys. Structure, Equi. Diagram,

Assessment, 7)

[1990Mab] Mabuchi, H., Hirukawa, K., Katayama, K., Tsuda, H., Nakayama, Y., “Formation of

Ternary L12 Compounds in TiAl3-Base Alloys Containing Ag”, Scr. Metall., 24, 1553-1558

(1990) (Equi. Diagram, Experimental, #, 25)

[1990Sch] Schuster, J.C., Ipser, H., “Phases and Phase Relations in the Partial System TiAl3-TiAl”,

Z. Metallkd., 81(6), 389-396 (1990) (Crys. Structure, Equi. Diagram, Experimental,

Review, 33)

[1991Dur] Durlu, N., Inal, O.T., Yost, F.G., “L12-Type Ternary Titanium Aluminides of the

Composition Ti25X8Al67, TiA3-Based or TiAl2-Based?”, Scr. Metall., 25, 2475-2479

(1990) (Theory, Crys. Structure, 30)

[1992Dur] Durlu, N., Inal, O.T., “L12-Type Ternary Titanium Aluminides as Electron Concentration

Phases”, J. Mater. Sci., 27, 3225-3230 (1992) (Theory, Crys. Structure, 41)

[1993Nak] Nakayama Y., Mabuchi, H., “Formation of Ternary L12 Compounds in TiAl3-Base Alloys”,

Intermetallics, 1, 41-48 (1993) (Equi. Diagram, Experimental, 40)

[1995Lim] Lim, S.S., Rossiter, P.L., Tibballs, J.E., “Assessment of the Al-Ag Binary Phase Diagram”,

Calphad, 19(2), 131-141 (1995) (Equi. Diagram, Thermodyn., Calculation, 27)

[1998Sau] Sauter, N., “System Al-Ti” in “COST 507, Thermochemical Database for Light Metal

Alloys”, Vol. 2, I. Ansara, A.T. Dinsdale, M.H. Rand (Eds.), Office for Official Publications

of the European Communities, Luxembourg, 89-94 (1998) (Assessment, Equi. Diagram,

Thermodyn., Calculation, 27)

[1999Yam] Yamamoto, Y., Hashimoto, K., Kimura, T., Nobuki, M., Kohno, N., “L12 Single Phase

Region in Al-Ti Base Ternary and Quaternary Systems at 1450 K” (in Japanese), J. Jpn.

Inst. Met. 63(10), 1317-1326 (1999) (Equi. Diagram, Experimental, 15)

[2001Bra] Braun, J., Ellner, M., “Phase Equilibria Investigations on the Aluminium-Rich Part of the

Binary System Ti-Al”, Metall. Mater. Trans. A, 32A, 1037-1048 (2001) (Crys. Structure,

Equi. Diagram, Experimental, #, *, 34)

[2002Tia] Tian, W.H., Nemoto, M., “Precipitation Behavior in Ag-Modified L12-Al3Ti and

L10-TiAl(Ag)”, Mater. Sci. Eng. A., 329-331, 653-660 (2002) (Crys. Structure, Equi.


[2002LB] Landolt-Börnstein, Numerical Data and Functional Relationship in Science and

Technology, New Series, Ed. in Chief: W. Martienssen, Group IV: Physical Chemistry, Vol.

19, Thermodynamic Properties of Inorganic Materials compiled by SGTE, Subvol. B,

Binary Systems: Phase Diagrams, Phase Transition Data, Integral and Partial Quantities of

Alloys. Part 1. Elements and Binary System from Ag-Al to Au-Tl. Ed. Lehrstuhl f.

Werkstoffchemie, RWTH Aachen; Authors: Scientific Group Thermodata Europe (SGTE)

Springer Verlag, Berlin, Heidelberg, pp. 33-37 Ag-Al, pp. 92-94 Ag-Ti, pp. 205-209 Al-Ti

(2002)

[2002Li] Li, C., Lebrun, N., Dobatkina, T., Kuznetsov, V., “Ag-Ti (Silver-Titanium)”, MSIT Binary

Evaluation Program, in MSIT Workplace, Effenberg, G. (Ed.), MSI, Materials Science

International Services GmbH, Stuttgart; Document ID: 20.26006.1.20, (2002) (Equi.

Diagram, Assessment, 5)

[2003Sch] Schmid-Fetzer, R., “Al-Ti (Aluminium-Titanium)”, MSIT Evaluation Program, in MSIT


Stuttgart, to be published, (2002) (Equi. Diagram, Assessment, 86)

19


MSIT®

Ag–Al–Ti


Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

(Ti)(h)

1715-882

cI2

Im3m

W

a = 330.65 pure element, 900°C

[Mas2]

(Ti)(r)

< 1500

hP2

P63/mmc

Mg

a = 295.06

c = 468.35

pure element, 25°C

[Mas2]

(Ag)

< 962

cF4

Fm3m

Cu


[Mas2]

(Al)

< 661

cF4

Fm3m

Cu


[Mas2]

Ti2Ag

< 940

tI6

I4/mmm

MoSi2

a = 295

c = 1180

[1965Sch]

TiAg

< 1020

tP4

P4/nmmTiCu

a = 290

c = 814

[1965Sch]

Ti3Al

< 1190

hP8

P63/mmc

Ni3Sn

a = 577.5

c = 463.8

[2001Bra]

TiAl

< 1444

tP4

P4/mmm

CuAu

a = 399.8

c = 407.6

[2001Bra]

TiAl2< 1181

tI24

I41/amdHfGa2

a = 397.6

c = 2497

[1962Poe, 1990Sch]

Ti5Al111379-996

tI16

I4/mmm

ZrAl3

a = 391.7

c = 1652.4

[1965Ram, 1990Sch]

TiAl3< 1373

tI8

I4/mmm

TiAl3

a = 384

c = 857.9

[1965Ram, 1990Sch]

Ag3Al(h)

780-610

cI2

Im3m

W

a = 330.2 700°C [V-C2]

Ag3Al(r)

< 448

cP20

P4132

Mn

a = 693.4 [V-C2]

Ag2Al

< 727

hP2

P63/mmc

Mg

a = 288.5

c = 458.2

[V-C2]

* , Ti(Al1-xAgx)3 cP4

Pm3m

AuCu3

a = 399.0 to 400.4 [1990Mab]

20


MSIT®

Ag–Al–Ti

L+

TiA

l+τ

Fig

. 1:

Ag-A

l-T

i. T

enta

tive

reac

tion s

chem

e

Ag-T

iA

l-T

iA

g-A

l-T

i

(Ti)

(h)

(Ti)

(r)+

Ti 2

Ag

855

e 6

TiA

g+

(Ti)

(h)

Ti 2

Ag

940

p5

l(A

g)

+ T

iAg

960

e 5

l +

(T

i)(h

) T

iAg

10

20

p4

L+

(Ti)

(h)

(Ti)

(r)+

TiA

g9

75

U4

(Ti)

(h)+

Ti 3

Al

L+

(Ti)

(r)

1033

U3

L +

TiA

l +

Ti 5

Al 11

τ1220

P2

Ti 5

Al 11

TiA

l 3+

TiA

l 2,

τ996

D2

Ti 5

Al 11

TiA

l+T

iAl 2

,τ

1181

D1

L +

Ti 5

Al 11

TiA

l 3 +

τ1202

U2

L+

(Ti)

(r)

TiA

l+T

i 3A

l1271

U1

L+

Ti 3

Al

(A

g)+

TiA

l849

U8

TiA

g+

(Ti)

(h)

(Ti)

(r)+

Ti 2

Ag

902

U7

(Ti)

(r)+

(Ag)

TiA

g+

Ti 3

Al

832

U9

L+

(Ti)

(r)

(Ag)+

Ti 3

Al

948

U6

L+

TiA

g(T

i)(r

)+(A

g)

953

U5

L +

TiA

l (A

g)

+ τ

778

U10

L+

Ti 5

Al 11+

τ

(Ti)

(h)+

(Ti)

(r)+

Ti 3

Al

L+

(Ti)

(h)+

(Ti)

(r)

Ti 3

Al

12

80

P1

L+

(Ti)

(r)+

Ti 3

Al

TiA

g+

(Ti)

(h)+

(Ti)

(r)

L+

(Ti)

(h)+

(Ti)

(r)

L+

TiA

g+

(Ti)

(r)

Ti 5

Al 11 T

iAl 3

+τ

TiA

l+T

iAl 2

+τ

TiA

l 3+

TiA

l 2+

τ

Ti 3

Al+

(Ag)+

TiA

l

L+

(Ag)+

TiA

l

(Ag

)+T

iAg

+T

i 3A

l

L +

(T

i)(h

) +

Ti 3

Al

L+

TiA

l+T

i 3A

l

TiA

l+τ+

Ti 5

Al 11

Ti 5

Al 11+

TiA

l 2+

τ

L+

(Ti)

(r)+

(Ag

)

L+

(Ti)

(r)+

Ti 3

Al

(Ti)

(r)+

TiA

g+

Ti 3

Al

L+

TiA

l 3+

τT

iAl+

(Ag)+

τ

L+

(Ag)+

Ti 3

Al

(Ti)

(r)+

(Ag)+

TiA

g

TiA

g+

Ti 2

Ag+

(Ti)

(r)

L+

(Ag)+

τ

l +

(T

i)(h

) (

Ti)

(r)

1502

p1

Ti 5

Al 11

TiA

l 3+

TiA

l 2

996

e 4

(Ti)

(r)

TiA

l+T

i 3A

l

1126

e 3

Ti 5

Al 11

TiA

l+T

iAl 2

1181

e 2

lT

iAl 3

+ T

i 5A

l 11

1273

e 1

l +

TiA

l T

i 5A

l 11

1279

p3

l +

(T

i)(r

) T

iAl

1444

p2

21


MSIT®

Ag–Al–Ti

20

40

60

80

20 40 60 80

20

40

60

80

Ti Ag


Axes: at.%

TiAl3

Ti5Al11

TiAl2

TiAl

Ti3Al

(Ti)(r)

(Ti)(h)

L

(Ti)(h)+L

Ti3Al+L

τ+L

Ti3Al+TiAl+L

τ

TiA+L

TiAl3+L

20

40

60

80

20 40 60 80

20

40

60

80

Ti Ag


Axes: at.%

L

TiAl3

Ti5Al11

TiAl2

TiAl

Ti3Al

(Ti)(r)

(Ti)(h)

TiAg

τ+L

TiAl+Ti3Al+L

(Ti)(h)+L

τ

(Ti)(r)+L

(Ti)(r)+Ti3Al+L

Ti3Al+L

TiAl+L

TiAl3+L

Fig. 2: Ag-Al-Ti.


1100°C

Fig. 3: Ag-Al-Ti.


1000°C

22


MSIT®

Ag–Al–Ti

20

40

60

80

20 40 60 80

20

40

60

80

Ti Ag


Axes: at.%

L

TiAl3

TiAl2

TiAl

Ti3Al

(Ti)(r)

Ti2Ag TiAg

(Ag)Ti3Al+TiAg+(Ag)

Ti3Al+TiAl+(Ag)

TiAl+τ+L

Ti3Al+(Ag)

TiAl+L

τ

L+τ

TiAl3+L

TiAl+(Ag)

(Ti)(r)+Ti3Al+TiAg(Ti)(r)+TiAg

(Ti)(r)+Ti2Ag

Fig. 4: Ag-Al-Ti.


800°C

23


MSIT®

Ag–Cu–Mg

Silver – Copper – Magnesium

Ernst-Theo Henig

Literature Data

[1943Gue] investigated three ternary alloys to determine various ranges of homo- or heterogeneity, the

extension of the inter-mediate binary phases and any possible pseudobinary sections in the ternary system

(clear cross method). The alloys were annealed at 400°C and X-ray analyzed at room temperature after slow

cooling. AgMg3 - Cu2Mg and (Ag) - Cu2Mg are found to be quasibinary at room temperature.

[1979She] and [1980She] reported on metallographic, X-ray and “micro-X-ray spectral analysis” as well as

DTA measurements in the partial system Mg-Mg2Cu-AgMg, stating that AgMg-Mg2 is quasibinary

[1979She].

The statements of [1943Gue] and of [1979She, 1980She] contradict one another; due to the higher number

of alloys examined, the more recent results of [1979She, 1980She] are accepted here.


knowledge.

Binary Systems

The two binary systems Cu-Mg [1984Nay1] and Ag-Mg [1984Nay2] and the quasibinary AgMg-Mg2Cu

[1979She] are used as boundary systems (Fig. 1).

Solid Phases

No ternary phases have been found. The known binary phases are listed in Table 1. In the intermetallic phase

AgMg3 a considerable amount of Ag can be substituted by Cu ( 23 mass% Cu).


The section AgMg-Mg2Cu is established as quasibinary using DTA, metallography and X-ray analysis

[1979She]. Unfortunately the pseudobinary eutectic is not given explicitly, only the composition of the

liquid e1 (30% Ag, 35.7% Cu and 34.3% Mg) at 530°C. The section is thus constructed and displayed in

Fig. 1, using the information given in [1979She, 1980She]. Several mistakes in the liquidus surface given

in [1980She] must be corrected, e.g. 550 and 540°C isotherms and the eutectic point 530°C all meet at one

point; also the slope of the melting groove e1-P is reversed.


Three ternary invariant equilibria are reported (Table 2), these being: maximum decomposition of liquid at

530°C, peritectic formation of (Ag,Cu)Mg3 at 505°C and eutectic decomposition of liquid at 460°C. Only

the composition of the liquid phases are given explicitly in [1980She] the composition of the solid phases

are constructed from the three isopleths and the 400°C isothermal section of [1979She, 1980She]. The

reaction scheme (Fig. 2) and a projection of the invariant equilibrium phases and the connecting lines of

double saturation (Fig. 3) are presented.

Liquidus Surface

Figure 4 shows the isotherms of the liquidus surface and the melting grooves separating four areas of

primary crystallization; ', , and (refer to the section on “Pseudobinary Systems” to see the corrections

needed in the liquidus surface given in [1980She]).

24


MSIT®

Ag–Cu–Mg

Isothermal Sections

Figure 5 displays the isothermal section at 400°C after [1980She] with a minor correction to meet the

boundary system Ag-Mg. [1980She] reports that with decreasing temperature (300, 200°C), there is no

change in the solubility for ', and , but a decrease is seen in the Ag and Cu solubilities in Mg.


Two isopleths at Ag = 20 mass% = const. and Cu = 10 mass% are given as Figs. 6 and 7; in addition

[1980She] reports an isopleth at 15 mass% Ag.

Miscellaneous

[1982Miz] reports information about amorphous alloys of the type (Ag0.5Cu0.5)1-xMgx with 0 < x < 0.8

which are used to test the extended Ziman theory experimentally. [1984Miz, 1986Mat] measured electrical

resistivity, low-temperature specific heats and thermoelectric power of Ag-Cu-Mg metallic glasses.

Information about dendritic segregation of silver-rich alloys Ag-7.5Cu-0.2Mg (at.%) is reported in

[1981Duk].

References

[1943Gue] Gürtler, W., Rassmann, G., “The Use of X-Ray Find Structure Pattents to Identified Phase

Equilibria ternary System of Crystalline State”, Metallwirtschaft, 22, 34-42 (1943)

(Experimental, Equi. Diagram, 30)

[1979She] Shevakin, Y.F., Kolesnichenko, V.E., Karonik, V.V., Tsypin M.L., Meshkov, A.V., “Phase

Composition of Mg-Ag-Cu Alloys in the Mg-rich Range”, Izv. Akad. Nauk SSSR, Met., 5,

223-226 (1979) (Experimental, Equi. Diagram, #, *, 1)

[1980She] Shevakin, Y.F., Karonik, V.V., Kolesnichenko, V.E., Meshkov A.V., Tsypin, M.I.,

“Reactions of Magnesium with Silver and Copper”, Izv. Akad. Nauk SSSR, Met., 4, 237-239

(1980) (Experimental, Equi. Diagram, #, *, 1)

[1981Duk] Dukiet-Zawadzka, B., Pawlowski, A., Ciach, R., Tasior-Grabianowska K., Wolczynski, W.,

“Dendritic Segregation of AgCu Alloys with Additions of Ti, Al, Mg and Ni”, Arch. Hutn.,

26, 429-448 (1981) (Thermodyn., 20)

[1982Miz] Mizutani, U., Yoshida, T., “Experimental Test of the Extended Ziman Theory, Using Free

Electron-Like Ag-Cu Based Amorphous Alloys”, J. Phys. F: Met. Phys., 12, 2331-2348

(1982) (Experimental, 23)

[1984Miz] Mizutani, U., Yoshino, K., “Formation and Low-Temperature Electronic-Properties of

Liquid-Quenched Ag-Cu-Mg, Ag-Cu-Si, Ag-Cu-Sn and Ag-Cu-Sb Metallic Glasses”, J.

Phys. F: Met. Phys., 14(5), 1179-1192 (1984) (Electr. Prop., Experimental, 17)

[1984Nay1] Nayeb-Hashemi, A.A., Clark, J.B., “The Cu-Mg System”, Bull. Alloy Phase Diagrams, 5,

36-43 (1984) (Assessment, Review, Equi. Diagram, 81)

[1984Nay2] Nayeb-Hashemi, A.A., Clark, J.B., “The Ag-Mg System”, Bull. Alloy Phase Diagrams, 5,

348-358 (1984) (Assessment, Review, Equi. Diagram, 81)

[1986Mat] Matsuda, T., Mizutani, U., Sato, H., “Thermoelectric Power of Mg-based Simple Metallic

Glasses”, J. Phys. F: Met. Phys., 16, 1005-1014 (1986) (Electr. Prop., Experimental, 37)

25


MSIT®

Ag–Cu–Mg



Composition of the liquidus P, E and e1(max) given in [1979She] and [1980She]; other 4-phase equilibria phases

constructed from isopleths; values in < > for , of P and ', of e1(max) are estimated.

Phase /

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments

(Ag) cF4

Fm3m

Cu

a = 408.61 pure Ag [P]

(Cu) cF4

Fm3m

Cu

a = 361.49 pure Cu [P]

, (Mg) hP2

P63/mmc

Mg

a = 320.94

c = 521.05

pure Mg, 25°C [P]

Ag3Mg

< 392

cP4

Pm3m

AuCu3

a = 411.2 25.0 at.% Mg, annealing time 2 d,

[1984Nay2]

', AgMg cP2

Pm3m

CsCl

a = 333.00

a = 329.80

32.26 at.% Mg,

66.71 at.% Mg,

slowly cooled

, AgMg3 hP8

P63/mmc

AsNa3

a = 488.42

c = 778.68

25.17 at.% Mg, quenched from 440°C

, Mg2Cu oF48

Fddd

Mg2Cu

a = 905.0

b = 1824.7

c = 528.3

[1984Nay1]

MgCu2 cF24

Fd3m

MgCu2

a = 699 to 708.2 [1984Nay1]


Ag Cu Mg

L + ' + 505 P L

'

9.8

36.5

<2.5

<14.0

15.5

6.8

30.0

15.2

74.7

56.7

67.5>

70.8>

L + + 460 E L 7.5

14.1

1.4

0.4

10.1

13.0

29.8

0.1

82.4

72.9

68.8

99.5

L ' + 530 e1(max) L

'

12.4

<37.3

< 4.0

25.0

8.3

30.6

62.7

54.5>

65.3>

26


MSIT®

Ag–Cu–Mg

10 20 30 40400

500

600

700

800

Mg 66.67Cu 33.33Ag 0.00

Mg 50.00Cu 0.00Ag 50.00Ag, at.%

Tem

pera

ture

, °C

e1

820°C

568°C

530

L

β'γ

Fig. 1: Ag-Cu-Mg.

The pseudobinary

system Mg2Cu-

AgMg

60

70

80

90

10 20 30 40

10

20

30

40

Mg Mg 50.00Cu 50.00Ag 0.00

Mg 50.00Cu 0.00Ag 50.00 Data / Grid: at.%

Axes: at.%

β'

γ

E

P

e1

ε

e3

p

α

e2

Fig. 3: Ag-Cu-Mg.

Polythermal

projection of

four-phase equilibria

and edges of double

saturation

27


MSIT®

Ag–Cu–Mg

60

70

80

90

10 20 30 40

10

20

30

40

Mg Mg 50.00Cu 50.00Ag 0.00


Axes: at.%

800

750

700

650

550

530

550

475500

500

550

600

E, 460°C

β'

ε

γα

e2(485°C)

e1(530°C)

e3(472°C)

p(492°C)

600

P,505°C

Fig. 4: Ag-Cu-Mg.

Liquidus surface

60

70

80

90

10 20 30 40

10

20

30

40

Mg Mg 50.00Cu 50.00Ag 0.00


Axes: at.%

ε

β'

γα+γ+ε

α

β'+γ+ε

Fig. 5: Ag-Cu-Mg.

Isothermal section

with some tie lines at

400°C

28


MSIT®

Ag–Cu–Mg

10 20400

500

600

Mg 94.67Cu 0.00Ag 5.33

Mg 64.05Cu 28.19Ag 7.76Cu, at.%

Tem

pera

ture

, °C L

L+α

L+α+ε

α+ε α+ε+γ

L+α+γ

L+γ

L+ε+γ

L+γ+β'

γ+ε ε +γ

+β

'

γ +

β '

460

505

530°C

472°C

Fig. 6: Ag-Cu-Mg.

Temperature -

composition cut at 20

mass% Ag

60 70 80 90400

500

600

700

800

Mg 54.85Cu 9.12Ag 36.03

Mg 95.92Cu 4.08Ag 0.00Mg, at.%

Tem

pera

ture

, °C L

L+β'

L+γ+β'

γ+β'

ε +

γ +

β ' ε+γ

ε

L+ε

α+εα+ε+γ

α+γ

L+α+γ

L+α

485°C

460

505530°C

Fig. 7: Ag-Cu-Mg.

Temperature -

composition cut at 10

mass% Cu

29


MSIT®

Al–B–C

Aluminium – Boron – Carbon

Andriy Grytsiv and Peter Rogl

Literature Data

Due to the presence of carbon contaminant in aluminium borides the data on the constitution of the Al-B-C

ternary system and those of the binary Al-B system have to be reviewed carefully, which was done by

[1994Dus] to strictly differentiate between true aluminium borides and aluminium boron carbides.

High hardness in combination with high neutron absorption, high wear resistance and impact resistance

have triggered an early interest in high-strength and low-weight Al-B4C composite materials or cermets,

either in bulk form with a metal binder or by reinforcing an Al-base matrix with boron carbide particles or

with boron carbide-coated fibres. Understanding the phase equilibria proved of major importance in the

processing of Al-B4C composites particular in finding processing criteria at temperatures high enough to

promote wetting and low enough to control reactions and design microstructures.

Despite much effort was spent on the synthesis and crystallographic characterization of the various ternary

aluminum boron carbide compounds [1964Mat, 1965Eco, 1965Mat, 1966Gie, 1966Lip, 1969Per, 1969Wil,

1970Nei, 1977Mat, 1987Sar, 1980Ino, 1990Oka, 1992Via, 1994Kud, 1995Osc, 1996Hil1, 1996Hil2,

1997Mey], information on the equilibrium phase relations in the Al-B-C ternary system is scarce [1993Bau,

1997Via, 1998Rog]. These informations comprise early calculations of the phase equilibria disregarding the

boron-rich compounds or rather assuming the phases, AlB40C4 and Al2.1B51C8, to be part of the solid

solution range of “B4C” [1982Doe, 1993Kau]. Some confusion in the early experimental work on

aluminum borides arose from the fact that due to contamination either from high carbon level boron starting

material or from the use of graphite crucibles and substrates aluminum boron carbides were produced rather

than binary aluminum borides. This is particularly true for “AlB10” [1963Wil] - shown to be “AlB24C4” or

more precisely Al2.1B51C8 [1964Mat, 1967Wil, 1969Wil, 1969Per, 1990Oka] - and ( AlB12) [1960Koh],

later shown to be Al3B48C2 [1965Mat]. According to structural and DTA investigations [1996Hil1],

Al3B48C2 exists in a tetragonal high temperature modification, which on cooling below 650°C transforms

into a body-centered orthorhombic low temperature phase with a unique structure type. The mixture of two

orthorhombic phases with coherent boundary and commensurable lattice parameters (modifications A and

B), as claimed by [1965Mat, 1986Pes], thus simply explains by multiple twinning on cooling [1996Hil1].

An experimental study of the isothermal section at 1400°C by [1993Bau] confirmed the existence of four

ternary compounds Al2.1B51C8 [1964Mat, 1967Wil, 1969Wil, 1969Per], AlB40C4 [1966Gie, 1966Lip,

1970Nei], Al3B48C2 [1996Hil1] and Al3BC3 [1996Hil2]. The latter compound was first mentioned as

“Al4B1-3C4” [1964Mat] and later labelled as “Al8B4C7” [1980Ino] from a cursory investigation of its

crystal symmetry with X-ray single crystal photographs, although no details of the crystal structure were

derived. The relation to a wurtzite structure was discussed [1995Osc]. A structure determination is due to

[1996Hil2]. A fifth compound, Al3BC [1992Via, 1993Gon, 1997Mey, 2002Zhe], (earlier “Al4BC”

[1987Sar, 1989Hal, 1990Pyz]) was reported to exist below ~1000°C [1992Via], however, was shown in the

isothermal section at 1000°C [1997Via]. From a detailed analysis (XPD, LOM, SEM, EPMA) of the Al-rich

corner [1997Via] on about 30 specimens prepared from cold pressed and sintered powder compacts in the

temperature region from 627 to 1000°C, an isothermal section at 1000°C and a tentative liquidus projection

was derived assisted by a series of isothermal diffusion experiments by heating together in an alumina boat

an Al-B rod and an Al-C rod.

Phase equilibria at 900°C in the Al-C rich part of the ternary Al-B-C system were established [2002Zhe]

from XPD of about 45 ternary and binary alloys. Equilibrium conditions were not reached for boron-rich

samples. An attempt to obtain equilibrated samples from mixtures B4C+AlB2, B4C+Al and B4C+Al4C3

were also unsuccessful. Al3BC and Al4C3 phases form very easily and are observed in all samples even after

short time sintering in contrast to Al3BC3, which forms very slowly at 900°C. On the other hand Al3BC3

was always observed in arc melted samples containing 40-60 at.% Al and 10-30 at.% B.

30


MSIT®

Al–B–C

Experimental techniques for preparation concerned (a) melting of B4C in excess of Al for the synthesis of

AlB40C4 (at 1550°C, [1970Nei]), (b) melting of boron with excess of Al in a graphite crucible for synthesis

of Al3B48C2 (at 1400°C, [1964Mat]) (c) vapor deposition at 1400 to 1600°C for single crystals of Al3B48C2

[1967Bli] (d) hot pressing of B4C+Al in graphite dies for synthesis of Al2.1B51C8 (at 1800°C [1966Gie,

1966Lip]), (e) infiltration of B4C by liquid Al at 1100°C and anneal at 1000°C to obtain Al3BC [1987Sar],

(f) reaction sintering of Al+B+C powder compacts on alumina boats in sealed silica capsules 627 to 1000°C

for the synthesis of Al3BC and phase relations at 1000°C [1992Via, 1997Via] or at 1400°C for 10 h for the

production of the single crystals of Al3B48C2 [1994Kud] (g) melting of an Al8BC mixture in alumina under

argon for 160 h at 850°C and subsequent cooling at 150K/h to RT for production of black-bluish single

crystals of Al3BC [1997Mey] (h) melting of an Al40B2C3 mixture in alumina under argon at 1500°C and

subsequent cooling at 10K/h to 600°C for production of single crystals of Al3BC3 in the form of yellow,

transparent platelets [1996Hil2] and (i) Al-flux solvent method for a general production of single crystals

(see i.e. [1986Kis, 1990Oka, 1996Hil1]). Samples used for the isothermal section at 1400°C were prepared

from cold compacted powder mixtures of AlB2, B4C, B and/or C, which were reaction-sintered under Ar in

closed Knudsen-type graphite reactors at 1600°C for 1h prior to 48 h heat treatment at 1400°C [1993Bau].

Phase relations at 900°C were studied [2002Zhe] on elemental powder compacts sintered in alumina

crucibles (binary Al-B alloys) or in closed graphite crucibles (ternary alloys). The specimens were sealed

in evacuated quartz ampoules and were slowly heated for 10°/h to 720°C (slightly above the melting point

of aluminium) and kept at this temperature for 48h. After temperature was increased to 900°C at a rate of

20°/h, the tablets were sintered at this temperature for 1 week. Repeated repowderisation (under protective

cyclohexane) and sintering at 900°C were necessary to reach equilibrium conditions. Several studies dealt

with the kinetics of wetting of B4C surfaces by liquid aluminum; detailed discussions can be found in the

articles by [1979Pan] and [1989Hal]. Hot-pressing of B4.3C+Al powders at 1820°C, 45 MPa under Ar (5 to

20 mass% Al) revealed the formation of the ternary B4C- related Al-boron carbides (solution of Al in B4C,

and 2) although the products were all thought to belong to the B4C-based solid solution [2000Liu]. With

increasing Al-content (>5 mass% Al) the Al3BC3 phase evolved [2000Liu].

Thermodynamic calculations of the Al-B-C system have been attempted by [1982Doe, 1993Wen,

1993Kau], however, are not fully consistent with experimental observations. Reviews on the constitution

and on the crystal structures of the Al-B-C system have been presented by [1977Mat, 1990Luk, 1998Rog].

Binary Systems

The binary systems B-C and Al-C are consistent with the critical assessments of [1996Kas] and [2003Per],

respectively. In spite of numerous data available from literature on the constitution of the Al-B phase

diagram, contradictory results exist for the formation of aluminium diboride (Table 1). Fig. 1a shows the

various versions for the Al-rich part of the Al-B phase diagram. It should be noted, that recent experiments

[2002Zhe] confirmed the formation of AlB2 at 900°C, in contrast to data of [1997Via] suggesting peritectic

formation at 892 ± 5°C. In the present assessment we accept the temperature of 956 ± 5°C for the invariant

reaction L+AlB12 AlB2 as determined by [2000Hal]. The adopted Al-B phase diagram (Figs. 1b, 1c) is

based on the assessment of [1994Dus]. The composition of the peritectic liquid at 0.55 at.% B has been

confirmed by a recent thermodynamic assessment of [2001Fje]. AlB2 is still taken as a stoichiometric

compound in spite of the suggestions of [1964Mat, 1999Bur, 2002Bur] for Al-deficiency in terms of

Al0.9B2.

Although the assessment of [1994Dus] concluded a peritectic formation of AlB12, L+(B) AlB12 at 2050°C,

the thermodynamic calculation of [1993Wen] is based on congruently melting AlB12 (TM = 2150°C).

Solid Phases

The crystallographic information on all the binary and ternary phases pertinent to the Al-B-C system is

listed in Table 2. Some controversy exists in the crystallographic characterization of the modifications

reported for Al3B48C2. A single crystal study [1995Hil, 1996Hil1, 2000Mey] on an untwinned specimen

revealed a tetragonal high temperature form (closely related to the structure of I-tetragonal boron), which

on cooling undergoes a symmetry reduction resulting in microscopically twinned products that hitherto

31


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Al–B–C

were indexed on the basis of two orthorhombic modifications, labeled A and B by [1965Mat]. The

transformation was earlier proposed to be at ca. 850°C [1960Koh, 1965Mat], whereas new results from

DTA recorded 650°C [1996Hil1]. The transition seems to be rather fast, as the low temperature

modification is present in samples furnace-cooled from 1400°C to room temperature [1993Bau].

A second point of controversy concerns the phases AlB40C4 and Al2.1B51C8 for which detailed

crystallographic descriptions are available, however, AlB40C4 actually being isotypic with binary B4C,

hitherto is not thoroughly established as a ternary phase independent from binary B4C. As the two

structurally closely related phases AlB40C4 and Al2.1B51C8 generally are found together, a high and low

temperature transition between them may be inferred [1993Bau]. Without further details the maximum solid

solubility of Al in boroncarbide (“B13C2”, at 1950°C) was reported to be 1 mass% Al (equivalent to 2 at.%

Al in B4C) [1978Ekb].

Experiments to establish a possible homogeneous range for Al3BC3 (earlier: “Al8B4C7” [1980Ino], or

“Al4B1-3C4” [1964Mat]), were carried out at 1830°C by [1980Ino] resulting in a rather stoichiometric

composition without variation of the lattice parameters. These findings were confirmed by [1993Bau,

1996Hil2]. Details of the crystal structure with linear C-B-C chains are given by [1996Hil2]. Lattice

parameters of Al3BC3 were measured at room temperature up to 7.5 GPa using a multi-anvil synchrotron

system with B4C anvils; for a high temperature pressure experiment the sample was placed in a graphite

ampoule [2000Sol]. Al3BC3 is free of structural transitions up to 1523°C within the pressure range 2.5 to

5.3 GPa [2000Sol]. A further ternary compound 5 was observed after infiltration by liquid Al at 1170°C

with post heat treatment for 100 h at 800 to 1000°C [1987Sar]. The hexagonal lattice was established by

TEM; the approximate composition “Al~4BC” resulted from EELS-data [1987Sar]. This phase has been

also confirmed by [1989Hal, 1990Pyz]. From a detailed investigation of this Al-rich boroncarbide by X-ray

powder diffraction, LOM and EPMA, [1992Via] suggested a formula of Al3BC rather than “Al4BC” and

attributed a hexagonal cell; additional weak lines in the X-ray intensity pattern of Al3BC prompted a larger

unit cell a = a0/ [1993Gon]. Although the authors of [1997Mey] recognized the larger cell, the crystal

structure of Al3BC was solved for the high symmetry subcell from single crystals isolated from a sample

directly reacted from the elements - however, from EPMA a composition Al2.5BC was derived (see also

Table 2). Al6B-octahedra and trigonal Al5C-bipyramids are the characteristic structural elements

[1997Mey].

The various data on the compositional ranges of the 4 and 5 phases are summarized in Fig. 2. Half filled

circles correspond to the accepted stoichiometries Al3BC and Al3BC3.

From the significant change of the unit cell volume of Al4C3 comparing binary and ternary alloys, a

solubility of boron is suggested [1996Bid, 2002Zhe, 2000Mey]. Solubility of boron in Al4C3 was

established to be 3.4 at.% at 900°C [2002Zhe] and an interesting behavior of lattice parameters was

observed. In spite of the increase of the “a” parameter and of the cell volume with boron content, the “c”

parameter decreases. That may be explained by a preferential distribution of boron and carbon atoms among

different crystallographic sites. A significant solubility of boron in Al4C3 was also reported by [2000Mey]

to be about 9.3 at.%, however, no details on the relevant temperature were given. Furthermore these authors

claim for Al4C3-xBx lattice parameters increasing with boron content. Lattice parameters of Al4C3 for

samples located in three phase regions (Al)+Al4C3+Al3BC, Al4C3+Al3BC3+Al3BC and

Al4C3+Al3BC3+(C) are very close, assuming that these three phase regions meet at the Al4C3 phase at a

maximal boron solubility of Al4(C0.92B0.08)3.

Insignificant solubility of carbon in AlB2 is reported by [2002Zhe] comparing lattice parameters in ternary

and binary samples; AlB2 with 0.5 at.% C, heat treated at 900°C, already contains the Al3BC phase.

Isothermal Sections

Phase equilibria for the 1400°C isothermal section are summarized in Fig. 3, revealing the existence of four

ternary compounds 1 to 4. A small field of liquid phase exists at 1400°C which is in equilibrium with

Al3B48C2, Al2.1B51C8 and with Al3BC3 [1993Bau]. Boron-poor equilibria agree with an earlier work by

[1980Ino] who reported on the two-phase equilibria Al4C3+Al3BC3 (Al7B4C8), Al3BC3 (Al7B4C8)+B4C

and Al3BC3 (Al7B4C8)+C. In Fig. 3 two-phase equilibria are shown to exist between the binary solid

3

32


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Al–B–C

solution “B4C” and AlB40C and Al2.1B51C8. At 1400°C all ternary compounds seem to exist at their

stoichiometric compositions [1993Bau], whilst [1965Eco] claimed a homogeneity range for 1 at 1800°C

from “AlB48C8” to Al3B48C8. Binary AlB12 was never seen in combination with Al2.1B51C8 nor with

AlB40C4 [1993Bau].

The isothermal section at 1000°C, Fig. 4, was constructed on the basis of data from [1997Via]. Due to low

interaction kinetics in the boron- and carbon-rich part of the system at 1000°C, equilibria in this portions of

the diagram are preliminary. Moreover, ternary compounds 1 and 2 were not included in the 1000°C

section by [1997Via], 4 was listed as “Al8B4C7”, and no solubility of boron in Al4C3 was considered. For

consistency with the present knowledge on the Al-B-C system, the ternary compounds 1 and 2 were

introduced in Fig. 4 and the composition of 4 was changed to Al3BC3. The solubility of boron in Al4C3 at

1000°C was estimated to be about 4 at.%, extrapolating from data of [2002Zhe] at 900°C. Figure 5

represents the isothermal section at 900°C [2002Zhe] confirming the equilibrium AlB2+Al3BC, whereas

[1997Via] claimed this equilibrium to be only stable below 868 ± 4°C. Similar to 1000°C the equilibria at

900°C involving 1 and 2 are not well established due to low reactivity of the components.

Invariant Equilibria, Liquidus Surface

A tentative liquidus surface for the aluminum rich portion of the diagram (Fig. 6) was proposed by

[1997Via], presenting equilibria involving the 5 phase. The invariant equilibrium U5

(L+Al3B48C2 AlB2+Al3BC) was reported at 868 ± 4°C by [1997Via], but this temperature can not be

accepted in respect to the observed isothermal equilibrium AlB2+Al3BC at 900°C [2002Zhe] suggesting

such transformation above 900°C. Comparison of the reaction scheme and the isothermal section at 1000°C

(Fig. 4) with the isothermal section at 1400°C (Fig. 3) suggests a rather complicate picture of the phase

transformations in this regions mainly due to decomposition of 5.

Based on an earlier thermodynamic calculation by [1982Doe], a reaction scheme was derived [1990Luk],

which gives a tentative information of the solidification behavior in the Al-B-C ternary. The temperatures

of the invariant equilibria were estimated and the ternary compounds 1 to 3 were assumed to be part of

the solid solution arising from binary B4C; 5 was not included. A more recent thermodynamic modelling

of the Al-B-C phase diagram by [1993Wen] as part of the multi-component Al-B-C-N-Si-Ti system treated

the ternary compounds 1, 2, 3 as independent phases, however, the peritectoid formation of 4 (Al3BC3)

is in strict contradiction to the experimentally confirmed two-phase equilibrium 4+ 5 (Al3BC3+Al3BC)

[1997Via, 2002Zhe] as well as to the observed existence of 4+ 5 in as cast alloys [2002Zhe], thereby

strongly indicating direct formation of Al3BC3 from the liquid.

A closed ternary miscibility gap in the Al-rich liquid is suggested from thermodynamic calculations by

[1993Kau], however, hitherto without experimental confirmation [2002Zhe].

Figure 7 presents a reaction scheme for the major parts of the Al-B-C phase diagram. The reaction scheme

is essentially based (i) on the tentative liquidus projection for the Al-rich part as suggested by [1997Via],

(ii) on the experiments of [2002Zhe] concerning the solidification of the phases 4, 5 and (iii) on the

thermodynamic calculation of [1993Wen] for the B-rich part, however, accepting peritectic formation of

AlB12.

Thermodynamics

Enthalpies of formation and heat capacity measurements from a Calvet type automatic microcalorimeter in

the temperature range 310-1200 K were reported by [1987Kis] and are listed as follows:

Al3B48C2 : H0(T) - H0(298) = 0.7945 10-3T2+0.5182T - 225.1374 (in J g-1) and

Cp(T) = 0.1589 10-2T+0.5182 (J g-1K-1)

Al2.1B51C8 : H0(T) - H0(298) = 0.7226 10-3T2+0.5411T-225.5702 (in J g-1 for AlB24C4) and

Cp(T) = 0.1589 10-2T+0.5182 (J g-1 K-1 for AlB24C4).

Thermodynamic calculations of the Al-B-C system are due to [1982Doe, 1993Wen, 1993Kau], however,

are not fully consistent with experimental observations. For detailed discussion, see section Invariant

Equilibria.

33


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Al–B–C


Mechanical properties of Al-B4C cermets and boron/carbon fiber-aluminium composites have been

investigated by various groups [1972Bak, 1973Her, 1975Mun, 1984Via, 1985Che, 1985Hal, 1985Kov,

1985Pyz, 1985Sar, 1986Che, 1986Dub,1990Ram,1996Pyz, 2002Ars]; the effect of reaction on the tensile

behavior of infiltrated composites was reported by [2002Kou2] and size dependent strengthening in particle

reinforced Al by [2002Kou1]; reaction products were studied by [2001Lee]. An increase of surface hardness

of about 25 to 40 % can be achieved by impulse laser radiation on B4C/Al cermets [1988Kov].

Wetting of B4C by Al has been studied by many research teams with rather contradicting results, until the

temperature and time dependent occurrence of chemical reactions/compound formation was analyzed in

detail (for discussion see i.e. [1979Kis, 1979Pan, 1989Hal, 2000Kha]). The kinetics of wetting by liquid

aluminium of flat, sintered boron carbide specimens with residual porosity less than 3 % were investigated

by [1979Pan]. The speed of spreading of liquid aluminium at 1100° to 1200°C was measured to be 0.1-0.8

mm s-1, in accordance with r2 = f(t), where r equals the radius of the contact circle. The angle of contact was

first ~92°, however, in 3 to 5 min decreased to 28°. The slow spreading was determined by the formation

of new aluminum boron carbide phases in the contact zone with a microhardness of ca. 13 GPa. The driving

force = (cos 0-cos ) ( = surface tension of the melt, 0 = contact angle of the melt, =contact angle

at time (t)) decreased sharply becoming zero in 4 to 5 min [1979Pan]. The contact angle of molten Al on

B4C as a function of processing time for various isotherms at 5 10-3 to 10-4 Pa was also given by [1989Hal]

based on sessile drops cooled to room temperature.

Mechanical properties, electrical and thermal conductivity as well as their temperature dependencies were

reported on the Knoop and Vickers microhardness for Al-flux grown (temperature region 1750 to 800°C)

‘‘amber’’ single crystals Al3B48C2 and for ‘‘black’’ crystals ( AlB12, AlB12 and AlB2.1B51C8)

[1986Kis]. These studies were also performed on hot pressed specimens of various compositions

x(AlB12)+(1-x)B4C and Al3B48C3 in the temperature range 24 to 827°C [1991Kha1, 1991Kha3]. For

Al3BC3 (”Al8B4C7”), Al3B48C3, Al2.1B51C8 [1991Kha2] also examined these properties as a function of

porosity and quantity of Fe-impurity. These data are summarized in Table 3 including information on

flux-grown crystals Al3B48C2 and Al2.1B51C8 [1990Oka]. Both types of crystals were said to be p-type

semiconductors [1986Kis].

In a ring test the strength of a powder compact of B13C2 +1 mass% Al, sintered at 1950°C, was found to be

0.50(7) GNm-2 [1978Ekb]. [1991Kha2] reported on the kinetics of thermal densification of hot pressed

powders of B4C, AlB12, Al3B48C2 and Al3BC3. Kinetics of dissolution in HCl, HNO3 and HCl-HNO3 was

studied by [1998Kha] as well as the resistance of Al-boron carbides to alkali and hydrogen peroxide.

[1989Hal] studied the densification kinetics of Al+B4C cermets in the range from 800 to 1400°C in

pressureless sintering as well as after applying hot isostatic pressure. The kinetic of metal depletion in post

heated dense cermets B4C/Al at temperatures between 600°C and 1000°C was investigated by [1990Pyz].

Chemical stability against various boiling acids, oxidation resistance, IR and EPR spectra of Al-borides and

Al-boron carbides (Al3B48C2, Al2.1B51C8) was studied by [1991Pri]. The spectra were taken at 77K and

300K and for different crystal orientations relative to the magnetic field. Absorption edge and IR-active

phonons in Al3B48C2 were reported by [1987Hau, 2000Wer] and IR spectra of boron carbide containing up

to 1.5 at.% Al were determined between of 8 to 500 mm-1 wave numbers and for temperatures between 70

to 450 K [1997Sch]. These data seem to suggest the incorporation of Al-atoms into binary boron-carbide in

form of pairs substituting the B-B-C or C-B-C chains [1997Sch]. Characteristic IR absorption bands for

finely dispersed powders of Al-borides and Al-boron carbides were listed by [1998Kha].

The Seebeck-coefficients were reported to linearly increase from 260 VK-1 for binary ”B4C” to 450

VK-1 for 1.4 at.% Al dissolved, revealing p type behavior [1997Sch]. Seebeck-coefficients, thermal and

electric conductivities were further reported by [2000Liu] for B4.3C-based samples containing 0.5, 10, 15,

20 mass% Al, highlighting the Z-value at RT of 1.04 10-6 K-1 for the 5 mass% Al sample. IR and Raman

spectroscopy on Al3BC3 (at RT) confirm the linear (CBC)5- unit as an isoelectronic CO2-analogon

[1996Hil2, 2000Mey].

On heating in air, Al3BC3 (earlier reported as Al8B4C7), Al3B48C3 and Al2.1B51C8 show low oxidation at

500°C (increase of mass ~4 mgh-1); intensive oxidation, with a mass increase of ~40 mgh-1) starts at

34


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Al–B–C

1280°C for Al2.1B51C8 and at 1370°C for Al3B48C2 [1991Pri, 1989Kha, 1991Kha4]. Oxidation in air of

single crystals Al2.1B51C8 and Al3B48C2 started at about 760°C and 710°C, respectively [1990Oka]. The

reaction products were 9Al2O3 2B2O3 for Al2.1B51C8 crystals and B2O3 for AlB40C4 specimens

[1994Kud]. Whereas Al3BC3 was said to be unstable in acids [1991Kha4], more detailed experiments

[1996Hil2] proved stability at room temperature against bases and dilute acids, except for HNO3 and HF.

Al3BC3 was furthermore said to be stable in air up to 600°C [1991Kha4,1996Hil2]. Al3BC is quickly

attacked by dilute HCl [1997Mey].

Thermophysical properties of sintered bodies of Al3BC3 have been derived by [2000Wan]. These are linear

thermal expansion in the range of 25 to 1200°C, specific heat and thermal diffusivity via laser flash

technique, Youngs modulus of 136.6 GPa, Vickers hardness of 12.1 GPa at a load of 196 N and

thermogravimetric recording of growth of an oxidized layer on heating in air up to 1500°C.

Fitting a Birch-Murnaghan equation of state to the pressure dependency of the lattice parameters of Al3BC3

up to 7.5 GPa, the isothermal bulk modulus was B0=153 ± 6 GPa (dB0/dp=19 ± 4) [2000Sol]. Despite high

bulk modulus the Vickers hardness of single crystals is as low as 20.7 GPa at a load of 25g and 18.2 GPa at

a load of 50g [2000Sol].

Al3BC was successfully prepared by self propagating high temperature synthesis induced by mechanical

activation of Al-B-C powder mixtures in air; mixtures low in boron (AlB0.1C) resulted in Al3BC3 under

violent emission of heat [1999Tsu]. In contrast to that [2000Sav] was unable to prepare ternary

aluminoborocarbides from mechanochemical synthesis. Elastic bulk and shear moduli for Al3BC (earlier

reported as Al4BC) were measured by [1995Pyz] and estimated by [1999Tor].

Miscellaneous

A series of patents covers the techniques to produce dense B4C/Al cermets by infiltration of the metal matrix

into the porous ceramic body without wetting reactions [1976Lan, 1986Hal, 1987Pyz, 1990Pyz, 1991Pyz,

1995Pyz, 1996Pyz, 1997Du, 2000Pyz, 2001Lee]; subsequent heat treatment results in materials with

designed chemistry and microstructures, flexure strength, hardness and fracture toughness. Fine

microstructures were obtained via ultrarapid microwave heating [1995Rug]. B4C/Al cermets have been

considered as an improved structural neutron absorber [1977Ros, 1978Boi, 1978Sur, 1986Ros, 1987Lev,

1992Bei] and for applications as friction materials for automotive brake applications [1999Cha]. Oxidation

protective B4C-coatings on C-fibers in Al-matrix were reported by [1996RMi] and [1996Vin] produced

C-fibres-Al composites by a squeeze casting technique. Explosive consolidation to produce Al/B4C

composites was studied by [1995Bon, 1997Yue]. Shock recovery experiments were performed on a 65 vol%

B4C-Al cermet as a function of shock pressure [1989Blu].

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35


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Al–B–C

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Al–B–C

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24(9), 51-54 (1985) (Mechan. Prop., Experimental, 6)

[1985Pyz] Pyzik, A. J., Aksay, I. A., “Processing, Microstructure, and Mechanical Properties of Boron

Carbide-Aluminum Alloys Composites”, Anon. Abst. 38th Annu. Pacific Coast Regional

Meeting American Ceramic Society, American Ceramic Society, Columbus, OH, (1985)

(Mechan. Prop., Experimental, 0)

[1985Sar] Sarikaya, M., Pyzik, A.J., Ilsay, I.A., Snowden, W. E., “Effect of Secondary Phases on the

Properties of B4C-A1 Composites.”, Anon. Abst. of the 38th Annu. Pacific Coast Regional

Meeting American Ceramic Society, American Ceramic Society, Columbus, OH, (1985)

(Mechan., Prop., Experimental, 0)

[1986Che] Chernyshova, T.A., Rebrov, A.V., “Interaction Kinetics of Boron Carbide and Silicon

Carbide with Liquid Aluminium”, J. Less-Common Met., 117, 203-207 (1986) (Kinetics,

Experimental, 4)

[1986Dub] Dub, S.N., Prikhna, T.A., Il'nitskaya, O.N., “Mechanical Properties of the Al-B-C

Compounds Crystals” (in Russian), Sverkhtverd. Mater., 6, 12-18 (1986) (Mechan. Prop.,

Experimental, 22)

[1986Hal] Halverson, D.C., Pyzik, A.J., Aksay, I.A., “Boron-Carbide-Aluminum and

Boron-Carbide-Reactive Metal Cermets”, US patent document 4,605,440/A/, (1986)

[1986Kis] Kisly, P.S., Prikhna T.A., Golubyak, L.S., “Properties of High-Temperature Solution

Grown Aluminium Borides”, J. Less-Common Met., 117, 349-353 (1986) (Experimental,

10)

[1986Pes] Peshev, P., Gyurov, G., Khristov, M., Gurin, V.N., Korsukova, M. M., Solomkin, F.Yu.,

Sidorin K.K., “Preparation and some Properties of Aluminium Carboboride Single

37


MSIT®

Al–B–C

Crystals”, J. Less-Common Met., 117, 341-348 (1986) (Crys. Structure, Mechan. Prop.,

Optical Prop., Experimental, 16)

[1986Ros] Roszler, J.J., “Process for the Manufacture of a Material Shielding Against Neutrons” (in

German), DE Patent Document 2643444/C2/, (1986)

[1987Hau] Haupt, H., Werheit, H., Siejak, V., Gurin, V.N., Korsukova, M.M., “Absorption Edge and

IR-active Phonons of Al3B48C2, “Boron, Borides and Related Compounds”, Proc. 9th Int.

Sympos., Werheit, H. (Ed.), Univ. Duisburg, Germany, 387-389 (1987) (Experimental, 2)

[1987Kis] Kisly, P.S., Prikhna, T.A., Gontar A.N., Podarevskaya, O.V.,“Structure and Properties of

Monocrystals of the Al-B-C System Compounds”, in “Boron, Borides and Related

Compounds”, Proceedings 9th Int. Sympos., Werheit, H. (Ed), Univ. Duisburg, Germany,

273-274 (1987) (Thermodyn., Crys. Structure, Phys. Prop., Experimental, 1)

[1987Lev] Levinskas, D., “Evaluation of Boron Carbide Coatings”, Western Region American Nuclear

Society Student Conference: Nuclear Technology for the Year 2000, American Nuclear

Society, La Grange Park, IL., NM(USA), 68-71 (1987) (Experimental, 0)

[1987Pyz] Pyzik, A.J., Aksay, I.A., “Multipurpose Boron Carbide-Aluminum Composite and its

Manufacture via the Control of the Microstructure”, US patent document 4,702,7707 A/, 27,

(1987)

[1987Sar] Sarikaya, M., Laoui, T., Milius D.L., Aksay, I.A., “Identification of a New Phase in the

Al-B-C Ternary by High-Resolution Transmission Electron Microscopy”. Proc. 45th Ann.

Meeting of the Electron Microscopy Society of America, Bailey, G.N., (Ed.), San Franc.

Press, USA, 168-169 (1987) (Crys. Structure, Experimental, 4)

[1988Kov] Koval'chenko, M.S., Paustovskij, A.V., Bolejko, B.M. Zhidkov, A.V., “Laser Surface

Hardening of Cermets on the Base of Boron Carbide”(in Russian), Poroshk. Metall., 5,

77-80 (1988) (Mechan. Prop., Experimental, 6)

[1989Blu] Blumenthal, W.R., Gray, G.T.,“Structure-Property Characterization of Shock-Loaded

B4C-Al”, Inst. Phys. Conf. Ser. No 102: Session 7, Paper Presented at Int. Conf. Mech. Prop.

Materials at High Rates of Strain, Oxford, 363-370 (1989) (Experimental, 8)

[1989Hal] Halverson, D.C., Pyzik, A.J., Aksay, I.A., Snowden, W.E., “Processing of Boron

Carbide-Aluminium Composites”, J. Am. Ceram. Soc., 72(5), 775-80 (1989) (Experimental,

33)

[1989Kha] Kharlamov, A.I., Duda, T.I., Lojchenko, S.V., Fomenko, V.V., “Preparation and Properties

of Aluminium Boridocarbide Powder of Al8B4C7 Composition”, 12th Ukrainian Republic

Conference on Inorganic Chemistry, Vol. 1, Simferopol’, Ukr. SSR, 44Pp. (1989) (Mechan.

Prop., Experimental, 0)

[1990Ase] Aselage, T.L., Tallant, D.R., Gieske, J.H., “Preparation and Properties of Icosahedral

Borides”, in “The Physics and Chemistry of Carbides, Nitrides and Borides”, Freer, R.

(Ed.), Proc. NATO Advanced Research Workshop, Manchester, U.K., 1989, published as

ASI-Series, Ser. E: Appl. Sci.,Vol. 185, Kluwer Acad. Publ., Dordrecht, 97-111 (1990)

(Crys. Structure, Review, Experimental,14)

[1990Luk] Lukas, H.L., ”Aluminium-Boron-Carbon”, in ”Ternary Alloys. A Comprehensive

Compendium of Evaluated Constitutional Data and Phase Diagrams”, Petzow, G.,

Effenberg, G., (Eds.), Vol. 3, VCH, Weinheim, 140-146 (1990) (Review, Equi. Diagram, 14)

[1990Oka] Okada, S., Kudou, K., Hiyoshi, H., Higashi, I., Hamano, K., Lundström, T., “Preparation of

AlC4B24 and Al3C2B48 Crystals”, J. Int. Ceram. Soc. Jpn., 98, 1342-1347 (1991), translated

from Nippon Seramikkusu Kyokai Gakujutsu Ronbunshi, 98(12), 1330-1336 (1990)

(Experimental, Crys. Structure, 24)

[1990Pyz] Pyzik, A.J., Williams P.D., McCombs, A., “New Low Temperature Processing for Boron

Carbide/Aluminium Based Composite Armor”, Final Report, US-Army Research Office,

DAAL 0388 C0030, 1990 (Experimental, 14 )

[1990Ram] Ramesh, K. T., Ravichandran, G., “Dynamic Behavior of a Boron Carbide-Aluminum

Cermet: Experiments and Observations”, Mech. Mater., 10(1-2) 19-29 (1990)

(Experimental, 22)

38


MSIT®

Al–B–C

[1991Kha1] Kharlamov, A.I., Loichenko, S.V.,“Electronic Transport Properties of Hot-pressed

Boron-rich Compounds of the Al-B-C System”, in “Boron-Rich Solids”, AIP Conf. Proc.

231, Emin, D. et al. (Eds.), Albuquerque, USA, 1990, AIP, New York, 94-97 (1991)

(Experimental, 5)

[1991Kha2] Kharlamov, A.I., Loichenko, S.V., “Investigation: The Process of Densification of

Boron-Rich Compounds of the Al-B-C System”, in “Boron-Rich Solids”, AIP Conf. Proc.

231, Emin, D. et al. (Eds.), Albuquerque, USA, 1990, AIP, New York, 473-481 (1991)

(Experimental, 2)

[1991Kha3] Kharlamov, A.I., Murzin, L.M., Loichenko, S.V., Duda, T.I., “Electrical Conductivity and

Seebeck Coefficient of Hot-Pressed Specimens of Aluminium Borides and Carboborides”,

Sov. Powder Metall. Met. Ceram., 9(345), 770-773 (1991), translated from Poroshk.

Metall., 9(345), 62-65 (1991) (Experimental, Electr. Prop., 7)

[1991Kha4] Kharlamov, A.I., Duda, T.I., Fomenko, V.V., “Preparation and Properties of

High-Dispersive Powders of Aluminium Dodecaboride and Carboborides”, in “Boron-Rich

Solids”, AIP Conf. Proc. 231, Emin, D. (Eds.), Albuquerque, USA, 1990, AIP, New York,

512-515 (1991) (Experimental, 0)

[1991Pri] Prikhina, T.A., Kisly, P.S.,“Aluminium Borides and Carboborides”, in “Boron-Rich

Solids”, AIP Conf. Proc. 231, Emin, D. et al. (Eds.),Albuquerque, USA, 1990, AIP, New

York, 590-593 (1991) (Experimental, 11)

[1991Pyz] Pyzik, A. J., Nilson, R.T., “B4C/A1 Cermets and Method for Making Same”, US Patent

Document 5,039,633, (1991)

[1992Bei] Beidler, C.J., Hauth III, W.E., Goel, A., “Development of a B4C/A1 Cermet for Use as an

Improved Structural Neutron Absorber”, J. Testing and Evaluation, 20(1), 67-70 (1992)

(Experimental, 6)

[1992Var] Vardiman, R.G., “Microstructures in Aluminium, Ion Implanted with Boron and Heat

Treated”, Acta Metall. Mater., 40, 1029-35 (1992) (Crys. Structure, Eperimental, 7)

[1992Via] Viala, J.C., Gonzales, G., Bouix, J., “Composition and Lattice Parameters of a New

Aluminium-Rich Boron Carbide”, J. Mater. Sci. Lett., 11, 711-714 (1992) (Crys. Structure,

Experimental, 9)

[1993Bau] Bauer, J., Bittermann, H., Rogl, P., “Phase Relations and Structural Chemistry in the

Ternary System Aluminium - Boron - Carbon”, COST-507, Annual Report, (1993) (Crys.


[1993Gon] Gonzalez, G., Esnouf, C., Viala, J.C., “Structural Study of a New Aluminium Rich

Borocarbide Formed by Reaction at the B4C/Al Interface”, Mater. Sci. Forum, 126-128,

125-128 (1993) (Crys. Structure, Experimental, 4)

[1993Ips] Ipser, H., privat communication (1993) (Experimental)

[1993Kau] Kaufmann, L., private communication (1993) (Thermodyn.)

[1993Wen] Wen, H., “Thermodynamic Calculations and Constitution of the Al-B-C-N-Si-Ti System”

(in German), Thesis, Univ. Stuttgart, 1-183 (1993) (Calculation, Equi. Diagram,

Thermodyn., 223)

[1993Wer] Werheit, H., Kuhlmann, U., Laux, M., Lundström, T., “Structural and Electronic Properties

of Carbon-Doped -Rhombohedral Boron”, Phys. Status Solidi (B), B179, 489-511 (1993)


[1994Dus] Duschanek, H., Rogl, P., “The System Al-B”, J. Phase Equilib., 15(5), 543-52 (1994) (Crys.

Structure, Equi. Diagram, Experimental, #, 78) see also ibid, 16(1), 6 (1995)

[1994Kud] Kudou, K., Okada, S., Hikichi, H., Lundström, T., “Preparation and Properties of Si-doped

Al3C2B48-Type Crystals” (in Japanese), J. Soc. Mater. Sci., Jpn., 43(485), 223-228 (1994)

(Experimental, Crys. Structure, Phys. Prop., 20)

[1995Bon] Bond, G.M., Inal, O.T., “Shock-Compacted Aluminium/Boron Carbide Composites”,

Compos. Eng. 5(1), 9-16 (1995) (Experimental, 18)

[1995Hil] Hillebrecht, H., Meyer, F., “B48A13C2 - a Filled Variant of Tetragonal Boron”,

Z. Kristallogr., Suppl. 10, 101 (1995) (Crys. Structure, Experimental, 2)

39


MSIT®

Al–B–C

[1995Osc] Oscroft, R.J., Roebuck P.H.A., Thompson, D.P., “Characterisation and Range of

Composition for Al8B4C7”, Br. Ceram. Trans., 94(1), 25-26 (1995) (Experimental, 11)

[1995Pyz] Pyzik, A.J., Beaman, D.R., “Al-B-C Phase Development and Effects on Mechanical

Properties of B4C/Al-Derived Composites”, J. Am. Ceram. Soc., 78(2), 305-312 (1995)

(Crys. Structure, Mechan. Prop., Experimental, 25)

[1995Rug] Ruginets, R., Fischer, R. “Microwave Sintering of Boron Carbide Composites”, Am. Ceram.

Soc. Bull., 74(1), 56-58 (1995) (Experimental)

[1996Bid] Bidaud, E., research at Univ. Wien, unpublished (1996)

[1996Hil1] Hillebrecht, H., Meyer, F.D., “The Structure of B48Al3C2 - A Filled and Distorted Variant

of Tetragonal Boron (I)”, in “Boron, Borides and Related Compounds”, Proc. 12th Int.

Symp., Baden/Wien, paper PA.4, 59 (1996) (Crys. Structure, Experimental, 6)

[1996Hil2] Hillebrecht, H., Meyer, FD., “Synthesis, Crystal Structure, and Vibrational Spectra of

Al3BC3, a Carbidecarboborate of Aluminium with Linear (C=B=C)5- Anions”, Angew.

Chem., 35(21), 2499-2500 (1996), translated from Angew. Chemie, 108(21), 2655-2657


[1996Kas] Kasper, B., “ Phase Equilibria in the B-C-N-Si System”, Thesis, Max Plank Institute-PML,

Stuttgart, (1996) (Equi. Diagram, Thermodyn.)

[1996Pyz] Pyzik, A.J., Deshmukh, U.V., Dunmead, S.D., Ott, J.J., Allen, T.L., Rossow, H.E., “Light

Weight Boron Carbide/Aluminium Cerments”, United States Patent: 5,521,016, (1996)

[1996RMi] R'Mili, M., Massardier, V., Merle, P., Vincent, H., Vincent, C., “Mechanical Properties of

T300/A1 Composites. Embrittlement Effects due to a B4C Coating”, J. Mater. Sci., 31,


[1996Vin] Vincent, H., Vincent, C., Berthet, M. P., Bouix, J., Gonzalez, G., “Boron Carbide Formation

from BCl3-CH4-H2 Mixtures on Carbon Substrates and in a Carbon-Fibre Reinforced Al

Composite”, Carbon, 34(9), 1041-1055 (1996) (Crys. Structure, Mechan. Prop.,

Experimental, 25)

[1997Du] Du, W.F., Watanabe, T., “High-Toughness B4C-AlB12 Composites Prepared by Al

Infiltration”, J. Eur. Ceram. Soc., 17, 879-884 (1997) (Mechan. Prop., Experimental, 15)

[1997Mey] Meyer, F.D. Hillebrecht, H., “Synthesis and Crystal Structure of Al3BC, the First

Boridecarbide of Aluminium”, J. Alloy. Compd., 252, 98-102 (1997) (Crys. Structure,

Experimental, 30)

[1997Sch] Schmechel, R., Werheit, H., Robberding, K., Lundström, T., Bolmgren, H., “IR-active

Phonon Spectra of B-C-Al Compounds with Boron Carbide Structure”, J. Solid State

Chem., 133, 254-259 (1997) (Experimental, 11)

[1997Via] Viala, J. C., Bouix, J., Gonzalez, G., Esnouf, C. “Chemical Reactivity of Aluminium with

Boron Carbide”, J. Mater. Sci, 32, 4559-4573 (1997) (Equi. Diagram, Experimental, 39 )

[1997Yue] Yücel, O., Tekin, A., “The Fabrication of Boron-Carbide-Aluminium Composites by

Explosive Consolidation”, Ceram. Int., 23, 149-152 (1997) (Experimental, Mechan. Prop.,

3)

[1998Kha] Kharlamov, A.I., Kirillova, N.V., Loichenko, S.V., Fomenko, V.V., “Properties of

Aluminium Borides and Borocarbides”, Russ. J. Appl. Chem., 71(5), 743-749 (1998),

translated from Zh. Prikl. Khim, 71(5), 717-724 (1998) (in Russian), (Crys. Structure,

Kinetics, Mechan. Prop., Experimental, 13)

[1998Rog] Rogl, P., “Al-B-C (Aluminium-Boron-Carbon)”, MSIT Ternary Evaluation Program, in


GmbH, Stuttgart; Document ID: 10.12170.2.20, (1998) aslo published in ”Phase Diagrams

of Ternary Metal-Boron-Carbon Systems”, Effenberg, G., (Ed.), ASM-Intl, MSI, 3-15

(1998) (Assessment, Crys. Structure, Experimental, Equi. Diagram, 50)

[1999Bur] Burkhardt, U., Grin, Y., “Refinement of the Aluminium Diboride Crystal Structure”, in

“Borides and Related Compounds”, Abst. 13th Int. Symp. on Boron, Dinar (France), 13pp.,

(1999) (Crys. Structure, 3)

40


MSIT®

Al–B–C

[1999Cha] Chapman, T.R., Niesz, D.E., Fox, R.T., Fawcett, T., “Wear-resistant Aluminum - Boron -

Carbide Cermets for Automotive Brake Applications”, Wear, 236, 81-87 (1999) (Mechan.

Prop., Experimental, 9)

[1999Tor] Torquato, S., Yeong, C.L.Y., Rintoul, M.D., Milius, D.L., Aksay, I.A., “Elastic Properties

and Structure of Interpenetrating Boron Carbide/Aluminum Multiphase Composites”,

J. Am. Ceram. Soc., 82(5), 1263-1268 (1999) (Mechan. Prop., 32)

[1999Tsu] Tsuchida, T., Kan, T., “Synthesis of Al3BC in Air from Mechanically Activated Al/B/C

Powder Mixtures”, J. Eur. Ceram. Soc., 19, 1795-1799 (1999) (Crys. Structure,

Experimental, 12)

[2000Hal] Hall, A., Economy, J., “The Al(L)+AlB12 AlB2 Peritectic Transformation and its Role in

the Formation of High Aspect Ratio AlB2 Flakes”, J. Phase Equilib., 21(1), 63-69 (2000)

(Equi. Diagram, Experimental, 21)

[2000Hig] Higashi, I., “Crystal Chemistry of -AlB12 and -AlB12”, J. Solid State Chem., 154,


[2000Kha] Kharlamov, A. I., Nizhenko, V.I., Kirillova, N.V., Floka, L.I., “Wettability of Hot-Pressed

Samples of Boron-Containing Aluminium Compounds by Liquid Metals and Alloys” (in

Russian), Zh. Prikl. Khim., 73(6), 884-888 (2000) (Experimental, 14)

[2000Liu] Liu, C.H., “Structure and Properties of Boron Carbide with Aluminum Incorporation”,

Mater. Sci. Eng. B, B72, 23-26 (2000) (Phys. Prop., Crys. Structure, Experimental, 10)

[2000Mey] Meyer, F.D., Hillebrecht, H., “Ternary Phases in the System Al/B/C”, in “High

Temperature Materials Chemistry”, Vol. 15, Part 1, K. Hilpert et al. (Eds.), Proc. 10th Intl.

IUPAC Conf., Forschungszentrum Jülich, Germany, Published by Schriften des

Forschungszentrums Juelich, 161-164 (2000) (Crys. Structure, 5)

[2000Pyz] Pyzik, A.J., Deshmukh, U.V., Krystosek, R. D., “Aluminum-Boron-Carbon Abrasive

Article and Method to Form Said Article”, US Patent: 6,042,627, (2000).

[2000Sav] Savyak, M., Uvarova, I., Timofeeva, I., Isayeva L., Kirilenko, S., “Mechanochemical

Synthesis in Ti-C, Ti-B, B-C, B-C-A1 Systems”, Mater. Sci. Forum, 343-346, 411-416


[2000Sol] Solozhenko, V.L., Meyer, F.D., Hillebrecht, H., “300-K Equation of State and

High-Pressure Phase Stability of Al3BC3”, J. Solid State Chem., 154, 254-256 (2000) (Crys.


[2000Wan] Wang, T., Yamaguchi, A., “Some Properties of Sintered Al8B4C7”, J. Mater. Sci. Letter.,

19, 1045-1046 (2000) (Calculation, Crys. Structure, 6)

[2000Wer] Werheit, H., Schmechel, R., Meyer, F. D., Hillebrecht, H., “Interband Transitions and

Optical Phonons of B48Al3C2”, J. Solid State Chem., 154, 75-78 (2000) (Optical Prop.,

Experimental, 10)

[2001Fje] Fjellstedt, J., Jarfors, A.E.W., El-Benawy, T., “Experimental Investigation and

Thermodynamic Assessment of the Al-rich Side of the Al-B System”, Mater. Des., 22(6),

443-449 (2001) (Thermodyn, Equi. Diagram, Experimental, 14)

[2001Lee] Lee, K. B., Sim, H.S., Cho, S.Y., Kwon, H., “Reaction Products of Al-Mg/B4C Composite

Fabricated by Pressureless Infiltration Technique”, Mater. Sci. Eng. A, 302, 227-234 (2001)

(Crys. Structure, Equi. Diagram, Experimental, 17)

[2002Ars] Arslan, G., Kara, F., Turan, S., “Mechanical Properties of Melt Infiltrated Boron

Carbide-Aluminium Composites”, Key Eng. Mater., 206-213(2), 1157-1160 (2002)

(Experimental, Mechan. Prop., 5)

[2002Bur] Burkhardt, U., Gurin, V., Borrmann, H., Schnelle, W., Grin, Y., “On the Electronic and

Structural Properties of Aluminium Diboride Al0.9B2”, in “Boron, Borides and Related

Compound”, Abst. 14th Int. Symp., (ISBB’02), Saint Petersburg, O4, (2002) (Crys.

Structure, 3)

[2002Kou1] Kouzeli, M., Mortensen, A., “Size Dependent Strengthening in Particle Reinforced

Aluminium”, Acta Mater., 50, 39-51 (2002) (Mechan. Prop., Experimental, 59)

41


MSIT®

Al–B–C

[2002Kou2] Kouzeli, M., Marchi, C. S., Mortensen, A., “Effect of Reaction on the Tensile Behavior of

Infiltrated Boron Carbide-Aluminum Composites”, Mater. Sci. Eng. A, A337, 264-273

(2002) (Experimental, Mechan. Prop., 51)

[2002Zhe] Zheltov, P., Grytsiv, A., Rogl, P., Velikanova, T.Ya., Research at Univ. Wien (unpublished)

(2002) (Equi. Diagram, Crys. Structure)

[2003Per] Perrot, P., “Aluminium-Carbon”, MSIT Binary Evaluation Program, in MSIT Workplace,

Effenberg, G. (Ed.), MSI, Materials Science International Services GmbH, Stuttgart, to be

published, (2003) (Equi. Diagram, Crys. Structure, Assessment, 19)

Table 1: Literature Data on Experimental Temperatures of Invariant Equilibrium L+AlB12 AlB2

* DSC measurements were performed with heating rate of 5, 15 and 40°/min., and extrapolated to 0°C/min.


Technique Heating Rate T [°C] References

Stability observation - 1000 -1500 [1936Hof]

Synthesis observation - 980 [1967Ser]

DTA 4°C/min 920 [1967Ato]

Stability observation - 1350-1500 [1972Sir]

DTA 5°C/min 1030±5 [1993Ips]

Synthesis observation - 892±5 [1997Via]

DSC and

Stability observation

0°C/min* 956±5 [2000Hal]

DSC 10°C/min 914±55 [2001Fje]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

(Al)

< 660.452

cF4

Fm3m

Cu

a = 404.96 [Mas2]

( B)

< 2092

hR333

R3m

B

a = 1093.30

c = 2382.52

a = 1092.2

c = 2381.1

a = 1096.5

c = 2386.8

a = 1097.4

c = 2387.7

[Mas2, 1993Wer]

at 1.1 at.% C [1993Wer]

linear da/dx, dc/dx

at AlB31 [V-C2]

from sample Al4B95C1, quenched from

1400°C, contains Al3B48C2 and AlB12

[1993Bau]

(C)

< 3827 (B.P.)

hP4

P63/mmc

C-graphite

a = 246.12

c = 670.90

a = 246.023

c = 671.163

a = 246.75

c = 669.78

[Mas2]

[1967Low]

at 2.35 at.% Bmax (2350°C)

linear da/dx, dc/dx, [1967Low]

42


MSIT®

Al–B–C

B4C

< 2450

hR45

R3m

B13C2

a = 565.1

c = 1219.6

a = 560.7

c = 1209.5

a = 560.3

c = 1209.8

9 to 20 at.% C [1990Ase]

from sample containing 2, 4, quenched

from 1400°C [1993Bau]

B25C tP52

P42m

B25C

a = 872.2

c = 508.0

[V-C2]

also B51C1, B49C3; all metastable?

Al2B3

525

hR*

Al2B3 (?)

a = 1840

c = 896

at 60 at.% B [1992Var]

metastable?

AlB2

956±5

hP3

P6/mmm

AlB2

a = 300.6

b = 325.2

a = 300.67 ± 0.01

b = 325.36 ± 0.02

a = 300.63 ± 0.01

b = 325.46 ± 0.01

a = 300.43 ± 0.03

b = 325.19 ± 0.06

[1994Dus],

temperature from [2000Hal]

[2002Zhe]

[2002Zhe] in 33.3Al-66.2B-0.5C,

in equilibrium with 5 at 900°C

[1999Bur] for Al0.9B2

AlB12

2050

tP216

P41212

AlB12

a = 1015.8

c = 1427.0

a = 1018

c = 1434.3

a = 1016.3

c = 1425.6

a = 1015.5

c = 1426.0

a = 1014.93 ± 0.07

c = 1425.0 ± 0.5

[1994Dus]

exp. = 2.65 Mgm-3

[1991Pri]


1400°C, contains Al3B48C2 [1993Bau]



[1993Bau]

[2002Zhe]

AlB12 oP384

P212121

AlB12

a = 1014.4

b = 1657.3

c = 1751.0

a = 1019.5

b = 1666

c = 1769

[1983Hig, 1994Dus, 2000Hig]

metastable phase or ternary product

stabilized by small amounts of impurity

metals present in Al-flux grown material

exp. = 2.56 Mgm-3

[1991Pri]

Al4C3

< 2156

hR21

R3m

Al4C3

a = 333.8

c = 2511.7

a = 334.21 ± 0.01

c = 2503.2 ± 0.5

a = 335.78 ± 0.02

c = 2499.6 ± 0.5

[2003Per, V-C2]

[2002Zhe]

[2002Zhe] in 57.1Al-4.3B-38.6C

Al4(C0.9B0.1)3, in equilibrium with 5 at

900°C

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

43


MSIT®

Al–B–C

* 1, Al2.1B51C8

(eventually low

temperature

phase of 2)

oC88

Cmcm

Al2B51C8 a = 569.0

b = 888.1

c = 910.0

a = 568.7

b = 887.7

c = 909.8

a = 569.0

b = 888.1

c = 910.0

a = 569.3

b = 884.7

c = 909.3

a = 567.6

b = 891.4

c = 909.5

a = 569.2

b = 889.2

c = 911.2

earlier labeled “AlB10” [1967Wil] or

AlB24C4 [1964Mat,1969Wil,1970Wil]]

[1969Per]

exp. = 2.54 Mgm-3

from sample containing 2 and 3,

quenched from 1400°C [1993Bau]

from sample containing 4, quenched

from 1400°C [1993Bau]

from sample Al4B92C4 quenched from

1400°C, contains Al3B48C2 (tetragonal),

Al3B48C2 (A) and AlB40C4 [1993Bau]

[1991Pri]

[1990Oka]

exp. = 2.54 Mgm-3

single crystals from Al-flux

* 2, AlB40C4

(eventually high

temperature phase

of 1)

hR45

R3m

B4C-deriv.

a = 564.2

c = 1236.7

a = 565.37

c = 1231.4

a = 564.8

c = 1239.9

a = 565.6

c = 1238.9

a = 563

c = 1129

a = 565

c = 1239

[1970Nei]

exp. = 2.52 Mgm-3

from sample containing 1, 3, quenched

from 1400°C [1993Bau]

from sample containing 4 and B4C,


from sample Al4B92C4 quenched from

1400°C, contains also Al3B48C2

(tetrag.), Al3B48C2 and Al2.1B51C8

[1993Bau]

[1966Gie] for composition “Al2B48C8”

[1966Lip] for composition “Al4B48C8”

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

44


MSIT®

Al–B–C

* 3, Al3B48C2 (r)

< 650

oI212

Imma

Al3B48C2

a0 = 1240.7

b0 = 1262.3

c0 = 1014.4

a = 1234

b = 1263

c = 508

a = 1232.5

b = 1261.4

c = 1016.2

a = 1233.72

b = 1262.41

c = 1016.06

a = 1232.5

b = 1264.7

c = 1016.2

a = 1230.2

b = 1262.1

c = 1016.1

a = 1229.1

b = 1262.2

c = 1015.88

a = 1233.62

b = 1262.40

c = 1015.94

a = 1239.0 ± 0.3

b = 1263.7 ± 0.3

c = 1013.6 ± 0.4

a = 1237.7

b = 1262.7

c = 507.9 to

a = 1236.3

b = 1261.6

c = 510.2

a = 616.6

b = 1263.5

c = 1065.6

a = 618.1

b = 1262.2

c = 1016.1

a = 617

b = 1263

c = 1016

a = 616.4

b = 1262.1

c = 1016.4

[1996Hil1], only one low temperature

modification!

[1965Mat], two modifications,

microscopically twinned;

modification A, c=c0/2

from a sample Al6B92C2 cooled from

1400°C contains “AlB12” [1993Bau]

from sample Al4B95C1 cooled from

1400°C contains also “AlB12”, AlB31

[1993Bau]

[1991Pri]

[1994Kud]


1400°C, [1993Bau] contains

Al2.1B51C8, AlB40C4 and tetragonal

Al3B48C2

[1993Bau] from sample Al4B95C1,

cooled from 1400°C, see above.

[2000Wer]

[1990Oka]


modification A ; c = c0/2

[1990Oka]


exp. = 2.59(2) Mgm-3

modification B, a = a0/2

[1965Mat]

modification B

a = a0/2

[1991Pri]

a = a0/2

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

45


MSIT®

Al–B–C

a) P63/mmc for subcell with a = a0/ , c = c0

* 3, Al3B48C2 (h)

> 650

tP52

P42/nnm

B25C -deriv.

a = 885

c = 508

a = 882

c = 509

a = 881.9

c = 508.25

[1996Hil1] high temperature

modification

[1965Mat]


1400°C, contains also Al2.1B51C8,

AlB40C4 and orthorhombic Al3B48C2

[1993Bau]

* 4, Al3BC3

< 1835

hP42

P3c1 a)

Mg3BN3

a = 589.97

c = 1589.0

a = 590.6

c = 1590.1

a = 590.7

c = 1591.3

a = 590.5

c = 1590.5

a = 340.1 ± 0.3

c = 1584 ± 0.2

a = 590.22 ± 0.3

c = 1589.4 ± 0.1

[1996Hil2] = 2.66 Mgm-3

temperature from [1980Ino]

[1980Ino], labelled as Al8B4C7

from sample containing 1,


from sample containing 2 and B4C,


[2000Sol], subcell with a = a0/

pressure dependence of the lattice

parameters is given up to 7.5GPa

[2002Zhe]

* 5, Al3BC

< 1100

hP20

P3c1

(P63/mmc

for subcell)

Al3BC

a = 605.0

c = 1154.0

a = 603.45

c = 1152.02

a = 6041.9 ± 0.2

c = 1154.0 ± 0.3

a = 349.1

c = 1154.1

a = 352.0

c = 582.0

[1993Gon, 1997Via]

[1997Mey] from single crystals,

“Al2.5BC” from EPMA

[2002Zhe]

[1992Via], subcell with a = a0/

[1987Sar], earlier “Al4BC“

subcell with a = a0/ , c = c0/2

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

3

3

3

3

46

Landolt-Börnstein New Series IV/11A1MSIT®

Al–B–C

Ta

ble

3:

Mic

roh

ard

nes

s, F

ract

ure

To

ug

hn

ess,

Ele

ctri

cal C

on

du

ctiv

ity

, A

ctiv

atio

n E

ner

gie

s fo

r E

lect

rica

l C

on

du

ctiv

ity

an

d T

her

mal

Co

nd

uct

ivit

y f

or

Var

iou

s

Alu

min

ium

Bo

rid

es a

nd

Alu

min

ium

Bo

ron

Car

bid

es.

Co

mp

ou

nd

Cry

stal

Fac

e

of

Ind

ent

Mic

roh

ard

nes

s [G

Pa]

at V

ario

us

Lo

ads

and

Tem

per

atu

res

Fra

ctu

re

To

ug

hn

ess

K1c

[MP

am

1/2

]

293

K [

m]

Act

ivat

ion E

ner

gy

E [

eV]

10

0K

to

40

0K

R=

R0ex

p(-

E/2

kT

)

Th

erm

al

Co

nd

uct

ivit

y

[Wm

-1K

-1]

Ref

eren

ces

Kn

oo

pV

ick

ers

Al 3

B4

8C

2(1

11)

(100)

(111)

26

.5(5

) (

2N

29

3K

)

23.1

(5

N, 2

93K

)

27

.1(5

) (

2N

, 2

93

K)

37

.6(2

.0)

(0

.5N

, 2

93

K)

31.7

(8)

(1

N,

2

93K

)

23.7

(6)

(4

.9N

, 2

93K

)

33.6

(1.6

) (2

N,

293K

)

25

.7 t

o

30

.5

(1

N,

29

3K

)

5.3

4(1

)

10

4-1

06

2.6

10

3-1

0-6

2.6

10

-6

1 0.6

- 1

.2

19

.6 (

31

0K

)

[19

86K

is]

[19

86K

is]

[19

86K

is]

[19

91P

ri]

[19

90O

ka,

199

4K

ud

]

[19

86D

ub]

[19

86D

ub]

[19

86D

ub]

Al 2

.1B

51C

8(1

00

)2

2.6

(2

N,

29

3K

)

26

(5

N,

29

3K

)

6

(5

N,

12

00

K)

24.2

(7)

(

2N

, 29

3K

)

25.0

-26

.9 (1

N,

293K

)

2.7

(2)

10

-3 -

1

2.0

2 1

05

0.1

0.0

8 -

0.1

8

38

.7 (

31

0K

)

60

(60

0K

)

[19

86K

is]

[19

86K

is]

[19

86K

is]

[19

91P

ri]

[19

90O

ka]

Al 3

BC

32

0.7

(

0.2

5N

, 2

93

K)

18

.2

(

0.5

0N

, 2

93

K)

[20

00

So

l]

AlB

12

(101)

19.6

(5)

(

2N

, 29

3K

)1

.5(3

)5.9

2

10

20.1

8 -

0.3

6[1

991P

ri]

AlB

12

(001)

29.6

(1.0

) (0

.5N

, 29

3K

)

25.8

(7)

(

1N

, 2

93K

)

22.8

(8)

(

2N

, 2

93K

)

21.6

(1.1

) (4

.9N

, 29

3K

)

34.4

(2.7

) (0

.5N

, 2

93K

)

31.0

(1.5

) (1

N,

293K

)

27

.3(1

.2)

(2

N, 2

93K

)

23.8

(9)

(

4.9

N, 2

93K

)

1.8

(2)

3.8

5

10

50

.22

[19

86D

ub]

[19

86D

ub]

[19

91P

ri]

[19

86D

ub]

47


MSIT®

Al–B–C

Al

600

660.452

700

800

900

1000

Temperature,°C

1100

0 0.2 0.4 0.6 0.8 2.4 2.5 2.6

[1967Ser]

[2001Fje]

[1994Dus]

[1984Sig]

[1976Mon]

L+AlB12

0.55

1030 5±2.5

980975

914

?

927

0.7

L+AlB2

659.7

L

0.055

(Al)+AlB2

0.025

0.0045

B, at.%

Fig. 1a: Al-B-C.

Various versions of

the Al-rich part of the

Al-B diagram

80 60 40 20

500

750

1000

1250

1500

1750

2000

Al BAl, at.%

Tem

pera

ture

, °C

956±5

659.7(Al)

AlB2

AlB12 (βB)

~20502092°C

0.55

0.055

97

Fig. 1b: A-B-C.

Accepted Al-B phase

diagram

48


MSIT®

Al–B–C

600

700

800

900

1000

1100

Al Al 99.30B 0.70

Al, at.%

Tem

pera

ture

, °C

956±5

(Al)+AlB2

0.55

0.0045

L

L+AlB12

0.055659.7

L+AlB2

20

40

60

80

20 40 60 80

20

40

60

80

Al B

C Data / Grid: at.%

Axes: at.%

~Al4BC

τ5Al3BC

Al3BC3τ4

Al8B4C7

Al4B1-3C4

Al2.6-3.0B1.8-1.2C

Al2.33-2.5BC

[1964Mat]

[1996Hil2]

[1995Pyz][1987Sar]Al3BC

[1992Via]

[1980Ino]

[1997Mey]

Fig. 1c: Al-B-C.

Accepted Al-B phase

diagram, enlarged

Al-rich region

Fig. 2: Al-B-C.

Superposition of

literature data on the

homogeneity regions

of τ4 and τ5 phases.

Half-filled circles

correspond to the

accepted

compositions

49


MSIT®

Al–B–C

20

40

60

80

20 40 60 80

20

40

60

80

Al B

C Data / Grid: at.%

Axes: at.%

Al4C3

B4C

AlB12

τ5

τ4

τ3

τ1

τ2

(βB)

L

τ2, AlB40C4

τ5, Al3BC

τ1, Al2.1B51C8

τ3, Al3B48C2

τ4, Al3BC3

Al B

C Data / Grid: at.%

Axes: at.%

AlB12

B4C

Al4C3

τ3

τ1τ2

τ5

τ4

(βB)

L

τ4, Al3BC3

τ1, Al2.1B51C8

τ2, AlB40C4

τ5, Al3BC

τ3, Al3B48C2

Fig. 4: Al-B-C.


1000°C

Fig. 3: Al-B-C.


1400°C; the position

of Al3BC is

indicated by a full

circle

50


MSIT®

Al–B–C

20

40

60

80

20 40 60 80

20

40

60

80

Al B

C Data / Grid: at.%

Axes: at.%

L

τ5

τ4

AlB12

B4C

τ3

τ1τ2

Al4C3

AlB2

(βB)

τ5, Al3BC

τ1, Al2.1B51C8

τ2, AlB40C4

τ3, Al3B48C2

τ4, Al3BC3

Fig. 5: Al-B-C.


900°C

e

e

e

��

��

��

��

��

��

��

��

Fig. 6: Al-B-C.

Tentative liquidus

surface projection

51


MSIT®

Al–B–C

Fig

. 7

:

Al-

B-C

. R

eact

ion s

chem

e

Al-

BB

-CA

-B-C

L +

(βB

) A

lB12

2050

p4

L B4C

+ (

C)

2390

e 1

L +

B4C

τ 3p1A

l-B

-C

L +

B4C

(βB

) +

τ3

U1

Al-

C

L +

(C

) A

l 4C3

2156

p2

L

(Al)

+ A

lB2

659.7

e 2

L +

AlB12

AlB2

956.5

p5

L(A

l) +

Al 4

C3 +

τ5

E2

L (

Al)

+ A

lB2 +

τ5

E1

L +

τ3

AlB2 +

τ5

U5

L +

AlB12

AlB2 +

τ3

U4

B4C

+ τ3

(βB

) +

τ2

U3

B4C

+ τ1

+τ 3

τ 2P2L +

B4C

+ τ3

τ 1P1

L +

(βB

) A

lB12 +

τ3

U2

L(A

l) +

τ5

e 3L

(A

l) +

Al 4

C3

660

e 4

L +

B4C

(βB

)

2103

p3

? ?

L +

AlB12

+ τ 3L

+ (

βB)

+ τ3

B4C

+ (

βB)

+ τ3

B4C

+ τ1

+τ 3

L +

B4C

+ τ1

?L

+ τ1

+τ 3

?B4C

+ τ3 +

τ2

B4C

+ τ1 +

τ2

τ 1+

τ 3 +

τ2

L +

AlB2

+τ 3

AlB12

+ A

lB2

+τ 3

L +

τ3

+τ 5

?

τ 3+

(βB

) +

τ2

B4C

+ (

βB)

+ τ2

L +

AlB2

+τ 5

τ 3+

AlB2 +

τ5

L +

Al 4

C3

+τ 5

?

(Al)

+ A

lB2

+τ 5

(Al)

+ A

l 4C3 +

τ5

(βB

) +

AlB12

+τ 3

52


MSIT®

Al–B–Mg

Aluminium – Boron – Magnesium

Qingsheng Ran, updated by Peter Rogl

Literature Data

Grain refining of boron additions to Al-Mg alloys was the basis for early studies of the Al-B-Mg system

[1949Ebo]. No complete phase diagram exists, although several groups investigated the interactions in the

ternary system [1959Hof, 1970Mat, 1971Vek, 1981Por, 1983Sho]. Considerable interest was further

devoted to the rather hard compound “MgAlB14” [1970Mat, 1971Vek, 1983Hig, 1990Hig, 1993Hig].

Single crystals were obtained from aluminum high temperature flux starting from the nominal composition

MgAl31B6 which was heated under argon in an alumina crucible to 1500°C, kept at this temperature for 1h

and slowly cooled to RT (10K min-1). The excess Al was then dissolved in hot HCl [1983Hig, 1993Hig].

From a batch with ~100 g, crystals were formed up to 5 mm in size and predominantly as plates with the

habit {001} [1993Hig]. When starting mixtures with smaller amounts of Mg were used, AlB12 type

crystals Mg0.45Al0.77B12 were obtained, mostly as thin hexagonal plates [1993Hig].

[1959Hof] mixed magnesium, aluminum and boron in order to study the formation of (Al,Mg)B2 solid

solutions. After sintering in argon at temperatures between 725 and 790°C the formation of such a solid

solution was identified despite the kinetic difficulty of formation. From 99.9 % pure metals and 99.2 % pure

amorphous boron [1971Vek] synthesized 22 ternary alloys. The mixtures were briquetted and heated to

temperatures of 850 to 1000°C under an argon atmosphere in sintered alumina crucibles. The reaction

products were investigated by X-ray phase analysis. [1970Mat] prepared “MgAlB14” by heating a mixture

of magnesium, aluminum and boron in atomic proportions of 1:2:14 to 900°C for 6 h. The sample was then

cooled and treated with concentrated hydrochloric acid. The crystal structure of this phase was determined

by X-ray (probably on single crystal) diffraction.


knowledge.

Binary Systems

The systems Al-B [1994Dus] and B-Mg [1978Spe] are accepted.

Solid Phases

According to [1971Vek] the phase “MgAlB12” is identical to “MgAlB14”. The structure of which was

determined in detail from several attempts to obtain single crystal material from high temperature aluminum

solutions [1983Hig, 1990Hig, 1993Hig]. In agreement with the chemical analysis (atom emission

spectroscopy, Mg0.79Al0.80B14), X-ray single crystal studies revealed significant defects on the metal sites:

Mg0.78Al0.75B14 [1983Hig, 1990Hig, 1993Hig]. For smaller Mg-concentrations in the Al-melt crystals

“Mg0.5Al1.4B22” of the AlB12 type were obtained [1990Hig, 1993Hig], suggesting a high temperature

solid solution of Mg in AlB12 (about 3.5 at.% Mg at ~1500°C).

Isothermal Sections

A tentative isothermal section at approximately 900°C (Fig. 1) is constructed from the results of [1971Vek].

[1971Vek] reported a region of (Al) solid solution containing more than 65 at.% B, which is quite

improbable and might be the result of the difficult formation of the (Al,Mg)B2 phase as stated by [1959Hof].

For the phase relations at 900°C a small solid solution of Mg in AlB12 was assumed as well as for Al in

( B). The ternary compound was taken at the composition Mg0.78Al0.75B14 [1983Hig, 1990Hig, 1993Hig].

53


MSIT®

Al–B–Mg


Microhardness (Vickers hardness under a load of 100g) for Mg0.78Al0.75B14 crystals was found to range

from 27.70 to 28.90 GPa [1993Hig].

References

[1949Ebo] Eboral, M.D., “Grain Refinement of Aluminium and its Alloys by Small Additions of Other

Elements”, J. Inst. Met. 76, 295-320 (1949) (Experimental, 29)

[1959Hof] Hofmann, H., “Studies of Some Borides of Lithium, Magnesium and Aluminium” (in

German), Thesis, University Stuttgart, (1959) (Experimental, 15)

[1970Mat] Matkovich, V.I., Economy, J., “Structure of MgAlB14 and a Brief Critique of Structural

Relations in Higher Borides”, Acta Crystallogr. Sect. B: Struct. Crystallogr. Crys. Chem.,

26B, 616-621 (1970) (Crys. Structure, Experimental, 24)

[1971Vek] Vekshina, N.V., Markovskii, Ya.L., Kondrashev, Yu.D., Voevedskaya, T.K., “Binary

Borides of Al and Mg”, J. Appl. Chem. 44, 970-974 (1971), translated from Zh. Prikl. Khim.,

44, 958-963 (1971) (Equi. Diagram, Experimental, 14)

[1978Spe] Spear, K.E., “Correlations and Predictions of Metal-Boron Phase Equilibria”, NBS Special

Publications 496, 744-762 (Equi. Diagram, Review, 21)

[1981Por] Portnoi, K.I., Bogdanov, V.I., Mikhailov, A.V., Fuks, D.L., “Interaction Parameters in

Interstitial Solid Solutions Based on Aluminium”, Russ. J. Phys. Chem., 55, 583-584 (1981)

(Experimental, 10)

[1983Hig] Higashi, I., Ito, T., “Refinement of the Structure of MgAlB14”, J. Less Common Met., 92,

239-246 (1983) (Experimental, Crys. Structure, 15)

[1983Sho] Shorshorov, M.Kh., Potatov, V.I., Antipov, V.I., Trutnev, V.V., Akinfieva, L.A., Potapova,

T.K., “Reaction of Boron with an Aluminium-Magnesium System Alloy, Fiz. Khim. Obrab.

Mater., 3, 142-143 (1983) (Experimental, 4)

[1990Hig] Higashi, I., Kobayashi, M., Takahashi, Y., Okada, S., Hamano, K., “Crystal Growth of

Icosahedral Boride (B12) Compounds from High-Temperature Metal Solutions”, J. Cryst.

Growth, 99, 1-4P2, 998-1004 (1990) (Experimental, Crys. Structure, 32)

[1993Hig] Higashi, I., Kobayashi, M., Okada, S., Hamano, K., Lundström, T., “Boron-Rich Crystals

in Al-M-B (M = Li, Be, Mg) Systems Grown from High-Temperature Aluminium

Solutions”, J. Cryst. Growth, 128, 1113-1119 (1993) (Experimental, Crys. Structure, 16)

[1991Pri] Prikhina, T.A., Kisly, P.S., “Aluminium Borides and Carboborides”, in “Boron-Rich

Solids” Emin, D., et al. (Eds.) Proc. Conf. 231, Albuquerque, 1990, published by AIP, New

York, 590-593 (1991) (Experimental, 11)


Treated”, Acta Metall. Mater., 40, 1029-1035 (1992) (Crys. Structure, Experimental, 7)

[1993Wer] Werheit, H., Kuhlmann, U., Laux M., Lundström, T., “Structural and Electronic Properties

of Carbon-Doped -Rhombohedral Boron”, Phys. Status Solidi B, B179, 489-511 (1993)


[1994Dus] Duschanek, H., Rogl, P., “The System Al-B”, J. Phase Equilib., 15 (5), 543-552 (1994)

(Crys. Structure, Equi. Diagram, Experimental, #, 78) see also ibid, 16 (1), 6 (1995)

54


MSIT®

Al–B–Mg


Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/ References

(Al)

< 660.452

cF4

Fm3m

Cu

a = 404.96 [Mas2]

( B)

< 2092

hR333

R3m

B

a = 1093.30

c = 2382.52

[1993Wer]

a = 1096.5

c = 2386.8

at AlB31 [V-C2]

Al2B3

525

hR*

Al2B3 (?)

a = 1840

c = 896

at 60 at.% B [1992Var]

AlB12

2050

tP216

P41212

AlB12

a = 1015.8

c = 1427.0

a = 1018

c = 1434.3

[1994Dus]

exp. = 2.65 Mgm-3

[1991Pri]

AlB12 oP384

P212121

AlB12

a = 1014.4

b = 1657.3

c = 1751.0

a = 1019.5

b = 1666

c = 1769

[1994Dus] metastable phase or ternary

product stabilized by small amounts of

impurity metals present in Al-flux

grown material

exp. = 2.56 Mgm-3

[1991Pri]

Mg0.25Al0.77B12 a = 1018.7

b = 1663.3

c = 1754.7

solid solution of Mg in AlB12

[1990Hig, 1993Hig]

(Al1-xMgx)B2

AlB2

975

hP3

P6/mmm

AlB2

a = 300.6

b = 325.2

0 < x < 1 [1959Hof, 1971Vek]

at x = 0 [1994Dus]

a = 304.7

c = 336.6

at x = 0.5 [1971Vek]

MgB2

1550(BP)

a = 308.5

b = 352.3

at x = 1 [V-C2]

MgB4

1775 (BP)

oP20

Pnma

MgB4

a = 546.4

b = 442.8

c = 747.2

[V-C2]

MgB7

2150 (BP)

oI64

Imma

MgB7

a = 597.0

b = 1048.0

c = 812.5

[V-C2]

* 1, Mg0.78Al0.75B14 oI68

Imma

MgAlB14

a = 584.8

b = 1031.2

c = 811.2

[1970Mat, 1983Hig, 1993Hig]

55


MSIT®

Al–B–Mg

10

20

30

40

60 70 80 90

10

20

30

40

Mg 50.00B 50.00Al 0.00

Mg 0.00B 50.00Al 50.00 Data / Grid: at.%

Axes: at.%

(Al,M

g)B 2

τ1, (AlMg)2-xB14

αAlB12

MgB7MgB4

L+(Al,Mg)B2

MgB2

AlB2

(βB)

B

Fig. 1: Al-B-Mg.

Tentative partial iso-

thermal section at

about 900°C

56


MSIT®

Al–B–N

Aluminium – Boron – Nitrogen

Vasyl’ Tomashik

Literature Data

A critical assessment of the Al-B-N ternary system has been published by [1990Jeh], which included the

literature data up to 1986. Literature data up to 1991 have been critically reviewed by [1992Rog] and later

by [1998Rem]. Subsequently this system was investigated experimentally by several techniques and for

different temperature and composition ranges and calculated thermodynamically. The present assessment

takes into account all available data.

Information on Al-B-N phase relations appeared for the first time in the work of [1965Pri], where the

prospects were discussed to develop from this system alloys with special physical properties. Today general

agreement exists that there are no ternary compounds in this system. Various methods were used to prepare

the specimens. [1966Pri, 1968Pri, 1972Mog, 1979Sir, 1980Ole, 1982And2] used pressure sintering of

polycrystalline samples Al+BN or AlN+B at various temperatures and found that the density of the Al+BN

samples decreases after sintering whilst the sintering of AlN+B samples leads to increasing density

[1966Pri, 1968Pri]. BN interacts with Al in the process of hot pressing and forms AlN [1972Mog]. The

sintering of polycrystalline BN-Al specimens (1500-3000°C and 5-9.5 GPa) yielded cubic BN containing

2-3 mass% dissolved Al; higher Al contents resulted in the formation of h-BN, AlB12 and AlN [1979Sir].

According to the data of [1999Bez] the interaction of Al melt and c-BN at 8GPa begins at 1270°C with the

formation of AlN, AlB2 and AlB12. It was determined that the lattice constant of c-BN increases at the

reaction sintering of c-BN and Al [2000Bez].

AlN was found to act as a catalyst for the synthesis of cubic BN from hexagonal BN under the inert or

reducing atmosphere in lowering the temperature and pressure conditions [1977But, 1979Maz, 1980Ole,

1981Hir]. At 1600°C and 6.5 GPa the well-crystallized hexagonal BN could be completely be converted

into c-BN by adding 20 mole% AlN and 20 mass% of toluene [1981Hir]. Reducing atmosphere in the

high-pressure cell should enhance the catalytic effect of AlN.

[1972Lyu, 1973Lyu] alternatively prepared Al+B+N alloys by nitrating complex Al and B salts or mixtures

of metal and complex salts in NH3 atmosphere.

The experimental results allow to conclude that the mutual solid solubility of AlN and BN in the quasibinary

system AlN-BN is small [1965Pri, 1972Lyu, 1973Lyu, 1979Sir, 1982And1, 1982And2, 1989Pol]. The

lattice parameter of BN increased from 361 to 364.4 pm on saturation with Al [1977But]. According to

calculations of the lattice parameters, using a model with the eight-atom clusters, the average value of lattice

constant varies linearly with t composition for the AlxB1-xN solid solution at 830°C and the calculated value

of the fluctuation a at x = 0.5 is equal to 37 pm [2002Tel].

In the reaction of BN crucibles with liquid Al, AlB2 and AlB12 boride inclusions are formed [1967Lue]. In

Al containing BN films prepared by dual-ion beam sputtering, the amount of cubic phase decreased

monotonically with increasing Al concentration. The recorded structure of such films changed to that of

hexagonal BN when the content of Al exceeded 3.2 at.% [2002Kur].

Binary Systems

For the best match of ternary and binary data the binary descriptions of the MSIT Binary Evaluation

Program are accepted here: Al-B [2003Ted], Al-N [2003Fer] and B-N [2003Rec].

Solid Phases

No ternary compound exists in the Al-B-N system. All unary and binary phases are listed in Table 1.

57


MSIT®

Al–B–N


A hypothetical phase diagram of the AlN-BN pseudobinary system was constructed in the investigation at

8-9 GPa and 2000-2500°C [1980Bar]. Homogeneous solid solutions were obtained at the simultaneous

nitration in the NH3 flow of BN and Al powder. Later [1983But] found that the c-BN solid solutions

contains up to 25 mole% AlN (Table 1). It is worth noting that the phase diagram presented there is in

disagreement with the Phase Rule and the large solubility ranges disagree with the information given by

[1989Pol], who reports that the solubility of BN in AlN is small and that the lattice parameter of AlN after

annealing of the mixtures AlN+BN at 7 GPa and 1500°C does not change. Quantum-chemical calculations

indicate that the phase based on BN has the highest stability in the system [1982And1, 1982And2].

Thermodynamic calculations based on a regular solution model have predicted an unstable region of mixing

to occur in the AlN-BN system [2001Tak]. The interaction parameter (138.5 kJ mol-1) that was used in the

calculations has been analytically obtained by the valence force field model, modified for wurtzite

structures. According to the interaction parameter the value of the critical temperature is found to be

8060°C. The phase diagram of the AlN-BN system including the spinodal and binodal curves was also

calculated using the generalized quasichemical approximation and ab-initio total energy method [2002Tel].

From these calculations the critical temperature appears to be very high, approximately 9230°C, which

results in a very large miscibility gap. The phase diagram as far as obtained experimentally, verifies that

there is spinodal decomposition for the AlxB1-xN alloys in the interval 0.051 < x < 0.963.


The reaction scheme given in Fig. 1 incorporates the “Thermo-Calc” calculations by [1993Wen] and the

binary data given by [2003Ted, 2003Fer, 2003Rec].

Isothermal Sections

At room temperature the Al-B-N system is divided into five triangles (Al-AlB2-AlN, AlN-AlB2-AlB12,

AlN-AlB12-BN, AlB12-B-BN and AlN-BN-N) without solid solubility of the third component in all binary

compounds [1979Sir, 1990Jeh]. According to the data of [2002Riz] the Al-B-N ternary system at 1500°C

can be divides into four triangles (Al-AlB12-AlN, AlB12-AlN-BN, AlB12-B-BN and AlN-BN-N).

Isothermal sections at 2500°C and 100 kPa or 2500°C and 8 GPa presented by [1982And2] reveal a rather

unusual extension of the AlN and BN solid solutions based on. Phase equilibria in the Al-B-N system at

900°C under 100 kPa argon (in the absence of external nitrogen) have been established from X-ray powder

diffraction analysis [1991Rem, 1992Rog] and are given in Fig. 2. This isothermal section was reproduced

in the review [1994Mch]. Lattice parameters suggest a mutual solubility of AlN and BN of less than ~4

mole% with no significant changes in solubility between 900 and 1600°C and nitrogen practically does not

dissolve in the binary aluminium borides. Some isothermal sections have been calculated using the program

Thermo-Calc (Figs. 3-9) [1993Wen].


The addition of 10 vol.% Al allows to improve the sintering ability of BN-TiB2 material for the manufacture

of evaporation boats [1972Mog].

The compressive stress of 5.6 GPa and the hardness value of 60 GPa of the BN films were reduced to 2 and

13 GPa respectively after adding 3.2 at.% Al [2002Kur]. Compared with pure cubic BN film the oxidation

resistance of the BN films improves drastically with Al additions of less then 2.3 at.%. The addition of Al

is a very effective technique for preventing delaminating and for controlling internal stress, as well as

improving the oxidation resistance.

A linear behavior of the bulk modulus with composition was obtained for AlxB1-xN ternary alloys (from

209 GPa for AlN to 386 GPa for BN) [2002Tel].

58


MSIT®

Al–B–N

Miscellaneous

The wetting angle of Al on h-BN, as measured by the sessile drop method at 1000°C, was given as =157°

[1966Yas]. For c-BN the wetting angle increases with increasing pressure: 40° at 2.5 GPa and 1450°C; 85°

respectively 60° at 8.0 GPa and 1700°C, respectively 2000°C [1999Bez].

References

[1965Pri] Prikhod’ko, L. I., “Prospects of Creation of Materials with Special Physical Properties in the

Aluminium-Boron-Nitrogen System” (in Russian), Vestn. Kiev. Politekhn. Inst., Ser.

Mekhan.-Tekhnol., (2), 59-63, (1965) (Theory, Equi. Diagram, 12)

[1966Pri] Prikhod’ko, L. I., “Investigation of Conditions for Obtaining of Materials Based on Boron

and Aluminium Nitrides” (in Russian), Poroshkov. Met., (1), 17-22 (1966) (Experimental,

Equi. Diagram, 11)

[1966Yas] Yasinskaya, G.A., “The Wetting of Refractory Carbides, Borides and Nitrides by the

Molten Metals”, Sov. Powder Metall. Met. Ceram., (7), 557-559 (1966), transl. from

Poroshkov. Met., (7), 53-56 (1966) (Experimental, Equi. Diagram, 5)

[1967Lue] Luetkemeyer, M., Kirner, K., “High-Temperature Reactions of Boron Nitride with

Aluminium” (in German), Prakt. Metallogr., 4, 83-87 (1967) (Experimental, Equi.

Diagram, 3)

[1968Pri] Prikhod’ko, L. I., “Investigation of the Boron - Aluminium - Nitrogen Alloys” in “Khimiya

i Fizika Nitridov” (in Russian), Nauk. Dumka, Kiev, 84-89 (1968) (Experimental, Equi.

Diagram, 13)

[1972Lyu] Lyutaya, M. D., Bartnitskaya, T. S., Fainer, I. S., “Investigation in the Field of Group IIIA

Mixed Nitrides”, Kristallokhim. Tugoplav. Soedin., Kiev, 53-61 (1972) (Experimental,

Equi. Diagram, 10)

[1972Mog] Mogilensky, V.I., Gropyanov, V.M., Zhunda, A.N., Zeberin, A.G., Egorova G.V.,

“Aluminium Vaporizers Made of Materials Based on Boron Nitride and Titanium

Diboride”, Sov. Powder Metall. Met. Ceram. (Engl. Transl.), 3(111), 203-206 (1972),

translated from Poroshk. Metall., (3), 42-47 (1972) (Experimental, Equi. Diagram, 7)

[1973Lyu] Lyutaya, M. D., Bartnitskaya, T. S., “Thermal Stability of Complex Nitrides of Elements of

Subgroup IIIB (Al-B-N System)”, Inorg. Mater. (Engl. Transl.), 9, 1052-1054 (1973),

translated from Izv. Akad. Nauk SSSR, Neorg. Mater., 9(8), 1367-1371 (1973)


[1977But] Butylenko, A.K., Bartnitskaya, T.S., Lugovskaya, E.S., Timofeeva, I.I., “Aluminium

Doping of Cubic Boron Nitride” (in Russian), Pis’ma Zhur. Tekh. Fiz., 3(20), 1094-1095

(1977) (Experimental, Equi. Diagram, 1)

[1979Maz] Mazurenko, A.M., Leusenko, A.A., Strukov, N.A., Nichipor, V.V., “Aluminium Influence

on the Formation and Cutting Properies of Cubic Boron Nitride Polycrystals” (in Russian),

Sverhtverd. Mater., (1), 13-16 (1979) (Experimental, Equi. Diagram, 11)

[1979Sir] Sirota, N. N., Zhuk, M. M., “Study of the Phase Composition and Some Properties of a

Super-Hard Material Obtained in the Boron Nitride - Aluminum System at High Pressures

and Temperatures” (in Byelorussian), Vestsi Akad. Navuk BSSR, Ser. Fiz.-Mat., (5), 85-88

(1979) (Experimental, Equi. Diagram, *, 8)

[1980Bar] Bartnitskaya, T.S., Butylenko, A.K., Lugovskaya, E.S., Timofeeva, I.I., “Study of the

Quasibinary Cross Section of AN-BN at High Pressures” (in Russian), Vys. Davleniya

Svoistva Mater., Mater Resp. Nauchn. Semin., 1978 (Pub.), Kiev, 90-94 (1980)

(Experimental, Equi. Diagram, *, 3)

[1980Ole] Olehnovich, N.M., Pashkovskyy, O.I., Starchenko, I.M., Sharay, V.T., Shipilo, V.B.,

“About Mechanism of Phase Transition in BN at its Interaction with Al at the High

Pressures and Temperatures” (in Russian), Izv. Akad. Nauk SSSR, Neorg. Mater., 16(10),

1780-1784 (1980) (Experimental, Equi. Diagram, 4)

59


MSIT®

Al–B–N

[1981Hir] Hirano, Sh., Yamaguchi, T., Naka, Sh., “Effects of AlN Additions and Atmosphere on the

Synthesis of Cubic Boron Nitride” J. Am. Ceram. Soc., 64(12), 734-736 (1981)


[1982And1] Andreeva, T.V., Timofeeva, I. I., Bartnitskaya, T. S., “About New Boron-Containing

Phases in the B-N-Al System” (in Russian), Vysokotemp. Boridy Silitsidy, Kiev, 80-82

(1982) (Calculation, Equi. Diagram, 3)

[1982And2] Andreeva, T.V., Bartnitskaya, T.S., Butylenko, A.K., Goryachev, Yu.M., Timofeeva, I.I.,

“Effect of Pressure on Phase Composition in a Boron-Nitrogen-Aluminum System” (in

Russian), Protsessy Vzaimodeistviay na Granitse Razdela Faz, Kiev, 70-74(1982)


[1983But] Butylenko, A.K., Timofeeva, I.I., Bartnitskaya, T.S., Makarenko, G.N., Kosolapova, T.Ya.,

Smolin, M.D., “Physico-Chemical Principles of Cubic Boron Nitride Doping” (in Russian),

In: Sverhtverdyye Materialy: Sintez, Svoystva, Primenieniye., Nauk. Dumka, Kiev, 66-69


[1989Pol] Polyakov, V.P., Elyutin, V.P., Polushin, N.I., Burdina, K.P., Lysenko, Yu.A., Kalashnikov,

Ya.A., “Interaction in the AlN-BN System Under Conditions of High Pressures and

Temperatures” (in Russian), Dokl. Akad. Nauk. SSSR, 306(6), 1413-1416 (1989)


[1990Jeh] Jehn, H.A., “Aliminium-Boron-Nitrogen”, in “Ternary Alloys. A Comprehensive

Compendium of Evaluated Data and Phase Diagrams”, Petzow G., Effenberg, G., (Eds.),

Vol. 3, VCH, 192-193 (1990) (Review, Equi. Diagam, #, *, 7)

[1991Rem] Remschnig, K., Duschanek, H., Rogl, P., “The Ternary System Al-B-N”, COST 507 Leuven

Proceedings; Part A, A2, (1991) (Experimental, Equi. Diagram, #, *, 31)

[1992Rog] Rogl, P., Schuster, J.C., “Al-B-N”, in “Phase Diagrams of Ternary Boron Nitride and

Silicon Nitride Systems” Monogr. Ser. Alloy Phase Diag., 3-5 (1992) (Equi. Diagram,

Review, #, *, 16)

[1993Wen] Wen, H.M.Sc., “Thermodynamic Calculations and Constitution of the Al-B-C-N-Si-Ti

System” (in German), Thesis, Univ. Stuttgart, 1-183 (1993) (Calculation, Equi. Diagram, #,

*, 223)




[1994McH] McHale, A.E., “VIII. Boron Plus Nitrogen Plus Metal; Al-B-N”, Phase Equilibria

Diagrams, Phase Diagrams for Ceramists, 10, 212-213 (1994) (Review, Equi. Diagram, 3)

[1998Rem] Remschnig, K., Duschanek, H., Rogl, P., ”Al-B-N (Aluminium - Boron - Nitrogen),” MSIT

Ternary Evaluation Program, in MSIT Workplace, Effenberg, G. (Ed.), MSI, Materials

Science International Services GmbH, Stuttgart; Document ID: 10.16348.1.20, (1998)

(Crys. Structure, Equi. Diagram, Assessment, 30)

[1999Bez] Bezhenar, M.P., “Physico-Chemical Interaction at the Sintering of Cubic Boron Nitride

with Aluminium at the High Pressures” (in Ukrainian), Sverhtverd. Mater., (2), 4-11 (1999)


[2000Bez] Bezhenar, M.P., Bozhko, S.A., Nahornyi, P.A., Bilyavina, N.M., Markiv, V.Ya,

“Interaction of Cubic Boron Nitride with Aluminium at the Carbon Presence” (in

Ukrainian), Sverhtverd. Mater., (4), 36-40 (2000) (Experimental, Equi. Diagram, 6)

[2001Tak] Takayama, T., Yuri, M., Itoh, K., Baba, T., Harris Jr., J.S., “Analysis of Phase-Separation

Region in Wurtzite Group III Nitride Quaternary Material System Using Modified Valence

Force Field Model”, J. Cryst. Growth, 222(1-2), 29-37 (2001) (Calculation, Equi. Diagram,

*, 20)

[2002Kur] Kurooka, S., Ikeda, T., Tanaka, A., “Influence of Al Addition on Mechanical and Oxidation

Properties of cBN Films”, Thin Solid Films, 415, 46-52 (2002) (Experimental, Equi.

Diagram, 23)

60


MSIT®

Al–B–N

[2002Riz] Rizzoli, C., Salamakha, P.S., Sologub, O.L., Bocelli, G., “X-Ray Investigation of the

Al-B-N Ternary System: Isothermal Section at 1500°C: Crystal Structure of the

Al0.185B6CN0.256 Compound”, J. Alloys Compd., 343, 135-141 (2002) (Experimental,

Equi. Diagram, Crys. Structure, 28)

[2002Tel] Teles, L.K., Scolfaro, L.M.R., Leite, J.R., Furthmueller, J., Bechstedt, F., “Spinodal

Decomposition in BxGa1-xN and BxAl1-xN Alloys”, Appl. Phys. Lett., 80(7), 1177-1179

(2002) (Calculation, Equi. Diagram, *, 14)

[2003Fer] Ferro, R., Bochvar, N., Sheftel, E., Ding, J.J., “Al-N (Aluminum-Nitrogen)”, MSIT Binary


International Services GmbH, Stuttgart, to be published, (2003) (Review, Equi. Diagram,

Assessment, 33)

[2003Ted] Tedenac, J.-C., “Al-B (Aluminium-Boron)”, MSIT Binary Evaluation Program, in MSIT


Stuttgart, to be published, (2003) (Crys. Structure, Equi. Diagram, Assessment, 23)

[2003Rec] Record, M.Ch., Tedenac, J.-C., “B-N (Boron-Nitrogen)”, MSIT Binary Evaluation

Program, in MSIT Workplace, Effenberg, G. (Ed.), MSI, Materials Science International

Services GmbH, Stuttgart, to be published, (2003) (Crys. Structure, Equi. Diagram,

Assessment, 50)


Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

( Al)

< 660.452

cF4

Fm3m

Cu

a = 404.96 at 25°C [Mas2]

( B)

< 2092

hR333

R3m

B

a = 1093.30

c = 2382.52

a = 1092.2

c = 2381.1

a = 1096.5

c = 2386.8

a = 1097.4

c = 2387.7

[Mas2, 1993Wer]

at 1.1 at.% C [1993Wer]

linear da/dx, dc/dx

at AlB31 [V-C2]

from samplr Al4B95C1, quenched from


[1993Bau]

( N)

< -237.54

cP8

Pa3

N

a = 566.1 [Mas2]

AlB12

< 2050

tP216

P41212

AlB12

a = 1015.7 ± 0.5

c = 1475 ± 11

[2003Ted]

AlB12

< 1450

oP384

P212121

AlB12

a = 1014.0

b = 1657.3

c = 1751.0

[2003Ted]

AlB2

956±5

hP3

P6/mmm

AlB2

a = 300.58 ± 0.05

c = 325.33 ± 0.08

[2003Ted]

61


MSIT®

Al–B–N

Al2B3

< 525

hR*

Al2B3

a = 1840

c = 896

[2003Ted]

metastable

AlN

< 2434.7

hP4

ZnS

a = 311.14

c = 497.92

at 25°C [2003Fer]

h-BN

< 2397

hP4

P63mc

BN

a = 250.4

c = 666.1

[2003Rec]

c-BN cF8

F43m

ZnS

a = 361.53 ± 0.04 [2003Rec]

w-BN hP4

P63/mmc

ZnS

a = 255.0 ± 0.5

c = 423 ± 1

[2003Rec]

r-BN hR6 a = 250.4

c = 999.1

[2003Rec]

Compressed h-BN mC4

C2/c or Cc

a = 433

b = 250

c = 310 to 330

= 92-95°

[2003Rec]

AlxB1-xN

AlxB1-xN

cF8

F43m

ZnS

a = 361

a = 364.4

a = 361 ± 0.5

a = 361.2 ± 0.5

a = 362.7 ± 0.5

a = 363.5 ± 0.5

at x = 0

at x = 0.333 [1977But]

at x = 0

at x = 0.05

at x = 0.09

at x = 0.25 [1983But]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

62


MSIT®

Al–B–N

Fig

. 1:

A

l-B

-N. R

eact

ion s

chem

e af

ter

[1993W

en]

wit

h s

om

e m

odif

icat

ions

regar

din

g t

he

acce

pte

d b

inar

y d

iagra

ms

from

[2003G

ry,

2002F

er,

2003R

ec]

Al-

BA

l-N

B-N

Al-

B-N

G +

L

AlN

2434.7

p1

L +

(βB

) A

lB12

2050

p3

G +

L

AlN

+ B

N2280

U1

L (

βB)

+ B

N

2092

d1

G +

L

BN

2397

p2

L A

lN +

(αA

l)

660.3

d2

(αA

l)+

AlB2

Al 2

B3

525

p5

L A

lB2

+ (

αAl)

659.7

e

L +

AlB12

AlB2

965

p4

L +

AlB12

AlB2,

AlN

975

D2

L (

αAl)

, A

lB2,

AlN

659.7

D3

(αA

l)+

AlB2

Al 2

B3,A

lN525

D4

L +

BN

A

lB12 +

AlN

1980

U2

L +

(βB

) A

lB12,

BN

2050

D1

(βB

) +

AlB12 +

BN

L +

AlB12 +

BN

L +

AlN

+ B

NG

+ A

lN +

BN

AlB12 +

AlN

+ B

NL

+ A

lB12 +

AlN

L +

AlB2

+ A

lN

AlB12 +

AlB2

+ A

lN

(αA

l) +

AlB2 +

AlN

(αA

l) +

Al 2

B3 +

AlN

AlB2 +

Al 2

B3 +

AlN

63


MSIT®

Al–B–N

20

40

60

80

20 40 60 80

20

40

60

80

Al B

N Data / Grid: at.%

Axes: at.%

AlN

BN

AlB2 AlB12 (βB)

L

AlN+AlB12+(βB)L+BN+AlB2

BN+AlB2+AlN

AlB2+AlN+AlB12

Fig. 2: Al-B-N.


900°C under 105 Pa

argon (in absence of

external nitrogen)

[1991Rem]

20

40

60

80

20 40 60 80

20

40

60

80

Al B

N Data / Grid: at.%

Axes: at.%

AlB12

BNAlN

Al2B3AlB2

(Al) AlB2+AlN+AlB12AlN+Al2B3+AlB2

(Al)+AlN+Al2B3

(βB)

AlN+BN+AlB12

BN+AlB12+(βB)

Fig. 3: Al-B-N

Calculated isothermal

section at 230°C

64


MSIT®

Al–B–N

20

40

60

80

20 40 60 80

20

40

60

80

Al B

N Data / Grid: at.%

Axes: at.%

AlB12

BNAlN

AlB2

L

(βB)

L+AlN+AlB2

AlN+AlB2+AlB12

AlN+BN+AlB12

BN+AlB12+(βB)

20

40

60

80

20 40 60 80

20

40

60

80

Al B

N Data / Grid: at.%

Axes: at.%

AlB12

BNAlN

L

BN+AlB12+(βB)

L+AlN+AlB12

L+AlN+AlB12

(βB)

Fig. 4: Al-B-N.


section at 730°C

Fig. 5: Al-B-N.


section at 1230°C

65


MSIT®

Al–B–N

20

40

60

80

20 40 60 80

20

40

60

80

Al B

N Data / Grid: at.%

Axes: at.%

BNAlN

AlB12L

BN+AlB12+(βB)

L+AlN+BN

L+BN+AlB12

(βB)

20

40

60

80

20 40 60 80

20

40

60

80

Al B

N Data / Grid: at.%

Axes: at.%

AlB12

BNAlN

L

BN+AlB12+(βB)

L+AlN+AlB12

AlN+BN+AlB12

(βB)

Fig. 7: Al-B-N.


section at 2060°C

Fig. 6: Al-B-N.


section at 1730°C

66


MSIT®

Al–B–N

20

40

60

80

20 40 60 80

20

40

60

80

Al B

N Data / Grid: at.%

Axes: at.%

BNAlN

G

BN

+G+L

AlN+G+L

L

20

40

60

80

20 40 60 80

20

40

60

80

Al B

N Data / Grid: at.%

Axes: at.%

G

L

Fig. 8: Al-B-N.


section at 2330°C

Fig. 9: Al-B-N.


section at 3430°C

67


MSIT®

Al–B–Ni

Aluminium – Boron – Nickel

Peter Rogl

Literature Data

Transient liquid bonding (TLB) using B-Ni eutectic filler material proved to be an efficient process to

produce interface-less joints in Ni-base superalloys. Control of process parameters avoiding the appearance

of brittle boride phases, however, requires profound understanding of the diffusion process, phase

boundaries and ultimately of phase equilibria in the ternary Al-B-Ni system.

Several research groups have dealt with the experimental constitution of the Al-B-Ni ternary system: (a)

[1962Sta1, 1963Sta] proposed a tentative liquidus projection for Ni-rich alloys (50-100 at.% Ni) from

metallographic and XRD inspection on about 40 ternary alloys prepared by high frequency induction

melting in sintered alumina crucibles (air-cooled cast melts). An 800 C isothermal section was constructed

[1962Sta1] based on alloys annealed in evacuated silica capsules for 300 h; (b) [1973Cha] prepared two

isothermal sections at 800°C and 1000°C, based on XPD and microstructural analyses. The specimens

(elemental powder compacts) were annealed in evacuated silica capsules at 1000, 800 and 600°C for not

less than 150, 600 and 1000 h, respectively. Alloys containing more than 60 mass% Al were investigated at

600°C. Results of [1973Cha] confirmed the formation of the 1 phase with an extended homogeneity region,

but showed the existence of further ternary compounds, 2 Ni5AlB4 and 3 Ni8AlB11; (c) crystallographic

studies were performed of the ternary boride, 1, (Cr23C6 type structure) with an extended homogeneity

region by [1962Sta2, 1963Sta] and [1998Hil]; (d) a thermodynamic assessment of the Al-B-Ni system is

due to [1999Cam] and in refined version from [2000Cam].

Phase relations in the Al-B-Ni system have been reviewed by [1989Sch, 1990Sch, 1999Cam].

Binary Systems

The binary boundary systems Al-Ni and B-Ni are accepted from critical assessments of [2003Sal] and

[Mas2], respectively. Although the system Al-B has been assessed and thermodynamically modelled by

several authors, the system was adopted in the form described in Al-B-C [2003Gry].

Solid Phases

Three ternary phases, 1 to 3, were detected by [1973Cha] (Table 1), the latter (Ni8AlB11) with a

polymorphic transition in the temperature range from 800 to 1000°C transforming from a monoclinic

high-temperature structure to an unidentified structure at 800°C. The ternary phase, 2 Ni5AlB4, was only

observed in the 800°C isothermal section [1973Cha]; its crystal structure is still unknown.

Whilst both research groups [1973Cha, 1962Sta1, 1962Sta2, 1963Sta] agree on the existence of the 1 phase

with an extended region of homogeneity, discrepancy exists on the extent of the 1 phase at 800°C:

[1962Sta1, 1962Sta2, 1963Sta] report on a narrow phase field extending from 21 to 34 at.% boron:

Ni20Al3B6-12 starting from the B-poor composition at 70Ni-8Al-22B (at.%) to the B-rich composition at

60Ni-10Al-30B (at.%). According to [1973Cha] the 1 phase region at 800°C is rather small extending at a

constant Al-content of 10.3 at.% from 20 to 28 at.% B. The 1 phase field is more extensive at 1000°C

ranging from 20 to 34 at.% B [1973Cha] in close resemblance to the data listed by [1962Sta1, 1962Sta2,

1963Sta] for 800°C. Only half the number of alloys were examined by [1973Cha] compared with

[1962Sta1] but they were annealed for twice the time. Although it is difficult to judge, which version

corresponds to true equilibrium, we may assume that Stadelmaier’s results have suffered from lack of

equilibrium and rather reveal the phase relations at about 1000°C.

[1962Sta2, 1963Sta] tried to explain the unusually large homogeneity region of 1 with strongly varying

boron content on the basis of a partial replacement of single boron atoms by boron-pairs within the

Archimedian Ni- prisms in the crystal structure of the Cr23C6 type.

68


MSIT®

Al–B–Ni

A detailed structural investigation of the homogeneity region of 1 employing X-ray single crystal

diffractometry [1998Hil] suggests two substitution mechanisms: (i) Ni/Al replacement Ni20+xAl3-xB6 and

(ii) substitution of Al-atoms by boron tetrahedra Ni20Al3-2yB6+8y. Whilst the variation of composition from

Ni20Al3B6 to Ni20Al2.4B8.4 seems to follow the experimental observations of [1962Sta1] and [1973Cha],

the endpoints of the structural series Ni20Al3-2yB6+8y for 0.3 y 1 are in conflict with the experimental

phase region and certainly provoke further experimental studies.

The possibility of ternary phase formation by reaction of transition metal borides with Al in terms of the

electron structure of the transition metals was discussed by [1981Ser].


Figure 1 presents the reaction scheme for the Ni-rich part of the system. The maximum melting point of

congruently-melting 1, was said to be at a composition close to 60Ni-9Al-31B (at.%), however, no melting

temperature was reported [1962Sta1]. Four ternary invariant reactions were proposed by [1962Sta1],

although no temperatures were given and composition of the phases involved can only be guessed from a

graph presented; see Table 2. Furthermore the B-Ni binary phase diagram adopted by [1962Sta1] has been

revised since, requiring amendments to the reactions proposed by [1962Sta1]: the ternary eutectic reaction

L (Ni)+ 1+Ni3B, originally had Ni2B as a product phase, but the transition reaction U1, L+NiAl Ni3Al+ 1

and the ternary eutectic reaction E1, L (Ni)+Ni3Al+ 1, are unchanged. The primary solidification region

for “Ni3B2” [1962Sta1] needs to be replaced by the phases o-Ni4B3and m-Ni4B3. According to [1962Sta1]

there are maximum points on three of the monovariant curves. These correspond to the pseudobinary

equilibria L (Ni)+ 1, L NiAl+ 1 and L Ni3B+ 1.

The fourth reaction, L 1+NiAl+NiB, as stated by [1962Sta1], is rather unlikely, as this region of the

ternary phase diagram is relatively complex due to binary reactions, which will extend into the ternary in a

manner currently unknown.

The thermodynamic calculation [1999Cam] lists the same four ternary invariant reactions as observed by

[1962Sta1]. Calculated reaction temperatures and compositions of the liquid phases involved are given

dependent on two different assessments for the Al-Ni binary, [1997Ans] and [1998Hua]. There are,

however, a series of major discrepancies, as seen from the comparison in Table 2.

A detailed study by DTA and Knudsen-effusion mass spectroscopy [1990Dha] comparing four binary

alloys, Ni1-xAlx, x = 0.20, 0.23, 0.24 and 0.26 with those containing 0.5 at.% B, showed that minor additions

of boron altered considerably the phase boundaries.

Liquidus Surface

A liquidus surface for the region with more than 50 at.% Ni was constructed by [1962Sta1]. As mentioned

under “Invariant Equilibria”, it needs revision to comply with the accepted binary B-Ni system. The region

with less than 30 at.% B is shown in Fig. 2. Due to casting alloys in air (eventual burn up of boron),

Stadelmaier's reaction isotherms, E1, E2 and U1 may have shifted to lower boron contents than shown

[1962Sta1]. This would be in better agreement to a non-depleted eutectic E1.

Isothermal Sections

A partial isothermal section at 1000°C (see Fig. 3) was determined by [1973Cha] for the region Ni-NiAl-B.

Phase equilibria at 800°C are presented in Fig. 4 and are essentially based on the investigation by

[1973Cha]: alloys containing more than 60 at.% Al were annealed at 600°C. However, no complete 600°C

isothermal section was reported by [1973Cha]. For an extensive discussion of the homogeneity region of

the 1 phase, see section “Solid Phases”. Both isothermal sections, Fig. 3 and Fig. 4, have been amended to

comply with the accepted binary boundary systems. Changes in particular concern the phase AlB12 as well

as the solubility of Al and Ni in ( B).

69


MSIT®

Al–B–Ni

Thermodynamics

A thermodynamic modelling of the system Al-B-Ni was performed by [1999Cam] using the CALPHAD

approach with Redlich-Kister polynomial description of the Gibbs energy functions [1985Sun]. The binary

systems Al-B and B-Ni were included in the modelling. In contrast to earlier treatment, boron was taken as

an interstitial element in the solid metal solutions and in Ni3Al [1999Cam]. Although most of the

experimental phase relations are revealed by the thermodynamic calculation, there are three major points of

disagreement:

(i) a rather high thermal stability of AlB12 favours equilibria with AlB12 over those with ( B) i.e. at 800°C

rather AlB12+NiB, AlB12+Ni8AlB11, AlB12+Ni5AlB4, than ( B)+Ni8AlB11, ( B)+Ni5AlB4;

(ii) a higher stability is calculated at 1000°C for the two-phase equilibrium m-Ni4B3+Ni8AlB11 than the

experimentally observed NiB+ 1;

(iii) the calculated homogeneity region of 1 is still significantly smaller than experimentally observed.

With respect to transient liquid bonding, particularly the location of the three-phase field 1+(Ni)+liquid at

1200°C and 1300°C was discussed with respect to the variation obtained in the calculation, when two

different assessments were used for the Al-Ni binary, namely [1997Ans] and [1998Hua].

Based on the thermodynamic assessment [1999Cam], TLP-simulations and experiments were performed by

[2000Cam] monitoring the diffusion path for the TLP bonds in a Ni-10.3Al (at.%) alloy + Ni-10B (at.%)

filler material at 1315°C after isothermal holds of 1, 900, 1800 and 3600 sec. Composition-dependent

diffusion mobilities were assessed for the ternary system. Adjusting the free energy of the 1 phase to yield

its experimentally observed mole fraction, the simulations predicted the observed precipitation and later

dissolution of the 1 phase during the bonding process [2000Cam]. The corresponding calculated

tie-triangle at 1315°C was given as: L(87Ni3Al10B)+ 1(69Ni310Al21B)+(Ni) (92.3Ni6.8Al0.5B) (read

from diagram in at.%).


Low density, high oxidation resistance and unusual yield strength dependence on temperature have raised

considerable interest in boron-doped polycrystalline intermetallic alloys, NiAl and Ni3Al, as high

temperature structural materials. The acute increase in ductility when a small amount of boron (less than

1 at.%) is added to Ni3Al has evoked a series of investigations, which are briefly summarized in the

following. The microstructure of boron-doped N-atomized Ni3Al powders (Ni0.76Al0.24)99.75B0.25 and

(Ni0.76Al0.25)99B1, has been characterized by LOM and REM revealing remarkable variation in

solidification morphology and phase reaction as a function of powder size [1989Hua]: the degree of boron

segregation appeared to be significantly reduced, as the formation of M23B6-boride was suppressed in

powders below 30 m diameter.

Ultimate and yield strength at 20 and 800°C of monocrystalline Ni3Al increase with the B-content to reach

a maximum for 0.52 and 1.37 at.% B, dropping slowly for higher B-contents up to 2.22 at.% [1991Guo].

When the B-content exceeds 1.37 at.%B, a eutectic structure Ni3Al+Ni20Al3B6 was formed [1991Guo]. Arc

melting behavior of continuously cast thin sheet and cast ingots of Ni3Al containing B and Zr was studied

by [1991Li]. The evolution of recrystallization texture in cold rolled Ni76Al24(B) on annealing has been

investigated by [2000Cho] dividing the annealing process into three stages: recovery, reordering and

recrystallization.

Monitoring the distribution of boron in a rapidly solidified alloy, (Ni76B24)99.76B0.24, via atom probe

field-ion microscopy, [1987Hor] found B to segregate to both anti phase boundaries and grain boundaries.

A -0.4 to 1.2 nm thick boron-enriched phase was observed on most of the grain boundaries in a nonuniform

distribution. Microstructure and mechanical properties of rapidly solidified Ni-Al ribbons (68-90 at.% Ni)

with 0, 200, 2000 and 4000 mass ppm B showed absence of antiphase domain boundaries for hypo-eutectic

compositions but a bimodal distribution of APD: for hyper-eutectic compositions [1996Lim]: explanation

was based on the metastable Ni-Al phase diagram. Single crystals of Ni3Al, doped with 0 to 1 at.% B, were

examined by TEM after slight compressive deformation. APB and SISF (superlattice intrinsic stacking

fault) energies were calculated [1991Yan].

70


MSIT®

Al–B–Ni

Intergranular segregation of B in Ni3Al was investigated by [1992Cho] in terms of equilibrium segregation

and segregation kinetics on high purity Ni76Al24 alloys containing 0.048, 0.144, 0.240 and 0.480 at.% B,

aged from 600 to 1050°C to attain equilibrium. The energy of binding of a B-atom to the grain boundary

was calculated to be in the range of 0.15-0.45 eV per atom increasing with increasing temperature and

decreasing bulk B-content [1992Cho]. The diffusion coefficient of B in Ni3Al at 500°C was given as 5

10-21m2 s-1, at 700°C between 10-16 and 10-17m2 s-1. The activation energy for diffusion of B in Ni3Al was

reported to be between 200 and 300 kJ mol-1.

Atomistic simulations (EAM= embedded atom method [2001Zhe, 2002Zhe], and LMTO= Linearized

Muffin Tin Orbital method [1990Che] have been employed to study the bulk effects of B on the Ni3Al -xB

grain boundary [2001Zhe, 2002Zhe] proposing that B atoms induce Ni for Al substitution and as a

consequence B for Ni substitution. It was found that when x increases from 0.1 to 1.0 the probability for B

to occupy interstitial sites decreases from 97.3 to 38.8 % whilst substitutional occupancy increases from 2.7

to 61.2 % [2001Zhe, 2002Zhe].

Defect strengthening and solution hardening by the addition of boron to NiAl alloys has been studied by

[1992Jay, 1993Wu, 1993Tan]. The addition of 0.05 mass% B was found to increase the lattice parameter

and the hardness of Ni-rich NiAl, whereas there was no effect for Al-rich NiAl.

The diffusive behavior of B-atoms in Ni3Al (0.98 at.% B) alloys was investigated by positron annihilation:

to achieve moderate segregation of B-atoms to grain boundaries without boride formation, the alloy was

recommended to be cooled in air after anneal at high temperature [1995Li].

Ni20Al3B6 was said to exhibit temperature independent susceptibility down to liquid nitrogen temperatures

[1967Hir]

By reacting compacted powders of 1Ni2B+5Al at 675°C under argon and subsequently dissolving the Al

with 6N KOH, [1966Jah] was able to produce a porous active B-Ni catalyst.

References

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Solidified Ni3Al”, J. Mater. Res., 1(1), 60-67 (1986) (Experimental, Mechan. Prop., 27)

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[1987Kha] Khadkikar, P.S., Vedula, K., “An Investigation of the Ni5Al3 Phase”, J. Mater. Res., 2(2),


71


MSIT®

Al–B–Ni

[1988Li] Li, X.Z., Kuo, K.H., “Decagonal Quasicrystals with Different Periodicities along the

Tenfold Axis in Rapidly Solidified Al-Ni Alloys”, Phil. Mag. Let., 58(3), 167-171 (1988)


[1989Ell] Ellner, M., Kek, S., Predel, B., “Ni3Al4 - A Phase with Ordered Vacancies Isotypic to

Ni3Ga4”, J. Less-Common Met., 154(1), 207-215 (1989) (Experimental, Crys. Structure, 26)

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of Boron on Ni3Al Grain Boundaries by Atomistic Simulations”, J. Mater. Res., 5(5),

955-970 (1990) (Calculation, Crys. Structure, Experimental, Mechan. Prop., 62)

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Thermal Analysis and Knudsen Effusion Mass Spectrometry in the Determination of Phase

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Status Solidi A, 125A, 469-479 (1991) (Experimental, 17)

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(1992) (Equi. Diagram, Experimental, Kinetics, Theory, Thermodyn., 41)

[1992Jay] Jayaram, R., Miller, M.K., “An APFIM Analysis of Garin Boundaries and Precipitation in

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72


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Al–B–Ni

[1993Wu] Wu, T.C., Sass, S.L., “The Influence of Boron Additions on Microstructure of

Stoichiometric NiAl”, Scr. Metall. Mater., 28(10), 1287-1292 (1993) (Experimental, Crys.

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(0.98at.%B) Investigated by Positron Annihilation Technique” (in Chinese), Nucl. Techn.,

18, 148-150 (1995) (Experimental)

[1996Lim] Lima, M.S.F., Ferreira, P.I., “Microstructure and Mechanical Properties of Ni-Al and

Ni-Al-B Alloys Produced by Rapid Solidification Technique”, Intermetallics, 4, 85-90

(1996) (Experimental, Mechan. Prop., Crys. Structure, 19)

[1996Pau] Paufler, P., Faber, J., Zahn, G., “X-Ray Single Crystal Diffraction Investigation on

Ni1+xAl1-x”, Acta Crystallogr. A, A52, C-319 (1996) (Crys. Structure, Experimental, 3)

[1996Vik] Viklund, P., Häußermann, U., Lidin, S., “NiAl3: A Structure Type of its Own?”, Acta

Crystallogr. A, A52, C-321 (1996) (Crys. Structure, Experimental)

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System”, J. Alloys Compd., 247, 20-30 (1998) (Thermodyn., Equi. Diagram, 70)

[1997Bat] Battezzati, L., Antonione, C., Baricco, M., “ Undercooling of Ni-B and Fe-B Alloys and

Their Metastable Phase Diagrams”, J. Alloys Compd., 247(1-2), 164-171 (1997)


[1997Bou] Bouche, K., Barbier, F., Coulet, A., “Phase Formation During Dissolution of Nickel in

Liquid Aluminium”, Z. Metallkd., 88(6), 446-451 (1997) (Thermodyn., Experimental, 15)

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Alloys”, Acta. Mater., 45, 2155-2166 (1997) (Experimental, Crys. Structure, 48)

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Transformations in Martensitic Ni-Al Alloys”, Metall. Mater. Trans. A, 28A, 1133-1142


[1998Hil] Hillebrecht, H., Ade, M., “Al-Atoms Versus B4-Tetrahedra - A Surprising Mode of

Substitution in Tau-Borides Ni20Al3B6 and Ni20AlB14” (in German), Angew. Chem.,

110(7), 981-983 (1998) (Crys. Structure, Experimental, 21)

[1998Hua] Huang, W., Chang, Y. A., “A Thermodynamic Analysis of the Ni-Al System”,

Intermetallics, 6, 487-498 (1998) (Thermodyn., Equi. Diagram, 56)

[1998Rav] Ravelo, R., Aguilar, J., Baskes, M., Angelo, J.E., Fultz, B., Holian, B.L., “Free Energy and

Vibrational Entropy Difference between Ordered and Disordered Ni3Al”, Phys. Rev. B,

57(2), 862-869 (1998) (Thermodyn., Theory, Calculation, 43)

[1998Sim] Simonyan, A.V., Ponomarev, V.I., Khomenko, N.Yu., Vishnyakova, G.A., Gorshkov, V.A.,

Yukhvid, V.I., “Combustion Synthesis of Nickel Aluminides”, Inorg. Mater., 34(6),

558-561 (1998), translated from Neorgan. Mater., 34(6), 684-687 (1998) (Crys. Structure,

Experimental, 12)

[1999Bur] Burkhardt, U., Grin, Y., “Refinement of the Aluminium Diboride Crystal Structure”,

Abstract 13th International Symposium on Boron, Borides and Related Compounds, Dinard,

France, P13, (1999) (Crys. Structure, 3)

[1999Cam] Campbell, C.E., Kattner, U.R., “A Thermodynamic Assessment of the Ni-Al-B System”,

J. Phase Equilib., 20(5), 485-496 (1999) (Assessment, Equi. Diagram, 50)



[2000Cam] Campbell, C.E., Boettinger, W.J., “Transient Liquid-Phase Bonding in the Ni-Al-B

System”, Metall. Trans. A, 31A, 2835-2847 (2000) (Equi. Diagram, Experimental, 37)

73


MSIT®

Al–B–Ni

[2000Cho] Chowdhury, S.G., Ray, R.K., Jena, A.K., “Texture Evolution During Recrystallization in a

Boron-doped Ni76Al24 Alloy”, Mater. Sci. Eng. A, A277, 1-10 (2000) (Crys. Structure,

Experimental, Mechan. Prop.)

[2000Hal] Hall, A., Economy, J., “The Al(L)+AlB12 AlB2 Peritectic Transformation and Its Role in



[2001Zhe] Zheng, L.-P., Li, D.-X., Qiu, S., Zhou, W.-J., Jiang, B.-Y., “Dependence of Ni, Al and B

Bondary Concentrations on the B Bulk Concentration for the Ni3Al-x at.% B Grain

Boundary”, Nucl. Instrum. Methods Phys. Res./B, 184, 354-360 (2001) (Experimental,

Phys. Prop., 20)

[2002Zhe1] Zheltov, P., Grytsiv, A., Rogl, P., Velikanova, T.Ya., Research at Univ. Vienna, (2002)

(Equi. Diagram, Crys. Structure)

[2002Zhe] Zheng, L.-P., Li, D.-X., Zhu, Z.-Y., Jiang, W.-Z., Jiang, B.-Y., Liu, X.-H., “Monte Carlo

Simulation Study of the Bulk Effects of Boron on the Ni3Al-x at.% B Grain Boundary”,

Mater. Lett., 56, 65-70 (2002) (Equi. Diagram, Experimental, Phys. Prop., 13)

[2003Gry] Grytsiv, A., Rogl, P., “Aluminium-Boron-Carbon”, MSIT Ternary Evaluation Program, in


GmbH, Stuttgart, to be published, (2003) (Equi. Diagram, Crys. Structure, Review, 116)

[2003Sal] Saltykov, P., Cornish, L., Cacciamani, G., “Al-Ni (Aluminium-Nickel)”, MSIT Binary


International Services GmbH, Stuttgart; to be published, (2003) (Equi. Diagram, Review,

164)


Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

( Al) hP2

P63/mmc

Mg

a = 269.3

c = 439.8

at 25°C, 20.5 GPa [Mas2]

( Al)

< 660.452

cF4

Fm3m

Cu

a = 404.96 at 25°C [Mas2]

dissolves 0.01 at.% Ni at 639.9°C

[Mas2]

(Ni)

< 1455

cF4

Fm3m

Cu

a = 352.40 at 25°C [Mas2]

dissolves 20.2 at.% Al at 1385°C [Mas2]

dissolves 0.3 at.% B at 1093°C[Mas2]

( B)

< 2092

hR333

R3m

B

a = 1093.30

c = 2382.52

a = 1096.5

c = 2386.8

a = 1096.15

c = 2385.44

a = 1095.84

c = 2385.46

[Mas2, 1993Wer]

dissolves up to ca 2 at.%Ni at 1035°C

at AlB31 [V-C2]

for NiB48.5 [V-C2]

for NiB 20 [V-C2]

Al2B3

525

hR*

Al2B3 (?)

a = 1840

c = 896

at 60 at.% B [1992Var]

Metastable?

74


MSIT®

Al–B–Ni

AlB2

956±5

hP3

P6/mmm

AlB2

a = 300.6

b = 325.2

a = 300.67 ± 0.01

b = 325.36 ± 0.02

a = 300.43± 0.03

b = 325.19 ± 0.06

temperature from [2000Hal]

[1994Dus]

[2002Zhe1]

[1999Bur] for Al0.9B2

AlB12

2050

tP216

P41212

AlB12

a = 1015.8

c = 1427.0

a = 1014.93 ± 0.07

c = 1425.0 ± 0.5

[1994Dus]

exp. = 2.65 Mgm-3

[2002Zhe1]

AlB12 oP384

P212121

AlB12

a = 1014.4

b = 1657.3

c = 1751.0

[1994Dus, 2000Hig] metastable phase or

ternary product stabilized by small

amounts of impurity metals present in Al

flux grown material; exp.= 2.56Mgm-3

NiAl3< 856

oP16

Pnma

NiAl3

a = 661.3 ± 0.1

b = 736.7 ± 0.1

c = 481.1 ± 0.1

a = 659.8

b = 735.1

c = 480.2

[1996Vik] [Mas2]

[1997Bou, V-C2]

Ni2Al3< 1138

hP5

P3m1

Ni2Al3

a = 402.8

b = 489.1

36.8 to 40.5 at.% Ni [Mas2]

[1997Bou, V-C2]

Ni3Al4< 702

cI112

Ia3d

Ni3Ga4

a = 1140.8 ± 0.1 [1989Ell, V-C2]

NiAl

< 1651

cP2

Pm3m

CsCl

a = 286.0

a = 287

a = 288.72 ± 0.02

a = 287.98 ± 0.02

42 to 69.2 at.% Ni [Mas2]

[1987Kha]

at 63 at.% Ni [1993Kha]

at 50 at.% Ni [1996Pau]

at 54 at.% Ni [1996Pau]

Ni5Al3< 723

oC16

Cmmm

Pt5Ga3

a = 753

b = 661

c = 376

63 to 68 at.% Ni [1993Kha, Mas2]

at 63 at.% Ni [1993Kha]

Ni3Al

< 1372

cP4

Pm3m

AuCu3

a = 356.77

a = 358.9

a = 356.32

a = 357.92

a = 357.3

73 to 76 at.% Ni [Mas2]

[1986Hua]

at 63 at.% Ni [1993Kha]

disordered [1998Rav]

ordered [1998Rav]

for Ni75Al24B [V-C2]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

75


MSIT®

Al–B–Ni

Ni2Al9 mP22

P21/c

Ni2Al9

a = 868.5 ± 0.6

b = 623.2 ± 0.4

c = 618.5 ± 0.4

= 96.50 ± 0.05°

Metastable

[1988Li, 1997Poh]

NixAl1-x tP4

P4/mmm

AuCu

m**

a = 383.0

c = 320.5

a = 379.5

c = 325.6

a = 379.5

c = 325.6

a = 375.1

c = 330.7

a = 379.9 to 380.4

c = 322.6 to 323.3

a = 371.7 to 376.8

c = 335.3 to 339.9

a = 378.00

c = 328.00

a = 418

b = 271

c = 1448

= 90°

= 93.4°

= 90°

Martensite, metastable

0.60 < x < 0.68

[1993Kha]

at 62.5 at.% Ni [1991Kim]

at 63.5 at.% Ni [1991Kim]

at 66.0 at.% Ni [1991Kim]

at 64 at.% Ni [1997Pot]

at 65 at.% Ni [1997Pot]

[1998Sim]

[1992Mur]

Ni2Al hP3

P3m1

CdI2

aP126

P1

a = 407

c = 499

a = 1252

b = 802

c = 1526

= 90°

= 109.7°

= 90°

Metastable

[1993Kha]

[1994Mur]

D1 decagonal Metastable [1988Li]

D4 decagonal Metastable [1988Li]

Ni3B

< 1156

oP16

Pnma

Fe3C

a = 521.99

b = 661.46

c = 436.30

a = 530.62

b = 667.50

c = 444.14

at 25°C [V-C2, Mas2]

at 1100°C [V-C2]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

76


MSIT®

Al–B–Ni

# for a discussion of phase region and equilibrium conditions, see section “Solid Phases”.

Ni2B

< 1125

tI12

I4/mcm

CuAl2

a = 499.1

c = 424.7

[V-C2, Mas2]

o-Ni4B3

< 1025

oP28

Pnma

o-Ni4B3

a = 1195.40

b = 298.15

c = 656.84

at 41.4 at.% B [V-C2, Mas2]

m-Ni4B3

< 1031

mC28

C2/c

m-Ni4B3

a = 642.82

b = 487.95

c = 781.90

= 103.47°

at 43.9 at.% B [V-C2, Mas2]

NiB

< 1035

oC8

Cmcm

CrB

a = 292.9

b = 739.2

c = 296.1

[V-C2, Mas2]

* 1, Ni20Al3B6+x

Ni23B6

cF116

Fm3m

Cr23C6

a = 1048.5

a = 1048

a = 1062

a = 1049.5

a = 1055.2

a = 1048.5 9

a = 1051.10

a = 1051.93

a = 1056.89

a = 1058.95

a = 1059.22

a = 1061.67

-

Ni7.1Al0.8B2.1 [V-C2]

Ni20Al3B6 [1973Cha]; 1000°C

Ni20Al3B12 [1973Cha]; 1000°C

alloy 65Ni10Al25B [1962Sta2]; 800°C#

alloy 60Ni10Al30B [1962Sta2]; 800°C#

Ni20.5Al2.5B6 [1998Hil]

Ni20Al3B6 [1998Hil]

Ni20Al2.7B7 [1998Hil]

Ni20Al2.4B8.4 [1998Hil]

Ni20Al1.1B13.5 [1998Hil]

Ni20Al1.2B13.2 [1998Hil]

Ni20AlB14 [1998Hil]

metastable, [1997Bat]

* 2, Ni5AlB4

800

- - [1973Cha]

* 3, Ni8AlB11(h)

> 800

monoclinic a = 3580

b = 1093

c = 1630

= 112°

[1973Cha], from single crystal rotation

photographs

* 3, Ni8AlB11(r)

800

- - [1973Cha]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

77


MSIT®

Al–B–Ni

Table 2: Invariant Equilibria (data are only available for the liquid phase)

* calculated data refer to the Al-Ni binary modeled by [1998Hua]; data changed slightly if the model of [1997Ans]

was used; for details see original work by [1999Cam].# values read from small diagram [1962Sta1].

Reaction T [°C]

Experimental,

[1962Sta1]

T [°C]

Calculated,*

[1999Cam]

Type Phase Composition (at.%)

Experimental#Composition (at.%)

Calculated [1999Cam]

Ni Al B Ni Al B

L NiAl+ 1 - - e, max L - - - - - -

L+NiAl Ni3Al+ 1 <1369 1348 U1 L 69 13 18 73.8 24.1 2.1

L (Ni)+ 1 - - e, max L 75 7 18 - - -

L (Ni)+Ni3Al+ 1 <U1 1349 E1 L 69 10 18 75.4 22.5 2.1

L (Ni)+Ni3B+ 1 <1093 1090 E2 L 79 3 18 83.8 0.03 16.2

L NiAl+NiB+ 1 - 692 E3 L 52 10 38 34.2 17.9 47.9

Ni3Al+NiAl+τ

1

Fig. 1: Al-B-Ni. Partial reaction scheme

Al-Ni A-B-C

l + (Ni) Ni3Al

1372 p1

L NiAl + τ1

e (max)

Al-B-Ni

L+NiAl Ni3Al+τ

1<1369 U

1

B-Ni

l Ni3B+Ni

2B

1125 e2

L+(Ni)+Ni3Al

l Ni3Al + NiAl

1369 e1

L (Ni) + τ1

e (max)

L (Ni)+Ni3Al+τ

1< U

1E1

L (Ni)+Ni3B+τ

1<1093 E

2

(Ni)+Ni3Al+τ

1

(Ni)+Ni3B+τ

1

L+Ni3B+τ

1

l (Ni)+Ni3B

1093 e3

L+Ni3Al+τ

1

L+NiAl+τ1

78


MSIT®

Al–B–Ni

60

70

80

90

10 20 30 40

10

20

30

40

Ni Ni 50.00B 50.00Al 0.00

Ni 50.00B 0.00Al 50.00 Data / Grid: at.%

Axes: at.%

p1

e1

(Ni)

τ

e3

Ni3B

e2

NiAl

Ni3Al

E2

E1

U1

Tmax

max

max max

Fig. 2: Al-B-Ni

Partial liquidus

surface in the Ni-rich

region after

[1962Sta1]

20

40

60

80

20 40 60 80

20

40

60

80

Ni B


Axes: at.%

AlB12

L

Ni2Al3

NiAl

Ni3Al

(Ni)τ

1

τ3, Ni8AlB11(h)

NiBm-Ni4B3o-Ni4B3Ni2BNi3B

(βB)

Fig. 3: Al-B-Ni.


1000°C

79


MSIT®

Al–B–Ni

20

40

60

80

20 40 60 80

20

40

60

80

Ni B


Axes: at.%

τ2, Ni5AlB4

τ1

(Ni)

Ni3Al

NiAl

Ni2Al3

NiAl3

L

AlB2

AlB12

NiBm-Ni4B3o-Ni4B3Ni2BNi3B

τ3, Ni8AlB11(r)

(βB)

Fig. 4: Al-B-Ni.


800°C

80


MSIT®

Al–B–Ti

Aluminium – Boron – Titanium

Anatoliy Bondar

Literature Data

The Al-rich corner in the system has been of great interest due to the fact that Ti and B additions are widely

used as grain refiner in the aluminium casting industry. The extensive literature on the phase relationship

including Al-base phase was repeatedly assessed by Hayes & Lukas [1991Hay, 1990Hay, 1989Hay],

Abdel-Hamid et al. [1986Abd, 1985Abd1, 1985Abd2] and others. However there were some confusions

and contradicting conclusions. The main concern whether the (Ti,Al)B2 solid solution is stable or

metastable. The cogent evidences of [1999Fje, 1999Zup, 1998Zup1, 1998Zup2, 1994Tok] have confirmed

instability of mixed diboride (Ti,Al)B2 in agreement with data of Abdel-Hamid et al. [1986Abd, 1985Abd1,

1985Abd2, 1984Abd] and others. Hayes & Lukas [1991Hay, 1990Hay, 1989Hay] stated that their

computed results show compatibility of the mixed boride phase (Al,Ti)B2 existence with all the

experimental results in the literature. However, their isopleth at 98 mass% Al and 1300°C liquidus isotherm

are not affected by whether the continuous solid solution (Al,Ti)B2 is stable or not.

Fjellstedt et al. [2001Fje, 1999Fje] prepared samples from pure Al (99.998 mass% purity), TiB2 (97 %), and

AlB2 (98 %) in a high-frequency induction furnace. The alloys were heated in Al2O3 crucible at 1530°C for

~1 h, then they were heat treated at 700, 800, and 900°C for 240-600 h. The samples were examined with

optical microscopy and SEM equipped with EDS. Besides, the Ti and B solubility in the (Al) melt was

calculated using a subregular solution model.

Zupanic et al. [1999Zup, 1998Zup1, 1998Zup2] prepared alloys by arc melting in purified Ar and

aluminothermal synthesis at 1050-1100°C. Some alloys were heated and cooled at a rate of 0.1-10 K min-1

from 500 to 1400°C in alumina crucibles. The specimens were annealed at 800 ± 2°C for 1000 h, being put

into alumina crucibles and sealed into evacuated silica tubes, followed by quenching in water bath, as well

as from 650 to 1000°C for 70 h and at 1600°C 10 h followed by cooling at 60 K min–1. The samples were

studied with X-ray powder diffractometer, light microscopy, and SEM (with EDS).

Stolz et al. [1995Sto, 1994Sto] used pure Al of 99.999 mass% purity and commercial master-alloys (~99.7

%). The samples were produced by casting in Ar and heat treated at 577°C for 20 days. They were examined

with XRD, DTA, Auger electron spectroscopy and SEM supplemented with EDS equipment.

Abdel-Hamid et al. [1985Abd1,1985Abd2, 1984Abd] used Al of 99.995 or 99.98 mass% purity, powder B

(99.7 %) and Ti. The samples prepared in the range from 700 to 1000°C were studied by optic microscopy,

SEM (with EPMA), and TEM, as well as melt composition was determined using electromagnetic

separation or decantation.

The Ti-rich alloys were investigated in [2002Art, 1992Gra, 1991Hym, 1991Sch, 1990Hym, 1989Hym, etc.]

not so comprehensively as the Al-rich one. In [2002Art] alloys were studied by methods of metallography,

XRD, DTA, EPMA, microhardness and hot hardness.

Hyman et al. [1991Hym, 1989Hym] studied arc melted and splat-quenched samples made of high-purity Ti

(<200 ppm O), Al (99.99 mass% Al), and nitrogen-free B powder (99.7 %). Optical microscopy, SEM, and

TEM were used to study structure.

In [1991Sch] two samples were studied with TEM using EDX analysis and high-resolution imaging. Flakes

of Ti-25Al-4B and Ti-48Al-5B (at.%) compositions were produced by electron beam melting and splat

quenching, and in addition they were annealed in quartz capsules at 800, 1000, and 1200°C for 1 h.

Binary Systems

The binary systems used were as followed: Al-B [2000Hal, 1994Dus], Al-Ti [1997Zha] and B-Ti

[1986Mur, 1987Mur]. For invariant equilibria of ( Ti), ( Ti) and phases with melt the [1997Zha] data

were used (recently experimentally confirmed for the lp + ( Ti) ( Ti) equilibrium by [1999Jun]).

81


MSIT®

Al–B–Ti

Nevertheless, somewhat less Ti contents for the lp + TiAl3 ( Al) equilibrium (0.1 at.% or 0.18 mass% Ti

for lp [2001Fje, 2000Ohn, 1992Kat]) seem to be preferred as more close to experimental data, as well close

to [E], [S], etc.

Solid Phases

No stable ternary phases have been reported. The binary phases, relevant to phase equilibria under

consideration, are listed in Table 1. Hayes & Lukas [1991Hay, 1990Hay, 1989Hay] reported that all of the

experimental evidence to date is consistent with complete solid solubility between AlB2 and TiB2 to form

(Ti,Al)B2. Namely the continuous solid solution (Ti1-xAlx)B2 was found in [1998Joh] to be in commercial

master alloys. This is the case that the mixed diboride (Ti,Al)B2 was synthesised by the reaction of molten

Al 99.99 with K2TiF6 and KBF4 at 750 and 1050°C in [1999Zup]. However, the mixed diboride (Ti,Al)B2

was shown to approach slowly toward the compositions of pure diborides at 800°C. At 800 and 1600°C

apparently pure diborides or TiB2 and AlB12, respectively, are in equilibrium with Al melt. Besides, the

almost pure diborides crystallise from the melt at cooling rates as slow as 0.1°C/min [1999Zup]. The same

result was reported before already in [1984Abd]. Crystallisation was also found in [1999Fje, 1998Zup1] to

yield titanium diboride not richer in Al than (Ti~0.99Al~0.01)B2. In the same time EDS analysis of [1999Fje]

showed that in samples annealed at 800 and 900°C, prepared by melting in crucible at 1630°C, the Al

solubility in TiB2 was on the level of standard deviations (on average 0.11±0.10 at.% Al) and the same was

for AlB12 and AlB2 (on average 0.03±0.02 and 0.05±0.04 at.% Ti). The close EDS data were obtained in

[1998Zup1].

In [1998Zup1] a special study was devoted to the problem of mutual solubility of TiB2 and AlB2. Two

alloys prepared by arc melting were heated and cooled at rates of 0.1-10 K min–1 from 500 to 1400°C in

alumina crucibles. The specimens were annealed at 800 ± 2°C for 1000 h, being put into alumina crucibles

and sealed into evacuated silica tubes, followed by quenching in water bath. In any case the compositions

of Al and Ti rich diborides were quite close to pure TiB2 and AlB2. The situation was not changed even

after annealing at 800°C for 1000 h.

In [1992Gra] conventional and high resolution TEM were applied to study the as-cast alloy

Ti-40.9Al-0.97B (at.%) prepared with arc-melting on water-cooled copper hearth in Ar (< 0.1 ppb O2) using

pure initial materials (the ingot of 35 g mass). Two monoborides were identified as having the FeB and CrB

crystal structure types. The former contains thin layers of the latter and in the latter there were found

nanoscale intergrowths of Ti3B4 and TiB2 of Ta3B4 and AlB2 crystal structure types, respectively. Clear

orientation relationships were revealed in all cases. Examination of sample annealed at 1150°C for 100 h

evidenced that the CrB crystal structure monoboride is metastable. The metastable TiB was postulated in

[1992Gra] to form instead of the stable Ti3B4 and TiB2 due to promoting kinetic factors.

Data on boron solubility in titanium aluminides are rare: [ 1984Sig, 1977Gur] reported unrealistic high

solubility of B in TiAl3 (1 and 8 mass% B, respectively) at unchanged lattice parameters. There is relevant

theoretical consideration [1991Kho] (using linearized combination of muffin-tin orbitals total energy

calculations) that boron atoms in phase should be accommodated substitutionally into aluminium sites.

A sputter deposition of Ti-7Al-7B (at.%) alloy on Ta substrate was single phase, it was identified with TEM

and XRD as metastable fcc structure [1995Loe]. A 900°C annealing yields the TiB dispersion embedded in

a single phase hcp matrix ( Ti).

A rapidly solidified alloy Al-5Ti-0.2B (mass%) contained diboride and metastable TiAl3 intermetallide of

AuCu3 structure type [1994Chu].


The reaction scheme (Fig. 1 and Table 2) for the Ti rich region is based on data of [2002Art, 1991Hym,

1990Hym]. Then there is a lack for phase fields between + TiB2 and TiAl3 + TiB2. The Al-rich portion

is based on data of [2001Fje, 1998Zup2, 1985Abd1].

The examination of samples in the region Al-TiB2-AlB2, which were annealed at 800 and 900°C, showed

the four-phase invariant equilibrium L + AlB12 AlB2 + TiB2 to be between the above-mentioned

temperatures [2001Fje]. A thermodynamic modelling, where the excess Gibbs energy calculated by

82


MSIT®

Al–B–Ti

interpolating between the three binary systems, resulted in 880°C [2001Fje]. It is consistent with

[1998Zup2] where the AlB12 phase was stable at 900°C and its sizes and volume fraction decreased during

annealing at 800°C, with its decomposition being not complete even after 1000 h exposure.

Thus, in the Al-B-Ti system there are two cascades of monovariant and invariant solidification reactions

that are originated in the B-Ti side and quasibinary eutectic e2 and come to the end in the Al-B side (e4

eutectic point at 659.7°C). Besides, as found in [1998Zup2], at conventional cooling rates the AlB2 diboride

does not crystallize and a metastable four-phase equilibrium L + TiB2 ( Al) + AlB12 takes place, which

is involved with a binary metastable three-phase equilibrium l ( Al) + AlB12 at ~655°C.

There are some contrary versions of solidification scheme in the Al-rich corner. As mentioned above Hayes

& Lukas [1991Hay, 1990Hay, 1989Hay] calculated the phase diagram on the assumption of stability of

mixed diboride (Ti,Al)B2. Their temperature of the invariant equilibrium L + TiAl3 ( Al) + TiB2 was

found to be 664.73°C. Stolz et al. [1994Sto, 1995Sto] accepted the diboride (Ti,Al)B2 stability and, basing

on two DTA effects of 660 and 666°C obtained for the three-phase ( Al) + TiB2 + TiAl3 alloys, reported

existence of the ternary peritectic reaction L + TiAl3 + TiB2 ( Al) at 666°C and xTi = 99.942 ± 0.04

mass %. Although these temperature effects are consistent with careful measurements of Bäckerud et al.

[1993Joh, 1991Bae1, 1991Bae2] (obtained as temperatures of incipient solidification and grain growth),

however, the ternary peritectic reaction existence dictates more boron content in solid ( Al) than in Al melt

that seems improbable. Besides, there are DTA data of Maxwell & Hellawell [1972Max], which are lower

only by 1°C, consistent with the L + TiAl3 ( Al) + TiB2 invariant equilibrium proposed (Figs. 1, 4d, and

8). Some other variants are criticized elsewhere [1985Abd1, 1985Abd2].

Liquidus and Solidus Surfaces. Phase Equilibria at Melting (Solidification)

The phase equilibria at alloy melting were reported for the Ti-rich region, from ( Ti) + TiB to +TiB2 phase

fields [2002Art, 1989Hym, 1990Hym, 1991Hym], and for the TiAl3 - TiB2 - AlB12 - Al portion [2001Fje,

1998Zup2, 1989Hay, 1986Sig, 1985Abd1, 1984Sig, 1976Jon].

The Ti-rich solidus surface projection after [2002Art] is presented in Fig. 2 and characterised by the

extensive two-phase ( Ti) + TiB field containing a maximum that corrensponds to the quasi-binary eutectic

Le (Ti~0.8Al~0.2) + TiB at ~1560°C. Close to the B-Ti side the combined eutectic crystallisation of ( Ti)

and TiB phases takes place practically at constant B content (around 7.5-7.0 at.%) (Fig. 3). In the vicinity

of the quasi-binary (Ti~0.8Al~0.2)+TiB eutectic and at higher Al content the liquidus curve of combined

metal-metallide/boride crystallization smoothly goes down to ~1 at.% B at 45-55 at.% Al [1990Hym,

1991Hym]. In what follows the liquidus line reaches as little B content as ~10-4 at.% in the Al-corner

[1989Hay, 1985Abd1].

The above-mentioned data are in agreement with [1991Sch] where a Ti-25Al-4B (at.%) flake sample,

prepared by electron beam melting and splat quenching, contained faceted TiB dispersoids free of Al, which

had distinct orientation with the ( Ti) matrix. The Ti-48Al-5B (at.%) sample prepared in the same manner

was three-phase + 2 + TiB2, with no orientation relationship being found.

Liquidus isotherms of the Al-corner from thermodynamic calculation of [2001Fje, 1989Hay] are shown in

Fig. 4. The TiB2 solubility after [2001Fje] practically follows the dependence

logTi·B2 = A + B/T

(where A and B are constants and T is temperature in K). The [2001Fje] data may be digitised as:

log B = –0.504 logTi + 2.15 – 6820/T

(where Ti and B are in at.%) that gives A = 4.28 and B = –1.36⋅104. After transformation of Ti and B from

at.% to mass % the parameters A = 3.74 and B = -1.36⋅104 are seen to be between the data of Stolz [1995Sto,

1994Sto] (A = 2.70 ± 0.01 and B = –1.27·10-4 ± 1·10-2) and Finch [1972Fin] (A = 5.22 and B = -1.62⋅104)

as well as Hayes and Lukas [1989Hay]. In comparison with the above mentioned, data of Kolesov et al.

[1990Kol] seem to be too overestimed, what is presumably related to the presence of solid TiB2 in molten

Al samples taken for chemical analysis.

As shown in Fig. 4a the liquidus curves of double saturation are so close to the Al-Ti and Al-B sides that

only logarithmic scales enable presentation of phase equilibria in the Al-corner in a single diagram (Fig.

4d). Some features of logarithmic phase diagram were outlined elsewhere [1976Jon]. Here it is worth to

83


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Al–B–Ti

note that co-lines in a logarithmic phase diagram should connect phase compositions under equilibrium with

a curve (see Fig. 6) instead of straight line (as in Figs. 5 and 7).

The concept of the ( Al) phase solidification becomes clear from Figs. 5 to 9 (along with Figs. 1, 4b and

Table 2). Corrections for instability of the (Ti,Al)B2 continuous solid solution were introduced in Fig. 5

(thick dashed lines), but the overestimated boron solubility in TiAl3 was kept unchanged in both

Figs. 5 and 7.

Isothermal Sections

The 1000°C isothermal section (Fig. 10) was constructed in the Ti-rich portion of the system by Rogl et al.

[1994Rog] based on EPMA data for three alloys levitation melted and annealed at 1000°C for 250 h. Initial

materials were powder Al, Ti (both of 99.9 mass% minimum purity), and B of 99.8 mass% purity.

[1994Tok] reported equilibrium at 1100°C between 2, TiB and TiB2 (X-ray and EPMA data), repeating

the 1000°C section of [1994Rog].

Data of [1964Rie] on phase equilibria at 1200°C are rather scarce, negligible solubility of B in titanium

aluminides and Al in titanium borides and existence of the TiB2 + TiB + (Ti) phase field.

In [1991Sch] Ti-25Al-4B and Ti-48Al-5B (at.%) samples, produced by electron beam melting and splat

quenching followed by annealing in quartz capsules at 800, 1000, and 1200°C for 1 h, contained 2+TiB

(the former) and +TiB2+ 2 (the latter) in agreement with [1994Rog, 1994Tok].

In [1999Li] an alloy Ti-46Al-0.1B (at.%) was studied in the temperature range 1000 to 1250°C. A 0.1 at.%

B addition was found to bias the ( 2)/ ( 2) + and ( 2) + / boundaries to the Al-rich side by ~0.5

at.%, with decreasing the ( Ti) 2 + equilibrium by 18°C.


A vertical section at constant 98 mass% Al (Fig. 11) was calculated in [1989Hay] on the two assumptions

of two separate diborides and mixed diboride (Ti,Al)B2, respectively. The only difference is: in the case of

mixed diboride the field L+TiB2+AlB2 does not exist, and liquid Al coexist with either the mixed diboride

(Al,Ti)B2 or the two separate diborides TiB2 and AlB2, respectively. The metastable section TiB2 - AlB2

was constructed in order to explain qualitatively experimental data [1998Zup1, 1998Zup2] (Fig. 12) and

takes into account the absence of AlB2 in as-cast alloys.

Thermodynamics

Thermodynamic modeling in the Al-B-Ti system was restricted to equilibria of Al-based phases (solid and

liquid) [2001Fje, 1991Hay, 1994Sto, 1995Sto, 1990Hay, 1989Hay, 1986Sig, 1984Sig, 1976Jon]. Only

Sigworth’s work [1986Sig] took into consideration a parameter of interaction between Ti and B as = 1500

(at 820°C). The parameter influence may be seen in Fig. 7. In other works an interpolation between the

three binary systems was applied. Thermodynamic parameters used in [2001Fje] are represented in Tables

3 and 4.


In situ titanium matrix composites reinforced with TiB were produced in [1991Sob, 1994Sob] using

plasma-arc-melting/centrifugal atomization. Powders were compacted by heating at 1065°C for 2 h

followed by extrusion. Composites contained 0.11-0.12 mass% O, 0.07-0.13 mass% C, 0.005-0.027 mass%

N, and 11-29 ppm H. Their tensile properties are presented in Table 5.

In [2002Art] Vickers hardness was measured on as-cast eutectic and hypoeutectic (Ti) + TiB alloys. A

marked growth of hardness was found with Al alloying. The difference in the hardness of the alloy

Ti79.7Al12.8B7.5 and the binary Ti92.5B7.5 eutectic is about 2 GPa in the temperature interval from RT to

600°C. At 800°C this difference is smaller (~0.5 GPa) but still four times higher then in the basic

binary alloy.

Al-based in-situ composites reinforced with TiB2 particles were recently reviewed by Tjong & Ma

[2000Tjo]. Stir casting technique was used in [2000Tee] to produce in-situ aluminium matrix composite,

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Al–B–Ti

containing ( Al) + TiB2 + TiAl3. Elemental Ti of 99.5 mass% purity and B of 99.5 mass% in stoichiometric

composition corresponding to 15 vol.% TiB2 were added to molten Al at 1040°C (18 min. exposition) and

1080°C (12 min.). Its room temperature tensile properties were as UTS = 225 MPa, 0.2% y = 167 MPa,

Young modulus E = 85 GPa, and elongation of 3.4 %. Aluminium matrix composite reinforced by TiB2 (as

well as by oxides Al2O3 and TiO2) was obtained via the in situ reaction Al + TiO2 + B2O3 Al2O3 + TiB2

[2001Lue].

In [2000Lu] a Ti66.3Al18.7B15 powder mixture was blended via MA (mechanical alloying) technique. Along

with elemental Ti and Al, a number of phases ( , 2, TiAl3, TiB, and TiB2) were detected after MA and

annealing at 720 and 850°C. The analogical technique, MA followed by HIP, was used to prepare

composites TiAl - (0, 10, 15, and 20 ) vol.% TiB2 in [1999Och] (for all the samples strain rate sensitivity

exponent was 0.3 at 1100°C).

Miscellaneous

Boron additions from ~0.03 to 0.1-0.2 at.% had an influence on lamellar formation on TiAl alloys

[2002Zha].

In [1996Har] Al-Ti-B alloys suitable for Al grain refining were obtained from oxide precursors, B2O3 and

TiO2 by reduction with Al in the presence of cryolite.

The grain refinement of Al alloys with Al-Ti-B master-alloys has been extensively studied for more than a

half of century. Detailed review of experimental results and a number of theories to explain them (in

particular, cumulative action of TiB2 and excess Ti) are out of the frame of the present issue and they are in

detail described elsewhere [1999Eas1, 1999Eas2, 1998Sch, 1995Moh, 1993Joh, 1991Bae1, 1991Bae2].

Only modern experimental observations and theoretical justifications are outlined below.

As shown AlB2 is a weak grain refiner for unalloyed aluminium alloys. Furthermore, a grain refinement test

showed that boride particles with a wide distribution in both composition (being on average at [Ti]/[B] <

2.2 in mass%) and size give a poorer grain-refining effect [1998Joh]. On the other hand, intermetallide

TiAl3 is accepted as strong refiner, although some doubts are cast whether it acts alone, even in quite pure

Al alloys. So, the TiB2 nucleant was revealed by SEM study (using EDS) in an Al-0.115 mass% Ti alloy

produced of Al of 99.99 mass% purity containing 5·10-5 mass% B as contamination, where Ti was

introduced from K2TiF6 (data could not themselves exclude (Ti,Al)B2 mixed diboride) [2002Mik1].

Data on grain refining efficiency of pure TiB2 have no single meaning, although an Al-2.2Ti-1B (mass%)

master alloy is taken for granted to be inefficient refining addition for unalloyed Al. Introduction of

synthetic TiB2 crystals shows that they do not nucleate Al grains alone [1995Moh]. In presence of excess

0.01 mass% Ti, effectiveness of the same TiB2 crystals was observed and TiAl3 was detected at excess 0.05

mass% Ti.

So, the cumulative refining effect of TiB2 and excess Ti is established unambiguously. An Al-5Ti-1B

(mass%) master alloy is accepted as the most effective in Al grain refining. As found in [1993May] (TEM,

scanning Auger microscopy, etc.) it contains duplex aluminide TiAl3 particles as either rough or faceted

blockies and entrained diboride platelets.

Incipient Ti content ensuring acceptance level of refinement for Al grains was found to be much below the

binary Al-Ti peritectic composition (0.1 at.% Ti or 0.18 mass% Ti [2000Ohn]), depending on the purity

of Al:

[2000Mik] found that ~0.05 mass% Ti (from K2TiF6) has sufficient effect for 99.7 % purity Al (~2 10-4

mass% B as contamination);

an Al-5Ti-1B (mass%) addition becomes effective at 0.1 % content, e.i. at ~0.005 mass% Ti and ~0.001

mass% B (~0.003 at.% Ti and ~0.002 at.% B) for 99.7 % purity Al [1976Jon, 2000Mik];

in [1999Eas2] aluminium of 99.97 mass% purity was refined at 0.01 mass% Ti and 0.03 mass % TiB2

(demonstrating cumulative action as addition of only Ti needs 0.055 mass%);

an analogical result was obtained in [1992Joh] where master alloys Al-4.8Ti-1B, Al-5.3Ti-0.1B, and

Al-6.2Ti-0.003B (mass%) added to Al of 99.995mass% purity showed effectiveness in increasing order of

boron content (the 0.5% addition of the Al-5Ti-1B master alloy effectively refines the 99.995 % Al, 0.025

mass% Ti and 0.005mass% B [1991Bae2]).

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Al–B–Ti

The results obtained and reviewed were considered by Mohanty & Gruzleski [1995Moh] as experimental

validation of the hypernucleation theory of Jones [1988Jon], which suggests that excess titanium segregates

in the TiB2/melt interface and results in precipitation of a thin layer of TiAl3 and hence activation of the

TiB2 refining ability. Really, such a TiAl3 interlayer was observed between the surface of TiB2 particles

and ( Al) phase in [1998Sch], where a Al85Y8Ni5Co2 alloy containing Al-4.5Ti-1.8B (mass%) refiner and

excess Ti up to ~0.1 at.% was studied with TEM after rapid quenching from 1300°C (along with the three

phases, the samples contained an amorphous matrix). In the three phases the close packed planes (and

corresponding directions) were reported to be parallel: {0001}TiB2||{112}TiA3||{111}( Al). Based on these

data Schumancher et al. [1998Sch] proposed a duplex nucleation theory, per se being concretization of

Jones’ hypernucleation theory. In [2001Mik], however, an intermediate layer of ~10 nm thickness, detected

at the boundary between ( Al) and intermetallide of composition (Ti0.8Zr0.2)0.22Al0.78, was found to be

close to amorphous (in an alloy Al-0.24Ti-0.18Zr (mass%) prepared from Al of 99.7 mass% purity).

In light of the necessity of excess titanium regarding the TiB2 stoichiometry, it is appropriate to mention

here that the TiB2 particles are poorly wetted by molten Al, the contact angle was measured to be 114° at

1000°C in vacuum or Ar [1966Yas]. A slightly different result was reported by [1972Sam]: 98° at 900°C

in vacuum.

Another interpretation of the role of excess Ti was proposed in [1999Eas1, 1999Eas2, 1996Sig, 1993Joh,

1992Joh] involving crystal growth stage. The solute titanium is required to slow down the growth of ( Al)

grains. So, Easton & StJohn [1999Eas1, 1999Eas2] state that the excess Ti provides constitutional

undercooling in front of the growing interface so that in the constitutionally undercooled layer further

nucleation can take place more easily. At high ratio Ti/B the Ti partition was found to be similar in the

binary Al-Ti and ternary Al-B-Ti systems [2002Mik2]. The EMPA data of [2002Mik2] for an Al-0.053

mass% Ti as-cast alloy produced of Al of 99.7 mass% purity (that suggests B contamination of ~2 10-4

mass%, e.i. in total 0.030 at.% Ti and ~5 10-4 at.% B; solidification at cooling rate of 1 K/s) point out that

the maximum Ti content reaches 0.33 mass% Ti (0.19 at.%) inside ( Al) grains. Concerning the

constitutional undercooling resulting from the action of excess Ti, Jones & Pearson [1976Jon] estimated it

for the binary Al-Ti alloys as ~0.07 K that means its effect should play a secondary part.

Thus, the hypernucleation theory of Jones [1988Jon] seems to get experimental validation. Concerning

arguments of Sigworth [1996Sig] against the theory, they would not have seemed so forcible if the author

had used the ternary phase diagram instead of treating data for ternary and even more multicomponent

alloys with the Al-Ti binary one. Just what is required to be taken into consideration is the appropriate phase

diagram at solidification of Al alloys (in the manner of [1986Sig], [1976Jon], [1975Max], [1971Mar] and

others). And in the case of “a peritectic metastable reaction” of [1993Joh], which “can occur a few degrees

above the stable peritectic point” (relatively to the binary Al-Ti system), it turns out to be a phase

transformation between ternary solidus and liquidus surfaces. Although the state of the art Al-B-Ti phase

diagram is far from perfection, it appears to be applicable in treating data on grain refinement of Al with

Ti+B additions in most cases.

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Al–B–Ti

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Al–B–Ti

[1990Hym] Hyman, M., Ph.D. Thesis, Univ. of California (1990); quoted from [1992Gra]

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[1994Rog] Rogl, P., Bauer, J., Bohn, M., “On the Phase Relations in the Al-B-Ti Ternary System”,

Annual Report COST 507 II, Group A, 1994, 1-10 (1994) (Equi. Diagram, Experimental,

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Sci. Forum, 217-222, 247-252 (1996) (Phys. Prop., Experimental, 7)

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[1997Zha] Zhang, F., Chen, S.L., Chang, Y.A., Kattner, U.R., “A Thermodynamic Description of the

Ti-Al System”, Intermetallics, 5, 471-482 (1997) (Equi. Diagram, Thermodyn.,

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[1998Joh] Johnsson, M., Jansson, K., “Study of Al1-xTixB2 Particles Extracted from Al-Ti-B Alloys”,

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[1998Sch] Schumancher, P., Greer, A.L., Worth, J., Evans, P.V., Kearns, M.A., Fisher, P., Green,

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Grain Refinement Practice”, Mater. Sci. Technol., 14, 394-404 (1998) (Equi. Diagram,


[1998Zup1] Zupanic F., Spaic, S., Krizman, A., “Contribution to Ternary System Al-Ti-B Part 1: Study

of Diborides Present in the Aluminium Corner”, Mater. Sci. Technol., 14, 601-607 (1998)

(Equi. Diagram, Crys. Structure, Experimental, 16)

[1998Zup2] Zupanic, F., Spaic, S., Krizman, A., “Contribution to Ternary System Al-Ti-B Part 2 - Study

of Alloys in Al-AlB2-TiB2 Triangle”, Mater. Sci. Technol., 14(2), 1203-1212 (1998) (Equi.

Diagram, Crys. Structure, Experimental, Review, 24)

[1999Eas1] Easton, M., StJohn, D., “Grain Refinement of Aluminium Alloys: Part I. The Nucleant and

Solute Paradigms - A Review of the Literature”, Metal. Mater. Sci. A, A30, 1613-1623

(1999) (Phys. Prop., Review, 79)

[1999Eas2] Easton, M., StJohn, D., “Grain Refinement of Aluminium Alloys: Part II. Confirmation of,

and a Mechanism for, the Solute Paradigm”, Metal. Mater. Sci. A, A30, 1625-1633 (1999)

(Phys. Prop., Experimental, Review, 23)

[1999Fje] Fjellstedt, J., Jarfors, A.E.W., Svendsen, L, “Experimental Analysis of the Intermediary

Phases AlB2, AlB12 and TiB2 in the Al-B and Al-Ti-B Systems”, J. Alloys Compd., 283,

192-197 (1999) (Equi. Diagram, Crys. Structure, Experimental, 27)

89


MSIT®

Al–B–Ti

[1999Jun] Jung, I.-S, Kim, M.-C., Lee, J.-H., Oh, M.-H., Wee, D.-M., “High Temperature Phase

Equilibria near Ti-50 at% Al Composition in Ti-Al System Studied by Directional

Solidification”, Intermetallics, 7, 1247-1253 (1999) (Equi. Diagram, Experimental, 20)

[1999Li] Li, J., Zong, Y., Hao, Sh., “Effects of Alloy Elements (C, B, Fe, Si) on the Ti-Al Binary

Phase Diagram”, J. Mater. Sci. Technol., 15(1), 58-62 (1999) (Equi. Diagram,

Experimental, 12)

[1999Och] Ochiai, S., “High Temperature Deformation Properties of Hip Processed Titanium

Boride-Titanium Aluminide”, Metal Powder Rep., (1), 36 (1999) (Mechan. Prop.,

Experimental, 0)

[1999Zup] Zupanich, F., Spaic, S., “Transformation of Diborides in Al-Ti-B Alloys Prepared by an

Aluminothermic Synthesis”, Metall., 53(3), 125-130 (1999) (Equi. Diagram, Crys.


[2000Hal] Hall, A., Economy, J., “The Al(L) + AlB12 - AlB2 Peritectic Transformation and its Role in





[2000Lu] Lu, L., Lai, M.O., Wang, H. Y., “Synthesis of Titanium Diboride TiB2 and Ti-Al-B Metal

Matrix Composites”, J. Mater. Sci., 35, 241-248 (2000) (Phys. Prop., Experimental, 17)

[2000Mik] Mikhalenkov, K.V.; Lysenko, S.I.; Reif, W., “Grain Refinement of Aluminium with

Titanium, Zirconium, and Ternary Master-Aloys AlTiB and AlTiC. Part 1” (in Rusian),

Casting Processes, (2), 21-31 (2000) (Phys. Prop., Experimental, 15)

[2000Ohn] Ohnuma, I., Fujita, Y., Mitsui, H., Ishikawa, K., Kainuma, R., Ishida, K., “Phase Equilibria

in the Ti-Al Binary System”, Acta Mater., 48, 3113-3123 (2000) (Equi. Diagram, Crys.

Structure, Thermodyn., Experimental, Assessment, 37)

[2000Tee] Tee, K.L., Lu, L., Lai, M.O., “In-situ Stir Cast Al-TiB2 Composite: Matrix Modification”,

Z. Metallkd., 91(3), 251-257 (2000) (Mechan. Prop., Experimental, 17)

[2000Tjo] Tjong, S.C., Ma, Z.Y., ”Microstructural and mechanical characteristics of in situ metal

matrix composites”, Mater. Sci. Eng. A, 29, 49-113 (2000) (Mechan. Prop., Review, 219).

[2001Bra] Braun, J., Ellner, M., “Phase Equilibria Investigations on the Aluminium-Rich Part of the

Binary System Ti-Al”, Metall. Mater. Trans. A, A32, 1037-1048 (2001) (Equi. Diagram,


[2001Fje] Fjellstedt, J., Jarfors, A.E.W., “Experimental and Theoretical Study of the Al-Rich Corner

in the Ternary Al-Ti-B System and Reassessment of the Al-Rich Side of the Binary Al-B

Phase Diagram”, Z. Metallkd., 92(6), 563-571 (2001) (Equi. Diagram, Thermodyn.,

Experimental, Calculation, Review, 36)

[2001Lue] Lü, L., Lai, M.O., Su, Y., Teo, H.L., Feng, C.F., “In Situ TiB2 Reinforced Al Alloy

Composites”, Scr. Mater., 45, 1017-1023 (2001) (Mechan. Prop., Experimental, 12)

[2001Mik] Mikhalenkov, K.V., Reif, W., “Experimental Observation of the Boundary Between

Nucleating Center and Aluminum Matrix” (in Russian), Metallofiz. Noveishie Technol.,


[2002Art] Artyukh, L.V., Bilous, O.O., Bondar, A.A., Borysov, D.B., Burka, M.P., Martsenyuk, P.S.,

Tsyganenko, N.I., Shapoval, T.A., “Phase Equilibria in the Ternary System Ti-Al-B and

High-Temperature Strength of Alloys” in “Science for Materials in the Frontier of

Centuries: Advantages and Challenges”, International Conference, Kyiv (Ukraine), 102

(2002) (Equi. Diagram, Experimental, 0)

[2002Mik1] Mikhalenkov, K.V., “Partition of Titanium at Crystallization of Aluminium” (in Russian),

Casting Processes, (2), 37-41 (2002) (Equi. Diagram, Experimental, 11)

[2002Mik2] Mikhalenkov, K.V., Reif, W., “Grain Refinement of Aluminium at Hypoperitectic

Additions of Titanium” (in Russian), Theory and Practice Metallurgy, 2, 6-13 (2002) (Equi.


90


MSIT®

Al–B–Ti

[2002Riz] Rizzoli, C., Salamakha, P.S., Sologub, O.L., Bocelli, G., “X-Ray Investigation of the

Al-B-N Ternary System”, J. Alloys Compd. 343, 135-141 (2002) (Experimental, Crys.

Structure, 28)

[2002Zha] Zhang, W.J., Deevi, S.C., “An Analysis of the Lamellar Transformation in TiAl Alloys

Containing Boron”, Mater. Sci. Eng. A, A337, 17-20 (2002) (Phys. Prop., Experimental, 25)


Phases/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/Referenses

( Al)

< 665

cF4

Fm3m

Cu

a = 404.96 at 25°C [Mas2]

Temperature from [1997Zha] at 0.8 at.%

Ti

( B)

<2092

hR333

R3m

B

a = 1093.30

c = 2382.52

[Mas2, 1993Wer]

( Ti)

< 1490

hP2

P63/mmc

Mg

a = 295.06

c = 468.35

[Mas2]

( Ti)

1670- 882

cI2

Im3m

W

a = 330.65 [Mas2]

AlB2

980 to <400

hP3

P6/mmm

AlB2

a = 300.5

c = 325.7

[2002Riz]

AlB12

2050 to <500

tP216

P41212

AlB12

a = 1016.1

c = 1428.3

[2000Hig]

2, Ti3Al

< 1166

hP8

P63/mmc

Ni3Sn

a = 577.5

c = 465.5

[V-C2]

, TiAl

< 1463

tP4

P4/mmm

AuCu

a = 400.0

c = 407.5

a = 398.4

c = 406.0

at 50.0 at.% Al [2001Bra]

at 62.0 at.% Al [2001Bra]

TiAl2< 1215

tI24

I41/amd

HfGa2

a = 397.0

c = 2497.0

[2001Bra]

TiAl3 (h)

1387-735

tI8

I4/mmm

TiAl3(h)

a = 384.9

c = 860.9

[2001Bra]

TiAl3 (l)

< 950 (Ti-rich)

tI32

I4/mmm

TiAl3 (l)

a = 387.7

c = 3382.8

[2001Bra]

TiAl3metastable

cP4

Pm3m

AuCu3

a = 397.2 0.1 [1994Bra, 1994Chu]

91


MSIT®

Al–B–Ti

Table 2: Composition of Liquid in Invariant Equilibria in the Al-B-Ti System

TiB

< 2180

oP8

Pnma

FeB

a = 610.5

b = 304.8

c = 454.2

[1987Mur]

TiB

Metastable

oC8

Cmcm

CrB

[1992Gra]

Ti3B4

< 2200

oI14

Immm

Ta3B4

[1987Mur]

TiB2

< 3225

hP3

P6/mmm

AlB2

a = 302.8 to 304.0

c = 322.8 to 323.4

a = 303.006

c = 323.009

for the binary system binary [1987Mur]

for the ternary Al-40B-17.5Ti (mass%)

as-cast alloy [1998Zup1]

(Ti1-xAlx)B2

metastable

hP3

P6/mmm

AlB2

a = 302.64 0.05

c = 323.18 0.09

(extracted from

Al-2.6Ti-1.4B

(mass%) master

alloy [1992Joh]

0 x 1, metastable [1999Fje,

1999Zup, 1998Zup1, 1998Zup2,

1994Tok, 1986Abd, 1985Abd1,

1985Abd2]

Ti86Al7B7

metastable

fcc a = 421.0(2) [1995Loe]

Equilibrium T [°C] Point in

Fig. 1

Composition of liquid (at.%) Comments/

ReferencesAl Ti B

L +( B) AlB12 + TiB2 unknown U1 unknown presumably

T<2050°C

L ( Ti) + TiB ~1560 e2 20 34.5 5.5 [2002Art]

L + TiB Ti3B4 + ( Ti) <1545 U2 44 54.6 1.4 [1990Hym]

L + Ti3B4 TiB2 + ( Ti) below U2 U3 45 53.7 1.3 [1990Hym]

L + ( Ti) ( Ti) + TiB2 below U3 U4 49 50 1.0 [1991Hym]

L + ( Ti) + TiB2 below U4 U5 55.5 43.8 0.7 [1991Hym]

L + Ti5Al11 TiAl3(h) + TiB2 <1393 U6 unknown presumably T

is ~1390°C

L + AlB12 AlB2 + TiB2 880 U7 to balance ~4·10-6 ~2.5 [2001Fje,

1998Zup2]

L + TiAl3(h) ( Al) + TiB2 ~664.5 U8 to balance

to balance

~0.08

0.1015

6.7·10-5

1.8·10-5[1985Abd1]

[1989Hay]

L + TiB2 ( Al) + AlB2 ~660 U9 to balance 6.7·10-6 ~0.06 [1985Abd1]

L + TiB2 ( Al) + AlB12 655 meta-

stable

to balance ~4·10-6 0.05 [1998Zup2]

Phases/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/Referenses

92


MSIT®

Al–B–Ti

Table 3:Thermodynamic Stability of Phases Being in Equilibrium with Solid and Liquid Aluminium

Phases [2001Fje]

Table 4: Optimised Parameters for Al-rich Melt [2001Fje]

Table 5: Tensile Properties of Titanium Matrix Composites at 25°C [1994Sob, 1991Sob]

Reaction (Standard State) 0Gf (J mol)–1

Al(l) + 2( B) AlB2 –119007 + 63.3886 T

Al(l) + 12( B) AlB12 –286607 + 8.76206 T

Ti(hcp) + 2( B) TiB2 –331761 + 22.9143 T

3Al(l) + Ti(hcp) TiAl3 –185871 + 64.5540 T

Liquid 0Li, j1Li, j

2Li, j

(Al,B) –394.627 – 2.02086 T 19322.4 10486.3

(Al,Ti) –196807 + 54.0763 T 73896.5

(Ti,B) –160670 – 37.3860 T –152116 + 47.0434 T

Composition

(mass%)

Annealed at 704°C for 24 h Annealed at 1200°C for 1 h

plus at 600°C for 24 h

Annealed at

815°C for

24 h

Yield

Stress

[MPa]

Elon-

gation

(%)

Modulus

E

[GPa]

K1c

[MPa m1/2]

Yield

Stress

[MPa]

Elon-

gation

(%)

K1c

[MPa m1/2]

K1c

[MPa m1/2]

Ti-6Al-0.5B 1055 8.1 135 38 896 3 57 42

Ti-6Al-1B 1158 1.5 142 23 68 16.5

Ti-7.5Al-1B 1241 0 17 1241 3.5 22.5 20

93


MSIT®

Al–B–Ti

Fig

. 1:

Al-

B-T

i. R

eact

ion s

chem

e at

soli

dif

icat

ion o

f al

loys

[2002A

rt,

2001F

je,

1991H

ym

, 1990H

ym

, 1985A

bd1]

B-T

iA

l-T

iA

l-B

Al-

B-T

i

l +

(βT

i) (

αTi)

1490

p4

l(β

B)

+ T

iB2

2080

e 1

L +

TiB

T

i 3B4 +

(βT

i)?

U2

l +

(βB

) αA

lB12

2050

p3

L (

βTi)

+ T

iB

1560

e 2(m

ax)

l +

TiB2

Ti 3

B4

2200

p1

l +

Ti 3

B4

TiB

2180

p2

l (

βTi)

+ T

iB

1530

e 3

l +

(αT

i)γ

1463

p5

l+

Ti 5

Al 11

TiA

l 3(h

)

1393

p6

l +

TiA

l 3(h

) (

αAl)

665

p8

l +

αA

lB12

AlB2

956

p7

l (

αAl)

+A

lB2

659.7

e 4

L +

(βB

) αA

lB12

+ T

iB2

?U1

L +

Ti 3

B4

TiB2

+ (

βTi)

?U3

L +

(βT

i) (

αTi)

+ T

iB2

?U4

L +

(αT

i)γ

+ T

iB2

?U5

L+

Ti 5

Al 11

TiA

l 3(h

)+T

iB2

1390

U6

L+

TiA

l 3(h

)(α

Al)

+T

iB2

664.5

U8

L+

αAlB12

AlB2+

TiB2

880

U7

L+

TiB2

(αA

l)+

AlB2

660

U9

(βB

)+αA

lB12+

TiB2

TiB

+T

i 3B4+

(βT

i)

Ti 3

B4+

TiB2+

(βT

i)

(βT

i)+

(αT

i)+

TiB2

(αT

i)+

γ+T

iB2

Ti 5

Al 11+

TiA

l 3(h

)+T

iB2

TiA

l 3(h

)+(α

Al)

+T

iB2

TiB2+

(αA

l)+

AlB2

αAlB12+

AlB2+

TiB2

?

94


MSIT®

Al–B–Ti

20

40

60

80

20 40 60 80

20

40

60

80

Ti Al

B Data / Grid: at.%

Axes: at.%

AlB2TiB2

880°C

~660°C

~664.5°C

~2080°C

~2050°C

659.7°C

956°Cmax, 3225°C

665°C

αAlB12

(βB)

(αAl)TiAl3

1500°C

1510

°C15

25°C

1540

°C

max

, ~15

60°C

1545

°C

(βTi)

TiB

50

60

70

80

90

10 20 30 40 50

10

20

30

40

50

Ti Ti 40.00Al 60.00B 0.00

Ti 40.00Al 0.00B 60.00 Data / Grid: at.%

Axes: at.%

TiB

(βTi)

TiB2

~1560°C

e1

p2

p1

U3U2e2,

p4 p5(αTi) γ

U4 U5

Ti3B4

Fig. 2: Al-B-Ti.

Partial solidus surface

projection.

Ti-rich region is from

[2002Art],

Al-rich region is from

[2001Fje, 1998Zup2,

1985Abd1, 1984Sig]

Fig. 3: Al-B-Ti.

Liquidus surface

projection in the

Ti-rich region

[2002Art, 1991Hym,

1990Hym]

95


MSIT®

Al–B–Ti

Ti 0.20Al 99.80B 0.00

Al


Axes: at.%

1300°C

1200°C

1100°C

1000°C900°C

Ti 0.00Al 99.99B 0.01 Data / Grid: a

Axes: at.%

900°C

800°C

700°C

Ti 0.01Al 99.99B 0.00

Al


Axes: at.%

900°C

800°C

700°C

Fig. 4b: Al-B-Ti.

Liquidus surface in

the Al-rich regoin as

projection on Gibbs'

triangle [1989Hay]

Fig. 4a: Al-B-Ti.

Liquidus surface in



triangle [2001Fje]

96


MSIT®

Al–B–Ti

Ti 0.50Al 99.50B 0.00

Al


Axes: at.%

1300°C

Al1

1

10-4

10-6

10-2

100B

100

Ti

10-1010-810-610-410-2

U9

U7

U8

1000°C900°C

800°C700°C

B,at.%

Ti, at.%

��Al)

� �Al �

Al�

TiB 2

TiAl

Fig. 4c: Al-B-Ti.

Liquidus surface in



triangle [1989Hay]

Fig. 4d: Al-B-Ti.

Liquidus surface in

the Al-rich region as

projection on

logarithmic scale after

[2001Fje]

97


MSIT®

Al–B–Ti

Al

Soli

d(

Al)

�

1 0.01 10 10 10 10-4 -6 -8 -

1

0.0

10-4

10-6

10-8

10-

TiA

l 3

AlB2

Ti, mass%

B,mass%

Liquid AlLiquid Al

TiA

l 3

AlB2

B,mass%

1

0.01

10-4

10-6

10-8

10-10

Al

1 0.01 10 10 10 10-4 -6 -8 -

Ti, mass%TiB

2

B

Tia)

100

100

TiB

2

b) Ti

100

B100

Fig. 5: Al-B-Ti. Phase equilibria in the range of melting/solidification of (Al) phase at 666°C (a), 664°C (b), 662°C

(c), 660.2°C (d), 660°C (e) and 659.708°C (f) after [1984Sig]

Al

Soli

d(

Al)

�

1 0.01 10 10 10 10-4 -6 -8 -10

1

0.0

10-4

10-6

10-8

10-

TiA

l 3

Ti, mass%B,mass%

Liquid AlLiquid Al

TiA

l 3

B,mass%

1

0.01

10-4

10-6

10-8

10-10

Al

1 0.01 10 10 10 10-4 -6 -8 -10

Ti, mass%c) d)

Soli

d(

Al)

�

TiB

2

TiB

2

B

Ti

100

100

Ti

100

B100

AlB2 AlB2

Al

Solid ( Al)�

1 0.01 10 10 10 10-4 -6 -8 -10

1

0.0

10-4

10-6

10-8

10-10

TiA

l 3

AlB2

Ti, mass%

B,mass%

LiquidA

l

Liquid Al

TiA

l 3

AlB2

B,mass%

1

0.01

10-4

10-6

10-8

10-10

Al

1 0.01 10 10 10 10-4 -6 -8 -10

Ti, mass%f)e)

Solid ( Al)�

TiB

2

TiB

2

B

Ti

100

100

Ti

100

B100

98


MSIT®

Al–B–Ti

L + TiB + AlB2 2 L + AlB2

AlB2

L+

TiB 2L

+T

iB+

TiA

l2

3

L+

TiAl 3

L

Al

TiB 2

TiAl310-210-1 10-1010-4 10-810-6

10-1

10-2

10-4

10-6

B,at.%

Ti, at.%

100B

100

Ti

10-810-6

10-4

10-6

10-40.011

0.01

1

AlB2

TiA

l 3

Liquid Al

Al

Ti, mass%

B,mass%

100B

100

Ti

TiB

2

Fig. 6: Al-B-Ti.

Partial isothermal

section at 727°C

[1976Jon]

Fig. 7: Al-B-Ti.

Partial isothermal

section at 820°C

[1986Sig].

The solid line gives the

TiB2 solubility

calculated taking into

account the interaction

coefficient of Ti and B as

= –1500.

The dashed straight line

is calculated without

interaction between Ti

and B

99


MSIT®

Al–B–Ti

�

�

�

�

��

TiB2

TiB2

TiB2

�TiB

2

TiB2

B

AlB2

U8

U9

U7

��Al)

p8TiAl3Ti Al

e4

p7

liquid

��Al) solid solutiontie lines

TiB2

TiB2

��

TiB2

TiB2 AlB12

Ti Al

B

TiB2

TiB2

�AlB12

e

U ��Al)

Fig. 8: Al-B-Ti.

Schematic

representation of

invariant and

monovariant equilibria

including phases of

liquid Al and solid

( Al) [1998Zup2,

1985Abd1]

Fig. 9: Al-B-Ti.

Schematic

representation of

metastable liquidus

projection in the

Al-AlB12-TiB2 region

[1998Zup2]

100


MSIT®

Al–B–Ti

40

60

80

20 40 60

20

40

60

Ti Ti 33.30Al 66.70B 0.00


Axes: at.%

(βTi) (αTi) α2γ TiAl2

TiB2

Ti3B4

TiB

750

1000

1250

1500

1750

2000

2250

Ti 1.14Al 98.86B 0.00

Ti 0.00Al 95.15B 4.85B, at.%

Tem

pera

ture

, °C

L+TiAl3+TiB2

L+TiB2+AlB2

L+TiB2

L

2 4

Fig. 10: Al-B-Ti.

Partial isothermal

section at 1000°C

[1994Rog]

Fig. 11: Al-B-Ti.

Vertical section at

constant 98 mass% Al

[1989Hay]

101


MSIT®

Al–B–Ti

3225°C

~1700°C

L + TiB2

<1700°C

L+( Al)+ AlB� 12�

� Al)+ AlB12� �( Al) + TiB + AlB� 2 12�

L + TiB + AlB2 12�

L + AlB12�

L

Al

Temperature,°C

TiB2 AlB

2

655°C~<

Fig. 12: Al-B-Ti.

Qualitative

metastable section

TiB -AlB [1998Zup2]

102


MSIT®

Al–Be–Cu

Aluminium – Beryllium – Copper

Gautam Ghosh, Hans Leo Lukas, Günter Effenberg and Bernd Grieb

Literatute Data

Earlier investigations of phase equilibria primarily involved microstructural observations, age hardening

behavior and hardness measurements [1929Mas1, 1929Mas2, 1936Ams, 1938Koc, 1938Fil, 1939Bal].

[1936Ams] reported the phase boundaries involving , and at 400, 500, 600, 700, 800 and 850°C.

[1936Ams] used alloys containing up to 2 mass% Be and 5 mass% Al. [1938Fil] used alloys up to 5 mass%

Be and 12.5 mass% Al, and determined vertical sections at 0.6, 1.5, 3.0 and 5.0 mass% Be.

The first comprehensive studies of phase equilibria were carried out by [1946Bad] in the Al-corner and by

[1957Nic, 1958Nic] in the copper-rich region. Nickel applied metallography, differential thermal analysis

(DTA), X-ray and dilatometry to investigate the Cu-corner up to 18 at.% Al and 26 at.% Be. The alloys were

prepared from the pure elements and annealed in a hydrogen atmosphere at 800°C to produce a

homogeneous state. Badaeva [1946Bad] investigated the Al-rich corner by DTA. A considerable number of

alloys were grouped into 6 series of constant Cu:Be mass ratios of 20:1, 12:1, 10:1, 7:1, 5:1 and 2:1. Within

each series the Cu content varied from 0 to about 50 mass% except in the 2:1 series in which the Cu content

was 0.07 to 33.67 and correspondingly the Be content 0.03 to 16.33 mass%. Part of the results of [1946Bad]

are reflected in Fig. 1, Fig. 2 and Fig. 11.

[1979Dri], [1980Cha] and [1990Eff] presented reviews of the Cu-rich part.

Binary Systems

The Al-Be system is accepted from [Mas], the Al-Cu binary phase diagram is accepted from the assessment

of [2003Gro], and the Be-Cu system is accepted from [2003Wat]. The phases called 0 and 1 by [Mas] are

identical to the ’ phase of [1957Nic]. The (Al) solvus in Al-Cu was calculated using the COST 507 data

set [1998Ans], as for this boundary the resolution in [2003Gro] is not sufficient.

Solid Phases

In the composition range investigated no ternary phase has been found. The phase of the Be-Cu system

has a large homogeneity range towards Al [1958Nic]. In an alloy with about 18 at.% Al and 43 at.% Be, he

found a cubic Laves phase containing superstructure reflections in the X-ray diffraction pattern, and

proposed a model of an ordering in this phase. This model, however, should be taken with caution, as its

symmetry is reduced from cubic to tetragonal, but no other evidence of this symmetry-reduction is reported.

[1967Sta] verified the 200, 222 and 420 superstructure X-ray reflections in an alloy of composition

CuBe2Al, but this alloy also contains (CuAl2) indicating that the phase contains less Al than according to

the formula CuBe2Al. It is not clear, if this phase is a ternary solid solution of the binary Cu-Be phase or

a ternary phase.

The phases originating from the binary systems are listed in Table 1. The distinction between 0 and 1 in

the Al-Cu system as made by [Mas, 1957Nic] could not verify by optical metallography.

[1987Kar] determined the solubility of Be in the phase by metallographic analysis as 0.8 mass% and by

EDS as 2.07 mass% (3 or 7 at.% respectively). They consider the metallographic determination as the most

accurate, the value corresponds to a solubility limit at the composition CuBe0.1Al1.9.

[1977Mye] investigated the effect of Al on the solubility of Cu in Be by ion implantation followed by

annealing at 500°C. They found that Al has no significant effect on the solubility of Cu in Be.

The combined solubilities of Be and Cu in (Al) [1946Bad] are shown in Fig. 1, Cu increases significantly

the solubility of Be in Al.

103


MSIT®

Al–Be–Cu

The solubilities of Al and Be in the ternary (Cu) solid solution where investigated by [1958Nic] at 800, 700,

600, 500 and 400°C by means of optical metallography and X-ray diffraction and they are shown in Fig. 2.

With decreasing temperature the maximum solubility of Al remains almost constant whereas that of Be

decreases.


The reaction scheme of the Cu-rich part, shown in Fig. 3a, is based on the results of [1957Nic]. Six ternary

invariant equilibria are reported by [1957Nic] and listed in Table 2. The compositions of all phases are taken

from [1957Nic], the equilibria are plotted in Figs. 4 and 5. Slight changes have been made to comply with

the accepted binaries. In particular, [1957Nic] observed a thermal effect at 1014°C and attributed it to the

invariant reaction L+ 0 + 0. In view of the accepted Al-Cu binary where 0 is not distinguished from ,

the nature of this invariant reaction can not be ascertained. Also, limited information preclude speculation

of any other invariant reaction that would be compatible with the Al-Cu binary. As a result, the participation

of the transition reaction U1 is not considered in the reaction scheme and the binary L+ 0 is considered

to participate directly into the transition reaction U2.

In the Al-rich corner of the ternary system [1946Bad] found an invariant equilibrium at 558°C. These

authors reported the (Al) solid solution to have a two-phase equilibrium with the phase besides the

two-phase equilibria (Al)+( Be) and (Al)+ known from the binary systems. That means, there are at least

two invariant four-phase equilibria in the Al corner. As the temperature 558°C is higher than that of the

binary eutectic L +(Al) the second one at 558°C must be a transition reaction L+ +(Al). This implies,

that the composition of the liquid phase is on the Be-poor side of the tie line (Al)- . The first invariant

equilibrium, L+( Be) +(Al) is very near to the Al-Be edge of the ternary system and was not explicitly

detected in the investigations of [1946Bad]. A tentative reaction scheme of the Al-rich corner is given in

Fig. 3b. Both invariant equilibria are included in Table 2. The compositions of liquid and (Al) are estimated

from the results of [1946Bad], that of from [1987Kar].

Liquidus Surface

Figure 4 shows the monovariant curves separating the areas of primary crystallization of (Cu), , 0, 1 and

in the Cu-rich corner. Liquidus isotherms were not reported in [1957Nic]. The monovariant curve, in

which liquid is in equilibrium with + , disappears at a critical tie line between and at 871°C.

The liquidus surface of the Al-rich corner in Fig. 6 was constructed by [1946Bad] from six T-C sections. It

is modified by adding tentatively the curve of double saturation L+( Be)+ , which was not given by

[1946Bad].

Solvus Surfaces

[1946Bad] gave isotherms of the (Al) solvus surface at 530, 480, 390 and 300°C. They did not draw the

lines of double saturation of (Al) with respect to + or +( Be). The line, where (Al) is saturated with +

can easily be deduced from the kinks of the isotherms given by [1946Bad]. The line of double saturation

(Al) with +( Be) is very near to pure Al (xAl > 99.5 at.%). The resulting diagram is shown in Fig. 1, where

also the (Al) traces of the three-phase equilibria L+(Al)+ , L+(Al)+ and L+(Al)+( Be) are given

tentatively, i.e. the boundaries between liquidus and solvus.

Isothermal Sections

Using a large number of alloys, [1957Nic] determined isothermal sections of the Cu-rich part

(xCu > 30 at.%) at 800, 600 and 500°C which are shown in Fig. 7, Fig. 8 and Fig. 9. Minor adjustments have

been made along the Al-Cu and Be-Cu edges to comply with the accepted binaries. Schematic isothermal

sections (without scaling) at 647, 640, 560 and 490°C were given by [1957Nic] to clarify the phase relations

in the solid state.

104


MSIT®

Al–Be–Cu


Cu-rich region [1957Nic]: an isopleth at 3 mass% Be is given in Fig. 10.

Al-rich region [1946Bad]: an isopleth at constant Cu:Be mass-ratio of 20:1 (mole ratio 2.836:1) is given in

Fig. 11. The Al-rich part of the diagram is tentatively completed by the additional information given by

[1946Bad] for the (Al) solvus (Fig. 1).

Thermodynamics

Thermodynamic properties of ternary alloys have not been determined. [1998Man] observed that the (A2)

1 (DO3) ordering transition is first-order. In a Cu-Be-22.72Al (at.%) alloy, the transition temperatures

are 511 and 496°C on heating and cooling, respectively. The ordering enthalpy is 1160±50 J mol-1. On the

other hand the enthalpy change associated with the martensitic transformation ( 1 18R) is 200 J mol-1.

The entropy change associated with these two transformations are comparable.


The copper-rich Be-Cu alloys with addition of aluminium have technical relevance because of their good

hardenability.

The ternary alloys in the vicinity of Cu-3.5Be-23Al (at.%) exhibit shape memory phenomenon. Guenin

[1995Gue] has provided a review of these results. The shape memory effect is strongly influenced by the

quench rate of the phase which determines the formation of , 2 and 2 phases, though in minor amounts,

and the vacancy concentration [1998Man, 1999Man, 1999Rom]. [1999Rom] observed that 1 ordering

transition is associated with a marked increase in vacancy concentration. Also, these vacancies are primarily

single vacancy type [1998Man]. The migration energy for the vacancies in Cu-3.55Be-22.72Al (at.%)

alloy is 1.0 ± 0.1 eV [1999Rom].

The shape memory behavior is also strongly influenced by stress [1992Hau, 2001Bal]. [1992Hau] studied

the martensitic transformation in a Cu-11.6Al-0.52Be (mass%) alloy using single crystals oriented along

[001] direction. The alloy has a natural Ms of –10°C. Below Ms, reorientation of ’ (18R) or ’ (2H)

martensite followed by ’ ’’ (18R2) and then ’’ ’ transformation takes place with increasing stress.

Above Ms, ’ and ’ ’ transformation takes place with increasing stress.

[1991Rio] measured the temperature dependence of single crystal elastic constants of Cu-11.36Al-0.78Be

(mass%) and Cu-0.47Be-11.65Al (mass%) alloys by pulse echo technique. [1999Man] determined the

phonon dispersion curves of b Cu-3.55Be-22.72Al (at.%) alloy using inelastic neutron scattering technique,

and also the specific heat by differential scanning calorimetry. Using the phonon dispersion results, the

elastic constants were calculated based on fifth-neighbor force constant.

[1946Har] developed casting and heat treatment procedure of (2 to 6)Cu-(0.1 to 1)Be-Al (mass%) alloys.

He noted that Be in excess of 0.75 mass% tends to cause a decrease in useful properties. These alloys have

high tensile strength, high thermal stability and good oxidation resistance.

Upon adding Be into Cu-Al alloys the cavitation-erosion resistance improves significantly.

Miscellaneous

[1967Pot] determined the partitioning ratio of Cu, between solid (Be) and liquid, in two-phase Al-Be alloys

as function of temperature and discussed the results in view of purification of Be by treating with liquid Al.

[1982Bre] presented a review of decomposition kinetics and microstructures of and phases, and

associated properties. In the temperature range of 400 to 550°C, the decomposition kinetics and the

microstructure of Al-Be-Cu alloys are sensitive to alloy composition [1962Phi, 1968Hor, 1969Hor]. In

general, the following transformations are observed: 1 , 1 2, 1 ( + 2) and 1 ( + 2+ ).

105


MSIT®

Al–Be–Cu

References

[1929Mas1] Masing, G., Dahl, O., “Ternary Beryllium Containing Alloys on the Copper Base” (in

German), Wiss. Veroeff. Siemens-Konzern, 8(1), 202-210 (1929) (Experimental, 1)

[1929Mas2] Masing, G., Dahl, O., “Aluminium Alloys Containing Beryllium”, Siemens-Werke/

Wissenschaftliche Veroeffentlichungen, 8, 248-256 (1929/30) (Experimental, Equi.

Diagram, 3)

[1931Pre] Preston, G.D., “An X-ray Investigation of Some Copper-Aluminium Alloys”, Philos. Mag.,


[1936Ams] Amsterdamsky, Ya.A., “Influence of Aluminium on Properties Copper-Beryllium Alloys”

(in Russian), Metallurgiya, (11), 90-102 (1936) (Equi. Diagram, 6)

[1938Koc] Koch, W., Röntgen, P., “On the Influence of Beryllium in Brass Alloys. I. Investigation of

Texture” (in German), Metall-Wirtschaft, 17, 997-1005 (1938) (Experimental, 3)

[1938Fil] Filin, N.A., Iokhel, L.L., “Constitution and Properties of Alloys in the

Copper-Aluminium-Beryllium (Copper Corner)” (in Russian), Metallurgiya, (12), 81-92

(1938) (Equi. Diagram, Experimental)

[1939Bal] Ballay, M., “Properties of Some Aluminium Alloys with Be (Glucinium)” (in French),

Compt. Rend. Acad. Sci. Paris, 208(17), 1309-1311 (1939) (Experimental, 6)

[1946Bad] Badaeva, T.A., Sal’dau, P.Ya., “Ternary Solid Solution of Copper and Beryllium in

Aluminium” (in Russian), Izv. Sekt. Fiz.-Khim. Anal., 16(2), 251-274 (1946) (Equi.

Diagram, Experimental, #, *, 16)

[1946Har] Harrington, R.H., “New Aluminium Alloys Containing Small Amounts of Beryllium”,

Trans. Am. Soc. Metals, 36, 311-323 (1946) (Experimental, 2)

[1957Nic] Nickel, O., “Equilibria in the Al-Be-Cu System I. The Ternary Phase Diagram” (in

German), Z. Metallkd., 48, 417-424 (1957) (Equi. Diagram, Experimental, #, *, 20)

[1958Nic] Nickel, O., “Equilibria in the Al-Be-Cu System II. Additional Investigations of Solubility

Isotherms, Structures and Microstructure-Evolution“ (in German), Z. Metallkd., 49, 47-62


[1962Phi] Philip, T.V., Mack, D.J., “Effect of Ternary Elements on the Eutectoid Transformation in

Al Bronze”, Trans. Met. Soc. AIME, 224, 34-42 (1962) (Experimental, 16)

[1967Pot] Potard, C., Bienvenu, G., Schaub, B., “Distribution of Fe, Cu and Mo Impurities Between

the Solid and Liquid Phases in Al-Be Alloys” (in French), Thermodynamics of Nuclear

Materials, Vienna, 67, Int. At. Energy Agency, 809-825 (1967) (Experimental, 11)

[1967Sta] Stadelmaier, H.H., Hofer, G., “Phases with Diamond Sublattice Structure in Ternary

Beryllium Alloys” (in German), Monatsh. Chem., 98, 45-48 (1967) (Crys. Structure,

Experimental, 2)

[1968Hor] Hori, M., “Effects of Addition of Be and both Be and Fe on -> + 2 Transformation of

Cu-Al Alloys” (in Japanese), Nippon Kinzoku Gakkai Shi, 32(10), 1003 (1968) (Crys.


[1969Hor] Hori, M., “Tempering Transformations of Copper-Aluminium-Beryllium and

Copper-Aluminium-Beryllium-Iron Alloys” (in Japanese), Nippon Kinzoku Gakkai Shi,

33(8), 878-882 (1969) (Crys. Structure, Equi. Diagram, Experimental, 11)

[1977Mye] Myers, S.M., Smugeresky, J.E., “Low-Temperature Solubility of Cu in Be, in Be-Al and in

Be-Si Using Ion Beams”, Metall. Trans., 8A, 609-616 (1977) (Experimental, 16)

[1979Ald] Aldinger, F., Petzow, G.,“Constitution of Beryllium and its Alloys” in “Beryllium Science

and Technology”, Vol. 1, Webster, D., London, G. (Eds.), Plenum Press, New York (1979)

(Equi. Diagram, Crys. Structure, Review, 302)

[1979Dri] Drits, M.E., Bochvar, N.R., Guzei, L.S., Lysova, E.V., Padezhnova, E.M., Rokhlin, L.L.,

Turkina, N.I., “Cu-Al-Be” (in Russian), in “Binary and Multicomponent Copper-Base

Systems”, Nauka, Moskow, 69-70 (1979) (Equi. Diagram, 5)

106


MSIT®

Al–Be–Cu

[1980Cha] Chang, Y.A., Neumann, J.P., Mikula, A., Goldberg, D., “The Al-Be-Cu

(Aluminum-Beryllium-Copper) System”, Bull. Alloy Phase Diagrams, 1(1), 46-48 (1980)

(Equi. Diagram, Review, 19).

[1982Bre] Brezina, P., “Heat Treatment of Complex Aluminium Bronzes”, Int. Met. Rev., 27(2),

77-120 (1982) (Equi. Diagram, Experimental, 210)

[1985Mur] Murray, J.L., “The Aluminium - Copper System”, Int. Met. Rev., 30, 211-233 (1985) (Equi.

Diagram, Review, #, *, 230)

[1987Kar] Karov, J., Yondelis, W.V., “Solubility of Beryllium in CuAl2”, Mater. Sci. Technol., 3,


[1990Eff] Effenberg, G., Ghosh, G., Grieb, B., “Al-Be-Cu (Aluminium-Beryllium-Copper)”, MSIT


Science International Services, GmbH, Stuttgart; Document ID: 10.11588.1.20, (1990)


[1991Rio] Rios-Jara, D., Belkahla, S., Canales, A., Flores, H., Guenin, G., “Elastic Constants

Measurements of Copper-Aluminum-Beryllium Alloys”, Scr. Metal. Mater., 25(6),

1351-5 (1991) (Phys. Prop., Experimental, 7)

[1992Hau] Hautcoeur, A., Eberhardt, A., Patoor, E., Berveiller, M., “Thermomechanical Behaviour of

Monocrystalline Cu-Al-Be Shape Memory Alloys and Determination of the Metastable

Phase Diagram”, J. Phys. IV, 5, C8-459-464 (1992) (Crys. Structure, Equi. Diagram,

Experimental, 12)

[1995Gue] Guenin, G., “Martensitic Transformation and Thermomechanical Properties”, Key Eng.

Mater., 101-102, 339-392 (1995) (Crys. Structure, Equi. Diagram, Phys. Prop., Review, 73)

[1998Ans] Ansara, I., Dinsdale, A.T., Rand, M.H., COST 507, Thermochemical Database for Light

Metal Alloys, Vol. 2, European Communities, Luxembourg, 311-315 (1998) (Equi.

Diagram, Thermodyn., Assessment)

[1998Man] Manosa, L., Jurado, M., Gonzalez-Comas, A., Obrado, E., Planes, A., Zaretsky, J., Stassis,

C., Romero, R., Somoza, A., Morin, M., “A Comparative Study of the Post-Quench

Behavior of Cu-Al-Be and Cu-Zn-Al Shape Memory Alloys”, Acta Mater., 46(3),


[1999Man] Manosa, L., Zarestky, J., Bullock, M., Stassis, C., “Low-Lying Phonon Dispersion Curves

of D03 Cu3Al(+Be)”, Phys. Rev. B, 59(14), 9239-9242 (1999) (Crys. Structure,

Experimental, 14)

[1999Rom] Romero, R., Somoza, A., “Point Defects Behavior in beta Cu-Based Shape Memory

Alloys”, Mater. Sci. Eng. A, A273-275, 572-576 (1999) (Crys. Structure, Experimental, 25)

[2001Bal] Balo, S.N., Ceylan, M., Aksoy, M., “Effects of Deformation on the Microstructure of a

Cu-Al-Be Shape Memory Alloy”, Mater. Sci. Eng. A, 311, 151-156 (2001) (Crys. Structure,

Equi. Diagram, Experimental, 18)

[2002Gul] Gulay, L.D, Harbrecht, B., “The Crystal Structures of the 1 and 2 Phases in the Al-Cu

System”, Abstr. VIII Int. Conf., “Crystal Chemistry of Intermetallic Compounds”,


[2003Gro] Gröbner, J., “Al-Cu (Aluminum-Copper)”, MSIT Binary Evaluation Program, in MSIT


Stuttgart; to be published, (2003) (Crys. Structure, Equi. Diagram, Assessment, 68)

[2003Wat] Watson, A., “Be-Cu (Beryllium-Copper)”, MSIT Binary Evaluation Program, in MSIT


Stuttgart; to be published, (2003) (Crys. Structure, Equi. Diagram, Assessment, 10)

107


MSIT®

Al–Be–Cu


Phase /

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

(Al)

< 660.452

cF4

Fm3m

Cu

a = 404.88 pure Al [V-C]

( Be)

1289-1109

cI2

Im3m

W

a = 255.15 pure Be [V-C]

( Be)

< 1270

hP2

P63/mmc

Mg

a = 228.58

c = 358.43

pure Be [V-C]

(Cu) cF4

Fm3m

Cu

a = 361.48 pure Cu [V-C]

, BeCu

< 930

cP2

Pm3m

CsCl

a = 270.2 [V-C]

, Be4...2Cu

< 1219

cF24

Fm3m

Cu2Mg

a = 596.9 [1979Ald]

18.2 - 37.6 at.% Cu

, BeCu2

AlCu3

CI2

Im3m

W

a = 280

a = 295.64

solid solution from

BeCu2 to AlCu3 (h2) [V-C]

[V-C]

0, AlCu3

1037-964

- - [Mas]

2, AlCu3

< 363

DO22 long period

superlattice [Mas]

0, Al4Cu9(h)

1022-780

cubic - probably disordered form of 1

1, Al4Cu9(r)

< 873

cP52

P43m

Al4Cu9

a = 870.6 [V-C]

31-40 at.% Al

1, Al2Cu3

958-848

- - [Mas]

2, Al2Cu3

850-560

hP6

P63/mmc

NiAs

a = 414.6

c = 506.3

T = 630°C [V-C]

, Al2Cu3

686-RT

- - [Mas]

1, Al4Cu5

590-560

oF88 4.7

Fmm2

Cu47.8Al35.5

a = 812.67

b = 1419.85

c = 999.28

[Mas, 1985Mur]


108


MSIT®

Al–Be–Cu


2, Al4Cu5

< 570

oI24 3.5

Imm2

Cu11.5Al9

a = 409.72

b = 703.13

c = 997.93

55.2 to 56.3 at.% Cu

[Mas, 1985Mur]


1, AlCu(h)

< 624

o*32 a = 401.5

b = 1202

c = 865.2

49.8 to 52.4 at.% Cu

[Mas, 1985Mur]


2, AlCu

< 563

mC20 a = 1206.6

b = 410.5

c = 691.3

[V-C]

, Al2Cu

< 590

tI12

I4/mmc

Al2Cu

a = 606.6

c = 487.4

a = 604.2 ± 1.0

c = 484.8 ± 1.0

at Cu0.98Al2.08

[1987Kar]

at Cu0.86(Al1.92Be0.22)


Al Be Cu

L + 0 + 890 U2 L

0

7.9

2.9

10.0

2.1

32.4

43.4

29.9

66.0

59.7

53.7

60.1

31.9

L + + 875 U3 L 13.6

4.6

16.9

16.9

28.4

63.6

20.1

25.4

58.0

31.8

63.0

57.7

(Cu) + 647 emax

(Cu)

4.1

6.8

0.4

24.7

7.4

47.6

71.2

85.8

52.0

+ (Cu) + 560 U4

(Cu)

18.0

0.8

15.4

0.2

8.9

47.6

2.9

69.7

73.1

51.6

81.7

30.1

(Cu) + 1 + 490 E1

(Cu)

1

20.4

16.6

26.7

0.4

7.5

1.4

8.5

69.6

72.1

82.0

64.8

30.0

L + ( Be) (Al) + 640 U5 L

(Al)

96

99.5

3

0.4

1

0.1

L + (Al) + 558 U6 L

(Al)

83.6

96.3

64

1.4

1.5

3

15

2.2

33

Phase /

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

109


MSIT®

Al–Be–Cu

Be 5.00Cu 0.00Al 95.00

Be 0.00Cu 5.00Al 95.00


Axes: at.%300°C

480°C

530°C

390°C

U6

e6

e5

U5

Fig. 1: Al-Be-Cu.

Solubility isotherms

for Be and Cu in (Al)

[1946Bad]

10

90

10

Be 20.00Cu 80.00Al 0.00

Cu

Be 0.00Cu 80.00Al 20.00 Data / Grid: at.%

Axes: at.%

800700

600

500 400°C

Fig. 2: Al-Be-Cu.

Solubilities of Al and

Be in the ternary (Cu)

solid solution

110


MSIT®

Al–Be–Cu

Fig. 3a: Al-Be-Cu. Reaction scheme in the Cu-rich corner

Be-Cu Al-Be-Cu Al-Cu

1 + δ γ933 p

3

β (Cu) + γ647 e

max

L + ? β + γ0

1014 U1

l + β γ0

1037 p1

l + γ β900 p

4

1 + (Cu) β863 p

5

β (Cu) + γ618 e

3

L + γ0

β + δ890 U2

L + δ β + γ875 U3

β (Cu) + γ1

+ δ> 490 E1

β + γ (Cu) + δ> 560 U4

β (Cu) + γ1

559 e4

ε1

l + ε2

848 e2

ε1 + γ

1 ε2

850 p6

l + γ0

ε1

958 p2

1 (Cu) + β1032 e

1

L + β + γ0 L + γ

0 + δ

?

L + β + δ γ0

+ β + δ

δ + β + γL + β + γ

871

(Cu) + γ + δ(Cu) + β + δ

(Cu) + γ1

+ δ

Fig. 3b: Al-Be-Cu. Tentative reaction scheme in the Al-rich corner

Al-Be A-B-C

l (Al) + (αBe)

645 e5

Al-Be-Cu

L+(αBe) (Al)+δ640 U5

(αBe) + (Al) + δ

Al-Cu

l (Al) + θ548 e

6

L + (Al) + δ

L + δ (Al) + θ558 U6

L +(αBe) + δ

L +δ+θ

δ + (Al) + θ

111


MSIT®

Al–Be–Cu

20

40

60

40 60 80

20

40

60

Be 70.00Cu 30.00Al 0.00

Cu


Axes: at.%

e4E1490

560

U4

e3

647max.

20

40

60

40 60 80

20

40

60

Be 70.00Cu 30.00Al 0.00

Cu


Axes: at.%

δ875°C U3 871°C (Cu)

β

γ0

890°CU2

γp3 p5

e1

p1

δ

Fig. 5: Al-Be-Cu.

Solid state reactions

comprising γ1+β+δcurve going from U2

to E1 and δ+β+γ curve

going from U3 to U4

Fig. 4: Al-Be-Cu.

Reactions during

solidification

112


MSIT®

Al–Be–Cu

10

10

90

Be 20.00Cu 0.00Al 80.00

Be 0.00Cu 20.00Al 80.00


Axes: at.%

900°C

800°C

700°C

600°C

580°C

560°C

(Al)

θ

640°C

620°C

U6

δ

U5

(αBe)

20

40

60

40 60 80

20

40

60

Be 70.00Cu 30.00Al 0.00

Cu


Axes: at.%

(Cu)(Cu)+β

β

β+γ

β+γ 0

γ0

β+γ 0+δ

β+δ

β+γ+δδ

γ+δ γ

Fig. 6: Al-Be-Cu.

Liquidus surface of

the Al-rich corner

[1946Bad]

Fig. 7: Al-Be-Cu.

Isothermal section of

the Cu-rich corner at

800°C

113


MSIT®

Al–Be–Cu

20

40

60

40 60 80

20

40

60

Be 70.00Cu 30.00Al 0.00

Cu


Axes: at.%

(Cu)(Cu)+γ

(Cu)+β+γ

β

γ1

β+γ1

β+γ1+δγ1+δ

β+δ

δ

γ(C

u)+β

β+γ+δ β+γ

20

40

60

40 60 80

20

40

60

Be 70.00Cu 30.00Al 0.00

Cu


Axes: at.%

γ1

(Cu)+γ1

(Cu)+β+γ1

(Cu)+β

(Cu)

(Cu)+γ(Cu)+δ1

(Cu)+β+δ

β

β+γ1

β+γ1+δβ+δ

δ

γ+δ γ

(Cu)+γ+δ

Fig. 8: Al-Be-Cu.



600°C

Fig. 9: Al-Be-Cu.



500°C

114


MSIT®

Al–Be–Cu

10 20400

500

600

700

800

900

1000

Be 17.90Cu 82.10Al 0.00

Be 15.10Cu 58.00Al 26.90Al, at.%

Tem

pera

ture

, °C

(Cu)+γ+δ1

(Cu)+δ1(Cu)+γ

(Cu)+β+γ

(Cu)+β

L+(Cu)+β

L+(Cu)

L

L+β

L+β+γ' L+γ'

L+γ'+δ1

γ'

β+γ'β

β+γ+δ1

β+δ1

β+γ

(Cu)+β+δ1

(Cu)+γ'+δ1

β+γ'+δ1

γ'+δ1

70 80 90

500

600

700

Be 10.53Cu 29.47Al 60.00

AlAl, at.%

Tem

pera

ture

, °C

660.452°

L+(Al)+δ

(Al) +δ+θ

L+θ+δ

L+δL

L+ (Al)

L+(Al)+δ(Al)+θ

(Al)

Fig. 10: Al-Be-Cu.

Isopleth in the

Cu-rich corner at

constant Be content 3

mass%

Fig. 11: Al-Be-Cu.

Isopleth along

constant mass ratio

Cu:Be = 20:1 (mole

ratio = 2.8:1)

115


MSIT®

Al–Be–Mg

Aluminium – Beryllium – Magnesium

Sybille Stiltz

Literature Data

[1926Kro] investigated eight alloys by metallography and hardness measurements up to 3.21 mass% Be and

1.4 mass% Mg. The alloys were prepared in spinel crucibles, coated with Al2O3. The Al used contained

0.07 mass% Si and about 0.25 mass% Fe. The ingots were aged for 30 min at 550°C or 640°C, quenched in

water and annealed for 48h at 150°C or 170°C, respectively. [1929Mas] studied the Al-rich corner by

thermal and microscopical analysis of 10 alloys with constant Al content of 90 and 80 mass%. Two vertical

sections and a partial liquidus surface were presented. Using the data of [1929Mas], partial isothermal

sections at the ternary eutectic temperature, 449°C, at room temperature [1943Mon] and at a temperature

slightly below 447°C (solid state) [1952Han, 1934Fus] were presented. In the review work of [1952Han]

the Al-rich part of the liquidus surface including the four phase plane at 449°C were shown. Sections of the

Al-Be-Mg system with 0.6, 10, 20, 30 and 50 mass% Be were investigated by thermal, chemical and

microstructural analysis [1966Nag]. The stratification boundaries in the molten state were determined.

Starting materials were 99.99% Al, 99.91% Mg and distilled 99.4% Be. The samples were prepared by

using Al-Be and Al-Mg master alloys. The results of [1966Nag] were cited in the review work of [1966Age]

and [1970Fri]. Mechanical properties such as the modulus of elasticity of Al-Be and Al-Be-Mg alloys were

investigated by [1970Fri]. Hardness values were published by [1926Kro].


knowledge.

Binary Systems

The binary systems Al-Be, presented by [Mas] and Al-Mg by [1981Sch] are accepted and used as boundary

systems.

The equilibrium phase diagram of the Be-Mg system has not yet been determined. A eutectic reaction

l (Mg) + MgBe13 is mentioned [1987Nay]. A sketch of this phase diagram is shown by [1976Mof].

Solid Phases

All stable phases are listed in Table 1.


A ternary eutectic reaction occurs at 449°C [1929Mas, 1952Han] (Table 2). It agrees with the data of

[1966Nag] who determined it at 445 ± 3°C. Beyond this the reaction scheme contains a further tentative,

very probable ternary invariant transition reaction L+Be13Mg +(Be). The invariant reactions of the

binary Al-Mg system lead to degenerate ternary four phase equilibria (Fig. 1).

Liquidus Surface

The liquidus surface (Fig. 2) contains the partially tentative boundary line of the miscibility gap (L1+L2),

reported by [1966Nag]. Its critical point as well as the tie lines are unknown.

Figure 2 shows the ternary eutectic point E and the likewise partially tentative lines of double saturation

according to [1929Mas].

Isothermal Sections

Isothermal sections for the Al-rich part of the system were given by [1943Mon] for room temperature (Fig.

3) and by [1943Mon] and [1952Han] for T ~ 447°C after solidification. The section of [1952Han] is

confined to about 35 mass% Mg and differs only in the homogeneity range of , compared to the isothermal

116


MSIT®

Al–Be–Mg

section at room temperature [1943Mon]. Mondolfo's section for T ~ 447°C extends to about 40 mass% Mg.

In the region 35 to 40 mass% Mg it has to be taken as tentative and is not consistent with the accepted

boundary Al-Mg system [1981Sch].


Two vertical sections, partially tentative, at 90 and 80 mass% Al were presented [1929Mas]. The isopleths

at 80 and 90 mass% Al are consistent with the accepted binary phase diagrams Al-Be [Mas] and Al-Mg

[1981Sch]. The latter isopleth contains a three-phase-field + +(Be), whereas after [1981Sch] does not

occur in this composition range. The liquidus lines had to be lowered by about 30 K respectively at their

start in the boundary Al-Be system (Figs. 4 and 5).

Three temperature-composition cuts for 50, 60 and 0.6 mass% Be were established [1966Nag]. The liquidus

and solidus temperatures are corrected as well with respect to the binary Al-Be system [Mas] (Figs. 6, 7, 8).

References

[1926Kro] Kroll, W., “Age Hardenable Aluminium Alloys” (in German), Metall und Erz, 23, 613-616


[1929Mas] Masing, G., Dahl, O., “Beryllium Containing Aluminium Alloys” (in German), Wiss.

Veröff. Siemens-Konzern, 8, 248-256 (1929) (Equi. Diagram, Experimental, 3)

[1934Fus] Fuss, V., “Metallography of Aluminium and Its Alloys” (in German), Verlag J. Springer,

Berlin, 167-168 (1934) (Equi. Diagram, Review, 1)

[1943Mon] Mondolfo, L.F., “Metallography of Aluminium Alloys”, Wiley & Sons, Inc., New York,

London; Chapman and Hall Ltd., London, 56-57 (1943) (Equi. Diagram, Review, 1)

[1952Han] Hanemann, H., Schrader, A., “Ternary Aluminium Alloys” (in German), in “Atlas

Metallographicus”, Verlag Stahleisen M.B.H., Düsseldorf, Vol. III, part 2, 57-59, Tafel 1

(1952) (Equi. Diagram, Crys. Structure, Experimental, Review, 1)

[1966Age] Ageev, N.V., “Phase Diagrams of Metallic Systems” (in Russian), Moscow, 130-130a

(1966) (Equi. Diagram, Review, 1)

[1966Nag] Nagorskaya, N.D., Gol'denberg, A.E., Novoselova, A.V., Borisova, A.P., Fridlyander, I.N.,

Yatsenko, K.P., “Phase Diagram of Part of the Al-Be-Mg System”, Izv. Akad. Nauk SSSR,

Met., 5, 137-147 (1966) (Equi. Diagram, Crys. Structure, Experimental, 25)

[1968Sam] Samson, S., Gordon, E.K., “The Crystal Structure of -Mg23Al30”, Acta Crystallogr., B24,


[1970Fri] Fridlyander, I.N., Yatsenko, K.P., Nekrasova, G.A., Sandler, V.S., Semenova, Z.G., Gulin,

A.N., “Relationships Between Changes in the Structure and Properties of Beryllium-

Aluminium Alloys”, Met. Sci. Heat Treat., 7, 599-603 (1970), translated from Metall. Term.

Obra. Metallov, 7, 50-55 (1970) (Experimental, 8)

[1976Mof] Moffat, W.G., “Handbook of Binary Phase Diagrams”, Business Growth Services, General

Electric Co., New York , (1976) (Equi. Diagram, Review, #)

[1981Sch] Schürmann, E., Voss, H.-J., “Investigation of the Melting Equilibria of

Magnesium-Lithium-Aluminium Alloys, Part 4, Melting Equilibria of the Binary System

Magnesium- Aluminium” (in German), Giessereiforschung, 33, 43-46 (1981) (Equi.


[1982Mur] Murray, J.L., “The Al-Mg (Aluminium-Magnesium) System”, Bull. Alloy Phase Diagrams,

3, 60-74 (1982) (Equi. Diagram, Review, 112)

[1987Nay] Nayeb-Hashemi, A.A., Clark, J.B., “The Be-Mg (Beryllium-Magnesium) System”, Bull.

Alloy Phase Diagrams, 8, 57-58 (1987) (Equi. Diagram, Review, 25)




117


MSIT®

Al–Be–Mg



Phase/

Temperature Range

[°C]

Pearson Symbol/

Prototype

Lattice Parameters

[pm]

Comments/References

(Be)(h)

1289-1270

cI2

Im3m

W

a = 255.2 at 1260°C [L-B]

(Be)(r)

1270

hP2

P63/mmc

Mg

a = 228.66

c = 358.33

at 22°C [L-B]

, (Mg)

650

hP2

P63/mmc

Mg

a = 320.94

c = 521.03

at 25°C [L-B]

, (Al)

660.5

cF4

Fm3m

Cu

a = 404.96 at 25°C [L-B]

, Mg2Al3< 453

cF1168

Fd3m

Mg2Al3


[2003Luk]

39.4 at.% Mg [L-B, 1981Sch]

and [1982Mur]

, Mg23Al30

450-428

hR159

R3

Mg23Al30

a = 1282.54

c = 2174.78

[1968Sam, 1981Sch]

159 atoms refer to hexagonal unit cell

[2003Luk]

, Mg48Al52

452-410

- - [1981Sch]

, Mg17Al12

460

cI58

I43m

Mn

a = 1048.11

a = 1053.05

a = 1057.91

52.58 at.% Mg [L-B]

56.55 at.% Mg [L-B]

60.49 at.% Mg [L-B]

Be13Mg cF112

Fm3c

NaZn13

a = 1016.6 at room temperature [L-B]

Al-Be-Mg


Al Be Mg

L + + (Be) 449 E L

, (Al)

, Mg2Al3

(Be)

67.86

88.28

60.6

0

0.02

0

0

100

32.12

11.72

39.6

0

118


MSIT®

Al–Be–MgB

e-M

gA

l-M

gA

l-B

eA

l-B

e-M

g

l 1 (B

e) +

l2

1270

e 1

Fig

. 1:

A

l-B

e-M

g.

Rea

ctio

n s

chem

e

l +

γ ξ

452

p2

l 2+

(B

e) B

e 13M

g

950

p1

l 2 δ

+ B

e 13M

g

650

e 2

l +

ξ ε

450

p3

1100 (

c 1)

l α

+ β

450

e 4

l β

+ ε

448

e 5

l γ

+ δ

438

e 6

ε β

+ ξ

428

e 7

ε β

+ γ

410

e 8

L

γ, B

e 13M

g

463

d1

l 2 α

+ (B

e)

644

e 3

L +

Be 13

Mg

γ +

(B

e)?

U

γ +

(B

e) +

Be 13

Mg

L +

γξ,

(B

e)452

D1

L +

ξε,

(B

e)450

D2

Lε

+ β,

(B

e)448

D3

Lδ

+ γ

+ B

e 13M

g435

E2

γ +

δ +

Be 13

Mg

L +

γ +

(B

e)

ξ +

ε +

(Be)L

+ ξ

+ (B

e)

L +

ε +

(B

e)

ξγ

+ ε,

(B

e)428

D4

εβ

+ γ,

(B

e)410

D5

β +

γ +

(Βe)

γ +

ε +

(Be)

β +

ε +

(Be)

Lα

+ β

+ (B

e)449

E1

α +

β +

(Βe)

L

β, (

Be)

451

d2

ξ +

γ +

(B

e)

119


MSIT®

Al–Be–Mg

20

40

60

80

20 40 60 80

20

40

60

80

Be Mg


Axes: at.%

E1

p3p2

e3

e4

e4

e5

e1

L1+L2

(Be)

α

β

Fig. 2: Al-Be-Mg.

Liquidus surface

20

40

60

80

20 40 60 80

20

40

60

80

Be Mg


Axes: at.%

β + γ + (Be)

β + (Be)

α + β + (Be)

α + (Be)

Fig. 3: Al-Be-Mg.


the Al-corner at room

temperature after

[1943Mon]

120


MSIT®

Al–Be–Mg

10 20300

400

500

600

700

800

900

1000

1100

Be 0.00Mg 10.97Al 89.03

Be 24.96Mg 0.00Al 75.04Be, at.%

Tem

pera

ture

, °C

α+(Be)

α

508°C

α+(Be)+Lα+L

605°C

(Be)+L

L

1006°C

10 20300

400

500

600

700

800

900

1000

1100

Be 42.82Mg 0.00Al 57.18

Be 0.00Mg 21.70Al 78.29Mg, at.%

Tem

pera

ture

, °C

α+β+(Be)

α+(Be)

α+(Be)+L L+α

540°C

644°C

(Be)+L

L

449

Fig. 4: Al-Be-Mg.

Vertical section at 90

mass% Al

[1929Mas]

Fig. 5: Al-Be-Mg.

Vertical section at 80

mass% Al; after

[1929Mas]

121


MSIT®

Al–Be–Mg

40 50

500

750

1000

1250

Be 41.82Mg 23.26Al 34.92

Be 42.81Mg 0.00Al 57.19Al, at.%

Tem

pera

ture

, °C

α+β+(Be)α+(Be)

644°C

L+(Be)

1100°C

L1+L2+(Be)

L1+L2L

449

20400

500

600

700

800

900

1000

1100

1200

1300

Be 74.14Mg 11.01Al 14.85

Be 74.96Mg 0.00Al 25.04Al, at.%

Tem

pera

ture

, °C

α+β+(Be)α+(Be)

L+(Be)

644°C

L1+L2+(Be) k'

LL1+L2

1150°C

449

Fig. 7: Al-Be-Mg.

Partial vertical

section at 20 mass%

Be; after [1966Nag]

Fig. 6: Al-Be-Mg.

Partial vertical

section at 50 mass%

Be; after [1966Nag]

122


MSIT®

Al–Be–Mg

60 70 80 90400

500

600

700

Be 1.70Mg 42.05Al 56.25

Be 1.78Mg 0.00Al 98.22Al, at.%

Tem

pera

ture

, °C

α+β+(Be)

α+(Be)

L+α+(Be)

L+α

L

650°C644°C

449

Fig. 8: Al-Be-Mg.

Partial vertical

section at 0.6 mass%

Be; after [1966Nag]

123


MSIT®

Al–C–Fe

Aluminium – Carbon – Iron

Gautam Ghosh

Literature Data

After preliminary investigations [1930Kei, 1931Soe] the first detailed studies of the iron corner of the

system were reported by [1934Mor, 1936Vog] and [1938Loe]. The system was reinvestigated later by

[1968Nis, 1969Loe, 1980Gor1] and [1980Gor2]. For studying the Fe-rich side [1968Nis] prepared 24

ternary alloys using electrolytic Fe, graphite (99.8% C) and Al (99.99%) in an argon atmosphere. As C does

not dissolve in liquid Al-Fe alloys [1936Vog, 1938Loe] and [1968Nis], the ternary alloys were always

prepared by adding Al to liquid C-Fe alloys. They were isothermally annealed between 1000 and 1250°C

over a period of 1.5 to 6h in an argon atmosphere. Then the samples were quenched in iced brine and

examined by means of X-ray diffraction, metallography and hardness measurements. Using thermodynamic

data from [1987Yok] liquidus curves were calculated which agree fairly well with the values measured at

1600°C [1955Chi, 1963Mor]. [1986Sch] investigated the iron rich part of the liquidus surface by isothermal

saturation of melts and by thermal analysis. [1987Sch] calculated the surfaces of primary crystallization of

Fe, Fe and graphite.

[1989Ode] investigated the ternary system in the temperature range of 1500 to 2300°C. He reported

isothermal sections of the entire system and also the solubility of C in two Al-Fe liquid alloys. Using 99.99

mass% Fe, [1989Ode] prepared several binary Al-Fe alloys, which were equilibrated in graphite crucibles,

heated in a graphite resistance furnace above atmospheric pressure of high purity Ar. Isothermal sections

were constructed from the chemical analyses and metallographic observations.

These results were assessed by [1987Rag], [1990Gho] and [1993Rag].

Recently, [1995Pal] reinvestigated the phase equilibria of the Fe-corner and reported the liquidus surface,

three isothermal sections and three temperature-composition sections. [1995Pal] used 99.99% Al, 99.97%

Fe and graphite. They prepared 50 ternary alloys by arc melting. The alloys were equilibrated at 1200 (24

or 2 h), 1000 (50h) and 800°C (240h) and water quenched. The microstructure and phases were

characterized by EPMA, SEM and XRD.

The effect of pressure on the phase equilibria has been studied by [1978Kam, 1992Put]. [1996Koc]

presented a review of the effect of pressure on the Al-C-Fe phase equilibria. [1978Kam] determined the

liquid/solid equilibria of Fe-rich alloys up to 10 GPa. [1992Put] quenched ternary alloys from 1527 to 25°C

at a pressure of 6 GPa. They determined the solid-state phase equilibria using metallography, microprobe

and XRD techniques.

All these results have been reviewed by [1987Rag, 1993Rag, 2002Rag]. Raghvan [2002Rag] has provided

an update summerizing these results.

Binary Systems

The Al-C binary is accepted from [2003Per]. Both liquid and solid solubilities of C in Al are very limited

and the only reported compound in this system is Al4C3. The Al-Fe binary is accepted from [2003Pis]. The

C-Fe binary is adopted from [1982Kub]. Since Al is a graphite stabilizer the stable form (graphite) of the

C-Fe diagram is accepted here.

Solid Phases

The known solid phases are listed in Table 1. So far only one ternary phase Fe3AlCx( ) has been reported

[1934Mor, 1938Loe, 1958Hue, 1961Hen, 1962Mas, 1964Bae, 1964Pal, 1968Nis, 1971Kuc, 1973Nud,

1975Ver, 1976Pog]. Structurally, Fe and Al form an AuCu3-type superlattice in which C atoms occupy

interstitial positions. The x in the formula Fe3AlCx can vary from 0.5 to 1.0. [1985Cho] reported the

variation of lattice parameter as a function of x: a = 366.26±0.33+0.59x, in pm. However, to account for the

atom distributions and deviation from stoichiometry the formula Fe4-yAlyCx has been suggested [1985And]

124


MSIT®

Al–C–Fe

for the phase. [1985And] did not report the ranges for x and y. Adopting this formula, [1995Pal] reported

the composition dependence of lattice parameter of as: a = 362.5+0.14 (at.% Al)+0.72 (at.% C), in pm.

This empirical relationship is valid in the composition range between Fe3.2Al0.8C0.71 and Fe2.8Al1.2C0.42.

The data of [1983Lys] also confirm the increase in lattice with Al content in phase.


Figure 1 shows the partial reaction scheme based on the experimental results for the Fe-rich alloys

[1995Pal]. However, [1993Rag] presented a complete reaction scheme based on the thermodynamic

calculations of [1991Kum].

The invariant temperatures for U1, U2 and U3 reactions differ by less than 20°C compared with earlier

results [1938Loe, 1969Loe, 1985Gor, 1986Sch]. Within the composition range studied by [1969Loe], the

solidification was not complete, and the complete path starting from the U2 reaction is not known. The

temperature of the U4 reaction is 825°C [1995Pal] which higher than 780°C reported by [1980Gor2]. The

temperature of the three-phase peritectic reaction p2 is 1410°C [1995Pal], and the temperature of the

three-phase eutectic reaction e1 is 1335°C [1995Pal] which is much lower than 1410°C suggested by

[1986Sch]. The compositions of the phases [1995Pal] participating in the invariant reactions are listed in

Table 2. The predicted invariant temperatures [1991Kum], based on thermodynamic modeling, for U1, U2,

U3 and U4 reactions agree within 5°C of the experimental values reported by [1995Pal].

Liquidus Surface

Figure 2 shows the liquidus surface and the extent of the fields of primary crystallization of the phases ,

, and graphite [1995Pal]. They observed significant differences in compositions of phases participating

in the invariant equilibria, particularly , , and , compared with earlier results [1938Loe, 1969Loe,

1980Gor1]. The liquidus surfaces of both [1936Vog, 1980Gor1] were rejected. [1936Vog] assumed that the

double carbide reported by [1934Mor] was a ternary solid solution of the high temperature phase of the

Al-Fe system. [1980Gor1] presented the liquidus surface as Al-C-Fe containing both graphite and

cementite. However, here we accept the stable form of the C-Fe diagram. With the addition of Al to the

binary C-Fe alloys, the temperature of the graphite eutectic reaction increases [1930Kei, 1931Soe, 1938Loe,

1977Car, 1988Mag] and the eutectic carbon content decreases up to the addition of about 10 mass% Al.

Isothermal Sections

Figures 3, 4, 5 show isothermal sections of the Al-C-Fe system at 2000°C, 1850°C and 1700°C respectively

after [1989Ode]. Isothermal sections of the Fe-rich corner have been investigated several times [1934Mor,

1936Vog, 1938Loe, 1959Vyk, 1968Nis] and [1995Pal]. Three isotherms at 1200, 1000, and 800°C reported

by [1995Pal] are shown in Figs. 6, 7 and 8, respectively. [1968Nis] reported isothermal sections at 1250,

1200, 1100 and 1000°C. The results of [1968Nis] and [1995Pal] essentially agree very well in terms of the

topology of the phase fields. However, the main differences between these two sets of results are that

[1995Pal] reported higher Al solubility in , higher C solubility in , and larger homogeneity range of the

phase. The isothermal section determined by [1934Mor] is essentially the same as [1968Nis] except for

the extents of the ( + ), ( + +graphite) and ( + + ) regions. As aluminum is a graphitizing element, the

fraction of graphite formation increases with the addition of aluminum, giving a maximum at about 4

mass% Al and then decreases to about zero at 10 mass% Al. The double carbide Fe3AlCx appears in the

composition range of about 10-17 mass% Al. Beyond 17 mass% Al, graphite again dominates the phase

equilibria. As shown in Figs. 6, 7 and 8 with increasing temperature the homogeneity range of increases.


[1936Vog] determined several isopleths at 2, 7, 10, 13 and 20 mass% Al and at 0.5, 1.0, 1.4, 2.0 and 2.7

mass% C. [1938Loe] reported the vertical sections at 0.5, 7, 10 and 15 mass% Al and 0.4, 0.7, 1.1 and 2.2

mass% C. [1967Ken] determined a vertical section at 0.3 mass% C.

125


MSIT®

Al–C–Fe

[1995Pal] reported three vertical sections at 5, 10.5 and 23 at.% C. These are shown in Figs. 9, 10 and 11,

respectively.

Thermodynamics

Thermodynamics of ternary Al-C-Fe alloys have been reported by [1955Chi, 1963Mor, 1973Rim, 1974Sig,

1977Cho, 1983Jan, 1983Vre, 1987Yok] and [1991Kum]. Among these, the thermodynamic modeling of

[1991Kum] is the most comprehensive. Aluminum increases the activity of C in liquid iron. [1978Zhu,

1979Zhu] provided the thermodynamic explanations of the composition dependence of the graphitizing

power of Al in ternary alloys.

[1987Yok] calculated isothermal sections at 2027 and 1600°C. On the other hand, [1991Kum] calculated

eight isothermal sections at 2000, 1850, 1700, 1300, 1200, 1100 and 800°C, and also presented a complete

reaction scheme.


The atomic and magnetic structures of the phase have been discussed by several authors [1985And,

1994Mor, 1994Oda, 1995Fuj, 1998Iva]. The latter authors found that the stoichiometric Fe3AlC is

paramagnetic while non-stoichiometric Fe3AlC0.64 is ferromagnetic with Tc = 210°C. The magnetic

moment of Fe is determined primarily by the nearest neighbour C atoms. Quantum-mechanical calculations

show that the transition from para to ferromagnetic state, with increasing Al content, is caused by the charge

transfer and p-d hybridization [1994Mor].

[1989Jun] and [1997San] investigated the strength, ductility and creep of Fe3AlCx alloys. These were either

single phase, duplex and three-phase microstructures containing ( Fe) and/or graphite phase. The strength

and ductility were sensitive to microstructure. [1989Jun] found that the creep exponent is 4.4 ± 1.1, and

activation energy is 355 kJ mol-1 for single phase , 365 kJ mol-1 for +graphite microstructure, 244

kJ mol-1 for +( Fe) microstructure, and 365 kJ mol-1 for +( Fe)+graphite microstructure. On the other

hand, [1997San] reported that in Fe3AlCx (0.3 x 0.8) alloys the stress exponent for creep is 3 and

activation energy lies between 250 to 320 kJ mol-1.

The hardening, softening, tensile and compressive properties of B2 alloys [2001Mun, 2001Oca, 2001Rad,

2002Bal]. The hardening and softening of the B2 phase have been attributed to the precipitation of

Fe3AlC0.5 and graphite, respectively.

[1991Jia] investigated the shape memory behavior in an Fe-7Al-2C (at.%) alloy. They found that the shape

memory effect is restricted by the alloy brittleness and precipitation of carbide. The precipitation of phase

during aging of martensite has also been reported by [1982Suy] and [1983Lys].

Miscellaneous

[1989Ode] reported the solubility of C in liquid Fe-12.5Al (at.%) and Fe-25.0Al (at.%) alloys over an

extended temperature range. The C solubility can be expressed as:

In Fe-12.5 at.% Al:

C = - 0.55067+0.01112 T (in °C)

In Fe-25.0 at.% Al:

C = - 8.46728+0.01373 T (in °C)

The solid solubility of C in Al-Fe ferrite has been measured by [1966Jae]. Whose results, in the temperature

range of 548 to 723°C and up to 2.1 mass% Al, can be described by the empirical equation:

log (mass% C) = - 2200/T+0.0675 (mass% Al)+0.52,

where T is in K.

Using single crystals, [1995Pal] investigated the effect of C on the order-disorder transition temperature

involving ( Fe) and B2 phases. Their results are shown in Fig. 12. It is obvious that at a constant Al content,

C increases the order-disorder temperature. This was attributed to the fact that in B2 structure six Fe atoms

create favorable sites for the C atoms.

126


MSIT®

Al–C–Fe

[1978Kam] reported that under high pressure, cementite is stabilized despite the presence of significant

quantity of graphitizing elements. Also, under high pressure the primary crystallization products of liquid

Fe-rich ternary alloys were reported to be austenite, graphite, cementite and diamond.

Figure 13 shows the 25°C isothermal section at pressure of 6 GPa. An important feature to be noted that in

addition to the binary phases at ambient pressure, high pressure phases FeAl6, Fe7C3 and diamond.

[1991Sar] investigated the microstructure of Fe-(8 to 10) wt.% Al-(1.8 to 2.4) wt.% C alloys by melt

spinning and levitation melting. They found the melt spun alloys yielded + ’(L12) microstructure while

levitation melting always yielded + +Fe3C microstructure.

Fe-rich alloys containing Al and C undergoes martensitic transformation [1986And]. One particular feature

of Al-C-Fe martensite that has receive numerous attention is the abnormally high tetragonality [1972Lys,

1980Dra, 1980Lys, 1981Koz, 1981Lys, 1986Lys, 1986Pro1, 1986Pro2, 1992Ueh]. The abnormal

tetragonality has been attributed to the presence of short-range order, nanoscale fcc ordered (L12) domains

and the elastic strain fields around them.

References

[1930Kei] Keil, O.V., Jungwirth, O., “Contribution to the Knowledge of Fe-Al-C Alloys” (in German),

Arch. Eissenhuettenwes., 4, 221-224 (1930) (Equi. Diagram, Experimental, 8)

[1931Soe] Soehnenchen, E., Piwowarsky, E., “The Influence of the Alloy Elements Ni, Si, Al and P on

the Solubility of C in Liquid and Solid Fe” (in German), Arch. Eissenhuettenwes., 5,

111-120 (1931) (Experimental, 49)

[1934Mor] Morral, F.R., “The Constitution of Iron-Rich Iron-Aluminium-Carbon Alloys”, J. Iron Steel

Inst., London, 130, 419-428 (1934) (Equi. Diagram, Experimental, #, *, 45)

[1936Vog] Vogel, R., Mäder, H., “The Fe-Al-C System” (in German), Arch. Eissenhuettenwes., 9,


[1938Loe] Loehberg, K., Schmidt, W., “The Fe Corner of the Fe-Al-C System” (in German), Arch.

Eissenhuettenwes., 11, 607-614 (1938) (Equi. Diagram, Experimental, #, *, 16)

[1955Chi] Chipman, J., Floridis, T.P., “Activity of Al in Liquid Ag-Al, Fe-Al, Fe-Al-C and Fe-Al-C-Si

Alloys”, Acta Metall., 3, 456-459 (1955) (Experimental, Thermodyn., 8)

[1958Hue] Huetter, L.J., Stadelmaier, H.H., “Ternary Carbides of Transition Metals with Aluminium

and Magnesium”, Acta Metall., 6, 367-370 (1958) (Crys. Structure, Review, 6)

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Alpha Solid Solution” (in Czech), Hutn. Listy, 14, 118-127 (1959) (Equi. Diagram,


[1961Hen] Henry, J.M., Baker, J.M., Bellot, J., Bogot, R., Herzog, E., “The Formation of Aluminium

Carbides in Alloy Steels and Their Effects on the Mechanical Properties”, Mem. Sci. Rev.

Met., 58, 117-128 (1961) (Experimental, Mechan. Prop., 12)

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Fiz. Metall. Metalloved., 14, 633-635 (1962) (Experimental, Mechan. Prop., 12)

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the Solubility of Graphite in Liquid Iron”, Mem. Fac. Eng. Kyoto Imp. Univ., 25, 83-105


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Cementite and Ferrite in Steels”, Mem. Sci. Rev. Metall., 61, 865-892 (1964) (Experimental,

35)

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Alloys”, Sov. Phys.-Crystallogr., (Engl. Transl.), 9, 163-165 (1964), translated from

Krystallografiya, 9, 209-212 (1964) (Crys. Structure, Experimental, 9)

[1966Jae] Jaeniche, W., Brauner, J., Heller, W., “Effect of Aluminium on the Damping Curve and

Solubility of Carbon in Iron”, Arch. Eissenhuettenwes., 37, 719-728 (1966)

(Experimental)

127


MSIT®

Al–C–Fe

[1967Ken] Kenford, A.S., Rance, V.E., Turner, S., “Constitution, T-T-T Characteristics and

Hardenability of a 0.3% Steel with Al Additions up to 2.45%”, J. Iron Steel Inst., London,

205, 665-667 (1967) (Experimental, #, 11)

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the Fe-C-Al System” (in German), Giessereiforschung, 21, 171-173 (1969) (Equi. Diagram,


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Containing 6.43% C”, (in French), Compt. Rend. Acad. Sci. Paris, Ser. C, 272C, 898-901


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Three- and Multicomponent Systems” (in German), Thesis, Tech. Univ. Clausthal, (1973)

(Experimental, 40)

[1974Sig] Sigworth,G.K., Elliot, J.F., “Thermodynamics of Liquid Dilute Iron Alloys”, Met. Sci., 8,

298-310 (1974) (Thermodyn., 249)

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Iron-Aluminium and Ternary Iron-Aluminium-Carbon Alloys by use of the Mössbauer

Effect” (in Russian), Proc. 5th Int. Conf. Mössbauer Spectroscopy, 1973, Hucl, M., Zemcik,

T. (Eds.), Nuclear Int. Centre, Prague, 314-317 (1975) (Crys. Structure, Experimental, 7)

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Russian), Metall. Koksokhimiya Resp. Mezhaved. Nauk.-Tekhn. Sb., (49), 24-28 (1976)

(Experimental, 1)

[1977Car] Carlberg, T., Fredriksson, H., “Influence of Silicon and Aluminium on the Solidification of

Cast Iron”, Int. Conf. Solidification Casting, Sheffield, Vol. 1, Metals Society, London,

115-124 (1977) (Experimental, #, 19)

[1977Cho] Choudary, U.V., Belton, G.R., “Activities of Carbon- Saturated in Fe-Al Alloys and

Stability of Al4C3 at 1873 K”, Metall. Trans. B, 8B, 531-534 (1977) (Experimental,

Thermodyn., 23)

[1978Kam] Kamenetskaya, D.S., Korsunskaya, I.A., Litvin, Y.A., “The Effect of Graphitizing Elements

on the Equilibria with the Melt in the Iron-Carbon System Under High Pressure”, Phys. Met.

Metallogr., 45, 101-111 (1979), translated from Fiz. Metall. Metalloved., 45, 569-579

(1978) (Equi. Diagram, Experimental, Thermodyn. *, 27)

[1978Zhu] Zhukov, A.A., “The Geometric Thermodynamics of Iron-Carbon Alloys Alloyed with

Graphitizing Elements”, Izv. Akad. Nauk SSSR, Met., (5), 210-218 (1978) (Thermodyn., 8)

[1979Zhu] Zhukov, A.A., “Thermodynamics of Structure Formation in Cast Iron Alloyed with

Graphitizing Elements”, Met. Forum, 2, 127-136 (1979) (Experimental, Thermodyn., 13)

[1980Dra] Drachinskaya, A.G., Lysak, L.I., Storchak, N.A., “Role of Mn and Al in Alterning the

Crystalline Structure of Martensite Heated in the Low-Temperature Range”, Phys. Met.

Metallogr., 47, 80-86 (1980) (Crys. Structure, Experimental, 22)

[1980Gor1] Gorev, K.V., Gurinovich, V.I., “The Diagram of State of Fe-Al-C Alloys with a Low

Content of Aluminium”, Vest. Akad. Navuk B. SSR (Fiz.-Tekh.) Navuk, (4), 26-30 (1980)


[1980Gor2] Gorev, K.V., Gurinovich, V.I., Topalov, Yu.F., “Phase Composition and Structure of Iron

Alloys with Carbon and Aluminium Adjacent to the Iron Corner”, Vest. Akad. Navuk B. SSR

(Fiz.-Tekh.) Navuk, (3), 27-34 (1980) (Experimental, 7)

128


MSIT®

Al–C–Fe

[1980Lys] Lysak, L.I., Drachinskaya, A. G., Andryushchenko, V.A., “On the Nature of the

Abnormally High Tetragonality of the Martensite Lattice of Fe-Al-C Alloys”, Russ. Metall.,


[1981Koz] Kozlova, O.S., Makarov, V.A., “Mössbauer Study of the Austenite of Alloy Fe-Al-C”,

Phys. Met. Metallogr., 48, 63-67 (1981) (Crys. Structure, Experimental, 17)

[1981Lys] Lysak, L.I., Drachinskaya, A.G., Andryushchenko, V.A., Bogaichuk, I.L., “The Role of

Aluminium and Carbon in the Formation of the Anomalous Tetragonality of the

-Martensite of Fe-Al-C” (in Russian), Fiz. Met. Metalloved., 52(5), 1068-1073 (1981)


[1982Kub] Kubaschewski, O., “Iron-Aluminium and Iron-Carbon”, Iron - Binary Phase Diagrams,

Springer Verlag, Berlin, 5-9, 23-31 (1982) (Equi. Diagram, Review, #, 26, 21)

[1982Suy] Suyazov A.V., Usikov, M.P., “Structure Transformations of High-Carbon Aluminium

Steels During Tempering”, Phys. Met. Metallogr., 54(1), 109-117 (1982) (Crys. Structure,

Experimental, 21)

[1983Jan] Janas, M., Mamro, M., Ludinikowski S., Jowsa, J., “Carbon Solubility in Fe-Cmax-Al,

Fe-Cmax-Co, Fe-Cmax-Cu Alloys”, Metal. Odlew., 9, 99-118 (1983) (Experimental, 10)

[1983Lys] Lysak, L.I., Drachinskaya, A.G., Andryushchenko, V.A., “Influence of the Chemical

Composition of Alloy Fe-Al-C on Formation of an Ordered Carbide Phase”, Phys. Met.

Metallogr., 56(3), 183-185 (1983) (Experimental, 5)

[1983Vre] Vrestal, J., Pokorna, A., “Effects of Aluminium on the Thermodynamic Activity of Carbon

in Iron” (in Czech), Kovove Mater., 21, 223-227 (1983) (Experimental, Thermodyn., 11)

[1985And] Andryushchenko, V.A., Gavrilyuk, V.G., Nadutov, V.M., “Atomic and Magnetic Ordering

in the -Phase of Fe-Al-C Alloys”, Phys. Met. Metallogr., 60(4), 50-55 (1985) (Crys.


[1985Cho] Cho W.K., Han, K.H., “Phase Constitution and Lattice Parameter Relationships in Rapidly

Solidified (Fe0.65Mn0.35)0.83Al0.17-xC and Fe3Al1-xC Pseudobinary Alloys”, Metall. Trans.

A, 16A, 5-10 (1985) (Crys. Structure, Experimental, *, 14)

[1985Gor] Gorev K.V., Gurinovich, V.I., “The Stable Phase Diagram of Fe-C-Al Alloys in the

Iron-Rich Region” (in Russian), in “Stable and Metastable Phase Equilibria in Metallic

Systems”, Nauka Moscow, 119-124 (1985) (Equi. Diagram, Experimental, #, 6)

[1986And] Andrushchenko V.A., Lysak, L.I., “Two Stage Kinetics of the Martensitic Transformation

in Alloy Fe-Al-C”, Phys. Met. Metallogr., 61(1), 92-97 (1986) (Crys. Structure,

Experimental, 9)

[1986Lys] Lysak, L.I., Drachinskaya, A.G., Andryushchenko, V.A., “Influence of Atomic Ordering on

the Phase and Structural Changes in High-Carbon Alloys of the Fe-Al-C System”, Met. Sci.

Heat Treat. (USSR), (7), 485-487 (1986), translated from Metalloved. Term. Obrab. Met.,

(7), 20-21 (1986) (Crys. Structure, Experimental, 6)

[1986Pro1] Prokoshkin, S.D., Kaputkina, L.M., Bernshtein, M.L., Moszhukhin, V.E., Andreeva,S.A.,

“The Structure of Martensite During Cluster Formation and Two-Phase Decomposition”,

Acta Metall., 34(1), 177-186 (1986) (Crys. Structure, Experimental, 29)

[1986Pro2] Prokoshkin, S. D., Kaputkina, L. M., Bernshtein, M. L., “The Mechanism of

Low-Temperature Lattice Changes of Martensite with Abnormal Tetragonality. Part 2.

Martensite with Abnormally High Tetragonality”, Scr. Metall., 20, 299-304 (1986) (Crys.


[1986Sch] Schürmann, E., Schweinichen, J.V., “Investigation of the Liquidus Equilibria of Iron Rich

Carbon Containing Ternary Systems Fe-C-X with X = Al, Cu, Ni and Cr” (in German),

Giessereiforschung, 38, 125-132 (1986) (Review, Equi. Diagram, Experimental, 63)

[1987Rag] Raghavan, V., “The Al-C-Fe (Aluminium-Carbon-Iron) System” in “Phase Diagrams of

Ternary Iron Alloys. Part I”, ASM International, Metals Park, OH, 89-97 (1987) (Equi.

Diagram, Review, 30)

[1987Sch] Schürmann, E., Schweinichen, J.V., Völker R., Fischer, H., “Calculation of the / resp.

Liquidus Surfaces of Iron and the Liquidus Surface of Carbon as well as the Lines of Double

129


MSIT®

Al–C–Fe

Saturation in Iron Rich Carbon Containing Ternary and Higher Systems Fe-C-X1-X2” (in

German), Giessereiforsch., 39, 104-113 (1987) (Review, Equi. Diagram, Thermodyn., 19)

[1987Yok] Yokokawa, H. Fujishige, M., Ujie, S., Dakiya, M., “Phase Relations Associated with the

Aluminum Blast Furnace: Aluminum Oxycarbide Melts and Al-C-X (X=Fe,Si) Liquid

Alloys”, Metall. Trans. B, 18B, 433-444 (1987) (Review, Thermodyn., 74)

[1988Mag] Magnin, P., Kurz, W., “ Stable and Metastable Eutectic Temperatures of Fe-C with Small

Additions of a Third Element”, Z. Metallkd., 79, 282-284 (1988) (Experimental, 5)

[1989Jun] Jung, I., Sauthoff, G., “High-Temperature Deformation Behavior of the Perovskite-type

Phases Fe3AlC and Ni3AlC”, Z. Metallkd., 80, 490-496 (1989) (Experimental, 45)

[1989Ode] Oden, L.L., “Phase Equilibria in the Al-Fe-C System: Isothermal Sections 1500°C to

2300°C”, Metall. Trans. A, 20A, 2703-2706 (1989) (Experimental, Equi. Diagram, #, *, 12)

[1990Gho] Ghosh, G., “Al-C-Fe (Aluminium-Carbon-Iron)”, MSIT Ternary Evaluation Program, in


GmbH, Stuttgart; Document ID: 10.13509.1.20 (1990) (Equi. Diagram, Review, 40)

[1991Jia] Jian, L., Wayman, C.M., “Assessment Fe-7Al-2C as a Shape Memory Alloy”, Scr. Metall.

Mater., 25(11), 2435-2440 (1991) (Experimental, 13)

[1991Kum] Kumar K.C.H., Raghavan, V., “A Thermodynamic Analysis of the Al-C-Fe System”,

J. Phase Equilib., 12(3), 275-286 (1991) (Equi. Diagram, *, 32)

[1991Sar] Sarreal, J.A., Koch, C.C., “Metastable Microstructures of Rapidly Solidified and

Undercooled Fe-Al-C and Fe-(Ni, Mn)-Al-C Alloys”, Mater. Sci. Eng. A, 136, 141-149

(1991) (Crys. Structure, Equi. Diagram, Experimental, 12)

[1992Put] Putyatin, A.A., Davydov, V.E., Nesterenko, S.N., “High Temperature Interactions in the

Fe-Al-C System at 6 GPa Pressure”, J. Alloy. Compd., 179(1-2), 165-175 (1992) (Equi.


[1992Ueh] Uehara, S., Kajiwara, S., Kikuchi, T., “Origin of Abnormally Large Tetragonality of

Martensite in High Carbon Iron Alloys Containing Aluminum”, Mater. Trans., JIM, 33(3),


[1993Rag] Raghavan, V., “Al-C-Fe (Aluminum-Carbon-Iron)”, J. Phase Equilib., 14(5), 615-616


[1994Mor] Moravetski, V.I., Andryushchenko, V.A., Sheludchenko, L.M., “Computer Simulation of

the Electronic Structure of the Fe(4-y)Al(y)C Carbide Phase in its Para- and Ferromagnetic

States”, J. Phys. Chem. Solids, 55(2), 195-200 (1994) (Crys. Structure, Theory, 9)

[1994Oda] Oda, K., Fujimura, H., Ino, H., “Local Interactions in Carbon-Carbon and Carbon-M (M:

Al, Mn, Ni) Atomic Pairs in FCC -Iron”, J. Phys., Condens. Matter, 6, 679-692 (1994)

(Experimental, 32)

[1995Fuj] Fujimura, H., Ino, H., “Ordering of -Phase and Formation of -Phase in Melt-Quenched

Fe-Al-C Alloys and Treir Magnetic Structures” (in Japanese), J. Jpn. Inst. Met., 59(7),

686-693 (1995) (Crys. Structure, Equi. Diagram, Moessbauer, 29)

[1995Pal] Palm, M., Inden, G., “Experimental Determination of Phase Equilibria in the Fe-Al-C

System”, Intermetallics, 3, 443-454 (1995) (Equi. Diagram, Experimental, #, *, 33)

[1996Koc] Kocherzhinski, Yu.A., Kulik, O.G., “Equilibrium Phase Diagrams and Manufacture of

Synthetic Diamond”, Powder Metall. Met. Ceram., 35(7-8), 470-483 (1996) (Equi.


[1997San] Sanders, W., Sauthoff, G., “Deformation Behaviour of Perovskite-type Phases in the

System Fe-Ni-Al-C. I: Strength and Ductility of Ni3AlCx and Fe3AlCx Alloys with Various

Microstructures”, Intermetallics, 5, 361-375 (1997) (Equi. Diagram, Experimental, 57)

[1998Iva] Ivanovskii, A.L., Sabiryanov, R.F., Skazkin, A.N., “Band Structure and Magnetic

Properties of M3M’C Antiperovskites (M=Mn, Fe; M’= Zn, Al, Ga, Sn)”, Phys. Solid State,

40(9), 1516-1519 (40) (Calculation, 16)

[2001Mun] Munitz, A., Fields, R.J., “Mechanical Properties of Hot Isostatically Pressed Nanograin Iron

and Iron Alloy Powder”, Powder Met., 44(2), 139-147 (2001) (Crys. Structure,

Experimental, Mechan. Prop., 14)

130


MSIT®

Al–C–Fe

[2001Oca] Oca, C.G., Morris, D.G., Munoz-Morris, M.A., “The Role of Carbon and Vacancies in the

Quench Hardning and Age Softening of a Fe-40Al-C Alloy”, Scr. Mater., 44(4), 561-568

(2001) (Experimental, Mechan. Prop., 14)

[2001Rad] Radhakrishna, A., Baligidad, R.G. Sarma, D.S., “Effect of Carbon on Structure and

Properties of FeAl Based Intermetallic Alloy”, Scr. Mater., 45(9), 1077-1082 (2001) (Crys.

Structure, Experimental, Mechan. Prop., 18)

[2002Bal] Baligidad, R.G., Radhakrishna, A., “Effect of B, Zr, Ce and Nb Addition on Structure and

Mechanical Properties of High Carbon Fe-10.5 wt% Al Alloy”, J. Mater. Sci. Lett., 21(16),

1231-1235 (2002) (Experimental, Mechan. Prop., 17)

[2002Rag] Raghavan, V., “Al-C-Fe (Aluminum-Carbon-Iron)”, J. Phase Equilib., 23 (6), 508-510


[2003Per] Perrot, P., “Al-C (Aluminium -Carbon)”, MSIT Binary Evaluation Program, in MSIT


Stuttgart, to be published, (2003) (Equi. Diagram, Review, 19)

[2003Pis] Pisch, A., “Al-Fe (Aluminum-Iron)” MSIT Binary Evaluation Program, in MSIT


Stuttgart; to be published, (2003) (Equi. Diagram, Review, 58)


Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

(Al) cF4

Fm3m

Cu

a = 404.88 Pure Al at 24°C

[V-C]

(C) hP4

P63/mmc

C (graphite)

a = 246.4

c = 671.1

[V-C]

, ( Fe)(h2) cI2

Im3m

W

a = 293.78 pure Fe at 1480°C

[V-C]

, ( Fe)(h1) cF4

Fm3m

Cu

a = 366.60 pure Fe at 1167°C

[V-C]

, ( Fe)(r) cI2

Im3m

W

a = 286.65 pure Fe at 20°C

[V-C]

Al4C3 hR7

R3m

Al4C3

a = 855.0

= 22.28°

[V-C]

1, Fe3Al

552

cF16

Fm3m

BiF3

a = 579.23 [V-C]

Solid solubility ranges from 22.5 to 36.5

at.% Al

2, FeAl

1310

cP2

Im3m

CsCl

a = 290.9 [V-C]

Solid solubility ranges from 22 to 54.5

at.% Al

131


MSIT®

Al–C–Fe


, Fe2Al31215-1092

cI16 [1982Kub]; Solid solubility ranges from

54.5 to 62.5 at.% Al

, FeAl2 1154

aP18

P1

FeAl2

a = 487.8

b = 646.1

c = 880.0

= 91.75°

= 73.27°

= 96.89°

[V-C]

Solid solubility ranges from 65.5 to 67

at.% Al

, Fe2Al5 1171

oC56

Cmcm

a = 767.5

b = 640.3

c = 420.3

Solid solubility ranges from 71 to 72.5

at.% Al

, Fe4Al13

1160

mC102

C2/m

Fe4Al13

a = 1548.9

b = 808.3

c = 1247.6

= 107.72°

[V-C]

Solid solubility ranges from 74.5 to 75.5

at.% Al

sometimes called FeAl3 in the literature

, Fe3AlCx cP5

Pm3m

CaTiO3

a = 366.6 to 366.8

a = 375.8

0.5 x 1.0

Solid solubility is up to 14 at.% C and 21

at.% Al [V-C]


Al C Fe

L + + 1315 U1 L

6

20.2

27.0

24.5

24.0

7.9

0.7

4.0

8.5

71.9

72.3

71.5

67.7

L + + C 1295 U2 L

C

34.2

27.3

33.7

0.0

5.4

8.7

0.7

100.0

60.4

64.0

65.6

0.0

L + + C 1282 U3 L

C

13.4

19.0

16.5

0.0

12.4

13.0

4.5

100.0

74.2

68.0

79.0

0.0

+ + C 825 U4

C

8.5

17.6

8.5

0.0

4.7

14.6

0.7

100.0

86.7

67.8

90.0

0.0

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

132


MSIT®

Al–C–Fe

Fig. 1: Al-C-Fe. Reaction scheme

C-Fe

l + α γ1495 p

1

L + (C) κ1410 p

2

Al-C-Fe

L + α γ + κ1315 U1

Al-C

γ α + (C)

738 e3

l γ + (C)

1154 e2

L + κ γ + (C)1282 U3

γ + κ α + (C)825 U4

L α + κ1335 e

1

L + κ α + (C)1295 U2

α + γ + κL + γ + κ

κ + γ + (C)

α + κ + (C)

κ + α + (C) L + α + (C)

?

60

70

80

90

10 20 30 40

10

20

30

40

Fe Fe 50.00Al 50.00C 0.00

Fe 50.00Al 0.00C 50.00 Data / Grid: at.%

Axes: at.%

U2α

p2

U1

U3κ

graphite

1300

1200

1400

1500 1350

e2

p1

γ

14501300

1500e1

Fig. 2: Al-C-Fe.

Liquidus surface

133


MSIT®

Al–C–Fe

20

40

60

80

20 40 60 80

20

40

60

80

Fe Al

C Data / Grid: at.%

Axes: at.%

L

Al4C3L+(C)

L+Al4C3

L+(C)+Al4C3

(C)Fig. 3: Al-C-Fe.


2000° C

20

40

60

80

20 40 60 80

20

40

60

80

Fe Al

C Data / Grid: at.%

Axes: at.%

L

Al4C3L+(C)

L+Al4C3

L+(C)+Al4C3

(C)Fig. 4: Al-C-Fe.


1850°C

134


MSIT®

Al–C–Fe

20

40

60

80

20 40 60 80

20

40

60

80

Fe Al

C Data / Grid: at.%

Axes: at.%

L+(C)+Al4C3Al4C3

L+Al4C3

L

L+(C)

(C)Fig. 5: Al-C-Fe.


1700°C

60

70

80

90

10 20 30 40

10

20

30

40

Fe Fe 50.00Al 50.00C 0.00


Axes: at.%

α

α+(C)

α+κ+(C)

κ+(C)

κ

α+κγ+κ

γ+κ+

(C)

γ+(C)

γ

L+γ

L

L+(C)

L+γ+

(C)

α+γ

Fig. 6: Al-C-Fe.

The isothermal

section at 1200°C

135


MSIT®

Al–C–Fe

60

70

80

90

10 20 30 40

10

20

30

40

Fe Fe 50.00Al 50.00C 0.00


Axes: at.%

α

α+(C)

α+κ+(C)κ+(C)

κ

α+κα+κ

+γγ+κ

γ+κ+(C)γ+(C)

γα+γ

Fig. 7: Al-C-Fe.

The isothermal

section at 1000°C

60

70

80

90

10 20 30 40

10

20

30

40

Fe Fe 50.00Al 50.00C 0.00


Axes: at.%

κ

κ+(C)

α+κ+(C)

α+κ

α+κ+(C)

α+(C

)

γ+(C)

γ α+γα

Fig. 8: Al-C-Fe.

The isothermal

section at 800°C

136


MSIT®

Al–C–Fe

10 20 30 40700

800

900

1000

1100

1200

1300

1400

1500

Fe 95.00Al 0.00C 5.00

Fe 50.00Al 45.00C 5.00Al, at.%

Tem

pera

ture

, °C

γ+L

γ

γ+(C)

α+(C)

α+κ

α+(C)

α+L+(C)

L+(C)α

+ κ+(C

)

α+γ+κ

α+γ

α +κ +

(C)

κ+γ

α+L

L

1315

1282

1295

825

7

56

21

3

4

1: L+α+γ2: L+α+κ3: L+γ+κ4: L+γ+(C)5: γ+(C)6: κ+γ+(C)7: α+γ+(C)

Fig. 9: Al-C-Fe.

The vertical section

at a constant C

content of 5.0 at.%

10 20 30700

800

900

1000

1100

1200

1300

1400

1500

Fe 89.50Al 0.00C 10.50

Fe 49.50Al 40.00C 10.50Al, at.%

Tem

pera

ture

, °C

L+(C)

α+L+(C)

L+κ+(C)

α+(C)

α+κ+(C)

L

L+γ

γ+(C)

α+(C) α+κ+(C)

κ

L+κ

κ+γ

κ +γ+

(C)

α +γ+κ

α+κ

κ+(C) 1295

1282

825

L+κ+γ

L+γ+(C)

α+γ+(C)

Fig. 10: Al-C-Fe.


at a constant C

content of 10.5 at.%

137


MSIT®

Al–C–Fe

10 20800

900

1000

1100

1200

1300

1400

1500

1600

Fe 77.00Al 23.00C 0.00

Fe 47.00Al 23.00C 30.00C, at.%

Tem

pera

ture

, °C

L

L+(C)

L+κ+(C)

α+κ+(C)

κ+(C)

κα+κ

1: α+κ+L

α+L

L+κ1315

α

1295

α+γ+κ

3: γ+κ

α+γ

5: L+γ

2: γ+κ+L

6: α+γ+L

4: γ

1

234

56

Fig. 11: Al-C-Fe.


at a constant Al

content of 23.0 at.%

30 40

700

800

900

1000

1100

1200

1300

Fe 80.00Al 20.00

Fe 55.00Al 45.00

Al, at.%

Tem

pera

ture

, °C A2

B2

0 at.% C0.5-1.0 at.% CFig. 12: Al-C-Fe.

The effect of C on the

order-disorder

temperature of Al-Fe

alloys

138


MSIT®

Al–C–Fe

20

40

60

80

20 40 60 80

20

40

60

80

Fe Al

C Data / Grid: at.%

Axes: at.%

Al4C3+κ+Dia

Fe7C3+κ+Dia

Al4C3

FeAl6Fe4Al13Fe2Al5FeAl2FeAlFe3Al

Fe3C

Fe7C3

Fe3AlC(κ)

Fig. 13: Al-C-Fe.

The isothermal

section at a pressure

of 6 GPa and at 25°C

139


MSIT®

Al–C–Si

Aluminium – Carbon – Silicon

Hans Leo Lukas, updated by K.C. Hari Kumar

Literature Data

Phase diagram of the Al-C-Si system is of interest e.g. in the development of carbothermic reduction

process for producing aluminium from alumina and also for understanding interfacial reaction between

aluminium and silicon carbide in the of Al-based metal matrix composites containing SiC.

A ternary phase with the stoichiometry Al4SiC4 was first reported by [1961Bar]. Its presence was later

ascertained by [1978Sch, 1979Sch, 1980Ino1, 1980Ino2, 1984Beh, 1984Bey, 1984Kid, 1987Ode1,

1987Yok, 1990Ode, 1990Via]. [1961Bar] additionally proposed a polymorphic transition of Al4SiC4 phase,

but could not index the X-ray diffraction pattern. Other investigators could not confirm the transformation

of Al4SiC4, though [1978Sch, 1979Sch] described the presence of a low temperature phase between

Al4SiC4 and Al5C3N that formed a continuous series of solid solutions at high temperatures. Another

ternary phase, Al4Si2C5 was established by [1980Ino1, 1980Ino2] to be stable only at temperatures between

1900 and 1970°C. This phase could be retained at room temperature by rapid or moderately rapid cooling.

Other researchers [1984Kid, 1987Ode1] could not verify this phase, despite several attempts to prepare it.

[1984Kid] reported the existence of another phase Al8SiC7 that formed sluggishly between 2000 and

2100°C by a peritectic reaction. Existence of this phase was later confirmed by [1990Via].

[1987Ode1] determined the section Al4C3-SiC between 1900 and 2300°C by thermal analysis and X-ray

diffraction of hot pressed samples. The same authors determined the solubility of carbon in the liquid phase

at 2000 and 2150°C by chemical analysis of samples equilibrated in graphite crucibles and then rapidly

cooled. The carbide phases in equilibrium with melt were identified by X-ray diffraction. By careful

micrography, the authors verified that the parts of the samples analyzed corresponded to a homogeneous

liquid at the equilibration temperature. Complete isothermal sections at 2150 and 2000°C, as well as a

reaction scheme, were reported.

[1990Via] studied the Al-C-Si system under atmospheric pressure and at temperatures up to 1627°C, using

X-ray diffraction, optical microscopy, scanning electron microscopy and electron microprobe analysis.

Metastable isothermal sections at 567 and 997°C (i.e. without ternary carbides), stable isothermal section

at 1497°C, and stable and metastable liquidus projections near the Al-corner were elucidated. From the

results obtained, a thermodynamic model based on stable and metastable phase equilibria in the Al-C-Si

ternary system was set up in order to provide a general description of the chemical interaction between

aluminium and SiC. [2001Aks] also determined the metastable state of the phase diagram in Al-C-Si system

between 700 to 900°C, employing essentially same techniques as [1990Via]. Using their own experimental

data and data from literature they constructed metastable phase diagrams and their non-equilibrium variants

to explain specific features of crystallization of Al-SiC composite materials.

[1966Rom] investigated microstructure and mechanical properties of an Al-SiC composite material.

[1982Lil, 1985Lil] measured the compositions of the gaseous species in equilibrium with an Al-SiC mixture

and analyzed them thermodynamically. [1984Bey] determined the heat capacity of Al4SiC4 between 5.26

and 1047 K (774°C). [1984Beh] measured the partial pressure of Al(g) above Al4SiC4+SiC+C using

Knudsen Cell with mass spectrometry and evaluated thermodynamic functions of Al4SiC4. Referring to the

formation of Al4SiC4 from Al4C3 and SiC, the values are smaller than the uncertainties. [1987Ode2]

measured the molar heat capacity in the temperature range 174-1174°C and the enthalpy of peritectic

decomposition of Al4SiC4 and Al8SiC7 by DSC.

[1982Doe, 1987Yok, 1993Wen, 1996Gro] calculated the ternary phase diagram based on data from the

binary subsystems and the ternary phases. [1982Doe, 1987Yok] considered only the ternary carbides

Al4SiC4 and Al4Si2C5. [1993Wen, 1996Gro] included ternary phases Al4SiC4 and Al8SiC7, but ignored

Al4Si2C5 in their calculation of the phase diagram.

The present evaluation updates the work of [1990Luk] taking into account all literature published

since then.

140


MSIT®

Al–C–Si

Binary Systems

Binary systems Al-Si [2003Luk] and Al-C [2003Per] are from the MSIT Binary Evaluation Program. The

C-Si phase diagram is from [1996Gro].

Solid Phases

Table 1 gives crystallographic details of the solid phases of the system. All the three ternary carbides lie

along Al4C3-SiC plane. Crystal structures of Al4SiC4 and Al4Si2C5 proposed by [1980Ino2] were said to

contain alternating layers of the Al4C3 and SiC structures. Al4Si2C5 is treated as metastable, since other

investigators could not establish its presence. For Al8C7Si, only the unit cell dimensions were given

[1984Kid].


There are no true pseudobinary sections known in the system, although the section Al4C3-SiC below solidus

may be treated as pseudobinary (Fig. 5), since the amount of the phase C(gr.) is extremely low in this region.


The invariant equilibria associated with the liquid phase are given in Table 2. Figure 1 shows the reaction

scheme after [1987Ode1, 1996Gro] assuming the phase Al4C5Si2 to be metastable. All invariant reaction

temperatures and compositions are calculated using the thermochemical data from [1996Gro]. They are in

reasonable agreement with experimental data.

Liquidus Surface

The liquidus surface, calculated according to [1996Gro] is shown in Fig. 2. Isotherms above 2400°C are

drawn with dotted lines to indicate that at these temperatures gas phase should be present. A schematic view

of the Al corner is given in Fig. 2a. The calculated mole fractions of carbon for all the lines shown are

below 10-8.

Isothermal Sections

The calculated isothermal sections at 2150°C and 2000°C are shown in Fig. 3 and Fig. 4 respectively. They

agree well with those reported by [1987Ode1].


Figure 5 is the calculated vertical section along the Al4C3-SiC plane according to [1996Gro]. The solubility

of Si in Al4C3 is about 2 at.% at 2085°C. Note that the phase C(gr.) is not indicated in the sub-solidus region

of the diagram, since its amount is very low (< 6 10-4 mole%).

References

[1961Bar] Barczak, V.J., “Optical and X-Ray Powder Diffraction Data for Al4SiC4”, J. Am. Ceram.

Soc., 44, 299 (1961) (Experimental, Crys. Structure, 1)

[1966Rom] Romadin, Yu.P., Prosvirov, E.N., Pogodin-Alekseev, G.I., “Structure and Equilibria of a

Composite of Aluminium with Silicon Carbide” (in Russian), Metall. Term. Obra.

Metallov., (2), 46-48 (1966) (Experimental, 0)

[1978Sch] Schneider, G., “Investigations of Equilibria in the Si, Al, Be/C, N System” (in German),

Thesis, Univ. Stuttgart, (1978) (Experimental, Equi. Diagram, Crys. Structure, 71)

[1979Sch] Schneider, G., Gauckler, L.J., Petzow, G., “Phase Equilibria in the Si, Al, Be/C, N System”,

Ceramurgia Int., 5, 101-104 (1979) (Experimental, Equi. Diagram, Crys. Structure, 8)

[1980Ino1] Inoue, Z., Inomata, Y., Tanaka, H., “A New Phase of Aluminium Silicon Carbide,

Al4Si2C5”, J. Mater. Sci., 15, 255-256 (1980) (Experimental, Crys. Structure, 4)

141


MSIT®

Al–C–Si

[1980Ino2] Inoue, Z., Inomata, Y., Tanaka, H., “X-Ray Crystallographic Data on Aluminium Silicon

Carbide, Al4SiC4 and Al4Si2C5”, J. Mater. Sci., 15, 575-580 (1980) (Experimental, Crys.

Structure, 4)

[1982Doe] Doerner, P., “Constitutional Investigations on High Temperature Ceramics of the

B-Al-C-Si-N-O System by Means of Thermochemical Calculations” (in German,), Thesis,

Univ. Stuttgart, 1982, (Thermodyn., Calculation, 126)

[1982Lil] Lilov, S.K., “Investigation of Aluminium Solubility Process in Silicon Carbide”, Cryst. Res.

Technol., 17, 783-786 (1982) (Theory, Thermodyn., 13)

[1984Beh] Behrens, R.G., Rinehart, G.H., “Vaporization Thermodynamics and Enthalpy of Formation

of Aluminum Silicon Carbide”, J. Am. Ceram. Soc., 67, 575-578 (1984) (Experimental,

Thermodyn., 13)

[1984Bey] Beyer, R.P., Johnson, E.A., “Heat Capacity of Aluminum Silicon Carbide (Al4SiC4) from

5.26 to 1047 K”, J. Chem. Thermodyn., 16, 1025-1029 (1984) (Experimental, Thermodyn.,

13)

[1984Kid] Kidwell, B.L., Oden, L.L., Mcune, R.A., “2Al4C3·SiC: A new Intermediate Phase in the

Al-Si-C System”, J. Appl. Crystallogr., 17, 481-482 (1984) (Experimental, Crys. Structure,

10)

[1984Ole] Olesinski, R.W., Abbaschian, G.J., “The C-Si (Carbon-Silicon) System”, Bull. Alloy Phase

Diagrams, 5, 486-489 (1984) (Review, Equi. Diagram, 28)

[1985Lil] Lilov, S.K., “Thermodynamic Analysis of the Equilibrium Composition of the Gas Phase in

the SiC-Al System” (in Russian), Electroprom-st. Priborostr., 20(2), 17-19 (1985) (Theory,

Thermodyn., 13)

[1987Ode1] Oden, L.L., McCune, R.A., “Phase Equilibria in the Al-Si-C System”, Metall. Trans. A,

18A, 2005-2014 (1987) (Experimental, Equi. Diagram, #, *, 19)

[1987Ode2] Oden, L.L., Beyer, R.P., “Heat Capacity of 2Al4C3·SiC from 447 to 1447 K and Enthalpy

of Peritectic Decomposition of Al4C3.2Al4C3 SiC, and Al4C3 SiC”, Thermochim. Acta,

115, 11-19 (1987) (Experimental, Thermodyn., 11)

[1987Yok] Yokokawa, H., Fujishige, M., Ujiie, S., Dokiya, M., “Phase Relations Associated with the

Aluminum Blast Furnace: Aluminum Oxycarbide Melts and Al-C-X (X=Fe,Si) Liquid

Alloys”, Metall. Trans. B, 18B, 433-444 (1987) (Review, Equi. Diagram, Thermodyn., 74)

[1990Ode] Oden, L.L., McCune, R.A., “Contribution to the Phase Diagram Al4C3-AIN-SiC”, J. Am.

Ceram. Soc., 77, 1529-1533 (1990) (Experimental, Equi. Diagram)

[1990Via] Viala, J.C., Fortier, P., Bouix, J., “Stable and Metastable Phase Equilibria in the Chemical

Interaction between Aluminium and Silicon Carbide”, J. Mater. Sci., 25(3), 1842-1850


[1990Luk] Lukas, H.L., ”Al-C-Si (Aluminium - Cardon - Silikon),” MSIT Ternary Evaluation


Services GmbH, Stuttgart; Document ID: 10.13552.1.20, (1990) (Crys. Structure, Equi.


[1991Sch] Schuster, J.C., “A Reinvestigation of the Thermal Decomposition of Aluminum Carbide

and the Constitution of the Al-C System”, J. Phase Equilib., 12 (5), 546-549 (1991) (Equi.


[1996Gro] Gröbner, J., Lukas, H., Aldinger, F., “Thermodynamic Calculation of the Ternary System

Al-Si-C”, Calphad, 20(2), 247-254 (1996) (Calculation, Equi. Diagram, Thermodyn., 37)

[1993Wen] Wen, H.M.Sc., “Thermodynamic Calculations and Constitution of the Al-B-C-N-Si-Ti

System” (in German), Thesis, Univ. Stuttgart 1993, 1-183 (1993) (Calculation, Equi.

Diagram, Thermodyn., 223)

[2001Aks] Aksenov, A.A., Belov, N.A., Medvedeva, S.V., “The Al-Si-C Phase Diagram and Its Use

for Microstructural Analysis of MMCp and MMCf Composite Materials”, Z. Metallkd.,

92(9), 1103-1110 (2001) (Equi. Diagram, Experimental, 15)

142


MSIT®

Al–C–Si

[2003Luk] Lukas, H.L., “Al-Si (Aluminum-Silicon)”, MSIT Binary Evaluation Program, in MSIT


Stuttgart, to be published, 2003 (Assessment, Equi. Diagram, Crys. Structure, 29)

[2003Per] Perrot, P., “Al-C (Aluminium-Carbon)”, MSIT Binary Evaluation Program, in MSIT


Stuttgart, to be published, (2003) (Equi. Diagram, Crys. Structure, Assessment, 19)



Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

(Al)

< 660.452

cF4

Fm3m

Cu

a = 404.96 at 25°C [Mas2]

(C)

< 3827 (subl.)

hP4

P63/mmc

C (graphite)

a = 246.12

c = 670.9

at 25°C [Mas2]

(Si)

< 1414

cF8

Fd3m

C (diamond)

a = 543.06 at 25°C [Mas2]

Al4C3

< 2156

hR7

R3m

Al4C3

a = 330.75

c = 2490.6

[1991Sch]

SiC, SiC

< 2824

cF8

Fd3m

ZnS (sphalerite)

a = 435.8 [V-C] only stable modification of SiC?

[1984Ole]

* Al8SiC7

< 2085

hP16 a = 331.27(7)

c = 1924.2(4)

[1984Kid]

* Al4SiC4

1920

hP18

Al5C3N

a = 327.71

c = 2167.6

[1961Bar,1980Ino2]

* Al4Si2C5

~1970-1910

hR11

Al6C3N2

a = 325.12

c = 4010.8

[1980Ino2] metastable

by [V-C] erroneously given as hR22

Reactions T [°C] Type Phase Composition (at. %)

Al C Si

L + (C) + Al4C3 Al8SiC7 2085 P1 L 71.3 13.7 15

L + (C) Al8SiC7 + Al4SiC4 2080 U1 L 69.8 13 17.2

L + (C) Al4SiC4 + SiC 2075 U2 L 65.6 11.6 22.8

L + Al4C3 (Al) + Al8SiC7 655 U3 L 99.07 < 10-8 0.93

L + SiC (Si) + Al4SiC4 612 U4 L 85.8 < 10-8 14.2

L + Al8SiC7 (Al) + Al4SiC4 605 U5 L 91.57 < 10-8 8.43

L (Al) + (Si), Al4SiC4 577 D1 L 87.9 ~0.0 12.1

143


MSIT®

Al–C–Si

Fig

. 1:

A

l-C

-Si.

Rea

ctio

n s

chem

e

Al-

CA

l-S

iA

-B-C

l +

C

Al 4

C3

2156

p2

l (

Al)

+ S

i

577

e 1

L +

C

Al 4

SiC4

ca.

2080

p3

Al-

C-S

i

L +

C +

Al 4

C3

Al 8

SiC7

2085

P1

C-S

i

l +

C

SiC

2823

p1

l (

Al)

, A

l 4C3

660.5

d2

L (

Al)

+ S

i, A

l 4S

iC4

577

D1

L +

Al 8

SiC7

(A

l) +

Al 4

SiC4

605

U5

L +

Al 4

C3

(A

l) +

Al 8

SiC7

655

U3

L +

C

Al 4

SiC4 +

SiC

2075

U2

L +

C

Al 8

SiC7

+ A

l 4S

iC4

2080

U1

l S

i, S

iC

1414

d1

L +

C +

Al 8

SiC7

C +

Al 4

C3

+ A

l 8S

iC7

C +

Al 8

SiC7

+ A

l 4S

iC4 L +

(A

l) +

Al 8

SiC7

(Al)

+ A

l 4C3

+ A

l 8S

iC7

L +

Al 8

SiC7 +

Al 4

SiC4

L +

Al 4

SiC4

+ S

iC

C +

Al 4

SiC4 +

SiC

(Al)

+ A

l 8S

iC7 +

Al 4

SiC4

L +

(A

l) +

Al 4

SiC4 (A

l) +

Si

+ A

l 4S

iC4

L +

SiC

S

i +

Al 4

SiC4

612

U4

Al 4

SiC4 +

Si

+ S

iC

L +

Al 4

SiC4 +

Si

L +

Al 4

C3 +

Al 8

SiC7

144


MSIT®

Al–C–Si

20

40

60

80

20 40 60 80

20

40

60

80

Al Si

C Data / Grid: at.%

Axes: at.%

d2

U3U4U5

e1D1

d1

4200

4000

3800

3600

3400

3200

3000

2800

26002400

22002000

(C)

SiCAl4C3

U1

U2

P1

p3

p2p1

Al8SiC4

Fig. 2: Al-C-Si.

Liquidus surface

80

90

10 20

10

20

Al Al 7C 3Si

Al 70.00C 0.00Si 30.00 Data / Grid: at.%

Axes: at.%

d2

U3 U4U5e1, D1

from P1

from U1from U2

from d1

Fig. 2a: Al-C-Si.

Schematic liquidus

surface near the

Al-corner

145


MSIT®

Al–C–Si

20

40

60

80

20 40 60 80

20

40

60

80

Al Si

C Data / Grid: at.%

Axes: at.%

L+SiC

L+(C)+SiCL+(C)

L

SiCAl4C3

L+(C)+Al4C3

(C)

20

40

60

80

20 40 60 80

20

40

60

80

Al Si

C Data / Grid: at.%

Axes: at.%

Al4C3

L+Al4C3

Al8C7SiAl4C4Si

(C)+SiC+Al4C4Si

L+SiC+Al4C4Si

L+SiC

L

SiC

(C)

Fig. 3: Al-C-Si.


2150°C

Fig. 4: Al-C-Si.


2000°C

146


MSIT®

Al–Ca–Li

Aluminium – Calcium – Lithium

Joachim Gröbner

Literature Data

The first investigations in the ternary Al-Ca-Li system was published by [1986Lee] who calculated vapor

pressures over ternary melts on the basis of thermodynamic data of binary Al and Li liquid alloys. [1990Mil]

reported, in the form of an abstract, that the equilibria between the binary Laves phases CaAl2 (Cu2Mg

structure type) and Li2Ca (MgZn2 structure type) does not occur on the 33.33 at.% Ca section. A ternary

Laves phase of the Ni2Mg structure type occurs on this section and enters into equilibrium with CaAl2 and

Li2Ca. No further details were given. [1992Mil] reported crystal structure determination of a ternary phase

“LixCa8-xAl3”. This phase is part of ternary solubility of the later reported binary phase Ca8Al3 [2001Kev].

[1993Nes] synthesized series of compounds LixCaAl2-x in Mo crucibles and structurally characterized them

afterwards. They confirmed the ternary MgNi2 type Laves phase between 0.80 x 1.0 and a second one

of MgZn2 type between 0.80 x 1.0. A schematic ternary phase diagram is shown. Small ternary

solubilities of the binary Laves phases CaAl2 and Li2Ca were indicated. In this isothermal section two

additional ternary phases were included. The phase Li11Ca6Al12 is reported later in detail by [1996Hae].

For the further phase with the composition LixCa8Al7-x no information is given in the text.

Phase equilibria in the Al-Ca-Li system were studied by [1988Gan, 1999Gan, 2000Gan] using X-ray phase

and differential thermal analyses. A partial isothermal section up to 33 at.% Ca at 150°C is given by

[1999Gan]. [2000Gan] show additionally six vertical sections and a constructed partial liquidus surface. In

these investigations neither the existence of a large solubility range of the Laves phase, nor the earlier

reported ternary phases was considered. In contrast recent experimental work in this system [2003Jan]

confirmed clearly the stability of the ternary Laves phase of the Ni2Mg structure and the phase Li11Ca6Al12.

The phase Li2Ca6Al2 reported by [1993Nes] was not confirmed in this work.

Binary Systems

For Al-Li [2002Gro] and Al-Ca [2002Ted] the evaluation in MSIT Binary Evaluation Program already

assessed binary diagrams were used. The binary system Ca-Li was taken from [Mas2].

Solid Phases

No complete solid solution between the two binary Laves phases Li2Ca and CaAl2 was observed. [1993Nes]

found a two-phase field between Li2Ca and “LiCaAl”. Towards CaAl2 a continuous series Ca(LixAl2-x) of

two phases, 1 crystallizing in the MgZn2 (0.80 x 1.0) structure type and 2 in the MgNi2 (0.25 x

0.75) structure type were found. Additional two ternary phases were reported by [1993Nes]. [1996Hae]

determined the crystal structure of 3, Li11Ca6Al12, one of these phases. The second phase, 4, LixCa8Al7-x,

was found to be metastable by [2003Jan]. All phases together with the crystallographic data are given in

Table 1.

Liquidus Surface

A partial liquidus surface constructed from thermoanalytic results is shown by [2000Gan]. It is questionable

since it is in contradiction with all other authors and therefore is not reproduced here.

Isothermal Sections

The only isothermal section is given by [1999Gan, 2000Gan] at 150°C. It is partial up to 33 at.% Ca and

disregard the already earlier known ternary phases. Figure 1 shows the isothermal sections at room

temperature concerning the investigations of [1993Nes] and [2003Jan].

147


MSIT®

Al–Ca–Li


Six vertical sections from CaAl2 to Li2Ca, CaAl2 to Li, CaAl2 to Li9Al4, CaAl4 to LiAl, CaAl2 to LiAl and

CaAl2 to Li3Al2 are given by [2000Gan]. They are classified to be tentative because they are in substantial

contradiction with the established ternary phases.

References

[1982McA] McAlister, A.J., “The Al-Li (Aluminum-Lithium) System”, Bull. Alloy Phase Diagrams,

3(2), 177-183 (1982) (Equi. Diagram, Thermodyn., Review, #,*, 31)

[1986Lee] Lee, J.J., Sommer, F., “Thermodynamic Properties of Li in Liquid Aluminum Alloys” (in

Korean), Taehan Kumsok Hakhoechi, 24(10), 1185-1189 (1986) (Experimental, Theory,

Thermodyn., 23)

[1988Gan] Ganiev, I.N., Ikromov, A.Z., Kurbanova, H.A., Kinzhibalo, V.V., “Physical Chemical

Analysis of the Alloys of the Systems Al-Zn-Sc(Y,La,Ce,Pr,Nd) and Al-Li-Ca”

(in Russian), 7th Vsesoyuznoe Sovescchanie po Phisiko-Chimicheskomu Analizu

Metallicheskih Sistem, Frunze, 333 (1988) (Equi. Diagram, Experimental, 0)

[1990Mil] Miller, G.J., Nesper, R., Curda, J., “Laves Phases in the Ca/Li/Al System: Structural

Characteristics and Chemical Bonding”, 15th Congress and General Assembly Internat.

Union Crystallography, Bordeaux, France, Abstract Vol. C-270 (1990) (Crys. Structure,

Experimental, 3)

[1992Mil] Miller, G.J., Nesper, R., “Ca8-xLixAl3: Defects and Substitution in the Fe3Al Structure

Type”, J. Alloy. Compd., 185(2), 221-234 (1992) (Crys. Structure, 22)

[1993Mil] Miller, G.J., Li, F., Franzen, H.F., “The Structural Phase Transition in Calcium-Aluminum

Compound (CaAl4): A Concerted Application of Landau Theory and Energy Band Theory”,

J. Am. Chem. Soc., 115(9), 3739-3745 (1993) (Crys. Structure, 26)

[1993Nes] Nesper, R., Miller, G.J., “A Covalent View of Chemical Bonding in Laves Phases

CaLixAl(2-x)”, J. Alloy. Compd., 197(1), 109-121 (1993) (Crys. Structure, Experimental,

Equi. Diagram, 26)

[1996Hae] Haeussermann, U., Woerle, M., Nesper, R., “Ca6LixAl23-x, Sr9Li7+xAl36-x and

Ba2Li3+xAl6-x: New Ternary Intermetallic Compounds Linking Close-Packed Metal

Structures and Zintl Phases”, J. Am. Chem. Soc., 118, 11789-11797 (1996) (Crys. Structure,

Experimental, 20)

[1998Hua] Huang, B., Corbett, D., “Two New Binary Calcium-Aluminium Compounds: Ca13Al14 with

a Novel Two-Dimensional Aluminium Network, and Ca8Al3, an Fe3Al-Type Analogue”,

Inorg. Chem., 37(22), 5827-5833 (1998) (Crys. Structure, Experimental, 30)

[1999Gan] Ganieva, N.I., Nazarov, Kh.M., Ganiev, I.N., “Phase Equilibrium in Al-Li-Ca-(Sr,Ba)

Systems at 423 K”, Russ. Metall., (5), 131-133 (1999) (Equi. Diagram, Experimental, 7)

[2000Gan] Ganiev, I.N., Nazarov, H.M., Ganieva, N.I., “The Al-Li-Ca System in the Aluminium Rich

Region” (in Russian), Metally, (3), 124-127 (2000) (Equi. Diagram, Experimental, 3)

[2001Kev] Kevorkov, D., Schmid-Fetzer, R.,“The Al-Ca System Part 1: Experimental Investigation of

Phase Equilibria and Crystal Structures”, Z. Metallkd., 92, 946-952 (2001) (Equi. Diagram,

Experimental, 14)

[2002Gro] Gröbner, J., “Al-Li (Aluminium - Lithium)”, MSIT Binary Evaluation Program, in MSIT

Workplace, Effenberg, G. (Ed.), Materials Science International Services GmbH, Stuttgart;

Document ID: 20.13517.1.20 (2002) (Equi. Diagram, Review, 29)

[2002Ted] Tedenac, J.-C., Kevorkov, D., Velikanova, T., “Al-Ca (Aluminum - Calcium)”, MSIT

Binary Evaluation Program, in MSIT Workplace, Effenberg, G. (Ed.), Materials Science

International Services GmbH, Stuttgart; Document ID: 20.12711.1.20 (2002) (Equi.


[2003Jan] Janz, A., “Untersuchung von Phasengleichgewichten im System Al-Ca-Li”, (in German)

Proc. 10th Int. Studententag der Metallurgie, Montanuniversität Leoben, Austria, 76-80

(2003) (Equi. Diagram, Experimental, *, 10)

148


MSIT®

Al–Ca–Li


Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

( Al)

< 660.452

cF4

Fm3m

Cu

a = 404.96 at 25°C [Mas2]

( Ca)

842-443

cI2

Im3m

W

a = 448.0 [Mas2]

( Ca)

< 443

cF4

Fm3m

Cu

a = 558.84 at 25°C [Mas2]

(Li)

< 180.6

cI2

Im3m

W

a = 351.0 pure Li at 25°C [V-C2]

Li2Ca hP12

P63/mmc

MgZn2

a = 631.3

c = 1028

[Mas2]

Li9Al4 ( )

347-275

mC26

C2/m

a = 1915.51

b = 542.88

c = 449.88

= 107.671°

[1982McA]

Li9Al4 ( `)

< 275

? ?

Li3Al2 ( )

< 520

hR15

Rm

a = 450.8

c = 1426

[1982McA]

60 to 61at.% Li [Mas2]

LiAl ( )

< 704

cF16

Fd3m

NaTl

a = 637 at 50 at.% Li [1982McA]

45 to 61 at.% Li [Mas2]

CaAl4 (h)

700-170

tI10

Al4Ba

a = 435.3

b = 1107

[V-C2]

CaAl4 (l)

< 170

mC10 a = 615.26 ± 0.15

b = 617.30 ± 0.13

c = 632.90 ± 0.14

= 118.026 ± 0.016°

[1993Mil]

CaAl2< 1086

cF24

Fd3m

Cu2Mg

a = 804.0 [V-C2] Powder X-ray diffraction

Ca13Al14

< 633

mC54 a = 1555.1 ± 0.4

b = 987.3 ± 0.2

c = 972.6 ± 0.2

= 108.09 ± 0.02°

[1998Hua]

Single-crystal X-ray diffraction

149


MSIT®

Al–Ca–Li

Ca8Al3< 578

aP22

Ca8In3

a = 948.4 ± 0.3

b = 959.2 ± 0.3

c = 967.1 ± 0.3

= 99.02 ± 0.03°

= 101.13 ± 0.03°

a = 947.0 ± 0.2

b = 960.2 ± 0.2

c = 964.6 ± 0.2

= 99.17 ± 0.02°

= 101.08 ± 0.02°

[1998Hua]

Single-crystal X-ray diffraction

[1992Mil]

at 0.13 at.% dissolved Li

* 1, LixCaAl2-x hP12

P63/mmc

MgZn2

a = 582.0 to 626.8

c = 936.6 to 1021.9

0.80 x 1.0

[1993Nes]

* 2, LixCaAl2-x hP24

Ni2Mg

a = 573.0 to 579.6

c = 1856.4 to 1875.4

0.25 x 0.75 [1993Nes]

* 3, Li11Ca6Al12 cF116

Fm3m

Th6Mn23

a = 1343.0 [1996Hae]

* 4, LixCa8Al7-x ? ? [1993Nes]

metastable [2003Jan]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

20

40

60

80

20 40 60 80

20

40

60

80

Li Ca


Axes: at.%

CaAl4(l)

CaAl2

Ca13Al14

Ca8Al3

Li2Ca

Li9Al4

Li3Al2

LiAlτ

3

τ1

τ2

(αCa)

Fig. 1: Al-Ca-Li.


room temperature

150


MSIT®

Al–Ca–Si

Aluminium – Calcium – Silicon

Rainer Schmid-Fetzer

Literature Data

The liquidus surface of the Al-corner has been studied and fundamental agreement was obtained between

most of the earlier experimental work [1926Doa, 1927Gro, 1928Shi] and reviewing papers [1934Fus,

1943Mon, 1952Han, 1960Spe, 1969Wat]. Samples were made from Al-Ca and Al-Si master alloys under a

CaCl2 or KCl-NaCl-BaCl2 protective layer. Their composition was checked by chemical analysis, and

thermal and metallographic analyses were performed [1926Doa]. A dominating CaSi2 liquidus surface

extending close to the Al-corner and an eutectic type Al-CaSi2 pseudobinary system was deduced from

these data [1926Doa] and essentially confirmed by similar studies [1928Shi, 1962Kol] and [1966Tom]. The

coexistence of (Al) and a compound, assumed to be CaSi2, was also seen in micrographs of Al-rich samples

that were cast, forged or hot rolled, annealed for 30 min at 460°C and then used for Brinell and tensile tests

[1927Gro]. Similar interpretations are given in [1934Fus, 1943Mon] and also by [1952Han] who made

additional experiments to quantify the location of ternary eutectics and accepts the binary phase CaAl4instead of CaAl3 as given in previous literature. The interpretation of an (Al)-CaSi2 equilibrium is, however,

inconsistent with reports on some ternary compounds that form after annealing for a long time. [1967Gla]

studied 39 samples in the Al-Si-CaSi2-CaAl2 subsystem at 400°C by X-ray methods and metallography and

detected the compound CaAl2Si2 ( ) in equilibrium with (Al), (Si), CaSi2, CaAl4, CaAl2 and another

ternary compound, CaAl1-xSi1+x( ) [1965Bod]. [1967Gla] also prepared single crystals of and performed

a detailed X-ray structure analysis. The phase was also observed by electron microprobe in Al-20 mass%

Si samples containing 0.13 to 2.6 mass% Ca, which were equilibrated at 800°C, cast and found to consist

of (Al)+(Si)+ [1976Tag]. The precipitation of and Ca2Si was found in metallurgical grade silicon (< 0.5

mass% Al, <0.3 mass% Ca) by optical metallography and electron microscopy (SEM, TEM, EMPA)

[1990Ang].

The CaAl1-xSi1+x( ) phase was also prepared at x = 0 by [2002Ima] and in the range -0.4 < x < 0.2 by

[2002Lor], studied by X-ray diffraction and also for their superconducting behavior with a transition

temperature of 7.8 K for CaAlSi [2002Ima].

The congruent melting point of was reported at 975°C by DTA [1994Ang] and the pseudobinary eutectic

L +(Si) at 927°C, and the “pseudobinary” eutectic L +CaSi2 at 925°C. [1994Ang] also performed a

brief Calphad-type thermodynamic analysis of the ternary system and produced calculated isopleths. This

included the modelling of the Ca-activity in ternary liquids on the Al0.5Si0.5 - Ca section at 1350°C. This

Ca-activity was experimentally determined by [1975Sch] with 11 alloys at 1350°C and 3 alloys at 1210°C

using the boiling point method. The activity coefficients of Al and Ca in molten Si at 1450-1550°C were

determined by the Knudsen effusion method and also by a chemical equilibrium technique from the

distribution between liquid silicon and lead at 1450°C [1999Mik]. Two other compounds, Ca3Al6Si2 ( )

and Ca2Al4Si3 ( ) were prepared by pressing CaAl2-Si mixtures, heating to 700-1000°C, quenching and

studying by X-ray analysis [1955Chr, 1956Chr]. The reaction was complete only above 900°C and the

mutual equilibria CaAl2+ , + and +(Si) were observed at 1000°C, but not the phase located between

and (Si). The phase completely decomposes into and some Al and Ca at 1200°C, while the phase

only starts to decompose at this temperature, probably due to Ca-loss to the gas phase [1956Chr]. The most

Ca-rich compound, Ca3Al2Si2 ( ) was fused from the elements in corundum crucibles under argon,

continuously agitated for 4h at 1150-1200°C and slowly cooled to room temperature within 12h. Single

crystals could be extracted from the sample and a detailed X-ray structure analysis was performed

[1977Wid]. The composition change during preparation was found to be negligible by chemical analysis of

a similarly prepared Ba3Al2Si2 compound [1977Wid].

The present evaluation continues and updates the one published in [1990Sch] with respect to both new

ternary and binary data.

151


MSIT®

Al–Ca–Si

Binary Systems

The Al-Si system is accepted from [Mas2]. The Al-Ca system is taken from [2002Ted]. The Ca-Si system

is accepted from [2000Man], however, the shape of the liquidus lines may need some revision as indicated

by thermodynamic calculations [2003Gro].

Solid Phases

Data on all solid phases reported in this system are given in Table 1.

Electronic structure calculations of the stability of Al2Si26- chains in the compound Ca3Al2Si2 suggest that

all Si atoms reside in the twofold sites and all Al atoms in the threefold ones [1988Li].

Bonding in the CaAl2Si2 ( ) structure type was studied theoretically [1988Zhe]. The same structure type

was experimentally found to form also in 13 different, though related, ternary systems [1980Klu].

[1975Eml] mentioned the possible existence of a phase Ca0.8Al1.2Si, which is not included in Table 1.


The Al-CaSi2 section has been quoted as a eutectic pseudobinary system in the earlier literature [1926Doa]

to [1952Han]. The primary crystallization of CaSi2 from Al-rich liquids is probably metastable in view of

the formation of on that section. The phase may have been misinterpreted as CaSi2 in the metallographic

examination, since the conclusions in the basic early work on Al-Ca-Si [1926Doa] rely on the assumption

that no ternary compounds exist. The calculated isopleths Al-CaSi2 and Si-CaAl2 [1994Ang] contain the

phase, however, they are based on old versions of the Ca-Si and Al-Ca binaries and cannot be accepted. In

addition, the phases , , and had not been considered by [1994Ang]. Thermodynamic calculations

performed in the present assessment were based on the recent binaries and they show that both sections are

not pseudobinary systems. The Al-poor side of the Al-CaSi2 section exhibits phase fields of liquid with CaSi

and Ca14Si19. However the partial section Al-CaAl2Si2 ( ) is a pseudobinary eutectic as shown in Fig. 1,

according to the present calculation. Similarly, the Si-poor side of the Si-CaAl2 section exhibits phase fields

of liquid with CaSi. However the partial section Si-CaAl2Si2 ( ) is also a pseudobinary eutectic as shown

in Fig. 2, according to the present calculation. The calculated eutectic temperature 933°C is in close

agreement with the experimental value 927°C [1994Ang].


The three invariant equilibria of the Al-corner, given in Table 2, are from the present thermodynamic

calculation. Earlier work [1952Han] assumed the participation of CaSi2 instead of in the equilibria max,

E and D (with reported temperatures of 637, 615.8, and 576.5°C). This cannot be accepted as described in

the previous section. Also a eutectic reaction L (Al)+(Si)+ was given with a liquid composition of 0.7

at.% Ca [1966Tom]. This is virtually impossible based on the thermodynamic calculation, which shows that

this invariant (D) is essentially degenerate to the binary Al-Si eutectic. [1966Tom] also reported from

microradiograph examinations that the Ca-content in (Si) is much smaller than in (Al).

Liquidus Surface

The liquidus surface of the Al-corner given in Fig. 3 is from the present thermodynamic calculation. It

deviates from that given by [1952Han] as discussed in the previous section.

Isothermal Sections

An isothermal section at about 400°C is given in Fig. 4 [1967Gla, 1955Chr] and [1956Chr]. The equilibria

around the and phases are estimated by dashed lines. Both phases form above 900°C with appreciable

reaction rates [1955Chr] and are presumably stable down to 400°C. The reported - (Si) equilibrium at

1000°C [1955Chr] cannot be accepted in view of the congruent melting point of at 975°C.

The equilibria above 33 at.% Ca have not bee studied experimentally. The dashed tie line Ca5Si3-CaAl2(and the three more Ca-rich ones) given dashed in Fig. 4 are based on the present thermodynamic

152


MSIT®

Al–Ca–Si

calculation, disregarding the and phases and the mutual solubilities along the CaAl2-CaSi2 section. No

tie lines can be given around these phases.

The precipitation of and Ca2Si in metallurgical grade silicon (< 0.5 mass% Al, <0.3 mass% Ca)

[1990Ang] supports the existence of the (Si)+ +Ca2Si equilibrium with negligible solubility in (Si).

Thermodynamics

The measured Ca-activities [1975Sch] in the ternary liquid phase along the equal molar fractions of Al and

Si at 1350°C are well represented by the thermodynamic calculation of [1994Ang] shown in Fig. 5


Si and Ca are important additions to Al-alloys. The CaAl1-xSi1+x( ) phase shows superconducting behavior

[2002Ima, 2002Lor]. The de-oxidation of steel using complex Ca-Al-Si de-oxidizers was discussed by

[1983Gho].

Miscellaneous

The dissolution of CaSi2 from Al-Ca-Si alloys in HCl was discussed by [1953Tou].

References

[1926Doa] Doan, G., “On the Al-Ca-Si System” (in German), Z. Metallkd., 18, 350-355 (1926) (Equi.


[1927Gro] Grogan, J.D., “The Influence of Calcium on Aluminium Containing Silicon”, J. Inst. Met.,

37, 77-91 (1927) (Experimental, 6)

[1928Shi] Shinoda, G., “Improvement of Aluminium Alloy with X-Ray Study” (in Japanese), Nippon

Kogyo Kwai Shi, 44, 544-557 (1928) (Equi. Diagram, Experimental, 12)

[1934Fus] Fuss, V., Metallography of Al and its Alloys (in German), translated from Anderson, R.J.,

Sherwood Press Inc., Cleveland, Berlin, 163-166 and 207-219 (1936) (Equi. Diagram,

Review, #, 300)

[1943Mon] Mondolfo, L.F., Metallography of Aluminum Alloys, Wiley & Sons, Inc., New York, 61-63

(1943) (Equi. Diagram, Review, #, 3)

[1952Han] Haneman, H., Schrader, A., “Ternary Aluminum-Alloys” in “Atlas Metallographicus

(III/2)” (in German), Verlag Stahleisen, Düsseldorf, 62-65 (1952) (Equi. Diagram, Crys.

Structure, Review, Experimental, #, *, 5)

[1953Tou] Tournaire, M., Renouard, M., “Contribution to a Study of Al-Mg-Si Alloys” (in French),

Revue de Metallurgie/Memoires, 50, 328-332 (1953) (Experimental, 0)

[1955Chr] Chrétien, A., Freundlich, W., Deschanvres, A., “On Two New Ternary Ca-Al-Si

Compounds” (in French), Compt. Rend., 241, 1781-1783 (1955) (Equi. Diagram,

Experimental, #, 2)

[1956Chr] Chrétien, A., Freundlich, W., Deschanvres, A., “Properties of the New Ternary Compounds,

Ca3Al6Si2 and Ca2Al4Si3” (in French), Compt. Rend., 242, 784-785 (1956) (Crys.


[1960Spe] Spengler, H., “The Importance of Research on Eutectics and its Application to Ternary

Eutectic Aluminium Alloys” (in German), Metallwiss. Tech., 14(3), 201-206 (1960)

(Experimental, 11)

[1962Kol] Kolachev, B.A., “Quasi-Binary Sections of Ternary Systems, Studied by Withdrawing a

Solid Phase from a Melt” (in Russian), Tr. Mosk. Aviats. Tekhnol. Inst., 5, 124-132 (1962)

(Equi. Diagram, Experimental, #, 4)

[1965Bod] Bodak, O.I., Gladyshevsky, E.I., Zarechnyuk, O.S., Cherkashin, E.E., “Compounds with

Structures of the AlB2 Type in the Ternary Systems” (in Russian), Visn. Lviv. Univ., Ser.

Khim., 8, 75-79 (1965) (Crys. Structure, Experimental, 8)

153


MSIT®

Al–Ca–Si

[1966Tom] Tomochiro, I., Yamamoto, R., Fujisawa, K., “Mechanism of Structural Changes of Lo-Ex”

(in Japanese), Keikinzoku, 16, 30-35 (1966) (Equi. Diagram, Experimental, #, 2)

[1967Gla] Gladyshevsky, E.I., Kripyakevich, P.I., Bodak, O.I., “Crystal Structure of CaAl2Si2 and

Analogous Compounds” (in Russian), Ukrain. Fiz. Zhur., 12, 447-453 (1967) (Equi.


[1969Wat] Watanabe, H., Sato, E., “Phase Diagrams of Aluminum-Base Systems” (in Japanese),

Keikinzoku, 19(11), 499-535 (1969) (Equi. Diagram, 232)

[1975Eml] Emlin, B.I., Gasik, M.I., Kilesso, S.N., Elt’sova, Z.V., Vukelich, S.B., “Phase Composition

of Al-Si Alloys” (in Russian), Izvest. v. u. z. Tsvetn. Metall., 4, 156-158 (1975) (Equi.


[1975Sch] Schuermann, E., Fueders, P., Litterscheidt, H., “Vapor Pressure of Ca Above Ca-Si, Ca-Al

And Ca-Al-Si Alloys” (in German), Arch. Eisenhuettenwes., 46(8), 473-476 (1975)


[1976Tag] Tagami, M., Serita, Y., Komatsu, K., “The Influence of Ca Additions on the Grain Size of

Primary Si Crystals in a Hypereutectic Al-20% Si Alloy”, J. Jpn. Inst. Light Met., 26,

385-390 (1976) (Equi. Diagram, Experimental, *, 20)

[1977Wid] Widera, A., Schaefer, H., “Preparation and Crystal Structure of A3Al2Si2 (A = Ca, Sr, Ba)”

(in German), Z. Naturforsch. B, 32B, 1349-1351 (1977) (Crys. Structure, Experimental, 3)

[1980Klu] Kluefers, P., Neumann, H., Mewis, A., Schuster, H.-U., “AB2X2 Compounds with the

CaAl2Si2 Structure, VIII (1)” (in German), Z. Naturforsch. B, 35(10), 1317-1318 (1980)


[1983Gho] Ghosh, A., Naik, V., “Deoxidation of Steel with Ca-Si-Al and Mg-Si-Al Complex

Deoxidizers: a Thermodynamic Analysis”, Tool Alloy Steels, 17(7), 239-244 (1983)

(Experimental, 16)

[1988Li] Li, J., Hoffmann, R., “Ca3Al2Si2: An Inorganic Structure Analogous to but not Isoelectronic

with Polyacene”, J. Phys. Chem., 1988, 92(4), 887-893 (1988) (Crys. Structure, Theory, 18)

[1988Zhe] Zheng, C., Hoffmann, R., “Complementary Local and Extended Views of Bonding in the

ThCr2Si2 and CaAl2Si2 Structures”, J. Solid State Chem., 72(1), 58-71 (1988) (Crys.

Structure, Theory, 13)

[1990Ang] Anglezio, J.C., Servant, C., Dubrous, F., “Characterization of Metallurgical Grade Silicon”

J. Mater. Res., 5, 1894-1899 (1990) (Equi. Diagram, Crys. Structure, Experimental, 11)

[1990Sch] Schmid-Fetzer, R., ”Al-Ca-Si (Aluminium - Calcium - Silicon),” MSIT Ternary Evaluation




[1993Mil] Miller, G.J., Li, F., Franzen, H.F., “The Structural Phase Transition in Calcium-Aluminum

Compound (CaAl4): A Concerted Application of Landau Theory and Energy Band Theory”,

J. Am. Chem. Soc., 115(9), 3739-3745 (1993) (Crys. Structure, 26)

[1994Ang] Anglezio, J.C., Servant, C., Ansara, I., “Contribution to the Experimental and

Thermodynamic Assessment of the Al-Ca-Fe-Si System - I. Al-Ca-Fe, Al-Ca-Si, Al-Fe-Si

and Ca-Fe-Si Systems”, Calphad, 18(3), 273-309 (1994) (Equi. Diagram, Calculation, 71)

[1998Hua] Huang, B., Corbett, D., “Two New Binary Calcium-Aluminium Compounds: Ca13Al14 with

a Novel Two-Dimensional Aluminium Network, and Ca8Al3, an Fe3Al-Type Analogue”,

Inorg. Chem., 37(22), 5827-5833 (1998) (Crys. Structure, Experimental, 30)

[1999Mik] Miki, T., Morita, K., Sano, N., “Thermodynamic Properties of Si-Al, -Ca, -Mg Binary and

Si-Ca-Al, -Ti, -Fe Ternary Alloys”, Mater. Trans., JIM, 40(10), 1108-1116 (1999)

(Thermodyn., Experimental, 22)

[2000Man] Manfrinetti, P., Fornasini, M.L., Palenzona, A., “The Phase Diagram of the Ca-Si System”,

Intermetallics, 8, 223-228 (2000) (Equi. Diagram, Crys. Structure, Experimental, #, 31)

[2002Ima] Imai, M., Nishida, K., Kimura, T. Abe, H., “Superconductivity of Ca(Al0.5Si0.5)2, a Ternary

Silicide with the AlB2-Type Structure”, Appl. Phys. Lett., 80(6), 1019-1021 (2002) (Crys.

Structure, Experimental, Superconduct., 26)

154


MSIT®

Al–Ca–Si

[2002Lor] Lorenz, B., Lenzi, J., Cmaidalka, J., Meng, R.L., Sun, Y.Y., Xue, Y.Y., Chu, C.W.,

“Superconductivity in the C32 Intermetallic Compounds AAl(2-x)Six, with A = Ca and Sr;

and 0.6<x<1.2”, Physica C, 383(3), 191-196 (2002) (Crys. Structure, Electr. Prop.,

Experimental, Phys. Prop., 10)

[2002Ted] Tedenac, J.-C., Kevorkov, D., Velikanova, T., “Al-Ca (Aluminum - Calcium)”, MSIT

Binary Evaluation Program, in MSIT Workplace, Effenberg, G. (Ed.), MSI, Materials

Science International Services GmbH, Stuttgart, Document ID: 20.12711.1.20 (2002)

(Equi. Diagram, Assessment, Crys. Structure, 13)

[2003Gro] Gröbner, J., Chumak, I., Schmid-Fetzer, R., “Experimental Study of Ternary Ca-Mg-Si

Phase Equilibria and Thermodynamic Assessment of Ca-Si and Ca-Mg-Si Systems”,

Intermetallics, in print (2003)


Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

( Al) hP2

P63/mmc

Mg

a = 269.3

c = 439.8

at 25°C, 20.5 GPa [Mas2]

( Al)

< 660.452

cF4

Fm3m

Cu

a = 404.96 at 25°C [Mas2]

( Ca) ? ? at 25°C, 1.5 GPa [Mas2]

( Ca)

842-443

cI2

Im3m

W

a = 448.0 [Mas2]

( Ca)

< 443

cF4

Fm3m

Cu

a = 558.84 at 25°C [Mas2]

(Si)

< 1414

cF8

Fd3m

C-diamond

a = 543.06 at 25 °C [Mas2]

CaAl4 (h)

700 - 170

tI10

I4/mmm

Al4Ba

a = 435.3

b = 1107

[V-C2]

CaAl4 (l)

< 170

m*10

?

?

a = 615.26 ± 0.15

b = 617.30 ± 0.13

c = 632.90 ± 0.14

= 118.026 ± 0.016

[1993Mil]

CaAl2< 1086

cF24

Fd3m

Cu2Mg

a = 804.0 [V-C2] Powder X-ray diffraction

Ca13Al14

< 633

mC54

C2/m

Ca13Al14

a = 1555.1 ± 0.4

b = 987.3 ± 0.2

c = 972.6 ± 0.2

= 108.09 ± 0.02°

[1998Hua] Single-crystal X-ray

diffraction

155


MSIT®

Al–Ca–Si

Ca8Al3< 578

aP22

P1

Ca8In3

a = 948.4 ± 0.3

b = 959.2 ± 0.3

c = 967.1 ± 0.3

= 99.02 ± 0.03°

= 101.13 ± 0.03°

= 119.55 ± 0.03°

[1998Hua] Single-crystal X-ray

diffraction

CaSi2< 1030

hR18

R3m

CaSi2

a = 386.3

c = 3071.0

[2000Man]

Ca14Si19

1085- 900

hR198

R3c

Ca14Si19

a = 867.2

c = 6844.5

[2000Man]

Ca3Si4< 910

hP42

P63/m

Ca3Si4

a = 854.1

c = 1490.6

[2000Man]

CaSi

< 1320

oC8

Cmcm

CrB

a = 459

b = 1079.5

c = 391

[2000Man]

Ca5Si3< 1240

tI32

I4/mcm

Cr5B3

a = 764.1

c = 1487.6

[2000Man]

Ca2Si

< 1270

oP12

Pnma

anti-PbCl2

a = 766.7

b = 479.9

c = 900.2

[2000Man]

* , Ca3Al2Si2 oI14

Immm

Ca3Al2Ge2

a = 400 ± 1

b = 1824 ± 2

c = 457.6 ± 1.0

ordered variant of Ta3B4 [1977Wid]

* , CaAl2Si2< 975

hP5

P3m1

La2O2S

a = 413 ± 1

c = 714.5 ± 1.5

La2O3-type superstructure [1967Gla].

Congruent melting [1994Ang]

* ,

CaAl1-xSi1+x

hP3

AlB2

a = 419.05

c = 439.92

at x = 0 [2002Ima]

composition range x = -0.35 to + 0.55

[1967Gla] or

x = -0.4 to + 0.2 [2002Lor]

* , Ca3Al6Si2< 1150

hP c/a = 1.64 [1956Chr]

* , Ca2Al4Si3 cP18 a = 715 [1956Chr]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

156


MSIT®

Al–Ca–Si

Table 2: Invariant Equilibria in the Al-rich Corner


Al Ca Si

L + CaAl2 + CaAl4 688 U L

CaAl2

CaAl4

85.4

66.7

40

80

11.7

33.3

20

20

2.9

0

40

0

L (Al) + 649 emax L 97.96 0.65 1.39

L (Al) + + CaAl4 610 E L

(Al)

CaAl4

94

99.99

40

80

5.4

0

20

20

0.6

0.01

40

0

L (Al) + (Si), 577 D L

(Al)

(Si)

87.9

98.5

0

40

0

0

0

20

12.1

1.5

100

40

50 60 70 80 90500

600

700

800

900

1000

Ca 20.00Al 40.00Si 40.00

AlAl, at.%

Tem

pera

ture

, °C

β+(Al)

649°C

975°C

660.3°C

L

β+L

β (Al)

Fig. 1: Al-Ca-Si.

The pseudobinaty

section CaAl2Si2 - Al

157


MSIT®

Al–Ca–Si

50 60 70 80 90800

900

1000

1100

1200

1300

1400

1500

Ca 20.00Al 40.00Si 40.00

SiSi, at.%

Tem

pera

ture

, °C

β+(Si)

L+(Si)

L

(Si)β

933°C

1414°C

975°C

Fig. 2: Al-Ca-Si.

The pseudobinary

section CaAl2Si2 - Si

10

90

10

Ca 20.00Al 80.00Si 0.00

Al

Ca 0.00Al 80.00Si 20.00 Data / Grid: at.%

Axes: at.%

Al4Ca (Al)

β

D

E

e1, 613°C

649

800

p1, 700°C

CaAl2

700

800

900°C

U

Fig. 3: Al-Ca-Si.

Liquidus surface of

the Al-rich corner

(>80 at.% Al)

158


MSIT®

Al–Ca–Si

20

40

60

80

20 40 60 80

20

40

60

80

Ca Al

Si Data / Grid: at.%

Axes: at.%

CaAl4CaAl2

δ

εγ

α

β

CaSi2

CaSi

Ca2Si

Ca3Si4

Ca5Si3

Ca8Al3 Ca13Al14

(Ca)(Al)

(Si)Fig. 4: Al-Ca-Si.


400°C; some tie lines

above 33 at.% Ca are

estimated. Equilibria

with the phases α,

CaSi, and Ca3Si4 are

not given

0.0 20 40 60 80 1000.0

0.2

0.4

0.6

0.8

1.0

Al

Si

Ca

[1975Sch]

calculated [1994Ang]

Ca, at.%

aCa

50.0050.000.00

Al

Si

Ca

0.000.00

100.00

Fig. 5: Al-Ca-Si.

Calculated activities

of Ca in the liquid

phase at 1350°C and

xAl = xSi

159


MSIT®

Al–Cd–Cu

Aluminium – Cadmium – Copper

Qingsheng Ran, updated by Pierre Perrot

Literature Data

The partial system Al-Cd-Al2Cu was studied by thermal analysis and metallography [1962Boc, 1974Wat]

and by electrical resistivity and lattice spacing measurements [1974Wat]. Samples were prepared from

99.999% Al, 99.99% Cu and Cd (KD0) [1962Boc] or from 99.99% Al, 99.99% Cu and 99.9% Cd

[1974Wat]. 40 samples were examined by [1974Wat] for constructing the liquidus projection of this

section. The samples were homogenized in silica ampoules at 430°C for 24h. No experimental details were

given by [1962Boc]. The results of [1962Boc] were summarized as liquidus isotherms. The proposed

temperature of the ternary monotectic-eutectic reaction is in good agreement with that of [1974Wat]. Some

other works concerned the phase relationships in the solid state near the Al-corner. [1965Boc] carried out

electrical conductivity measurements on samples of 54 compositions at 530, 500 and 400°C, some

microstructural observations and determined the simultaneous solid solubility of Cd and (Cu) in (Al).

Samples with up to 8Cu-0.3Cd (mass%) were prepared from materials of nearly the same purity as used by

[1962Boc] and then annealed in evacuated silica tubes at 530, 500 and 400°C for 50, 100 and 500h,

respectively. The samples were then quenched in cold water. Before measuring the electrical conductivity

the surface of the samples was removed by polishing. Cheng et al. established first the Cu-rich corner with

more than 70 mass% Cu [1965Che] and then studied the whole isothermal section at room temperature

[1966Che, 1975Che]. The experimental methods used by [1965Che, 1966Che] and [1975Che] are similar.

Spectroscopically pure Cd, Al of 99.994% and Cu of >99.9% purity were melted in vacuum in a high

frequency induction furnace, Al-Cd-Cu putting Cd on the bottom and Cu on the top and locating the heating

coil first on top and moving it downwards to prevent Cd evaporation. The massive alloys were annealed and

then filed to powder. The powders were then annealed again and cooled slowly to room temperature. The

melting and heat treatment procedures were carried out in evacuated silica tubes. The phases were

determined by X-ray diffraction. The annealing and heat treatments were different. Annealing of massive

alloys: 500-700°C for 1-2 weeks [1965Che]; 350-700°C for 4-7 weeks [1966Che]; 200-600°C for 2 weeks

[1975Che]. Annealing of powders: 400-450°C for 2 days [1965Che]; a little lower than for massive alloys

for 2 days [1966Che]; 150-450°C for 2 days [1975Che]. Cooling: 10 K/h [1965Che]; 5 K/h [1966Che]; 10

K/h [1975Che]. The number of alloys examined are: 111 [1965Che]; 278 [1966Che]; 251 [1975Che]. The

results of [1966Che, 1975Che] are identical, but differ slightly from [1965Che]. According to [1965Che]

Cu2Cd is in two phase equilibrium with (Cu), , , 2, respectively, whereas [1965Che, 1975Che] observed

only the two phase equilibrium between Cu2Cd and (Cu). The reason for these differences was analyzed by

[1975Che]. The Al-corner in the solid state was also studied by [1974Wat] at 520°C on 45 alloy

compositions. The results are in good agreement with the other works.

The present evaluation continues and updates that of [1991Ran].

Binary Systems

The boundary binary systems Al-Cu, Al-Cd and Cd-Cu are respectively accepted from [2003Gro],

[1980Ell, 1982McA] and [1990Sub].

Solid Phases

No ternary compound was observed. Some binary compounds have solubilities for the third element. The

isothermal section at room temperature, given in Fig. 1, is from [1966Che, 1975Che, 1979Dri]. All solid

phases mentioned in the presented diagrams are listed in Table 1.

160


MSIT®

Al–Cd–Cu


The section Cd - ,Cu2Al was proposed to be a pseudobinary one by [1962Boc], what was confirmed by

electrical resistivity, lattice spacings and thermal analysis measurements [1974Wat] and modified for taking

into account the peritectic decomposition of ,CuAl2 at 591°C. Figure 2 shows this section, redrawn from

[1974Wat]. The sections Cd - ,CuAl2 and Cd - 1,CuAl(r) are characterized by a miscibility gap in the

liquid phase theoretically described by [1991But].


The section Cd - involves a pseudobinary monotectic. A ternary monotectic and eutectic were determined

[1962Boc, 1974Wat]. The ternary invariant equilibria are given in Table 2, the compositions given there are

approximate values only. A reaction scheme of the partial Al-Cd-CuAl2 system is plotted in Fig. 3.

Liquidus Surface

A partial liquidus surface of the region Al-Cd-CuAl2 after [1974Wat, 1981Wat] is given in Fig. 4. The

extension of the lines of double saturation in the cadmium corner are too small to be plotted and therefore

are neglected. [1962Boc] plotted liquidus isotherms into the liquidus projection. But the curvatures are

smaller than expected from the binary and pseudobinary boundaries so that these liquidus isotherms are not

very reliable. This reliability can not be checked because [1962Boc] did not give the data by which the

diagram was constructed. Therefore no isothermal line for the liquidus is drawn in Fig. 4.

Isothermal Sections

Partial isothermal sections of the Al-corner in a quite small composition region were constructed by

[1965Boc] for 530, 500 and 400°C and by [1974Wat] for 520°C. The two sets of results are in good

agreement. Taking the binary diagrams into consideration, Al-Cd-Cu sections at 500 and 400°C are

Al-Cd-Cu drawn in Fig. 5a and Fig. 5b. The isothermal section at room temperature (Fig. 1) is taken from

[1966Che] and [1975Che]. It includes also the earlier work [1965Che] and is similar to the diagram

reproduced by [1980Cha].


Dilatometric tests on Cu4Al and CdCu4Al alloys have been carried out by [1969Kar]. The addition of Cd

shortens the time of occurrence of the Guinier-Preston zones and formation of a ” phase. [1984Zol]

showed that the strength properties of cast Al-Cu alloys may be improved by addition of Cd, then ageing at

170°C, due to the precipitation of a metastable ” phase.

References

[1931Pre] Preston, G.D., “An X-ray Investigation of some Copper-Aluminium Alloys”, Philos. Mag.,


[1962Boc] Bochvar, O.S., Pokhodaev, K.S., “On the Phase Diagram of the Al-Cu-Cd System” (in

Russian), Issled. Splavov Tsvet. Metallov, (3), 93-97 (1962) (Equi. Diagram, Experimental,

*, 8)

[1965Boc] Bochvar, O.S., Pokhodaev, K.S., “The Solubility of Cu and Cd in Al” (in Russian),

Metalloved. Legkikh. Splavov, Akad. Nauk SSSR, Inst. Met., 88-92 (1965) (Equi. Diagram,


[1965Che] Cheng, C.H., Kan, Y.P., Li, T.H., “A Phase Diagram of the Cu-Rich Alloys of the Ternary

System Al-Cd-Cu” (in Chinese), Chinese J. Phys. (Peking), 21, 1487-1493 (1965) (Equi.

Diagram, Experimental, *, 10)

[1966Che] Cheng, C.H., Chen, Y.C., Kann, Y.P., Li, T.H., “Phase Diagram of

Aluminium-Cadmium-Copper System at Room Temperature” (in Chinese),

Kexue-Tongbao, 17, 121-122 (1966) (Equi. Diagram, Experimental, #, 11)

161


MSIT®

Al–Cd–Cu

[1969Kar] Karlinski, W., “Dilatometric Investigation of the Decomposition Processes of Solid

Solution in AlCu4 and AlCu4Cd Alloys”, Pr. Inst. Mech. Precyz., 17(1), 49-53 (1969) (Equi.

Diagram, Mechan. Prop., Experimental, 13)

[1974Wat] Watanabe, H., Okamoto, T., Kono, N., “Study on the Phase Diagram at the Al Corner of the

Al-Cu-Cd Alloy System” (in Japanese), J. Jpn. Inst. Light Met., 24, 246-253 (1974) (Equi.


[1975Che] Cheng, C.S., Chen, Y.C., Li, D.X., “Phase Diagram of the Alloys of the Ternary System of

Aluminium-Copper-Cadmium” (in Chinese), Chinese J. Phys. (Peking), 24(3), 174-179



Turkina, N.I., “Cu-Al-Cd” (in Russian), Binary and Multicomponent Copper-Base Systems.

Nauka, Moscow, 74 (1979) (Equi. Diagram, 2)

[1980Ben] Bennett, L.H., “The Cd-Cu (Cadmium-Copper) System”, Bull. Alloy Phase Diagrams, 1(1),

62-63 (1980) (Equi. Diagram, Review, #, 7)

[1980Cha] Chang, Y.A., Neumann, J.P., Mikula, A., Goldberg, D., “The Al-Cd-Cu

(Aluminum-Cadmium-Copper) System”, Bull. Alloy Phase Diagrams, 1(1), 58-59 (1980)

(Equi. Diagram, Review, #, 10)

[1980Ell] Elliott, R.P., “The Al-Cd (Aluminum-Cadmium) System”, Bull. Alloy Phase Diagrams,

1(1), 60-63 (1980) (Equi. Diagram, Review, #, 19)

[1981Wat] Watanabe, H., Sato, E., “Phase Diagram in Aluminium Alloys” (in Japanese), J. Jpn. Inst.

Light Metals, 31(1), 64-79 (1981) (Equi. Diagram, Experimental, 22)

[1982McA] McAlister, A.J., “The Al-Cd (Aluminum-Cadmium) System”, Bull. Alloy Phase Diagrams,

3(2), 172-177 (1982) (Equi. Diagram, Review, Thermodyn., #, 16)

[1984Zol] Zolotorevskii, V.S., Istomin-Kastrovskii, V.V., Bakirov, Zh., T., Rokhlina, A.L.,“Influence

of Cadmium on the Position of the Solvus Line for the ” Phase Formation in Al-Cu

Alloys”, Russ. Metall., (4), 216-217 (1984), translated from Izv. Akad. Nauk SSSR, Met.,

(4), 208-209 (1984) (Equi. Diagram, Experimental, 4)

[1985Mur] Murray, J.L., “The Al-Cu System”, Int. Met. Rev., 30, 211-233 (1985) (Equi. Diagram, Crys.

Structure, Review, 230)

[1989Mee] Meetsma, A., de Boer, J.L., van Smaalen, S., “Refinement of the Crystal Structure of

Tetragonal Aluminum-Copper (Al2Cu)”, J. Solid State Chem., 83(2), 370-372 (1989) (Crys.


[1990Sub] Subramanian, P.R., Laughlin, D.E., “The Cd-Cu (Cadmium-Copper) System”, Bull. Alloy

Phase Diagrams, 11 (2), 162-169 (1980) (Equi. Diagram, Crys. Structure, Review, #, 57)

[1991But] Butt, M.T.Z., Bodsworth, C., “Liquid Immisicibility in Ternary Metallic Systems”, Mater.

Sci. Technol., 7(9), 795-802 (1991) (Equi. Diagram, Theory, Review, 39)

[1991Ran] Ran, Q., ”Aluminium-Cadmium-Copper),” MSIT Ternary Evaluation Program, in MSIT



Assessment, 6)

[1994Mur] Murray, J.L., “Al-Cu (Aluminium-Copper)” in Phase Diagram of Binary Copper Alloys,

Subramanian, P.R., et al. (Eds.), ASM Intl., Materials Park, OH, 18-42 (1994) (Equi.

Diagram, Crys. Structure, Thermodyn., Review, #, 226)


the Cu-Al Binary System”, J. Alloys Compd., 264, 201-208 (1998) (Equi. Diagram,

Experimental, #,*,25)

[2002Gul] Gulay, L.D., Harbrecht, B., “The Crystal Structures of the 1 and 2 Phases in the Al-Cu



[2003Gro] Gröbner, J., “Al-Cu (Aluminium - Copper)”, MSIT Binary Evaluation Program, in MSIT


Stuttgart; to be published, (2003) (Equi. Diagram, Assessment, Crys. Structure, 68)

162


MSIT®

Al–Cd–Cu


Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments / References

(Al)

< 660.45

cF4

Fm3m

Cu

a = 404.96 at 25°C [Mas2]

0 to 2.48 at.% Cu

0 to 0.113 at.% Cd [1980Ell]

(Cd)

< 321.11

hP2

P63/mmc

Mg

a = 297.87

c = 561.66

21°C, pure, [1980Ben]

0 to 4.5 at.% Al [1980Ell]

(Cu)

< 1064.87

cF4

Fm3m

Cu

a = 361.46 25°C, pure, [Mas2]

0 to 19.7 at.% Al

2, Cu1-xAlx< 363

-

-

TiAl3long period

super-lattice

a = 366.8

c = 368.0

0.22 x 0.235 [Mas, 1985Mur]

76.5 to 78.0 at.% Cu

at 76.4 at.% Cu

(subcell only)

1, Cu9Al4< 890

cP52

P3m

Cu9Al4

a = 870.23

a = 870.68

62 to 68 at.% Cu[Mas2, 1998Liu];

powder and single crystal [V-C2]

from single crystal [V-C]

, Cu1-xAlx< 686

hR*

R3m

a = 1226

c = 1511

0.381 x 0.407 [Mas2, 1985Mur]

59.3 to 61.9 at.% Cu

at x = 38.9 [V-C]

1, Cu47.8Al35.5(h)

590-530

oF88 - 4.7

Fmm2

Cu47.8Al35.5

a = 812

b = 1419.85

c = 999.28

55.2 to 59.8 at.% Cu [Mas2, 1994Mur]


2, Cu11.5Al9(r)

< 570

oI24 - 3.5

Imm2

Cu11.5Al9

a = 409.72

b = 703.13

c = 997.93

55.2 to 56.3 at.% Cu [Mas2, 1985Mur]


1, CuAl(h)

624-560

o*32 a = 408.7

b = 1200

c = 863.5

49.8 to 52.4 at.% Cu

[V-C2, Mas2, 1985Mur]


2, CuAl(r)

< 560

mC20

C2/m

CuAl(r)

a = 1206.6

b = 410.5

c = 691.3

= 55.04

49.8 to 52.3 at.% Cu

[V-C2]

, CuAl2< 591

tI12

I4/mcm

CuAl2

a = 606.7

c = 487.7

31.9 to 33.0 at.% Cu [1994Mur]

single crystal [V-C2, 1989Mee]

CuCd3

< 397

hP28

P63/mmc

Al5Co2

a = 810

c = 876

[1980Ben, 1990Sub]

163


MSIT®

Al–Cd–Cu


Cu5Cd8

< 563

cI52

I43m

Cu5Zn8

a = 965.4 34 to 47.8 at.% Cu

[1980Ben, 1990Sub]

Cu4Cd3

< 547

cF1124

F43m

Cd3Cu4

a = 2587.1 55.9 to 58.2 at.% Cu

[1980Ben, 1990Sub]

Cu2Cd

< 549

hP12

P63/mmc

MgZn2

a = 496

c = 799

[1980Ben]


Al Cd Cu

L1 L2 + 586 e2 L1

L2

65.4

4

65.7

2.9

94.3

2.5

31.7

1.7

31.8

L1 + 1 L2 + ~ 582 U1 L1

1

L2

~ 66

49.5

~ 3

65.7

~ 3

1

~ 95

2.5

~ 31

49.5

~ 2

31.8

L1 L2 + (Al) + 544 E1 L1

L2

(Al)

77.7

2.2

97.7

66

6.1

97.0

0.1

2.0

16.2

0.8

2.0

32

L (Cd) + 321 e4 L

(Cd)

~0

0

66.7

~100

100

0

~0

0

33.3

L (Al) + (Cd) + 320 E2 L

(Al)

(Cd)

0.5

98.9

0

66.7

99

0.1

100

0

0.5

1.0

0

33.3

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments / References

164


MSIT®

Al–Cd–Cu

20

40

60

80

20 40 60 80

20

40

60

80

Cu Cd


Axes: at.%

θ

η2

ζ2

δγ

1

α2

(Cu)

CdCu2Cd3Cu4 Cd8Cu5 Cd3Cu

(Cd)

Fig. 1: Al-Cd-Cu.


room temperature

10 20 30 40 50 60

300

400

500

600

700

800

Cd Cu 33.30Cd 0.00Al 66.70Al, at.%

Tem

pera

ture

, °C

L1+L2

(Cd)+θ

586

321.11

L1+θ

L2+θ

L2+η1

591°C

Fig. 2: Al-Cd-Cu.

The pseudobinary

(Cd) - CuAl2 system

165


MSIT®

Al–Cd–Cu

Fig

. 3:

A

l-C

d-C

u.

Rea

ctio

n s

chem

e of

the

par

tial

syst

em A

l-C

d-C

uA

l 2

Al-

Cu

Al 2

Al-

Cd

Cd

-Cu

Al 2

Al-

Cd

-Cu

l 1 l2

+ (

Al)

650

e 1

l (

Al)

+ θ

548.2

e 3

L1

L2 +

(A

l) +

θ544

E1

l 1 l2 +

θ586

e 2

L (

Al)

+ (

Cd)

+ θ

320

E2

l (

Al)

+ (

Cd)

320.4

e 5l

(C

d)

+ θ

321

e 4

L +

(A

l) +

θ

(Al)

+ (

Cd)

+θ

l +

η1

θ591

p1

L1 +

η1

L2 +

θ582

U1

L1 +

η1 +

θ

166


MSIT®

Al–Cd–Cu

2.5

2.0

1.5

1.0

0.5

0.0

0.080.060.040.020.00 0.10

(Al) + + L�

(Al) + L(Al)

(Al) + �

Cd, at.%

Cu,at.%

Al

20

40

60

80

20 40 60 80

20

40

60

80

Cu Cd


Axes: at.%

E1

e1

e3

e2

(Al)

θ

U1

η1

p1

(Cd)

Fig. 5a: Al-Cd-Cu.

Partial isothermal

section at 500°C

Fig. 4: Al-Cd-Cu.

Schematic liquidus

surface of the region

Al - Cd - CuAl2

167


MSIT®

Al–Cd–Cu

2.5

2.0

1.5

1.0

0.5

0.0

0.080.060.040.020.00 0.10

(Al) + + L�

(Al) + L(Al)

(Al) + �

Al

Cu,at.%

Al

Fig. 5b: Al-Cd-Cu.

Partial isothermal

section at 400°C

168


MSIT®

Al–Cd–Mg

Aluminium – Cadmium – Magnesium

Lazar Rokhlin, updated by Hans J. Seifert, Andriy Grytsiv, Riccardo Ferro and Yuriy Voroshilov

Literature Data

There are many data available on the phase equilibria in the Al-Cd-Mg ternary system. The liquidus surface

is reported by [1925Val, 1926Val, 1935Hau, 1937Koe, 1938Jae, 1938Rie, 1946Mik]. The isothermal

sections have been reported by various groups, at 395°C by [1946Mik], 302°C by [1993Kal], 230°C by

[1938Rie] and [1946Mik] reports the phase equilibria at room temperature (25°C). Several vertical sections

are given by [1926Val, 1937Koe, 1946Mik].

[1925Val] and [1926Val] investigated the system by thermal analysis and studied the alloys’

microstructures; which allowed them to determine the boundaries of the miscibility gap, the liquidus

surfaces and phase transformations involved, across the entire composition range of the system.

The liquidus surface and the (Mg) solid solubility limits in alloys containing up to 22Al-5.2Cd (at.%) were

examined by [1935Hau] using thermal analysis and metallography. The Mg corner of the Al-Cd-Mg phase

diagram was investigated by [1937Koe]. There is agreement between the results of [1935Hau] and

[1937Koe]. [1938Rie] investigated numerous alloys by X-ray diffraction and metallography, constructed a

projection of the liquidus surface, an isothermal section at 230°C and re-determined the boundaries of the

miscibility gap. The liquidus and solidus surfaces proposed by [1938Jae] show invariant reactions and

strongly contradict both, the result [1938Rie] and the accepted Al-Cd binary system.

[1946Mik] also investigated many alloys by thermal analysis and metallography. From this work results a

description of the liquidus surface, 13 isopleths and isothermal sections at 25 and 395°C. Solid phase

interactions in the system at 302°C have been examined by [1993Kal] by means of superposition of

diffusion zones and the isothermal section at this temperature was constructed. The purity of the starting

materials was better than 99.99% for Al and Cd and 99.95% for Mg.


knowledge.

Binary Systems

The binary phase relations for the systems Al-Cd and Cd-Mg are accepted as described by [Mas2]. For the

Al-Mg phase diagram several different versions have been proposed over time. The most consistent

description is that by [2003Luk] which is integrated into the present evaluation. It is based on experimental

investigations of the Al-Mg system between 47 and 63 at.% Al, and calculated phase diagram equilibria

presented by [1998Lia].

Solid Phases

No ternary compounds have been found in the Al-Cd-Mg system. The crystal structures of the binary phases

are listed in Table 1. Adding Cd decreases the solubility of Al in solid (Mg) [1935Hau, 1937Koe, 1946Mik],

how Cd effects the solubility of Al at different temperatures [1935Hau] is shown in Fig. 1. The results of

[1935Hau] agree with those of [1937Koe] and seem to be reliable. The phase can take up to about 1 at.%

Cd at 395°C and about 0.6 at.% Cd at 20°C [1946Mik]. The phase contains at these temperatures more

than 5 at.% Cd and 4 at.% Cd [1946Mik]. The solid solubility of Al in (Mg,Cd) at room temperature seems

to be negligible [1946Mik]. The solubility of Cd at 302°C in the Al-Mg phases , , and as found by

[1993Kal] are listed in Table 2. The ordered phases of the Cd-Mg system have the following concentration

limits: ´ (MgCd3) - from 25 to 32 at.% Mg, ´´ (MgCd) - from 38 to 60 at.% Mg, ´´´ (Mg3Cd) - from 65

to 82 at.% Mg.

169


MSIT®

Al–Cd–Mg


The invariant equilibria have not been determined reliably yet in spite of the many investigations. [1925Val]

and [1926Val] reported a eutectic reaction at 395°C with the eutectic point at about 45Mg-37.5Cd-17.5Al

(at.%). This result is close to that of [1946Mik] who reported a ternary eutectic equilibrium point at

54Mg-32Cd-14Al (at.%) and 396 ± 0.5°C. However, in the diagram presented the ternary eutectic point is

approached by only two monovariant eutectic reactions: L (Al)+ and L +(Mg,Cd). This is incorrect

because it indicates an equilibrium of five phases at the eutectic point. Thus, it is not clear which solid

phases are formed during the ternary eutectic reaction [1925Val, 1926Val]. The data of [1926Val] suggests

the occurrence of a reaction L1 L2+(Al)+X where X is most likely the phase, but there is no proof of this

in the literature. [1976Mon] proposed a similar reaction, with the X phase being unknown. [1938Rie]

informs about two invariant equilibria in this system, but the nature and temperatures of the invariant

equilibria are not clear.

The invariant equilibria proposed by all these works can not be accepted because they are contradictory and

adopted on incorrect Cd-Mg phase diagram.

Liquidus Surface

Figure 2 shows a tentative liquidus surface. The region of immiscibility after [1946Mik] extends up to

53Mg-15Al (at.%) and is appreciably larger than determined by [1926Val, 1938Jae, 1938Rie]. The

isotherms of the liquidus surface are taken from [1946Mik] with minor corrections according to the

accepted binary diagrams.

Isothermal Sections

Isothermal sections of the Al-Cd-Mg phase diagram are reported by [1938Rie, 1938Jae, 1946Mik,

1993Kal]. They contain a number of incorrect features originating from erroneous edge binary Cd-Mg and

Al-Mg systems and have been amended accordingly. The isothermal sections of Figs. 3 and 4 are based on

[1938Rie, 1946Mik, 1993Kal] with modification being applied to match with the accepted edge

binary systems.

The compositions of coexisting phases in the three-phase equilibria at 302°C were determined by [1993Kal]

by microprobe analyses (see Table 2). These data have been used in this evaluation to construct the

isothermal section at 302°C (Fig. 3).

Although [1993Kal] (Table 2) postulates a homogeneity range of about 1 at.% Mg for the phase, it is

treated here as a line compound (Fig. 3) to be consistent with the well established Al-Mg binary diagram.

The isothermal section at 230°C after [1938Rie] was adopted to the accepted binary systems (Fig. 4). The

isothermal sections constructed by [1946Mik] for temperatures of 25 and 395°C are incompatible with both,

the accepted binary phase diagrams and the isothermal sections after [1938Rie] and [1993Kal] at 302°C and

at 230°C. Therefore these data are not presented here.

References

[1925Val] Valentin, J., Chaudron, G., “On the Solidification of Ternary Al-Mg-Cd Alloys” (in

French), Compt. Rend., 180, 61-63 (1925) (Experimental, Equi. Diagram, 7)

[1926Val] Valentin, J., “Contribution to the Study of Ternary Alloys” (in French), Rev. Metall., 23,


[1935Hau] Haughton, J.I., Pain, J.M, “Alloys of Magnesium. Part III. Constitution of the

Magnesium-Rich Alloys Containing Aluminium and Cadmium”, J. Inst. Met., 57, 287-296


[1937Koe] Köster, W., Dullenkopf, W., “The Mg-Corner of the Mg-Al-Cd System” (in German),

Z. Metallkd., 29, 202-204 (1937) (Equi. Diagram, Experimental, 3)

[1938Jae] Jaenecke, E., “On Mg-Cd Containing Ternary Alloys and the Binary Mg-Cd Phase Diagram

II” (in German), Z. Metallkd., 30, 424-429 (1938) (Equi. Diagram, Review, 21)

170


MSIT®

Al–Cd–Mg

[1938Rie] Rieder, K., “X-Ray and Micrographic Investigations on the Al-Mg-Cd Phase Diagram” (in

German), Z. Metallkd., 30, 15-16 (1938) (Equi. Diagram, Experimental, 4)

[1946Mik] Mikheeva, V.I., Vasil’eva, V.P., Kryukova, O.N., “Physico-Chemical Analysis of

Magnesium-Rich Alloys of Magnesium-Aluminium-Cadmium System” (in Russian), Izv.

Sekt. Fiz.-Khim. Anal., 16, 275-294 (1946) (Equi. Diagram, Experimental, 21)

[1968Sam] Samson, S., Gordon, E.K., “The Crystal Structure of -Mg23Al30”, Acta Crystallogr., B24,


[1976Mon] Mondolfo, L.F., “Aluminium Alloys: Structure and Properties”, Butterworths,

London-Boston, 463 (1976) (Equi. Diagram, Crys. Structure, Phys. Prop., Review, 8)

[1981Sch] Schürmann, E., Voss, H.-J., “Study of the Melting Equilibria of Mg-Li-Al Alloys” (in

German), Giessereiforschung, 33, 43-46 (1981) (Equi. Diagram, Experimental, 17)

[1993Kal] Kalmykov, K.B., Dunaev, S.F., Slyusarenko, E.M., “Interaction of Elements in the

Al-Cd-Mg at 575 K” (in Russian), Vestn. MGU Khim, 34(4), 384-387 (1993) (Equi.


[1997Su] Su, H.-L., Harmelin, M., Donnadieu, P., Baetzner, C., Seifert, H.J., Lukas, H.L., Effenberg,


Al”, J. Alloys Compd., 247, 57-65 (1997) (Experimental, Crys. Structure, Equi. Diagram, #,

*, 20)


Seifert, H. J., Lukas, H.-L., Aldinger, F., “Experimental Investigation and Thermodynamic

Calculation of the Central Part of the Mg-Al Phase Diagram”, Z. Metallkd., 89, 536-540

(1998) (Equi. Diagram, Thermodyn., Experimental, Theory, *, 33)





Phase /

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

(Al)

< 660

cF4

Fm3m

Cu

a = 404.96 pure Al at 25°C [Mas2]

(Mg,Cd)

< 650

hP2

P63/mmc

Mg

a = 297.88

c = 561.67

a = 320.94

c = 521.05

pure Cd at 21°C [Mas2]

pure Mg at 25°C [Mas2]

, Mg2Al3< 452

cF1168

Fd3m

Mg2Al3


[2003Luk]

60-62 at.% Al [1997Su]

, Mg23Al30

410-250

hR159

R3

Mg23Al30

a = 1282.54

c = 2174.78

[V-C, 1981Sch, 1968Sam]


[2003Luk]

, Mg17Al12

< 458

cI58

I43m

Mn

a = 1048.11

a = 1053.05

a = 1056

a = 1057.91

52.58 at.% Mg [L-B]

56.55 at.% Mg [L-B]

58.62 at.% Mg (Mg17Al12) [P]

60.49 at.% Mg [L-B]

171


MSIT®

Al–Cd–Mg

Table 2: Solid Phases Compositions in the Three-Phase Fields of the Al-Cd-Mg System at 302°C [1993Kal]

´, MgCd3

< 125

hP8

P63/mmc

Ni3Sn

a = 623.35

c = 504.50

at 24.8 at.% Mg and 25°C

[Mas2, V-C2]

´´, MgCd

< 253

oP4

Pmma

AuCd

a = 500.51

b = 322.17

c = 527.00


[Mas2, V-C2]

´´´, Mg3Cd

< 186

hP8

P63/mmc

Ni3Sn

a = 631.3

c = 507.4


[Mas2, V-C2]

Three-Phase Field Phase Composition (at.%)

Al Cd Mg

+ + (Al)

(Al)

0.9

61.3

95.6

42.1

0.5

0.3

57.0

38.2

4.1

+ + 2.1

60.5

54.2

36.9

0.4

3.1

61.0

39.1

42.7

+ + 2.9

53.1

42.7

34.9

3.0

7.0

62.2

43.9

50.3

Phase /

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

172


MSIT®

Al–Cd–Mg

90

10

10

Mg Mg 85.00Cd 15.00Al 0.00

Mg 85.00Cd 0.00Al 15.00 Data / Grid: at.%

Axes: at.%

200°C

291°C

358°C

420°C

Fig. 1: Al-Cd-Mg.

Boundaries of (Mg)

solid solution at

different

temperatures

20

40

60

80

20 40 60 80

20

40

60

80

Mg Cd


Axes: at.%

600

550

500450

?

?

?

L1+L2

(Al)

(Al)

e1,450.5

e2,449.5

e3,436

450

l1, 650°C

l2, 650e4, 320δ(Mg,Cd)

δ(Mg,Cd)

γ

β ?

Fig. 2: Al-Cd-Mg.

Tentative liquidus

surface

173


MSIT®

Al–Cd–Mg

20

40

60

80

20 40 60 80

20

40

60

80

Mg Cd


Axes: at.%

(Al)+δ+ββ

δ(Mg,Cd)

δ+β+ε

δ+ε+γ

ε

γ

(Al) + δ

δ + γ

(Al)

20

40

60

80

20 40 60 80

20

40

60

80

Mg Cd


Axes: at.%

(Al) + δ + ββ

δ(Mg,Cd)

δ + ε + γ

γ

(Al) + δ

δ + γ

α'''

α''' + δ(Mg,Cd)

(Al)

Fig. 3: Al-Cd-Mg.


302°C

Fig. 4: Al-Cd-Mg.


230°C

174


MSIT®

Al–Ce–Co

Aluminium – Cerium – Cobalt

Oksana Bodak

Literature Data

Critical analysis of the literature data has been carried out by [1991Gri], based on 11 articles, from which

the following information could be retrieved: the partial isothermal section at 600°C [1980Zar],

composition and structure of several compounds such as CeCoAl4 [1974Yar, 1977Ryk], CeCoAl [1971Oes,

1983Gri], Ce2Co15Al2 [1962Zar], structure of the phases at 33.3 [1968Man, 1982Eva] and 16.7 at.% Ce

(RCo5-xAlx) [1976Zak, 1982Eva], enthalpy of formation of the CeCoAl compound [1987Shi].

Three new works contain the results of investigations concerning crystal structure and magnetic properties

of the CeCoAl4 compound [1997Moz] and the Ce2Co17-xAlx phase [1999Hu, 1999She1, 1999She2].

The samples were generally prepared by arc melting the pure metals. Both annealed and as cast alloys were

investigated. Mainly the X-ray diffraction methods were used for crystal structure determination. Only the

CeCoAl4 crystal structure was studied also by neutron diffraction [1997Moz]. Magnetic properties were

studied by means of a SQUID magnetometer in the 5-300 K temperature range and in magnetic fields up to

5 T [1997Moz, 1999Hu]. Extracting sample magnetometer in fields up to 65 kOe was used by [1999She1,

1999She2]. Foner magnetometer and Faraday method were used in older works.

Binary Systems

Ce-Co and Al-Ce binary systems were taken from [Mas2]. Al-Co system was accepted from the [2003Gru]

assessment.

Solid Phases

Four ternary compounds were found in the system, for all of them the crystal structure has been determined:

1, CeCo2Al8 by [1974Yar], 3, CeCoAl4 by [1977Ryk, 1997Moz]. [1962Zar] described the Ce2Co15Al2ternary phase. The existence of this phase was confirmed by [1999Hu, 1999She1, 1991She2]. However the

stability ranges of the rhombohedral phase significantly differ in these articles: it is Ce2Co15-14Al2-3

according to [1999Hu], and Ce2Co16-14Al1-3 according to [1999She2]. Moreover, in the latter article, at the

composition Ce2Co13-12Al4-5 a hexagonal phase similar to CaCu5 was reported. This discrepancy may

result from different investigation temperatures (1000°C in [1999She1, 1999She2]). An earlier

investigation of the Ce1-xCo5Alx composition, annealed at 1000°C, was made by [1982Eva]. It showed that

substitution of 1 to 3 at.% Al (0.06 x 0.18) for Ce in CeCo5 produces a mixture of the 1:5 and 2:17

phases; there are two variations of the 2:17 phase which are isostructural with the hexagonal Th2Ni17 type

and rhombohedral Th2Zn17 type phases respectively. At the composition Ce0.76Co5Al0.24 (4 at.% Al) the

alloy consists of the 2:17 type phases and the metallographic appearance is single phase.

Some uncertainty is with the CeCoAl compound. [1968Man, 1969Tes] adopted for this phase the MgZn2

type structure. Previously [1971Oes] had proposed a different crystal structure, even though [1968Man]

reported the presence of an additional phase. [1980Zar] also reports that CeCoAl does not belong to MgZn2

type structure. Complete investigation of the CeCoAl structure using single-crystal technique was

performed by [1983Gri]: he determined a monoclinic structure related to MgZn2.

The crystal structure of all the phases included in the investigated part of the system is presented in Table 1.

Isothermal Section

The Al-Ce-Co isothermal section at 600°C is presented in Fig. 1. It is built according to [1980Zar], but

modified taking into account new data on the Al-Co system [2003Gru]. The CeCo5-xAlx phase is reported

to exist in the ternary [1976Oes, 1980Zar, 1982Eva] but, at this temperature, it is not stable in the Ce-Co

subsystem.

175


MSIT®

Al–Ce–Co

Miscellaneous

In most cases, the magnetic properties of CeCoAl, CeCoAl4 and of the solid solutions based on Ce2Co17,

CeCo5 and CeCo2 were investigated. Only for CeCoAl phase also the enthalpy of formation was measured

[1987Shi].

References

[1962Zar] Zarechnyuk, O.S., Kripyakevich, P.I., ”The Crystal Structures of Ternary Compounds in the

Systems Cerium-Transition Metal-Aluminium” (in Russian), Kristallografiya, 7, 543-554

(1962) (Experimental, Crys. Structure, 9)

[1968Man] Mansey, R.C., Raynor, G.V., Harris, I.R. “Rare-Earth Intermediate Phases. VI. Pseudo

binary Systems Between Cubic Laves Phases Formed by Rare-Earth Metals with Fe, Co, Ni,

Al and Rh”, J. Less-Common Met., 14, 337-347 (1968) (Experimental, Crys. Structure, 6)

[1969Tes] Teslyuk, M.Yu., “Intermetallic Compounds with Structure of Laves Phases” (in Russian),

Intermetallic Compounds with Structure of Laves Phases, Moscow, Nauka, 1-138 (1969)

(Review, Crys. Structure, Equi. Diagram, 132)

[1971Oes] Oesterreicher, H., “Structural Studies of Rare-Earth Compounds RCoAl”, J. Less-Common

Met., 25, 228-230 (1971) (Experimental, Crys. Structure, 13)

[1974Yar] Yarmolyuk, Ya.P., Rykhal, R.M., Zarechnyuk, O.S., “Crystal Structure of CeFe2Al8 and

LaCoAl4” (in Russian), Tezisy Dokl.-Vses. Konf. Kristallokhim. Intermet., 2nd., 39-40


[1976Oes] Oesterreicher, H., McNeely, D., “Low-Temperature Magnetic Studies on Various

Substituted Rare Earth”, J. Less-Common Met., 45, 111 (1976) (Experimental, Crys.

Structure, 6)

[1976Zak] Zakharova, M.I., Gladyshev, S.N., Khatanova, N.A., Tulupov, I.F., Vereshnikov, E.E.,

Bal’zhinev, S.A., “Phase Composition and Structure of RCo5 Type Alloys with Additional

Elements (Cu, Al, Mn, Nb, Ni)”, Russ. Metall., (3), 156-159 (1976) translated from Izv.

Akad. Nauk SSSR, Met., (3), 205-209 (1976) (Crystal Structure, Experimental, 3)

[1977Ryk] Rykhal, R.M., Zarechnyuk, O. S., Yarmolyuk, Y.P., “Crystal Structure of the Compounds

LaCoAl4, GeCoAl4 and PrCoAl4” (in Ukrainian), Dop. Akad. Nauk Ukr. RSR A, Fiz-Mat.

Tekh. Nauki, 3, 265-268 (1977) (Experimental, Crys. Structure, 2)

[1980Zar] Zarechnyuk, O.S., Rykhal, R.M., Korin, V.V. “X-Ray Structural Study of Alloys of the

Ternary Cerium-Cobalt-Aluminium System in the Region 0-33.3 at.% Cerium” (in

Ukrainian), Dop. Akad. Nauk Ukr. RSR, 1A, 84-85 (1980) (Experimental, Crys. Structure,

Equi. Diagram, #, *, 9)

[1982Eva] Evans, J., Harris, I. R., “Constitution, Structure and Magnetic Properties of Some

Rare-Earth-Cobalt-Aluminium Alloys”, J. Mater. Sci., 17(1), 17-30 (1982) (Experimental,

Crys. Structure, 18)

[1983Gri] Grin, Yu. N., Sichevich, O.M., Bruskov, V.A., Rykhal, R.M., Yarmolyuk,Ya.P. “Crystal

Structure of CeAlCo and CeGaCo Compounds”, Sov. Phys. Crystallogr., 28(3), 346-347


[1987Shi] Shilov, A.L., “Heats of Formation of Intermetallic Compounds”, Russ. J. Phys. Chem.,

61(5), 719 (1987), translated from Zh. Fiz. Khim., 61, 1384-1385 (1987) (Experimental,

Thermodyn., 13)

[1988Gsc] Gschneidner, Jr.K.A., Calderwood, F.W., “The Aluminum-Cerium (Al-Ce) System”, Bull.

Alloy Phase Diagrams, 9(6), 669-72 (1988) (Review, 35)

[1991Gri] Grieb, B., “Aluminium-Cobalt-Cerium”, MSIT Ternary Evaluation Program, in MSIT


Stuttgart, Document ID: 10.14766.1.20 (1991) (Review, Equi. Diagram, Crys. Structure,

11)

176


MSIT®

Al–Ce–Co

[1997Moz] Moze, O., Tung, L.D., Franseand, J.J.M., Buschow, K.H.J., “Crystal Structure and the

Magnetic Properties of the Compound CeCoAl4”, J. Alloys Compd., 256, 45-47 (1997)

(Experimental, Crys. Structure, Magn. Prop., 8)

[1999Hu] Hu, S.J., Wei, X.Z., Zeng, D.C., Kou, X.C., Liu, Z.Y., Brueck, E., Klaasse, J.C.P., de Boer,

F.R., Buschow, K.H.J., “Structure and Magnetic Properties of Ce2Co17-xAlx Compounds”,

J. Alloys Compd., 283, 83-87 (1999) (Experimental, Crys. Structure, Magn. Prop., 10)

[1999She1] Shen, B., Cheng, Z., Zhang, S., Wang, J., Liang, B., Zhang, H., Zhan, W., “Magnetic

Properties of R2Co15Al2 Compounds with R= Y, Ce, Pr, Nd, Sm, Gd, Tb, Ho, Er, Tm”,

J. Appl. Phys., 85(5), 2787-2792 (1999) (Experimental, Crys. Structure, Magn. Prop., 43)

[1999She2] Shen, B., Wang, J., Zhang, H., Zhang, S., Cheng, Z., Liang, B., Zhan, W., Lin, C.,

“Magnetocrystalline Anisotropy of Ce2Co17-xAlx Compounds with x = 0-3”, J. Appl. Phys.,

85(8), 4666-4668 (1999) (Experimental, Crys. Structure, Magn. Prop., 6)

[2003Gru] Grushko, B, Cacciamani, G., “Al-Co (Aluminium-Cobalt)”, MSIT Binary Evaluation


Services GmbH, Stuttgart; to be published, (2003) (Equi. Diagram, Assessment, Crys.

Structure, 72)


Phases/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

(Al)

< 660.452

cF4

Fm3m

Cu

a = 404.88 [Mas2]

( Co)

1495-422

cF4

Fm3m

Cu

a = 354.46 [Mas2]

( Co)

< 422

hP2

P63/mmc

Mg

a = 250.71

c = 406.95

[Mas2]

Co2Al9< 970

mP22

P21/a

...

a = 855.6

b = 629.0

c = 621.3

= 94.76°

[2003Gru]

O-Co4Al13

< 1080

oP102

Pmn21

O-Co4Al13

a = 815.8

b = 1234.7

c = 1445.2

[2003Gru]

M-Co4Al13

1093-?

mC102

C2/m

Fe4Al13

a = 1517.3

b = 810.9

c = 1234.9

= 107.84°

[2003Gru]

Y

1127-?

either (o-Co4Al13)

or (m-Co4Al13)

...

Immm

mC34

C2/m

Os4Al13

a = 1531.0

b = 1235.0

c = 758.0

a = 1704.0

b = 409.0

c = 758.0

= 116.0°

[2003Gru]

177


MSIT®

Al–Ce–Co

Z

< 1158

C-centr. monocl. a = 3984.0

b = 814.8

c = 3223.0

= 107.97°

[2003Gru]

Co2Al5< 1188

hP28

P63/mmc

Co2Al5

a = 767.2

c = 760.5

[2003Gru]

Co1-xAlx< 1640

cP2

Pm3m

CsCl

a = 285.7

a = 286.2

a = 285.9

x = 0.52 [2003Gru]

x = 0.5

x = 0.43

Ce3Al11

1235-1020

tI10

I4/mmm

BaAl4

a = 437.4

c = 1012

[Mas2, V-C2]

Ce3Al11

< 1020

oI28

Immm

La3Al11

a = 439.5

b = 1302.5

c = 1009.2

[Mas2, V-C2]

CeAl3< 1135

hP8

P63/mmc

Ni3Sn

a = 654.1

c = 461.0

[Mas2, V-C2]

CeAl2-xCox

< 1480

cF24

Fd3m

MgCu2

a = 804.73

a = 801.5 ± 2

0 < x < 0.3 at 600°C [1980Zar]

x = 0 [1968Man]

x = 0.166 [1968Man]

CeAl

< 845

oC16

Cmc2 or Cmcm

CeAl

a = 926.9

b = 768.0

c = 576.1

[1988Gsc]

Ce3Al

655-250

cP4

Pm3m

AuCu3

a = 498.9 [1988Gsc]

Ce3Al

< 250

hP8

P63/mmc

Ni3Sn

a = 704.2

c = 545.1

[1988Gsc]

Phases/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

178


MSIT®

Al–Ce–Co

Ce2Co17-xAlx1220-~1050

hP38

P63/mmc

Th2Ni17

hP6

P6/mmm

CaCu5

a = 839

c = 816.3

a = 838

c = 812

a = 838.1

c = 814.0

a = 838.8

c = 814.4

a = 840.2

c = 816.4

a = 846.2

c = 1232.8

a = 843.0

c = 1235.1

a = 493.3

c = 411.6

a = 494.8

c = 409.3

x = 0 [1976Oes]

x = 0 [1962Zar] at 500°C

x = 0 [1999She2] at 1000°C

x = 0 [1999Hu] at 1000°C

x = 1 [1999She2]at 1000°C

x = 3 [1999She2] at 1000°C

x = 3.5 [1999Hu] at 1000°C two phase

sample (1:5)

x = 4 [1999Hu] at 1000°C

x = 5 [1999Hu] at 1000°C

Ce2Co17-xAlx1050

hR57

R3m

Th2Zn17

a = 837.8

c = 1220.6

a = 839.7

c = 1222.7

a = 841.1

c = 1225.4

a = 843.4

c = 1228.8

a = 843.3

c = 1230.2

x = 0 [Mas2, V-C2]

x = 1 [1999Hu]at 1000°C

x = 2 [1999Hu] at 1000°C

x = 2 [1999She2] at 1000°C

x = 3 [1999Hu] at 1000°C

Phases/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

179


MSIT®

Al–Ce–Co

CeCo5-xAlx

CeCo5

1134-600

hP6

P6/mmm

CaCu5

a = 491.97

c = 402.9

a = 491.6

c = 401.2

a = 493

c = 402

a = 492.92

c = 401.73

a = 492.87 ± 50

c/a = 0.815

a = 492.92 ± 50

c/a = 0.815

a = 493.00 ± 50

c/a = 0.815

a = 492.9

c = 402.2

a = 493.8

c = 403.2

a = 490.2

c = 410.5

a = 491.0

c = 410.4

a = 503

c = 407

0.03 < x < 1.2 at 600°C [1980Zar]

x = 0 [Mas2, V-C2]

x = 0 [1976Oes]

x = 0, at 600°C

[1980Zar]

x = 0, at 1000°C

[1982Eva]

x = 0.06 (Ce1-xCo5Alx) [1982Eva]

x = 0.12 (Ce1-xCo5Alx) [1982Eva]

x = 0.18 (Ce1-xCo5Alx) [1982Eva]

x = 0.3 [1976Oes]

x = 0.6 [1976Oes]

x = 0.9 [1976Oes]

x = 1.2 [1976Oes]

x = 1.2 [1980Zar]

Ce5Co19

< 1134

hR72

R3m

Ce5Co19

a = 494.75

c = 4874.34

[Mas2, V-C2]

Ce2Co7

< 1130

hP36

P63/mmc

Ce2Ni7

a = 494.9

c = 2449

[Mas2, V-C2]

CeCo3

< 1103

hR36

R3m

NbBe3

a = 496.4

c = 2481.4

[Mas2, V-C2]

CeCo2-xAlx< 1036

CF24

Fd3m

MgCu2

a = 714.67

a = 715

a = 717.6

a = 719

0.3 < x < 0 [1980Zar]

x = 0 [1968Man]

x = 0 [1980Zar]

x = 0.167 [1968Man]

x = 0.3 [1980Zar]

Ce24Co11 hP70

P63mc

Ce24Co11

a = 958.7

c = 2182.5

[V-C2]

* 1, CeCo2Al8 oP44

Pbam

CeFe2Al8

a = 1241

b = 1430

c = 412

[1974Yar, 1980Zar]

Phases/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

180


MSIT®

Al–Ce–Co

* 2, Ce2Co15Al2 hR57

R3m

Th2Zn17

a = 844

c = 1230

a = 844

c = 1250

[1962Zar]

[1980Zar]

* 3, CeCoAl4 oC12

Pmma

LaCoAl4

a = 770.1

b = 408.2

c = 702.3

a = 7589

b = 404.8

c = 701.4

a = 766.024

b = 405.616

c = 691.355

[1977Ryk]

[1980Zar]

[1997Moz]

* 4, CeCoAl hP12

P63/mmc

MgZn2

mC12

C2/m

PdBi2

a = 514.0

c = 800.0

a = 549.0

c = 866.0

a = 1109.8(7)

b = 441.0(1)

c = 480.7(3)

= 104.61(5)°

[1969Tes]

[1968Man]

(related to MgZn2 ) [1983Gri]

Phases/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

20

40

60

80

20 40 60 80

20

40

60

80

Ce Co


Axes: at.%

Ce3Al11

CeAl3

CeAl2

Co2Al9

Co2Al5

Co1-xAlx

CeCo2

CeCo3Ce5Co19

Ce2Co7Ce2Co17

O-Co4Al13

Zτ

1

τ5

τ3 τ

2

τ4

(Co)

Fig. 1: Al-Ce-Co.


600°C

181


MSIT®

Al–Ce–Cu

Aluminium – Cerium – Copper

Peter Rogl, updated by Paola Riani, Pierre Perrot

Literature Data

No complete phase diagram exists for the Al-Ce-Cu system and information about the phase equilibria inthe Al-rich part of the system is mainly based on the investigations by [1961Gla1, 1964Zar, 1991Yun]. Thecrystallographic characterization of the ternary compounds is due to [1961Gla2, 1963Zar, 1964Che,1964Zar, 1968Dwi, 1976Bus, 1985Cor1, 1985Cor2], while interesting physical properties were reported by[1987Bau, 1988Fis, 1991Kim, 2000Jav] and structural properties by [1978Tak, 1985Rau, 1990Cor,1996Moz]. Investigations on magnetic properties were made by [1973Oes, 1982Fel, 1992Bau, 1996Moz,1998Jav, 1999Kon] and thermal effects studied by [2000Kon, 2001Che].[1961Gla1] was the first to examine the phase relations in the Al-rich corner employing X-ray,metallographic and chemical analysis and micro-hardness measurements on a total of 130 alloys. Ce-richspecimens were prepared from 99.9 mass% pure Al, 98.6% pure Ce and 99.89% pure Cu by melting theconstituents; Ce-poor specimens were prepared from a “hardener” alloy in Al2O3-crucibles under carnallite.All the alloys were annealed in vacuum at 500 and 400 2°C for 120 or 240 h, respectively and were finallyquenched in toluene. Lattice parameters were measured with a claimed precision of 0.01 pm on polishedsample surfaces in a back-reflection camera at 400 and 500°C for three series of alloys with constantamounts of 1 mass% Ce, 5 mass% Ce and 5 mass% Cu, respectively. The plots of the unit cell dimensionsversus concentration were used to establish the extension limits and vertices of the two- and three-phaseequilibria of the (Al) solid solution. A series of successive crystallographic investigations [1961Gla2,1963Zar, 1964Che, 1964Zar, 1990Cor, 1996Moz] confirmed and completed the description of the ternarycompounds originally reported by [1961Gla1], with some changes in the composition and homogeneityfields of the intermediate phases. A more complete version of the phase equilibria in the Al-rich part of the400°C isothermal section was presented in a review article by [1985Bod]. Similar preparation methods wereemployed by [1968Dwi, 1973Oes, 1982Fel, 1985Cor1, 1985Cor2]. [1991Yun] employed DTA andmicrostructural analysis to investigate the specimens prepared by melting the constituent metals andannealing them at 500°C for 240 h. The liquidus surface and a number of vertical sections in the Al-richregion have been constructed by [1991Yun]. The present evaluation updates and completes the evaluationmade earlier by P. Rogl in the MSIT Evaluation Program [1991Rog].

Binary Systems

The present evaluation of ternary data is consistent with the description of the edge binary diagrams Al-Ceby [2000Oka], Al-Cu by [2003Gro] and Ce-Cu by [2002Per].

Solid Phases

Crystallographic data of all the binary and ternary compounds are listed in Table 1. On the basis of X-raypowder data for 1(CeCu4Al8), [1963Zar] and [1976Bus] agree on the existence of complete atomic orderwith Ce in the 2a sites, Cu in 8f and Al in the 8i and the 8j sites of space group I4/mmm. There is, however,a slight discrepancy in the unit cell dimensions reported by the two research groups possibly due tohomogeneity differences. The existence of the 2 homogeneous range extending at 500°C fromCe2Cu6.5Al10.5 to Ce2Cu7.3Al9.7 was determined by [1963Zar]. From an analysis of the X-ray powderintensity data a partial atomic order was revealed for Ce2Cu6.5Al10.5 with Ce in the 6c-sites, Cu in 9d,(10.5Cu+7.5Al) in 18 h, Al in 6c (0, 0, 0.097) and Al in the 18f sites of space group R3m. Single crystal andpowder X-ray intensity data for 4(CeCuxAl4-x) (0.75 x 1.00) revealed Ce atoms in 2a, Al atoms in 4dand a statistical distribution of Cu and Al atoms in the 4e-positions (0, 0, 0.385(3)) [1964Zar]. A partiallyordered structure for CeCuAl3 and its conversion into the completely ordered BaNiSn3 type has beendescribed by [1995Hul]. According to [1996Moz] the refinement results of neutron powder diffraction

182


MSIT®

Al–Ce–Cu

patterns show that the CeCuAl3 compound does not crystallize as a disordered form of the ThCr2Si2structure but belongs to the more ordered BaNiSn3-type. Refinement of single crystal X-ray data of

3(CeCu6.5Al6.5) confirmed isotypism with the NaZn13 type and a statistical distribution of Cu, Al atomsin the 96i-sites (0, 0.1780(2), 0.1181(2)) of space group Fm3c with Ce in 8a and Cu in 8b. No indicationsfor the existence of a homogeneous range were made by [1985Cor1, 1985Cor2], however, significantlylarger cell parameters for a stoichiometry of “CeCu6Al6” were reported by [1982Fel].

Liquidus Surface

A projection of the liquidus surface was suggested by [1991Yun]. However it does not completely fit neitherthe vertical sections presented in the same work, nor the accepted binary diagrams, and therefore theliquidus projection is not reproduced in this evaluation. Figure 1 shows the primary crystallization domainsin the Al-CeAl2-CuAl2 part of the diagram after [1991Yun] with some modifications made to comply withthe accepted binary edge diagrams. The 1, CeCu4Al8 and 4,CeCuxAl4-x compounds are considered asstoichiometric and melt congruently at 825 and 1230°C, respectively. The stoichiometry given for

4,CeCuxAl4-x by [1991Yun] differs slightly from that proposed by [1964Zar]: 4,CeCuxAl4-x (with0.75 < x < 1). Invariant equilibria and reaction scheme are presented in Table 2 and Fig. 2, respectively.However it has to be noted that phase compositions at invariant reactions given by [1991Yun] in a tabularpresentation are not compatible with those shown in the diagram in the same publication. The values givenin Table 2 in the present evaluation are estimated from the diagram given by [1991Yun] and should beconsidered as tentative.For the 5,CeCuAl compound a peritectoid decomposition above 650°C was suggested by [2001Che], withthe formation of CeCu5-xAlx, CeAl2 and a new ternary phase with unknown structure corresponding to theCe2Cu2Al composition.

Isothermal Sections

Figures 3 and 4 show the equilibria in the Al-rich region at 400 and 500°C. The phase field distribution at400°C is mainly based on [1961Gla1] with small corrections made regarding to the position andhomogeneity ranges of the binary and ternary phases. The two-phase equilibrium

Ce3Al11 + 4CeCu0.75Al3.25 as shown in Figs. 3 and 4 was also observed at 800°C by [1964Zar], whereasalloys with 20 at.% Ce and with 40 and 50 at.% Al at 800°C were reported to reveal a two-phasedequilibrium between CeCuxAl4-x and CeCu5-xAlx (CaCu5 type). The extended solid solution of Al in CeCu5with the CaCu5 type structure is confirmed by [1978Tak], who claimed the existence of CeCu4Al andCeCu3Al2 with this structure, whilst an alloy “CeCu2Al3” was found to be multi-phase. There are, however,no details available concerning the extended solid solution CeCu4-xAlx reported by [1985Bod].


A number of vertical sections of the phase diagram, (Al)- 1,CeCu4Al8, (Al)- 4,CeCuAl4, 1,CeCu4Al8-

4,CeCuAl4 and 4,CeCuAl4-CeAl2, all showing a simple eutectic behavior were studied by [1991Yun].They are shown in Figs. 5, 6, 7 and 8. The eutectic temperatures have been accepted as given by the authors.However, the positions of the eutectic e5 (Fig. 5) and e4 (Fig. 6) have been modified for the sake ofcoherence with crystallization domains shown in Fig. 1.


[1961Gla1] reported on the microhardness of the (Al) solid solution; a microhardness of 200 MPa for abinary (Al - 1 mass% Ce) alloy is compared with 420 MPa for a ternary (Al - 1 mass % Ce - 6 mass % Cu)alloy. The microhardness of CeCu4Al8 was 3860 100 MPa, and that of CeCuAl3 was 3170 100 MPa[1961Gla1]. From a magnetic analysis, CeCuAl exhibits a small value of susceptibility and does not ordermagnetically [1973Oes]. For the ternary compounds CeCu4Al8, Ce2Cu7Al10 and CeCu6.5Al6.5 physicalproperties have been investigated by [1985Rau], such as electrical resistivity (30 mK to 400 K),thermoelectric power (1.5 to 400 K), low field a.c. susceptibility (117 Hz, 30 mK to 4.2 K, in fields up to

183


MSIT®

Al–Ce–Cu

8 T) and the specific heat (from 100 mK to 4.2 K, 0-8 T) CeCu6.5Al6.5 shows a magnetic transition at 0.5K, which displays spin-glass-like behavior although representing a periodic lattice of local moments[1985Rau]. “CeCu6Al6” (NaZn13 type) was claimed to exhibit paramagnetic behavior of trivalent cerium down to 1.7K [1982Fel]. [1996Shc] carried out LIII X-ray absorption (77 and 300 K) and magnetic susceptibilitymeasurements on RCu4Al8 compounds finding peculiarities of the valence state of Ce and Yb in RCu4Al8.Finally [2000Kon] studied magnetic properties of CeCu4+xAl8-x (0 x 0.55) by specific heat andelectrical resistivity, 27Al-NMR and 63Cu-NQR measurements.Spin fluctuations in the Ce2Cu8Al9 phase have been studied by neutron scattering [1999Ooh].[1996Aoy] carried out an NMR study on the heavy fermion material CeCuAl3 and [1996Kon] studied byNMR the effect of high pressure on the heavy fermion anti-ferromagnet CeCuAl3, up to 15 kbar.Subsequently [1999Kon] investigated magnetic properties of CeCuxAl4-x for x = 0.8, 0.9, 1, 1.1, bymagnetic susceptibility, high-held magnetization, specific heat and electrical resistivity measurements onsingle crystal samples.Recent papers about magnetic properties of the RCuAl phases are the following. [2000Jav] reported a comparative study of CeNiAl and CeCuAl with respect to crystal structure and specificheat: magnetic ordering below 5 K has been proposed for CeCuAl, the coefficient of the specific heat is~150 mJ mol-1K-2, as obtained in the range 12-20 K. Subsequently the electrical resistivity andmagnetization measurements, carried out by [2001Che], revealed the occurrence of antiferromagneticordering in CeCuAl below TN = 5.2 K; moreover electronic structure has been investigated by core-levelphotoemission spectroscopy by [1993Sin].Finally [2001Li] studied the effect of Ce addition on the hydrogen absorption of Al-32.2Cu (mass%)eutectic alloy melt. CeCu6.5Al6.5 was said to be stable in air but dissolves slowly in diluted acids [1985Cor1,1985Cor2].

References

[1931Pre] Preston, G.D., “An X-ray Investigation of Some Copper-Aluminium Alloys”, Philos. Mag.,12, 980-993 (1931) (Crys. Structure, Experimental, 11)

[1961Gla1] Gladyshevsky, E.I., Kolobnev, I.F., Zarechnyuk, O.S., “Aluminium-Rich Alloys in the Al-Ce-Cu System”, Russ. J. Inorg. Chem., 6, 1075-1078 (1961), translated from Zhur. Neorg.

Khim., 6, 2103 (1961) (Experimental, Equi. Diagram, 4) [1961Gla2] Gladyshevsky, E.I., Kripyakevich, P.I., Teslyuk, M.Yu., Zarechnyuk O.S., Kuz'ma, Yu.B.,

“Crystal Structures of Some Intermetallic Compounds”, Sov. Phys. Crystallogr., 6, 207-208(1961) (Crys. Structure, 11)

[1963Zar] Zarechnyuk, O.S., Kripyakevich, P.I., “Crystal Structures of Ternary Compounds in theSystems Cerium - Transition Metal - Aluminium”, Sov. Phys. Crystallogr., 7, 436-446(1963) (Experimental, Crys. Structure, 9)

[1964Che] Cherkashin, E.E., Zarechnyuk, O.S., Kripyakevich, P.I., Kolobnev, I.F., “Crystal Structureof the Compounds in the Ce-Mn-Cu-Al System and in the Corresponding Ternary System”,Vopr. Teorii i Primeneniya Redkozem. Metal., Akad. Nauk SSSR, 151-152 (1964)(Experimental, Crys. Structure, 8)

[1964Zar] Zarechnyuk, O.S., Kripyakevich, P.I., Gladyshevskij, E.I., “Ternary IntermetallicCompounds with a BaAl4 Type Superlattice”, Sov. Phys. Crystallogr., 9, 706-708 (1965),translated from Kristallografiya, 9, 835-838 (1964) (Experimental, Crys. Structure, 6)

[1968Dwi] Dwight, A.E., Muller, M.H., Conner, Jr., R.A. Downey, J.W., Knott, H., “TernaryCompounds with the Fe2P Type Structure”, Trans. AIME, 242, 2075-2080 (1968)(Experimental, Crys. Structure, 14)

[1973Oes] Österreicher, H., “Structural and Magnetic Studies on Rare Earth Compounds RNiAl andRCuAl”, J. Less-Common Met., 30, 225-236 (1973) (Experimental, Crys. Structure, Magn.Prop., 21)

184


MSIT®

Al–Ce–Cu

[1976Bus] Buschow, K.H.J., van Vucht, J.H.N., van den Hoogenhof, W.W., “Note on the CrystalStructure of the Ternary Rare Earth - 3d Transition Metal Compounds of the Type RT4Al8”,J. Less-Common Met., 50, 145-150 (1976) (Crys. Structure, Experimental, 2)

[1978Tak] Takeshita, T., Malik, S.K., Wallace, W.E., “Crystal Structure of RCu4Ag and RCu4Al(R=Rare Earth) Intermetallic Compounds”, J. Solid State Chem., 23, 225-229 (1978)(Experimental, Crys. Structure, 8)

[1982Fel] Felner, I., Nowik, I., “Magnetic Properties of RM6Al6 (R=Light Rare Earth, M = Cu, Mn,Fe)”, J. Phys. Chem. Solids, 43, 463-465 (1982) (Experimental, Crys. Structure, Magn.Prop., 4)

[1985Bod] Bodak, O.I., Gladyshevskij, E.I., Ternary Systems with Rare Earth Metals, Vyshcha Schola,Lviv, 79-80 (1985) (Review, Crys. Structure, Equi. Diagram, 3)

[1985Cor1] Cordier, G., Czech, E., Schäfer, H., “On the Knowledge of the Compounds Ca4Cd5Al3,CaAg4Al7, CaCu6.5Al6.5, SrAg6.5Al6.5 and CeCu6.5Al6.5” (in German), J. Less-Common

Met., 108, 225-239 (1985) (Experimental, Crys. Structure, 33) [1985Cor2] Cordier, G., Czech, E., Schäfer, H., Woll, P., “Structural Characterization of New Ternary

Compounds of Uranium and Cerium”, J. Less-Common Met., 110, 327-330 (1985)(Experimental, Crys. Structure, 5)

[1985Mur] Murray, J.L., “The Aluminum-Copper System”, Int. Met. Rev., 30(5), 211-233 (1985)(Equi. Diagram, Crys. Structure, Review, 230)

[1985Rau] Rauchschwalbe, U., Gottwick, U., Ahlheim, U., Mayer, H.M., Steglich, F., “Investigationof New Lanthanum-, Cerium- and Uranium-Based Ternary Intermetallics”, J. Less-

Common Met., 111, 265-275 (1985) (Experimental, Crys. Structure, 31) [1987Bau] Bauer, E., Gratz, E., Pillmayr, N., “Heavy Fermion Behavior of the Nonmagnetic CeCu4Al

Compound”, Solid State Commun., 62(4), 271-274 (1987) (Magn. Prop., Experimental, 22)[1988Fis] Fisk, Z., Thompson, J.D., Ott, H.R., “Heavy-Electrons: New Materials”, J. Magn. Magn.

Mater., 76/77, 637-641 (1988) (Crys. Structure, Experimental, 21)[1988Gsc] Gschneidner Jr, K.A., Calderwood, F.W., “The Aluminum-Cerium (Al-Ce) System”, Bull.

Alloy Phase Diagrams, 9(6), 669-672 (1988) (Review, 35)[1989Mee] Meetsma, A., de Boer, J.L., van Smaalen S., “Refinement of the Crystal Structure of

Tetragonal Al2Cu”, J. Solid State Chem., 83(2), 370-372 (1989) (Crys. Structure,Experimental, 17)

[1990Cor] Cordier, G., Doersam, G., Roehr, C., “New Ternary Representatives of ThCr2Si2- and ofCaZn2Al2-Structure Types in the Systems A-T-X and RE-T-X (A = Calcium, Strontium,Barium; RE = Lanthanum, Cerium, Praseodymium; T = Copper, Silver, Gold andX = Aluminum, Gallium)” (in German), J. Less-Common Met., 166(1), 115-124 (1990)(Crys. Structure, Experimental, 19)

[1990Vrt] Vrtis, M.L., Jorgensen, J.D., Hinks, D.G., “The Structural Phase Transition in the RECu6Compounds (RE = La,Ce,Pr,Nd)” J. Solid State Chem., 84, 93-101 (1990) (Crys. Structure,Experimental, 26)

[1991Ell] Ellner, M., Kolatschek, K., Predel, B., “On the Partial Atomic Volume and the Partial MolarEnthalpy of Aluminium in Some Phases with Cu and Cu3Au Structures”, J. Less-Common

Met., 170, 171-184 (1991) (Experimental, Crys. Structure, 57)[1991Kim] Kim, S.M., Buyers, W.J.L., Lin, H., Bauer, E., “Structure of the Heavy Electron Compounds

Cerium-Copper-Aluminum Ce(CuxAl1-x)5 and Cerium-Copper-Gallium Ce(CuxGa1-x)5”,Z. Phys. B, 84(2), 201-203 (1991) (Crys. Structure, Experimental, 7)

[1991Rog] Rogl, P., ”Aluminium - Cerium - Copper”, MSIT Ternary Evaluation Program, in MSIT

Workplace, Effenberg, G. (Ed.), MSI, Materials Science International Services GmbH,Stuttgart; Document ID: 10.17383.1.20, (1991) (Crys. Structure, Equi. Diagram,Assessment, 18)

[1991Yun] Yunusov, I., Ganiev, I. N., Shishkin, E. A., “Aluminum-Copper-Cerium Phase Diagram inthe Aluminum-Rich Corner” (in Russian), Izv. Akad. Nauk SSSR, Met., (3), 200-203 (1991)(Assessment, Equi. Diagram, 4)

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[1992Bau] Bauer, E., “Anomalous Properties of Ce-Cu-Based Compounds”, J. Magn. Magn. Mater.,108(1-3), 27-30 (1992) (Electr. Prop., Experimental, 19)

[1993Sin] Singhal, R.K., Saini, N.L., Garg, K.B., Kanski, J., Ilver, L., Nilsson, P.O., Kumar, R., Gupta,L.C., “Study of some Cerium Intermetallics by Core-Level Photoemission”, J. Phys.:

Condens. Matter, 5, 4013-4020 (1993) (Experimental, Electr. Prop., 23)[1994Mur] Murray, J.L., “Al-Cu (Aluminum-Copper)”, in “Phase Diagrams of Binary Copper Alloys”,

Subramanian, P.R., Chakrabati, D.T., Laughlin D.E. (Eds.), ASM International, MaterialsPark, OH, 1994, 18-42, (Equi. Diagram, Review, 226)

[1994Sub] Subramanian, P.R., Laughlin, D.E., “Ce-Cu (Cerium-Copper)”, in “Phase Diagrams of

Binary Copper Alloys”, Subramanian, P.R., Chakrabarti, D.J., Laughlin, D.E. (Eds.), ASMInternational 10, 127-133 (1994) (Equi. Diagram, Review, 29)

[1995Hul] Hulliger, F., “On Rare Earth Gold Aluminides LnAuAl3 and Related Compounds”, J. Alloys

Compd., 218, 255-258 (1995) (Crys. Stucture, Magn. Prop., 14)[1996Aoy] Aoyama, S., Ido, H., Nishioka, T., Kontani, M., “NMR Studies on Heavy Fermion Materials

CeCuAl3 and CeCuGa3”, Czech. J. Phys., 46, 2069-2070 (1996) (Experimental, 4)[1996Goe] Goedecke, T., Sommer, F., “Solidification Behaviour of the Al2Cu Phase”, Z. Metallkd.,

87(7), 581-586 (1996) (Equi. Diagram, Crys. Structure, 8)[1996Kon] Kontani, M., Sugihara, N., Murase, K., Mori, N., “High Pressure NMR of Heavy Fermion

Antiferromagnets CeAl2 and CeCuAl3”, Czech. J. Phys., 46, 2067-2068 (1996)(Experimental, Phys. Prop., 4)

[1996Moz] Moze, O., Buschow, K.H.J., “Crystall Structure of CeCuAl3 and its Influence on MagneticProperties”, J. Alloys Compd., 245, 112-115 (1996) (Crys. Structure, Experimental, Magn.Prop., 9)

[1996Shc] Shcherba, I.D., Koterlyn, M.D., Kushnir, A.P., Kutjanskyj, R.R., Synjushko, V.G.,Tsybukh, Y.D., Yatsyk, B.M., Margolych, I.I., “Peculiarities of the Valence State of Ce andYb in RM4Al8 (R = Rare Earth; M = Cr, Mn, Fe, Cu)”, J. Magn. Magn. Mater., 157-158,688-689 (1996) (Magn. Prop., Experimental, 4)

[1998Jav] Javorsky, P., Havela, L., Sechovsky, V., Michor, H., Jurek, K., “Magnetic Behavior ofRCuAl Compounds”, J. Alloys Compd., 264, 38-42 (1998) (Crys. Structure, Experimental,15)

[1998Liu] Liu, X.J., Ohnuma, I., Kainuma R., Ishida, K., “Phase Equilibria in the Cu-rich Portion ofthe Cu-Al Binary System”, J. Alloys Compd., 264(1-2), 201-208 (1998) (Equi. Diagram,Crys. Structure, 25)

[1999Kon] Kontani, M., Motoyama, G., Nishioka T., Murase, K., “Magnetic Properties of CeCuxAl4-x

and CeCuxGa4-x Single Crystals”, Physica B, 261, 24-25 (1999) (Crys. Structure,Experimental, Magn. Prop., 7)

[1999Ooh] Oohara, Y., Kubota, M., Yoshizawa, H., Itoh, S., Nishioka, T., Kontani, M., “SpinFluctuations in Ce2Cu8Al9 and U2Cu8Al9”, J. Phys. Chem. Solids, 60(8-9), 1197-1198(1999) (Magn. Prop., Experimental, 4)

[2000Jav] Javorsky, P., Chernyavsky, A., Sechovsky, V., “Valence Fluctuator CeNiAl Versus Ce(3+)State in CeCuAl”, Physica B, 281-282, 71-72 (2000) (Crys. Structure, Experimental,Thermodyn., 6)

[2000Kon] Kontani, M., Hamada, M., Mizukoshi, T., Mukai, H., “NMR/NQR and Specific HeatStudies on the ThMn12-Type CeCu4+xAl8-x System”, Physica B, 284-288, 1267-1268(2000) (Crys. Structure, Experimental, Magn. Prop., Thermodyn., 6)

[2000Oka] Okamoto, H., Desk Handbook, in “Phase Diagrams for Binary Alloys”, ASM International,Materials Park, OH, 2000 (Experimental, Equi. Diagram)

[2001Che] Chevalier, B., Bobet, J.-L., “On the Synthesis and Physical Properties of the IntermetallicsCeCuAl”, Intermetallics, 9, 835-838 (2001) (Crys. Structure, Electr. Prop., Experimental,Phys. Prop., 9)

[2001Li] Li, W.H., Bian, X.F., Li, H.Y., Duan, Y.F., “Interaction Between Rare Earth Ce andHydrogen in Al-Cu Eutectic Alloy Melt”, Acta Metall. Sin., 37(8), 825-828 (2001)

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[2002Gul] Gulay, L.D., Harbrecht, B., “The Crystal Structures of the 1 and 2 Phases in the Al-CuSystem”, Abstr. VIII Int. Conf. “Crystal Chemistry of Intermetallic Compounds”,September 2002, Lviv, P139, 73 (2002) (Crys. Structure, Experimental, 5)

[2002Per] Perrot, P., Ferro, R., “Ce-Cu (Cerium-Copper)”, MSIT Binary Evaluation Program, in MSIT

Workplace, Effenberg, G. (Ed.), MSI, Materials Science International Services GmbH,Stuttgart; Document ID: 20.16303.1.20, (2003) (Equi. Diagram, Assessment, 25)

[2003Gro] Groebner, J., “Al-Cu (Aluminium-Copper)”, MSIT Binary Evaluation Program, in MSIT

Workplace, Effenberg, G. (Ed.), MSI, Materials Science International Services GmbH,Stuttgart, to be published, (2003) (Equi. Diagram, Assessment, 68)


Phase/Temperature Range [°C]

Pearson Symbol/Space Group/Prototype

Lattice Parameters[pm]

Comments/References

(Cu)< 1084.62

Cu1-xAlx

cF4Fm3m

Cu

a = 361.46

a = 361.52a = 365.36

at 25°C [Mas2],0 to 19.7 at.% Al [Mas2]0 to 0.1 at.% Ce at 876°C [1994Sub][1991Ell], x = 0, quenched from 600°C[1991Ell], x = 0.152, quenched from 600°C

(Al)< 660.45

cF4Fm3m

Cu

a = 404.96 at 25°C [Mas2],0 to 2.48 at.% Cu [Mas2]

( Ce)798-726

cI2Im3m

W

a = 412 0 to 0.55 at.% Cu at 708°C [1994Sub]0 to 2.5 at.% Al at 720°C [2000Oka]

( Ce)726-61

cF4Fm3m

Cu

a = 510.10 0 to 0.37 at.% Cu at 708°C [1994Sub]

( Ce)61-(-177)

hP4P63/mmc

La

a = 308.10c = 1185.7

at 24°C [1994Sub]

( Ce)< -177

cF4Fm3m

Cu

a = 485 at –196°C [1994Sub]

, Cu3Al(h)1049-559

cI2Im3m

W

a = 295.64 70.6 to 82 at.% Cu [1985Mur][1998Liu]at 672°C in + (Cu) alloy

2, Cu1-xAlx< 363 TiAl3

Long period super-lattice

a = 366.8c = 368.0

0.22 x 0.235 [Mas2, 1985Mur]76.5 to 78.0 at.% Cuat 76.4 at.% Cu(subcell only)

0, Cu1-xAlxCu~2Al1037-800

cI52I43m

Cu5Zn8

0.31 x 0.402 [Mas2],0.32 x 0.38 [1998Liu]

1, Cu9Al4< 890

cP52P43m

Cu9Al4

a = 870.23a = 870.68

62 to 68 at.% Cu [Mas2, 1998Liu];powder and single crystal [V-C2]from single crystal [V-C]

187


MSIT®

Al–Ce–Cu

, Cu1-xAlx< 686

hR*R3m

a = 1226c = 1511

0.381 x 0.407 [Mas2, 1985Mur]59.3 to 61.9 at.% Cuat x = 0.389 [V-C]

1, Cu1-xAlx958-848

Cubic? - 0.379 x 0.40659.4 to 62.1 at.% Cu [Mas2, 1985Mur]

2, Cu2-xAl850-560

hP6P63/mmc

Ni2In

a = 414.6c = 506.3

0.47 x 0.78; 55.0 to 61.1 at.% Cu [Mas2, 1985Mur, V-C2]NiAs type in [Mas2, 1994Mur]

1, Cu47.8Al35.5(h)590-530

oF88 - 4.7Fmm2

Cu47.8Al35.5

a = 812b = 1419.85c = 999.28

55.2 to 57 at.% Cu [Mas2, 1994Mur]structure: [2002Gul]

2, Cu11.5Al9(r)< 570

oI24 - 3.5Imm2

Cu11.5Al9

a = 409.72b = 703.13c = 997.93

55.2 to 56.3 at.% Cu [Mas2, 1985Mur]structure: [2002Gul]

1, CuAl(h)624-560

o*32 a = 408.7b = 1200c = 863.5

49.8 to 52.4 at.% Cu [V-C2, Mas2, 1985Mur]Pearson symbol: [1931Pre]

2, CuAl(r)< 560

mC20C2/m

CuAl(r)

a = 1206.6b = 410.5c = 691.3

= 55.04°

49.8 to 52.3 at.% Cu[V-C2]

, CuAl2< 591

tI12I4/mcm

CuAl2 a = 606.7c = 487.7

32.05 to 32.6 at.% Cu at 549°C32.4 to 32.8 at.% Cu at 250°C [1996Goe]single crystal [V-C2, 1989Mee]

CeCu< 516

oP8Pnma

FeB

a = 737.0b = 462.3c = 564.8

[1994Sub]

CeCu2< 817

oI12Imma

CeCu2

a = 442.9b = 706.1c = 747.4

[1994Sub]

CeCu4-xAlxCeCu4< 796

oP20Pnnm

CeCu4

a = 458b = 810c = 935

0 x 2 [1985Bod]at x = 0 [1994Sub]

CeCu5-xAlx

CeCu5< 798

hP6P6/mmm

CaCu5

a = 525.1c = 417.3

a = 514.8c = 410.8

0 x 2.1 [1978Tak]at x = 2 [2001Che]

at x = 0 [Mas2, 1994Sub]




Comments/References

188


MSIT®

Al–Ce–Cu

CeCu6938 - (-43)

oP28Pnma

CeCu6

a = 810.88b = 510.04c = 1016.21a = 810.09b = 509.78c = 1015.48

at 22°C [1990Vrt]

at -23°C [1990Vrt]

CeCu6< -43

mP28P21/c

LaCu6

a = 509.5b = 1014.66c = 809.31

= 90.485°a = 508.92b = 1013.26c = 807.89

= 91.148°a = 508.41b = 1012.79c = 807.31

= 91.442°

at -73°C [1990Vrt]

at -173°C [1990Vrt]

at -263°C [1990Vrt]

Ce3Al11<1020

oI28 Immm

La3Al11

a = 439.5b = 1302.c = 1009

[1988Gsc]

Ce3Al111235-1020

tI10I4/mmm

BaAl4

a = 437.7c = 1008

[1988Gsc]

CeAl3<1135

hP8P63/mmc

Ni3Sn

a = 654.7c = 461.0

[1988Gsc]

CeAl2<1480

cF24Fd3m

Cu2Mg

a = 806.1 [1988Gsc]. Dissolves Al2Cu.Al2Ce1-xCux (0 < x < 0.1) [1991Yun]

CeAl<845

oC16Cmc2 or Cmcm

CeAl

a = 926.9b = 768.0c = 576.1

[1988Gsc]

Ce3Al655-250

cP4Pm3m

AuCu3

a = 498.9 [1988Gsc]

Ce3Al< 250

hP8P63/mmc

Ni3Sn

a = 704.2c = 545.1

[1988Gsc]

* 1, CeCu4Al8< 925

tI26I4/mmm

ThMn12

a = 884c = 517a = 882.9c = 515.7a = 885c = 518

[1963Zar], [1964Che]

[1976Bus]

[1985Rau], [1961Gla2]




Comments/References

189


MSIT®

Al–Ce–Cu


* 2,Ce2CuxAl17-x hR57R3m

Th2Zn17

a = 898c = 1307a = 897c = 1306a = 896c = 1304

6.5 x 7.3 [1963Zar]at x = 6.5 [1963Zar]

at x = 7.0 [1985Rau]

at x = 7.3 [1963Zar, 1964Che]

* 3,CeCu6.5Al6.5 cF112Fm3c

NaZn13

a = 1182.2 0.04a = 1180a = 1187

[1985Cor1, 1985Cor2][1985Rau][1982Fel]

* 4,CeCuxAl4-x tI10I4/mmm

BaAl4

I4mm

BaNiSn3

a = 427c = 1075a = 425c = 1065

a = 425.693c = 1063.414

0.75 x 1 [1964Zar] at x = 0.75 [1964Zar]

at x = 1.0 [1964Zar]

at x = 0 neutron diffraction data [1996Moz]

* 5,CeCuAl hP9P63m

Fe2P

a = 717.6c = 419.8a = 717.9c = 420.1

[1968Dwi]

[1973Oes]

Reaction Type T [°C] Phase Composition (at.%)

Al Ce Cu

L + CeAl2 Ce3Al11 p1 1235 LCeAl2Ce3Al11

78.766.778.6

21.333.321.4

000

L CeAl2 + 4,CeCuxAl4-x e1 1220 LCeAl2

4

66.766.766.6

20.030.116.7

13.33.216.7

L + CeAl2 Ce3Al11 +

4,CeCuxAl4-x

U1 1150 LCeAl2Ce3Al11

4

77.066.721.466.6

18.033.378.616.7

5.00016.7

L 1,CeCu4Al8 +

4,CeCuxAl4-x

e2 850 L

1

4

62.161.566.6

8.77.716.7

29.230.816.7

L (Al) + Ce3Al11 e3 640 L(Al)Ce3Al11

96.010021.4

4.0078.6

000




Comments/References

190


MSIT®

Al–Ce–Cu

L (Al) + 4,CeCuxAl4-x e4 595 L(Al)

4

96.098.466.6

2.00.816.7

2.00.816.7

L + 1,CuAl ,CuAl2 p2 591 L

1,CuAl2

67.850.267.2

000

32.249.832.8

L (Al) + 1,CeCu4Al8 e5 585 L(Al)

1

90.098.961.5

2.00.47.7

8.01.530.8

L + 1,CuAl ,CuAl2 +

1,CeCu4Al8

U2 584 L

1

1

73.050.267.261.5

1.5007.7

25.549.832.830.8

L (Al) + Ce3Al11 +

4,CeCuxAl4-x

E1 560 L(Al)Ce3Al11

4

95.010021.466.6

3.5078.616.7

1.50016.7

L (Al) + ,CuAl2 e6 548.2 L(Al)

,CuAl2

82.997.568.1

000

17.12.531.9

L (Al) + 1,CeCu4Al8 +

4,CeCuxAl4-x

E2 545 L(Al)

1

4

92.097.561.566.6

2.007.716.7

6.02.530.816.7

L (Al) + ,CuAl2 +

1,CeCu4Al8

E3 541 L(Al)

1

83.897.568.161.5

1.1007.7

15.12.531.930.8

Reaction Type T [°C] Phase Composition (at.%)

Al Ce Cu

191


MSIT®

Al–Ce–Cu

10

20

30

40

10 20 30 40

60

70

80

90

Ce 50.00Cu 0.00Al 50.00

Ce 0.00Cu 50.00Al 50.00


Axes: at.%

e5

U2

e2

U1

e1

CeAl2

τ4,CeCuAl4

E2

E1

e3

e6

θ,CuAl2

η1,CuAl2

τ1,CeCu4Al8

θ,CuAl2

(Al)

Ce3A

l 11

τ4

τ1

e4

p2CeAl2

E3

p1

(Al)

Fig. 1: Al-Ce-Cu.

Liquidus projection and crystallisation domains of the Al-rich part

192


MSIT®

Al–Ce–Cu

Fig

. 2:

Al-

Ce-

Cu

.

Par

tial

rea

ctio

n s

chem

e

Al-

Ce

Al-

Cu

Al-

Ce-

Cu

L (

Al)

+ C

e 3A

l 11 +

τ4

560

E1

l +

CeA

l 2 C

e 3A

l 11

1235

p1

lC

eAl 2

+

τ 1

1220

e 1

L +

CeA

l 2 C

e 3A

l 11

+τ 1

1150

U1

l +

η1

θ591

p2

l (

Al)

+ C

e 3A

l 11

640

e 3

l (

Al)

+ θ

548.2

e 6

l (

Al)

+ τ4

595

e 4

l (

Al)

+ τ1

585

e 5

lτ 1

+ τ4

850

e 2l

θ +

τ1

?e ?

L +

η1

θ +

τ1

584

U2

L (

Al)

+ τ1 +

τ4

545

E2

L (

Al)

+ θ

+ τ1

541

E3

?

?

(Al)

+ τ1+

τ 4

(Al)

+ θ

+τ 1

(Al)

+C

e 3A

l 11+

τ 4

?

η 1+

θ+τ 1

CeA

l 2+

Ce 3

Al 11+

τ 1

193


MSIT®

Al–Ce–Cu

20

40

60

80

20 40 60 80

20

40

60

80

Ce Cu


Axes: at.%

αCe3Al11

CeAl3

CeAl2

τ4CeAl

θ

η2

ξ2

δγ1

CeCu CeCu2 CeCu4CeCu5

βCe3Al

τ2

τ1

(Cu)(γCe)

(Al)

Ce 8.00Cu 0.00Al 92.00

Ce 0.00Cu 8.00Al 92.00


Axes: at.%

(Al)

(Al)+αCe3Al11

(Al)+τ4

(Al)+τ1

(Al)+CuAl2

Fig. 3: Al-Ce-Cu.

Isothermal section at 400°C

Fig. 4: Al-Ce-Cu.

Isothermal section of the Al-rich region at 500°C

194


MSIT®

Al–Ce–Cu

10400

500

600

700

800

900

1000

1100

1200

1300

Al Ce 16.70Cu 16.70Al 66.60Ce, at.%

Tem

pera

ture

, °C

τ4

660°C

1230°C

595°Ce4

L

(Al)

142 6

400

500

600

700

800

900

1000

Al Ce 7.70Cu 30.80Al 61.50Ce, at.%

Tem

pera

ture

, °C

e5

925°C

660°C

585°C

τ1(Al)

L

62 4

Fig. 6: Al-Ce-Cu.

The Al - 4quasibinary section

Fig. 5: Al-Ce-Cu.

The Al - 1quasibinary section

195


MSIT®

Al–Ce–Cu

10700

800

900

1000

1100

1200

Ce 7.70Cu 30.80Al 61.50

Ce 16.70Cu 16.70Al 66.60Ce, at.%

Tem

pera

ture

, °C

e2

τ1τ4

1230°C

850°C

925°C

L

8 12 14 16

20 301100

1200

1300

1400

1500

Ce 16.70Cu 16.70Al 66.60

Ce 33.30Cu 0.00Al 66.70Ce, at.%

Tem

pera

ture

, °C

1220°C1230°C

e1

1480°C

τ4

L

CeAl2

Fig. 7: Al-Ce-Cu.

The 1 - 4quasibinary section

Fig. 8: Al-Ce-Cu.

The 4 - CeAl2quasibinary section

196


MSIT®

Al–Ce–Fe

Aluminium – Cerium – Iron

Bernd Grieb, updated by Alexander Pisch

Literature Data

The first investigation in this ternary system was made in 1925 by Meißner [1925Mei] to describe the

“clear-cross method” of Guertler in practical examples when Ce is added to Al-Fe alloys. [1969Zar]

examined the ternary system with 106 alloys from 0 to 33.3 at.% Ce using X-ray structural analysis.

[1988Sok] studied the phase behavior of 75 to 100 at.% Al at 550°C using X-ray structural analysis. An

isothermal section for the Al-rich corner at the same temperature is presented by [1992Rae] without

specifying sample preparation details and the purity of the starting materials. Their results are in good

agreement. Solid solutions of Al in binary Ce-Fe phases became of interest with a view to obtaining a

material with good permanent magnetic properties after the discovery of rare-earth metal (R)-transition

metal (TM) magnets. [1985Fra] published lattice parameters and magnetic properties of alloys along

CeFe2-CeAl2. [1998Kuc, 2000Kny] measured the structural, magnetic and optical properties of a

Ce2Fe15.3Al1.7. Samples were prepared by levitation melting in an induction furnace, annealed at 1000°C

for 8h and analyzed by X-ray diffraction and a vibrating sample magnetometer. No information of the purity

of the starting material is given. The structural and magnetic properties of RE2Fe17-xAlx phases have been

reviewed and compared by [2002Ram] A new ternary phase with the composition Ce6Fe11Al3 has been

discovered recently [1992Hu]. The sample has been prepared by melting the elements (Ce,Fe 3N purity, Al

5N) followed by an anneal for 120h at 600 - 800°C wrapped in Mo foil and sealed in quartz. The water

quenched samples have been investigated by XRD and Mössbauer spectroscopy to determine the magnetic

properties. The structure and magnetic properties of CeFe2Al8 have been studied by low temperature

neutron diffraction [2001Kol] and Mössbauer spectroscopy by [2000Tam, 2001Kol]. No magnetic ordering

of this compound has been detected. Ce enhances the mechanical properties of Fe-Al alloys. Because of the

very limited solid solubility of transition metals and rare-earth elements in Al rapid solidification processing

of Al alloys with Fe and Ce is necessary to avoid intermetallic compounds. [1986Ang, 1986Fie, 1986Jha,

1987Yan, 1988Aye, 1988Sok, 1998Fas, 2000Cha, 2002Zha] produced and investigated rapidly solidified

Al-Ce-Fe alloys and found besides binary Fe-Al phases, stable and metastable ternary phases. Enthalpies of

formation of three-component liquid alloys were published by [1984Esi].

This evaluation proceeds that of [1991Gri] and integrates the substantial amount of data published

since then.

Binary Systems

The Al-Fe binary system has been taken from[2003Pis]. [1996Sac] revised the Al-Ce system and their

diagram is accepted. The Al-rich compound in the Al-Ce system, previously reported as CeAl4, is now

known to have the Ce3Al11 stoichiometry. The composition CeAl4 taken by [1969Zar] is corrected to

Ce3Al11 in the ternary evaluation and in Fig. 1. Ce-Fe is accepted from [Mas].

Solid Phases

The ternary phase CeFe4Al8 ( 1) has been studied in detail [1961Gla, 1962Zar, 1969Zar, 1974Viv,

1976Bus]. [1969Zar] found additionally the ternary phases CeFe2Al10 ( 2), CeFe2Al7, CeFe1-1.4Al1-0.6 and

a solid solution of Al in the binary Ce2Fe17 compound with a maximum Al-content of about 60 at.% and

having a Th2Ni17 type structure. CeFe2Al10 ( 2) is iso-structural to YbFe2Al10 [1998Thi]. The lattice

parameters of the 3 Ce6Fe11Al3 ternary compound has been determined by [1992Hu]. This compound has

a La6Fe11Ga3 type structure. The structures of CeFe2Al7, and CeFe1-1.4Al1-0.6 were not determined. The

ternary phase CeFe2Al7 is possibly identical to 1 CeFe2Al8, observed and investigated by [1974Yar].

According to [1971Oes], the compounds of the composition RFeAl with light rare-earths show a two phase

region of cF24 (MgCu2) type together with an unidentified second phase, as opposed to all alloys RFeAl

197


MSIT®

Al–Ce–Fe

with heavy rare-earths which form a single phase of the hexagonal hP12 (MgZn2) structure type. The

formation of successive types of the Laves phase family in the pseudobinary system RFe2-RAl2 seems to

be connected with Fermi surface-Brillouin zone interactions. It is not completely understood, however, why

this does not hold for light and heavy rare-earth elements together, but it is likely that the larger size and

higher valencies of the former may contribute to their exceptional behavior. [1985Fra] suggests that the

solubility limit for the formation of the pure MgCu2 type structure for Ce(Fe1-xAlx)2 may be placed near

x = 0.125. [1986Ang] found five dispersed phases in the as-extruded Al-8.8Fe-3.7Ce and Al-8.9Fe-6.9Ce

alloys; metastable FeAl6, two metastable Al-Ce-Fe phases and the equilibrium phases Fe4Al13 and

CeFe2Al10. The unit cell of one of the metastable ternary phases was observed as orthorhombic. [1987Yan]

produced a metastable icosahedral phase in rapidly cooled Al-8.8Fe-3.3Ce. In addition [1988Aye] found

two compounds 2 CeFe2Al10 and CeFe5Al20 in the as-extruded conditions. CeFe5Al20 is described as

decagonal quasicrystal. The known structure types and crystal parameters of all described solid phases are

listed in Table 1. The ternary phase CeFe2Al8 listed by [V-C] with the source [1980Zar] is not described in

the latter paper. [1980Zar] investigated the phase CeCo2Al with structure type CeFe2Al8. The lattice

parameters in [V-C] are those of CeCo2Al8.


The formation of 2 follows the peritectic reaction Ce3Al11+L 2. The formation temperature is 940°C

[1988Sok].

Isothermal Sections

The investigation of [1925Mei] is rather sketchy and incorrect in the region up to 33.3 at.% Ce. The results

of [1969Zar] confirmed several ternary compounds and solid solution of Al in Ce2Fe17. Figure 1 shows the

phase equilibria of the ternary system at 500°C with a maximum Ce content of 33.3 at.%. CeFe2 is printed

by [1969Zar] as phase with no Al solubility. This is corrected in the figure after the results of [1985Fra].

The phase, CeFe1-1.4Al1-0.6, detected by [1969Zar] is plotted, but it is necessary to point out the conflict

with the results of [1971Oes] as described above. The phase CeFe2Al7 of [1969Zar] is printed with the

composition 1 CeFe2Al8 as in [1974Yar]. At 550°C for Al concentration of 75 to 100 at.% [1988Sok]

found the two-phase regions Al+ 2’, Al+FeAl3, Al+Ce3Al11 and the tree phase regions Al+ 2+FeAl3 and

Al+ 2+Ce3Al11. The ternary compound is not observed in quenched material. The isothermal section in the

Al-rich corner at 550°C as presented by [1992Rae] is identical to Fig. 1.


[1988Sok] published two isopleths. One describes the section between Ce3Al11 and Fe4Al13, the second

between Al and CeFe2Al (Fig. 2). The isopleth is taken only partially because the shape of the lines with

less than 97.8 at.% Al is estimated. The results are based on thermal analysis. The isopleth between Ce3Al11

and Fe4Al13 is not accepted because of inconsistency with the accepted binary Al-Ce.


Magnetic properties of 2 CeFe4Al8 samples have been determined and analyzed by [1998Sch, 2000Hag,

2000Sik, 2001Gac] using neutron diffraction, specific heat and Mössbauer measurements. The magnetic

properties of a series of Ce2Fe17-xAlx solid solutions with x equal to 0.0, 0.88, 2.06, 2.80, 3.98, 5.15, 6.08,

7.21, 8.20, 9.08, 9.84, and 10.62 have been studied by magnetic measurements, neutron diffraction, and

Mössbauer spectroscopy by [1996Mis] and with 8 x 13 by susceptibility, magnetization and heat

capacity measurements by [2000Kon]. The Curie temperature increases from 238 K in Ce2Fe17 to a

maximum of 284 K in Ce2Fe14Al3. The Ce2Fe17-xAlx solid solutions behave as spin glasses for x greater

than 7 [1996Mis]. The magnetic moment of Ce2Fe15.3Al1.7 has been measured as Ms = 25.68 B

[2001Kny]. The origin for the magnetism of 2 CeFe2Al10 is the mixed Ce3+/Ce4+ valence [1998Thi].

Ce(Fe,Al)2 with an aluminium content of 6 at.% has a Curie temperature of 160K and a Néel temperature

of 136K [1997Fer]. The hydrogen storing capabilities of Ce(Fe,Al)2 have been investigated by [1997Spa],

198


MSIT®

Al–Ce–Fe

their magnetic properties by [1997Fer]. [2000Cha] investigated Ce(Fe1-xAlx)2 samples with X-ray

absorption spectroscopy (XAS) and confirmed the mixed valence of Ce upon Fe substitution to be the origin

of the anomalous magnetic behavior in this alloy.

References

[1925Mei] Meissner, K.L. “Some Examples of the Practical Use of the Clear-Cross Method” (in

German), Metall und Erz., 22, 243-247 (1925) (Experimental, Equi. Diagram, 9)

[1958Tay] Taylor, A., Jones, R.M., “Constitution and Magnetic Properties of Iron-Rich

Iron-Aluminium Alloys”, J. Phys. Chem. Solids, 6, 16-37 (1958) (Crys. Structure,

Experimental)

[1961Lih] Lihl, F., Ebel, H., “X-Ray Examination fo the Constitution of Iron-Rich Alloys of the

Iron-Aluminium System” (in German), Arch. Eisenhuettenwesen, 32, 483-487, (1961)

(Crys. Structure, Experimental)

[1961Gla] Gladyshevsky, E.I., Zarechnyuk, O.S., Teslyuk, M.Yu., Zarechnyuk, O.S., Kuz’ma, Yu.B.,

“Crystal Structures of some Intermetallic Compounds” (in Russian), Kristallografiya, 6,


[1962Zar] Zarechnyuk, O.S., Zarechnyuk, O.S., “The Crystal Structure of Ternary Compounds in the

System Ce-Transition Metal-Al” (in Russian), Kristallografiya, 7, 543-554 (1962)


[1969Zar] Zarechnyuk, O.S., Mys’kiv, M.G., Ryabov, V.R., “X-Ray Diffraction Study of the Phase

Composition of Ce-Fe-Al Alloys Containing up to 33.3 at.% Ce”, translated from Izv. Akad.

Nauk SSSR, Met., 2, 164-166 (1969) (Experimental, Crys. Structure, Equi. Diagram, #, *, 9)

[1971Oes] Oesterreicher, H., “Structural Studies of Rare-Earth Compounds RFeAl”, J. Less-Common


[1974Viv] Vivchar, O.I., Zarechnyuk, O.S., “Compounds with the ThMn12 type Structure in R-Fe-Al

Systems” (in Russian), Tezisy Dokl. Vses. Konf. Kristallokhim., Rykhal, R.M., (Ed.),

“Intermetalicheskie Soedineniya”, 2nd, 41, (1974) (Experimental, Crys. Structure, 0)

[1974Yar] Yarmolyul, Ya.P., Rykhal, R.M., Zarechnyuk, O.S., “Crystal Structure of CeFe2Al8 and

LaCoAl4" (in Russian), Tezisy Dokl. Vses. Konf. Kristallokhim., Rykhal, R.M., (Ed.),

“Intermetalicheskie Soedineniya”, 2nd, 39-40 (1974) (Experimental, Crys. Structure, 0)

[1976Bus] Buschow, K.H.J., van Vucht, J.H.N., van den Hoogenhof,W.W., “Note on the Crystal

Structure of the Ternary Rare-Earth-3d Transition Metal Compounds of the Type RT4Al8”,

J. Less-Common Met., 50, 145-150 (1976) (Experimental, Crys. Structure, 2)

[1980Zar] Zarechnyuk, O.S., Rykhal, R.M., Korin, V.V., “X-Ray Study of the

Cerium-Cobalt-Aluminium Ternary System Alloys in the Range of 0 to 33.3 at.% of

Cerium” (in Russian), Dop. Akad. Nauk Ukrain. RSR, Ser. A. Fiz.-Mat. Tekh. Nauki, 42,


[1984Esi] Esin, Yu.O., Pletneva, E.D., Ermakov, E.D., Valishov, M.G., “Enthalpy of Formation of

Three-Component Liquid Alloys Fe-Ce-Si and Fe-Ce-Al” (in Russian), Izv. VUZ Chern.

Metall., 12, 1-4 (1984) (Experimental, Thermodyn., 15)

[1985Fra] Franceschini, D.F., da Cunha, S.F., “Magnetic Properties of Ce(Fe1-xAlx)2 for x 0.20”, J.

Magn. Magn. Mater., 51, 280-290 (1985) (Experimental, Crys. Structure, Magn. Prop., 13)

[1986Ang] Angers, L., “Particle Coarsening in Rapidly Solidified Al-Fe-Ce Alloys”, Diss. Abstr. Int.,

46, 288 (1986) (Experimental, Crys. Structure, 0)

[1986Fie] Field, R.D., Zindel, J.W., Fraser, H.L., “The Intercellular Phase in Rapidly Solidified Alloys

Based on the Al-Fe System”, Scr. Metall., 20, 415-418 (1986) (Experimental, Crys.

Structure, 8)

[1986Gri] Griger, A., Syefaniay, V., Turmezey T., “Crystallographic Data and Chemical

Compositions of Aluminum-Rich Al-Fe Intermetallic Phases”, Z. Metallkd., 77, 30-35

(1986) (Equi. Diagram, Crys. Structure, Experimental)

199


MSIT®

Al–Ce–Fe

[1986Jha] Jha, S.C., Sanders, Jr., T.H., “Microstructure of Melt-Spun Al-Fe and Al-Fe-Ce Alloys”,

The Metallurgical Society/AIME, Warrendale, Pennsylvania 15086, USA, 243-254

Accession Number: 86(12), 72-498 (1986)

[1987Yan] Yang, L.Y., Zhao, J.G., Zhan, W.S., “Icosahedral Phase in Rapidly Cooled Al-Fe-Ce

Alloy”, J. Phys. F: Met. Phys., 17, L97-L99 (1987) (Experimental, Crys. Structure, 13)

[1988Aye] Ayer, R., Angers, L.M., Mueller, R.R., Scanlon, J.C., Klein, C.F., “Microstructural

Characterization of the Dispersed Phases in Aluminium-Cerium-Iron System”, Metall.

Trans. A, 19A, 1645-1656 (1988) (Experimental, Crys. Structure, Equi. Diagram, 17)

[1988Gsc] Gschneidner, Jr. K.A., Calderwood, F.W., “The Aluminum-Cerium (Al-Ce) System”, Bull.

Alloy Phase Diagrams, 9, 669-672, (1988) (Equi. Diagram, Review, 35)

[1988Sok] Sokolovskaya, E.M., Kazakova, E.F., Filippova, A.A., “Phase Diagrams of Equilibrium and

Fast-Quenched Al-Fe-Ce Alloys”, Russ. Metall., 1988 (2), 201-203 1988, translated from

Izv. Akad. Nauk SSSR, Met., 2, 209-210 (1988) (Experimental, Crys. Structure, Equi.

Diagram, #, *, 3)

[1991Gri] Grieb, B., ”Aluminium - Cerium - Iron”, MSIT Ternary Evaluation Program, in MSIT



Assessment, 17)

[1992Hu] Hu, B.P., Coey, J.M.D., Klesnar, H., Rogl, P., “Crystal Structure, Magnetism and 57Fe

Moesbauer Spectra of Ternary RE6Fe11Al3 and RE6Fe13Ge Compounds”, J. Magn. Magn.

Mater., 117, 25-231 (1992) (Crys. Structure, Experimental, Magn. Prop., Moessbauer, 14)

[1992Rae] Raevskaya, M.V., Tatarkina, A.L., Filippova, A.A., “Phase Equilibria in Systems Formed

by Aluminum with Iron, Palladium and Cerium”, Russ. Metall.(Engl. Transl.), 6, 161-165


[1993Kat] Kattner, U.R., Burton, B.P., “Aluminum-Iron” in Phase Diagrams of Binary Iron Alloys,

ASM, Metals Park, OH, 12-28 (1993) (Crys. Structure, Equi. Diagram, Review, Magn.

Prop., Thermodyn., 99)

[1994Bur] Burkhardt, U., Grin, J., Ellner, M., Peters, K., “Structure Refinement of the Iron-Aluminium

Phase with the Approximate Composition Fe2Al5”, Acta Crystallogr., Sect. B: Struct.

Crystallogr. Crys. Chem., B50, 313-316 (1994) (Crys. Structure, Experimental, 9)

[1994Gri] Grin, J., Burkhardt, U., Ellner, M., Peters, K., “Refinement of the Fe4Al13 Structure and its

Relationship to Quasihomological Homotypical Structures”, Z. Kristallogr., 209, 479-487


[1996Mis] Mishra, S.R., Long, G.J., Pringle, O.A., Hu, Z., Yelon, W.B., Middleton, D.P., Buschow,

K.H.J., Grandjean, F., “A Magnetic Neutron Diffraction, and Mossbauer Spectral Study of

the Ce2Fe17-xAlx Solid Solutions”, J. Appl. Phys., 79(8), 5945 (1996) (Abstract, Crys.


[1996Sac] Saccone, A., Cardinale, A.M., Delfino, S., Ferro, R., “Phase Equilibria in the Rare Eearth

Metals (R)-Rich Regions of the R-Al Systems (R=La, Ce, Pr, Nd)”, Z. Metallkd., 87(2),

82-87 (1996) (Equi. Diagram, Cryst. Structure, Experimental, 18)

[1997Fer] Fernandez, G.E., Gomez-Berisso, M., Trovarelli, O., Sereni, J.G., “Comparative Study of

the Ferro-Antiferromagnetic Transition in Ce(Fe, Co) and Ce(Fe, Al)2”, J. Alloys Compd.,

261, 26-31 (1997) (Experimental, Magn. Prop., Thermal Conduct., Thermodyn., 41)

[1997Kog] Kogachi, M., Haraguchi, T., “Quenched-in Vacansies in B2-Structured Intermetallic

Compound FeAl”, Mater. Sci. Eng. A, A230, 124-131 (1997) (Crys. Structure,

Experimental, 23)

[1997Spa] Spatz, P., Gross, K.J., Zuettel, A., Schlapbach, L., “Hydriding Properties of Ce(Mn,Al)2 and

Ce(Fe,Al)2 Intermetallic Compounds”, J. Alloys Compd., 260, 211-216 (1997) (Crys.


[1998Ali] Aliravci, C.A., Pekgueleryuez, M.O., “Calculation of Phase Diagrams for the Metastable

Al-Fe Phases Forming in Direct-Chill (DC)-Cast Aluminium Alloy Ingots”, Calphad, 22,

147-155 (1998) (Calculation, Equi. Diagram, 20)

200


MSIT®

Al–Ce–Fe

[1998Kuc] Kuchin, A.G., Ermolenko, A.S., Khrabrov, V.I., “Magnetic State of Pseudobinary Alloys

Lu2Fe15.3M1.7 and Ce2Fe15.3M1.7 (M = Si and Al)”, Phys. Met. Metallogr. (Engl. Transl.),


[1998Thi] Thiede, V.M.T., Ebel, T., Jeitschko, W., “Ternary Aluminides LnT2Al10(Ln =Y, La-Nd,

Sm, Cd-Lu and T=Fe,Ru,Os) with YbFe2Al10 Type Structure and Magnetic Properties of

the Iron-Containing Series”, J. Mater. Chem., 8(1), 125-130 (1998) (Crys. Structure,

Experimental, Magn. Prop., 31)

[1998Sch] Schobinger-Papamantellos, P., Buschow, K.H.J., Ritter, C., “Magnetic Ordering and Phase

Transitions of RFe4Al8 (R = La, Ce, Y, Lu) Compounds by Neutron Diffractioin”, J. Magn.

Magn. Mater., 186, 21-32 (1998) (Crys. Structure, Experimental, Magn. Prop., 13)

[1998Fas] Fass, M., Eliezer, D., Aghion, E., Froes, F.H., “Hardening and Phase Stability in Rapidly

Solidified Al-Fe-Ce Alloys”, J. Mater. Sci., 33(3), 833-837 (1998) (Equi. Diagram,


[1999Dub] Dubrovinskaia, N.A., Dubrovinsky, L.S., Karlsson, A., Saxena, S.K., Sundman, B.,

“Experimental Study of Thermal Expansion and Phase Transformations in Iron-Rich Fe-Al

Alloys”, Calphad, 23(1), 69-84 (1999) (Equi. Diagram, Experimental, 14)

[2000Kon] Konishi, K., Kamimori, T., Tange, H., Deguchi, H., Kawae, T., Takeda, K., “Magnetic

Properties of Heavy Fermion Compounds Ce2Fe17-xAlx”, Physica B, 284-288, 1275-1276

(2000) (Experimental, Magn. Prop., 6)

[2000Kny] Knyazev, Yu.V., Kuchin, A.G., Kuz'min, Yu.I., “Optical Properties of Intermetallic

Compounds Ce2Fe17 and Ce2Fe15.3M1.7 (M = Al, Si)”, Phys. Met. Metallogr., 89(6),

558-562 (2000) (Crys. Structure, Experimental, Magn. Prop., Optical Prop., 16)

[2000Tam] Tamura, I., Mizushima, T., Isikawa, Y., Sakurai, J., “Moessbauer Effect and Magnetization

Studies of CeFe2Al8 and LaFe2Al8”, J. Magn. Magn. Mater., 220, 31-38 (2000) (Crys.

Structure, Experimental, Moessbauer, 4)

[2000Sik] Sikora, W., Schobinger-Papamantellos, P., Buschow, K.H.J., “Symmetry Analysis of the

Magnetic Ordering in RFe4Al8 (R=La, Ce, Y, Lu and Tb) Compounds (II)”, J. Magn. Magn.

Mater., 213, 143-156 (2000) (Calculation, Crys. Structure, Magn. Prop., 8)

[2000Cha] Chaboy, J., Piquer, C., Garcia, L.M., Bartolome, F., Wada, Maruyama, H., Kawamura, N.,

“X-Ray Absorption Spectroscopy Study of the Instability of Ferromagnetism in CeFe2:

Effects of Co and Al Substitutions”, J. Appl. Phys., 87(9), 6809-6811 (2000) (Magn. Prop.,

11)

[2000Hag] Hagmusa, I.H., Brueck, E., de Boer, F.R., Buschow, K.H.J., “A Specific-Heat Study of

some RFe4Al8 Compounds (R = Ce, Pr, Nd, Dy, Ho, Tm)”, J. Alloys Compd., 298, 77-81

(2000) (Crys. Structure, Experimental, Thermodyn., 16)

[2001Gac] Gaczynski, P., Vagizov, F.G., Suski, W., Kotur, B., Iwasieczko, W., Drulis, H., “Magnetic

and Hyperfine Interaction in RFe4Al8 (R = Ce, Sc) Compounds”, J. Magn. Magn. Mater.,

225, 351-358 (2001) (Crys. Structure, Experimental, Magn. Prop., Moessbauer, 15)

[2001Ike] Ikeda, O., Ohnuma, I., Kainuma, R., Ishida, K., “Phase Equilibria and Stability of Ordered

BCC Phases in the Fe-Rich Portion of the Fe-Al System”, Intermetallics, 9, 755-761 (2001)

(Equi. Diagram, Experimental, Mechan. Prop., 18)

[2001Kny] Knyazev, Yu.V., Kuchin, A.G., Kuz'min, Yu.I., “Optical Conductivity and Magnetic

Parameters of the Intermetallic Compounds R2Fe17-xMx (R = Y, Ce, Lu; M = Al, Si)”,

J. Alloys Compd., 327, 34-38 (2001) (Crys. Structure, Experimental, Magn. Prop., Optical

Prop., 23)

[2001Kol] Kolenda, M., Koterlin, M.D., Hofmann, M., Penc, B., Szytula, A., Zygmunt, A., Zukrowski,

J., “Low Temperature Neutron Diffraction Study of the CeFe2Al8 Compound”, J. Alloys

Compd., 327, 21-26 (2001) (Crys. Structure, Experimental, Magn. Prop., 10)

[2002Ram] Rama Rao, K.V.S., Ehrenberg, H., Markandeyulu, G., Varadaraju, U.V., Venkatesan, M.,

Suresh, K.G., Murthy, V.S., Schidt, P.C., Fuess, H., “On the Structural and Magnetic

Properties of R2Fe(17-x)(A,T)x (R = Rare Earth; A = Al, Si, Ga; T = Transition Metal)

201


MSIT®

Al–Ce–Fe

Compounds”, Phys. Status Solidi A, 189(2), 373-388 (2002) (Crys. Structure, Magn. Prop.,

Review, 51)

[2002Zha] Zhang, C., Wu, Y., Cai, X., Zhao, F., Zheng, S., Zhou, G., Wu, S., “Icosahedral Phase in

Rapidly Solidified Al-Fe-Ce Alloy”, Mater. Sci. Eng. A, A323, 226-231 (2002) (Equi.


[2003Pis] Pisch, A., “Al-Fe (Aluminum-Iron)”, MSIT Binary Evaluation Program, in MSIT




Phase /

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

( Al) hP2

P63/mmc

Mg

a = 269.3

c = 439.8

at 25°C, 20.5 GPa [Mas2]

( Al)

< 660.452

cF4

Fm3m

Cu

a = 404.96 at 25°C [Mas2]

( Fe) hP2

P63/mmc

Mg

a = 246.8

c = 396.0

at 25°C, 13 GPa [Mas2]

( Fe)

1538-1394

cI2

Im3m

W

a = 293.15 [Mas2]

( Fe)

< 1394-912

cF4

Fm3m

Cu

a = 364.67 at 915°C [V-C2, Mas2] dissolves up to

1.2 at.% Al

( Fe)

< 912

cI2

Im3m

W

a = 286.65

a = 286.64 to 289.59

a = 286.60 to 289.99

a = 286.60 to 290.12

at 25°C [Mas2] dissolves up to 45.0 at.%

Al at 1310°C

0 - 18.8 at.% Al, HT [1958Tay]

0 - 19.0 at.% Al, HT [1961Lih]

0 - 18.7 at.% Al, 25°C [1999Dub]

( ’Ce) oC4

Cmcm

U

a = 304.9

b = 599.8

c = 521.5

at 25°C, 5.4 GPa [Mas2]

( Ce)

798-726

cI2

Im3m

W

a = 412 [Mas2]

( Ce)

726-61

cF4

Fm3m

Cu

a = 516.10 [Mas2]

( Ce)

61-(-177)

hP4

P63/mmc

La

a = 368.10

c = 1185.7

at 25°C [Mas2]

202


MSIT®

Al–Ce–Fe

( Ce)

< -177

cF4

Fm3m

Cu

a = 485 [Mas2]

Fe4Al13

< 1160

mC102

C2/m

Fe4Al13

a = 1552.7 to 1548.7

b = 803.5 to 808.4

c = 1244.9 to 1248.8

= 107.7 to 107.99°

a = 1549.2

b = 807.8

c = 1247.1

= 107.69°

74.16 - 76.70 at.% Al, [1986Gri]

sometimes called FeAl3 in the literature

at 76.0 at.% Al, [1994Gri]

Fe2Al5< 1169

oC24

Cmcm

-

a = 765.59

b = 641.54

c = 421.84

at 71.5 at.% Al, [1994Bur]

FeAl2< 1156

aP18

P1

FeAl2

a = 487.8

b = 646.1

c = 880.0

= 91.75°

= 73.27°

= 96.89°

at 66.9 at.% Al, [1993Kat]

1232-1102

cI16?

-

a = 598.0 at 61 at.% Al, [1993Kat]

FeAl

< 1310

cP2

Pm3m

CsCl

a = 289.48 to 290.5

a = 289.53 to 290.9

a = 289.81 to 291.01

a = 289.76 to 190.78

34.5 - 47.5 at.% Al, [1961Lih]

36.2 - 50.0 at.% Al, [1958Tay]

39.7 - 50.9 at.% Al, [1997Kog] 500°C

quenched in water

room temperature

Fe3Al

< 547

cF16

Fm3m

BiF3

a = 579.30 to 578.86

a = 579.30 to 578.92

~24-~37 at.% Al, [2001Ike]

23.1-35.0 at.% Al, [1958Tay]

24.7 - 31.7 at.% Al, [1961Lih]

Fe2Al9 mP22

P21/c

Co2Al9

a = 869

b = 635

c = 632

= 93.4°

metastable

81.8 at.% Al [1993Kat]

FeAl6 oC28

Cmc21

FeAl6

a = 744.0

b = 646.3

c = 877.0

a = 744

b = 649

c = 879

metastable

85.7 at.% Al [1993Kat]

[1998Ali]

FeAl4+x t** a = 884

c = 2160

(0 < x < 0.4) metastable

[1998Ali]

Phase /

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

203


MSIT®

Al–Ce–Fe

Ce2(Fe1-xAlx)17

Ce2Fe17

hR57

R3m

Th2Zn17 a = 851.2

c = 1245

a = 855.5

c = 1249.5

a = 899.8

c = 1297

0 x 0.67

x = 0 [1969Zar]

x = 0.1 [1998Kuc]

x = 0.67 [1969Zar]

Ce(Fe1-xAlx)2

CeFee

cF24

Fd3m

MgCu2

a = 734 ± 2

a = 730.4

0 x 0.125

[1985Fra] x = 0.125

[V-C]

Ce3Al11

< 1020

oI28

Immm

Al11La3

a = 439.5

b = 1302.

c = 1009

[1988Gsc]

Ce3Al11

1235-1020

tI10

I4/mmm

Al4Ba

a = 437.7

c = 1008

[1988Gsc]

CeAl3< 1135

hP8

P63/mmc

Ni3Sn

a = 654.7

c = 461.0

[1988Gsc]

CeAl2< 1480

cF24

Fm3m

MgCu2

a = 806.1 [1988Gsc]

CeAl

< 845

oC16

Cmc2 or Cmcm

CeAl

a = 926.9

b = 768.0

c = 576.1

[1988Gsc]

Ce3Al CP4

Pm3m

AuCu3

a = 498.9 [1988Gsc]

Ce3Al hP8

P63/mmc

Ni3Sn

a = 704.2

c = 545.1

[1988Gsc]

* 1, CeFe4Al8 tI26

I4/mmm

ThMn12

a = 886

c = 508

a = 880.5

c = 504.8

[1961Gla]

[1976Bus]

* 2, CeFe2Al10 oC52

Cmcm

YbFe2Al10

a = 900.02

b = 1022.2

c = 907.3

[1998Thi]

* 3, Ce6Fe11Al3 a = 819.03

c = 2310.08

[1992Hu]

* 4, CeFe2Al8 oP44

CeFe2Al8

a = 1251

b = 1448

c = 407

[1974Yar]

Phase /

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

204


MSIT®

Al–Ce–Fe

* 5, CeFe2Al7 ? ? [1969Zar]

perhaps CeFe2Al8

* 6, CeFe1-1.4Al1-0.6 ? ? [1969Zar],

not found and refused by [1976Bus]

* 7, CeFeAl orthorh. a = 1020

b = 1620

c = 420

metastable [1986Ang],

sample containing 7 to 9 mass% Fe and

3 to 7 mass% Ce

* 8, Ce7.4Fe27.4Al65.2 ? ? metastable [1987Yan]

* 9, CeFe5Al20 ? ? metastable [1988Aye]

decagonal quasicrystal

Phase /

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

20

40

60

80

20 40 60 80

20

40

60

80

Ce Fe


Axes: at.%

τ6

CeFe2Ce2Fe17

FeAl2

Fe2Al5

FeAl3

τ1

τ5

τ2

Ce3Al11

CeAl3

CeAl2

FeAl

Fe3Al

(αFe)

(Al)Fig. 1: Al-Ce-Fe.


500°C, after

[1969Zar] (revised)

205


MSIT®

Al–Ce–Fe

600

700

800

900

1000

1100

1200

Ce 0.80Fe 1.40Al 97.80

AlAl, at.%

Tem

pera

ture

, °C

L

CeAl2+L

L2+βCe3Al11

αCe3Al11+L

L+τ2

(Al)+τ2

αCe3Al11+L+τ2

CeAl2+βCe3Al11+L

Fig. 2: Al-Ce-Fe.

Isopleth along

CeFe2Al10 - Al

(partially), after

[1988Sok]

206


MSIT®

Al–Co–Fe

Aluminium – Cobalt – Iron

Andy Watson

Literature Data

Phase relationships in the Al-Co-Fe system are relatively well known in the composition range up to

approximately 35 mass% Al. Both the Al-Fe system and the Al-Co systems contain ordered bcc structures

of the CsCl-type (cP2) and form extensive solid solution ranges between them. At intermediate

temperatures, the ( Fe) phase (cI2) in the Co-Fe system characterizes the ternary system. The major

contribution to the understanding of the liquidus and solidus relationships in the ternary system up to 35

mass% Al is due to [1933Koe], who examined alloys by thermal, metallographic and magnetic methods.

Equilibria in the Al rich region have been established by [1948Ray, 1982Ray] using X-ray investigations

of alloys that had undergone long annealing treatments. Thermal analysis was used to determine phase

boundaries in vertical sections at high Al-contents. [1941Edw] used X-ray measurements to define single

and 2-phase fields in Co-rich regions of the phase diagram. Alloys were prepared from pure material by

induction melting, homogenizing at 1300°C, annealing at 800°C for 1 day and quenching. Phase separation

of ordering alloys in the Fe rich range has been determined by electron microscopy and magnetization

measurements, [1949Iva] and [1987Miy]. More recently, a series of articles presenting the results of TEM

studies and calculated phase equilibria based on the Bragg-Williams-Gorsky approximation to model phase

separation have been published [1994Koz1, 1994Koz2]. Despite the similar alloy preparation and

experimental techniques employed, some disagreement was found with the previous work of [1987Miy] in

relation to the location of the phase boundaries of the two-phase regions associated with the phase

separation. A critical review of the then available data made by [1991Kub] provides the bases of the present

evaluation. 1999Koz] used the information from [1994Koz1] together with new studies in the remaining

regions of the section to produce a complete isothermal section for 650°C. Some solubility for the third

element was reported in FeAl2, Fe2Al5, FeAl3, Co2Al9, Co2Al5 and Co4Al13. Furthermore, DTA

investigations revealed how the A2+B2 phase field varied with temperature.

Binary Systems

The Al-Co and Al-Fe systems are taken from the MSIT Binary Evaluation Program [2003Gru, 2003Pis].

The Co-Fe diagram is taken from [2002Ohn].

Solid Phases

The Fe-rich region of the ternary system exhibits two different types of phase separation at temperatures

below 700°C. The disordered A2 phase ( ) separates into a two phase region comprising the A2 and the

ordered B2 ( ') phase of the Al-Fe and Co-Fe systems. Also, a region of '1+ '2 exists adjacent to the + '

two phase field. All known phases of the Al-Co-Fe system and those in equilibrium with (Al) are listed in

Table 1. No ternary phases have been found.


A ternary eutectic exists at 653.9°C as determined by [1948Ray] using thermal analysis. The composition

was estimated to be 1.55Fe-0.35Co-98.1Al (mass%) by interpolation of cooling curve data. A partial

reaction scheme for the Al corner is shown in Fig. 1.

Liquidus Surface

Figure 2 shows liquidus contours at Al contents greater than 40 at.% based on the results of [1933Koe] and

[1982Ray]. The 1400°C liquidus contour has been amended so that it converges with the Al-Co binary L

( Co) + CoAl eutectic point, in contrast to the original publication where two contours converge at the ends

207


MSIT®

Al–Co–Fe

of the two solidus lines in the Al-Co binary. Also shown are projections of the liquidus and solidus lines

(the latter denoted a1a2 and b1b2). The monovariant reaction line extends from the peritectic point p1 in the

Co-Fe system to the eutectic point e1 in the Al-Co system and passes through a minimum; the composition

is approximately 70Co-7.5Al (mass%), but the temperature is uncertain. The ordered AlCo phase forms a

continuous solid solution with ( Fe) at appropriate temperatures. The maximum melting point of CoAl

(1645°C) persists in the ternary system as Fe replaces Co. The remainder of the liquidus surface of the

ternary system is unknown except for the surfaces in the extreme Al rich corner that were established by

[1948Ray] and depicted in Fig. 3.

Isothermal Sections

Figure 4 shows part of the isothermal section at 800°C as presented by [1941Edw], and Fig. 5 shows the

location of the phase boundary separating the A2 ( ) and B2 ( ') phase fields at 700°C, taken from

[1987Miy]. Figure 6 shows the complete isothermal section determined at 650°C taken from [1994Koz2,

1999Koz]. The iron rich part of the diagram showing equilibria between and ´ phases is in excellent

agreement with the diagram calculated at the same temperature [1999Koz, 2001Miy] by computer

simulation of the phase decomposition process using the Bragg-Williams-Gorsky approximation. Some

minor changes have been made to the points where the phase boundaries meet the binary edges to make the

section consistent with the accepted binary phase diagrams. Figures 7 and 8 are partial Al-rich sections

determined at 640 and 600°C by [1948Ray]. The lines depict two sides of the (Al)+Co2Al9+FeAl3three-phase region. There is some disparity between the locations of these phase boundaries (together with

those in the vertical sections presented by [1948Ray]) and those given in Fig. 6 [1999Koz]. For this reason,

the exact locations of the phase boundaries at high-Al contents remain unclear. Complete solubility exists

between CoAl and FeAl [1966Rid, 1973Sid]. A detailed discussion is given by [1982Ray].


Figures 9 and 10 show vertical sections at 98.75 and 97.5 mass% Al, respectively, taken from [1948Ray].

A third section (at 98.5 mass% Al) was also presented in the article, but the liquidus and eutectic

temperatures for 0 mass% Co were approximately 10°C lower than given in the accepted Al-Fe binary phase

diagram, and were not consistent with the other two vertical sections either. For this reason, this section has

been omitted from this review.


[1996Cha] studied the crystal structure and the magnetic moment of (FexCo(1-x))0.9Al0.1 alloys where the

mean number of 3d+4s electrons per transition atom was 9-x for 0 < x < 1. It was found that the presence

of the Al atom causes inflation of the unit cell and a corresponding decrease in the magnetic moment of the

transition metals atoms. This resulted in a decrease in the Curie temperatures and an increase in the

resistivity. [2000Szy] conducted Mössbauer and magnetic studies of Fe3-xCoxAl. It was found that Co

modifies the lattice parameter and Debye temperature by causing lattice shrinkage through Al-Co pair

interactions. The magnetic moment of Co was measured as ~ 0.05 B at x = 0.0 and 1.15 B at x = 2.0. The

magnetic moment of Fe was given as ~1.9 B for x < 1 and 2.7 B for x = 2. The saturation magnetization

at room temperature and 1.2 T measured by VSM is

(x) = 5.47 × (2-1.2(1)x+0.46(4)x2) B.

Miscellaneous

The extent of the + ' phase field with respect to temperature was studied by DTA [1994Koz1].

Temperature contours are shown in Fig. 11. Small Al additions increase the ordering temperature of CoFe

[1955Gri]. Co additions lead to a slight increase of the ordering temperature of Fe3Al (D03) [1969Bul]. This

is a characteristic of elements (Co, Cr, Mn, Ni), which substitute to the Al site in Fe3Al [1999Mek].

208


MSIT®

Al–Co–Fe

References

[1933Koe] Köster, W., “The System Iron-Cobalt-Aluminium” (in German), Arch. Eisenhuettenwes., 7,


[1941Edw] Edwards, O.S., “An X-Ray Investigation of the Aluminium-Cobalt-Iron System”, J. Inst.

Met., 67, 66-77 (1941) (Crys. Structure, Equi. Diagram, Experimental, 16)

[1948Ray] Raynor, G.V, Waldron, M.B., “The Constitution of the Aluminium Rich Aluminium-

Cobalt-Iron Alloys, with Reference of the Role of Transitional Elements in Alloy

Formation”, Proc. Roy. Soc. A, 194, 362-374 (1948) (Equi. Diagram, Experimental, 12)

[1949Iva] Ivanov, I.O.S., Skryabina, M.A., “Phase Constitution of Alloys Between Iron and the

Compound CoAl” (in Russian), Izv. Akad. Nauk SSSR, Otdel. Khim. Nauk, 242-253 (1949)


[1955Gri] Griest, A.J., Libsch J.F., Conard, G.P., “Effect of Ternary Additions of Si and Al on the

Ordering Reaction in Fe-Co”, Acta Metall., 3, 509-510 (1955) (Experimental, 7)

[1966Rid] Ridley, N., “Defect Structures in Binary and Ternary Alloys Based on CoAl”, J. Inst. Met.,

94, 255-258 (1966) (Crys. Structure, Equi. Diagram, Experimental, 9)

[1969Bul] Bulycheva, Z.N., Kondrat'ev, V.K., Pogosov V.Z, Svezhova, S.I., “The Effect of Chromium

and Cobalt on the Structure and Properties of Ordered Fe-Al Alloys” (in Russian), Sb. Tr.

Nauchno-Issled. Inst. Chern. Met., 71, 55-62 (1969) (Equi. Diagram, 7)

[1973Sid] Sidorenko, F.A., Kotov, A.P., Zelenin L.P., Gel'd, P.V., “Physical Properties of FeAl-CoAl

Solid Solutions” (in Russian), Fiz. Metall. Metalloved., 35, 218-219 (1973) (Crys. Structure,

Experimental, 5)

[1982Ray] Raynor, G.V., Rivilin, V.G., “Critical Evaluation of Constitution of Aluminium-Cobalt-Iron

System”, Int. Met. Rev., 27(3), 169-183 (1982) (Equi. Diagram, Review, 24)

[1987Miy] Miyazaki, T., Isobe, K., Kozakai T., Doi, M., “The Phase Separations of Fe-Al-Co Ordering

Alloys”, Acta Metall., 35(2), 317-326 (1987) (Equi. Diagram, Experimental, 30)

[1991Kub] Kubaschewski, O., “Aluminium - Cerium - Iron”, MSIT Ternary Evaluation Program, in



Assessment, 15)


Phase with the Approximate Composition Fe2Al5”, Acta Crystallogr., Sect. B: Struct.

Crystallogr. Crys. Chem., B50, 313-316 (1994) (Crys. Structure, Experimental, 9)

[1994Koz1] Kozakai, T., Miyazaki, T., “Experimental and Theoretical Studies on Phase Separations in

the Fe-Al-Co Ordering Alloy System”, J. Mater. Sci., 29(3), 652-659 (1994) (Equi.

Diagram, Experimental, Calculation, 25)

[1994Koz2] Kozakai, T., Miyazaki, T., “Experimental And Theoretical Investigations on Phase

Diagrams of Fe Base Ternary Ordering Alloys”, ISIJ Int., 34(5), 373-383 (1994) (Equi.

Diagram, Magn. Prop., 18)

[1996Bur] Burkhardt, U., Grin, J., Ellner, M., Grin, Yu., “Powder Diffraction Data for the Intermetallic

Compounds Co2Al5, Monoclinic m-Co4Al13 and Orthorhombic o-Co4Al13”, Powder Diffr.,

11(2), 123-128, (1996) (Crys. Structure, Experimental, 23)

[1996Cha] Chadjivasiliou, S.C., Efthimiadis, K.G., Tsoukalas, I.A., Hesse, J., “Crystal Structure,

Magnetization and Resistivity of 3d-Transition Metal Alloys with 10% Al Admixtures”,

Mater. Res. Bull., 31(12), 1471-1477 (1996) (Crys. Structure, Magn. Prop., Experimental,

10)

[1996Gru] Grushko, B., Wittenberg, R., Bickmann, K., Freiburg, C., “The Constitution of Aluminium-

Cobalt Alloys between Al5Co2 and Al9Co2”, J. Alloys Compd., 233, 279-287 (1996) (Crys.


[1999Koz] Kozakai, T., Okamoto, R., Miyazaki, T., “Phase Equilibria in the Fe-Al-Co Ternary System

at 923 K”, Z. Metallkd., 90(4), 261-266 (1999) (Equi. Diagram, Experimental, #, 12)

209


MSIT®

Al–Co–Fe

[1999Mek] Mekhrabov, A.O., Akdeniz, M.V., “Effect of Ternary Alloying Elements Addition on

Atomic Ordering Characteristics of Fe-Al Intermetallics”, Acta Mater., 47(7), 2067-2075

(1999) (Calculation, Theory, Thermodyn., 63)

[2000Szy] Szymanski, K., Biernacka, M., Dobrzynski, L., Perzynska, K., Recko, K., Satula, D.,

Waliszewski, J., Zaleski, P., “Mössbauer and Magnetic Studies of Fe3-xCoxAl”, J. Magn.

Magn. Mater., 210, 150-162 (2000) (Moessbauer, Magn. Prop., 36)

[2001Miy] Miyazaki, T., “Computational Investigation on the Microstructure Formation in

Multi-Component Alloy Systems Based on the Phase Field Method”, Calphad, 25(2),


[2002Ohn] Ohnuma, I., Enoki, H., Ikeda, O., Kainuma, R., Ohtani, H., Sundman, B., Ishida, K., “Phase

Equilibria in the Fe-Co Binary System”, Acta Mater., 50, 379-393 (2002) (Equi. Diagram,

Thermodyn., Experimental, Assessment, 50)

[2003Gru] Grushko, B, Cacciamani, G., “Al-Co (Aluminium - Cobalt)”, MSIT Binary Evaluation


Services, GmbH, Stuttgart; to be published, (2003) (Equi. Diagram, Assessment, Crys.

Structure, 72)

[2003Pis] Pisch, A., “Al-Fe (Aluminum-Iron)” MSIT Binary Evaluation Program, in MSIT

Workplace, Effenberg, G. (Ed.), MSI, Materials Science International Services, GmbH,



Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

,Fe1-x-yCoxAly

(Al)

< 660.452

( Co)

1495-422

( Fe)(h1)

1394-912

cF4

Fm3m

Cu a = 404.96

a = 354.47

a = 364.67

pure Al at 25°C [Mas2]

pure Co at 25°C [Mas2]

pure Fe at 915°C [Mas2]

( Co)

< 422

hP2

P63/mmc

Mg

a = 250.71

c = 406.86

at 25°C [Mas2]

,Fe1-x-yCoxAly

( Fe)(h2)

1538-1394

( Fe)(r)

< 912

cI2

Im3m

W a = 293.15

a = 286.65

0 x 0.77 at y = 0

0 y 0.55 at x = 0

at 1480°C [Mas2]

at 25°C [Mas2]

',(FexAl1-x)(FeyCo1-y)

CoAl

< 1640

FeAl

< 1310

FeCo

< 730

cP2

Pm3m

CsCl

a = 286.2

a = 290.9

a = 285.71

0 y 1 at x = 0

[1966Rid]

50 at.% Al (from 20 to 54 at.% Al

at 1400°C) [2003Gru]

50 at.% Al (from 36 at 50 at.% Al at

500°C) [2003Pis]

50 at.% Co [V-C2] (from 25 to 70 at.%

Co at 500°C) [2002Ohn]

210


MSIT®

Al–Co–Fe


Co2Al5< 1188

hP28

P63/mmc

Co2Al5

a = 767.2

c = 760.5

[1996Gru]

[1996Bur]

O-Co4Al13

< 1080

oP102

Pmn21

O-Co4Al13

a = 815.8

b = 1234.7

c = 1445.2

[1996Gru]

[1996Bur]

Co2Al9< 970

mP22

P21/a

Co2Al9

a = 855.65

b = 629.0

c = 621.3

= 94.76°

[2003Gru]

Fe3Al

< 547

cF16

Fm3m

BiF3

a = 579.23 [V-C2]. Ordered D03 phase

FeAl2< 1156

aP18

P1

FeAl2

a = 487.8

b = 646.1

c = 880.0

= 91.75°

= 73.27°

= 96.89°

at 66.9 at.% Al [V-C2]

Fe2Al5< 1169

oC24

Cmcm

a = 765.59

b = 641.54

c = 421.84

at 71.5 at.% Al [1994Bur]

FeAl3< 1160

mC102

C2/m

FeAl3

a = 1549.2

b = 807.8

c = 1247.1

= 107.69°

at 76.0 at.% Al [2003Pis]

Sometimes called Fe4Al13 in the

literature


Al Co Fe

L ( Co) + CoAl ? e (min) L ~14.9 ~63.5 ~21.5

L (Al) + FeAl3 + Co2Al9 653.9 E1 L

(Al)

FeAl3Co2Al9

99.08

~100

?

81.8

0.16

~0

?

18.2

0.76

~0

?

~0

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

211


MSIT®

Al–Co–Fe

Fig. 1: Al-Co-Fe. Partial reaction scheme

Co-Fe Al-Co Al-Co-Fe

l (Al) + Co2Al

9

657 e3

l (Al) + FeAl3

655 e4

L (Al) + FeAl3

+ Co2Al

9653.9 E

1

L + FeAl3

+Co2Al9

l + (δFe) (γFe)

1504 p1

l (αCo) + CoAl

1400 e1

L (αCo) + CoAl

? e2

(min)

Al-Fe

(Al) + FeAl3

+ Co2Al9

20

40

60

80

20 40 60 80

20

40

60

80

Fe Co


Axes: at.%

1300

1350 1400

1450 1500 1550

1600

1500

1450

1450

1400

b2

e1

a2

a1 b1

p1

α γ

α'

Fig. 2: Al-Co-Fe.

Part of the liquidus

surface

212


MSIT®

Al–Co–Fe

Fe 2.00Co 0.00Al 98.00

Fe 0.00Co 2.00Al 98.00


Axes: at.%

(Al)

E1

670

670

690

690Co2Al9

FeAl3

e3

e4

20

40

60

40 60 80

20

40

60

Fe 70.00Co 30.00Al 0.00

Co

Fe 0.00Co 30.00Al 70.00 Data / Grid: at.%

Axes: at.%

α

(γCo)

Al rich boundary ofthe CoAl phase

Fig. 3: Al-Co-Fe.

Liquidus surface of

the Al rich corner

Fig. 4: Al-Co-Fe.

Part of the isothermal

section at 800°C

213


MSIT®

Al–Co–Fe

20

40

60

80

20 40 60 80

20

40

60

80

Fe Co


Axes: at.%

FeAl3Fe2Al5

FeAl2

O-Co4Al13

Co2Al9

αα

α'

α'+α' α+α'

(Al)

(γCo)

Co2Al5

Z

1 2

60

70

80

90

10 20 30 40

10

20

30

40

Fe Fe 50.00Co 50.00Al 0.00

Fe 50.00Co 0.00Al 50.00 Data / Grid: at.%

Axes: at.%

α'

α

Fig. 6: Al-Co-Fe.


650°C

Fig. 5: Al-Co-Fe.

Isothermal section

(Fe-rich part) at

700°C

214


MSIT®

Al–Co–Fe

Fe 10.00Co 0.00Al 90.00

Fe 0.00Co 10.00Al 90.00


Axes: at.%

(Al)+FeAl3(Al)+FeAl3

+Co2Al9

(Al)+Co2Al9

(Al)

Fe 10.00Co 0.00Al 90.00

Fe 0.00Co 10.00Al 90.00


Axes: at.%

(Al)+FeAl3

(Al)+FeAl3+Co2Al9(A

l)+C

o 2A

l 9

(Al)

Fig. 7: Al-Co-Fe.


640°C (Al-rich part)

Fig. 8: Al-Co-Fe.


600°C (Al-rich part)

215


MSIT®

Al–Co–Fe

Fe 0.61Co 0.00Al 99.39

Fe 0.00Co 0.58Al 99.42Co, at.%

Tem

pera

ture

, °C

L

(Al)+L

(Al)+FeAl3+L

(Al)+FeAl3 (Al)+Co2Al9+FeAl3(Al)+Co2Al9

(Al)+Co2Al9+L

L+Co2Al9

650

660

670

0.20 0.40

700

Fe 1.22Co 0.00Al 98.78

Fe 0.00Co 1.16Al 98.84Co, at.%

Tem

pera

ture

, °C

L+Co2Al9+FeAl3

(Al)+Co2Al9+L(Al)+FeAl3+L

(Al)+Co2Al9+FeAl3

L

650

675

725

750

625

Fig. 9: Al-Co-Fe.

Isopleth at 98.75

mass% Al

Fig. 10: Al-Co-Fe.

Isopleth at 97.5

mass% Al

216


MSIT®

Al–Co–Fe

20

40

60

80

20 40 60 80

20

40

60

80

Fe Co


Axes: at.%

427°C577

677

727

Fig. 11: Al-Co-Fe.

Temperature limits of

the A2 + B2 phase

field

217


MSIT®

Al–Co–Gd

Aluminium – Cobalt – Gadolinium

Oksana Bodak

Literature Data

Experimental studies in this system are mostly motivated by the search for magnetic properties. Solid

solutions extending over significant ranges of compositions are confirmed in the literature. These phases

are based on the binary compounds GdCo2, GdCo5 and GdAl2 and on the ternary compounds GdCo2-xAlx(0.98 x 1.46) and Gd2Co6Al11, discovered by [1978Pop].

Since then there are numerous new publications on this system concerning phase equilibria, crystal

structures or properties of phases. The CoAl-Gd isopleth was established by [1993Wan, 1994Wan]. They

also confirmed the existence of the ternary phase GdCoAl ( 4) and presence of a new ternary phase of

stoichiometry Gd(Co,Al)1.5. [1994Liu, 2001Gu] prepared a series of alloys in the Gd2Co17-xAlx (x = 0-5)

solid solution region to examine structures and properties. [1999She] investigated the structure and

magnetic anisotropy of the alloy Gd2Co15Al2. Crystal structure and magnetic properties of several alloys,

for example GdCo4Al, were studied by [1996Tha, 1997Gal. [2001Rou] reported the existence of the ternary

phase Gd2Co3Al9 including its structure and magnetic properties.

All samples were prepared by arc-melting from high-purity metals [1967Oes, 1970Shi, 1971Oes, 1973Zar,

1976Oes, 1978Pop, 1985Chu1, 1985Chu2, 1993Wan, 1994Liu, 1994Wan, 1997Che, 1997Gal, 1999She,

2000Jar, 2001Gu, 2001Rou]. They were investigated both in annealed and as cast state. For crystal structure

determination the X-ray powder method was used. Single crystal of GdCo4Al composition was grown by

tri-arc Czochralski apparatus [1996Tha]. In most cases magnetic properties were studied, such as Curie

temperature, magnetization, magneto-crystalline anisotropy [1978Pop, 1996Tha, 1997Che, 1999She,

2000Jar, 2001Gu, 2001Rou]. For these purpose different type of magnetometers were used to measure in

magnetic fields up to 5.5T and in a temperature range of 2-300 K. In [1997Gal] the magnetic measurements

were performed at 27-527°C and the temperature dependence of the electric resistivity was explored in the

range of 4.2-500 K. The XPS measurements were performed in [2001Jar].

The present evaluation builds on a critical review of the literature data made in the MSIT Ternary

Evaluation Program by [1991Gri]. It was based on published information pertaining to investigation of

samples within the composition GdAl2-GdCo2 [1967Oes, 1969Tes, 1971Oes] and GdCo5-xAlx (x = 0-1.75)

[1970Shi, 1976Oes, 1985Chu1, 1985Chu2]. Combing the earlier data with the isopleth established by

[1993Wan, 1994Wan] now allows to draw an isothermal section at 600°C.

Binary Systems

For phase relations in the binary Co-Gd the description given by [Mas2] still applies. The other edge binary

data are accepted as evaluated in the MSIT Binary Evaluation Program: Al-Co by [2003Gru] and Al-Gd by

[2002Bod].

Solid Phases

Four ternary phases were found in the system. Crystal structure was studied for three of them. Data about

composition and structure of phases of the Al-Co-Gd system are shown in Table 1. Crystal structure and

electronic structure of GdCoAl compound as well as its magnetic properties were subjected to investigation

by [2000Jar, 2001Jar].


The invariant ternary reactions given in Table 2 are mainly based on data from [1993Wan, 1994Wan].

218


MSIT®

Al–Co–Gd

Isothermal Sections

A possible scheme of phase equilibria at 600°C shown in Fig. 1. It is obtained by combing (a) the data on

GdCo2-GdAl2 reported by [1967Oes, 1971Oes] (b) CoAl-Gd vertical section by [1993Wan, 1994Wan] and

(c) homogeneity ranges for the ternary as well as binary phases. According to the binary phase diagram

GdCo5 decomposes at ~850°C [Mas2], however in ternary alloys a phase with the same CaCu5 type (3)

structure was found in both as cast [1970Shi] and in alloys annealed at 900°C [1977Gal]. Figure 1 shows

how this phase with the CaCu5 structure possibly extends into ternary compositions.


The CoAl-Gd vertical section (Fig. 2) was determined by [1993Wan, 1994Wan]. At first sight this section

seems to describe a pseudobinary system but the abstract given by [1994Wan] points out that presence of a

three-phase field is possible on this section. According to [1993Wan, 1994Wan] solubility of Gd in CoAl

is about 0.5 at.% at 1040°C.

Miscellaneous

It is reported that the Curie temperature of solid solution phases decrease with increasing Al content

[1997Che, 2001Gu]. Gd2Co3Al9 presents two characteristic magnetic anomalies around 100 and 20 K

[2001Rou].

References

[1967Oes] Oesterreicher, H., Wallace, W.E., “Studies of Pseudo-Binary Laves-Phase Systems

Containing Lanthanides. I.”, J. Less-Common Met., 13, 91-102 (1967) (Experimental, Crys.

Structure, 22)

[1969Tes] Teslyuk, M.Yu., “Intermetallic Compounds with Structure of Laves Phases” (in Russian),

Nauka, Moscow, 1-136 (1969) (Review, Crys. Structure, Equi. Diagram, 312)

[1970Shi] Shidlovsky, I., Wallace, W.E., “Magnetic and Crystallographic Characteristics of the

Ternary Intermetallic Compounds Containing Lanthanides and Fe or Co”, J. Solid State

Chem., 2, 193-198 (1970) (Experimental, Crys. Structure, 23)

[1971Oes] Oesterreicher, H. “Structural Studies of Rare-Earth Compounds RCoAl”, J. Less-Common


[1973Zar] Zarechnyuk, O.S., Rykhal, R.M., Vivchar, O.I. “Laves Phases in Ternary Systems

Rare-Earth Metal-Transition Metal of the IV Period-Aluminium”, Sb. Nauch. Rab. Inst.

Metallofiz, Akad. Nauk Ukr. SSR, 42, 92-94 (1973) (Experimental, Crys. Structure, 22)

[1976Oes] Oesterreicher, H., McNeely, D., “Low-Temperature Magnetic Studies on Various

Substituted Rare Earth (R)-Transition Metal(T) Compound RT5”, J. Less-Common Met.,

45, 111-116 (1976) (Experimental, Crys. Structure, 6)

[1978Pop] Pop, I., Coldea, M., Wallace, W.E., “NMR and Magnetic Susceptibility of Gd2Cu6Al11 and

Gd2Co6Al11 Intermetallic Compounds”, J. Solid State Chem., 26, 115-121 (1978)


[1985Chu1] Chuang, Y.C., Wu, C.H., Chen, H.B., “Structure and Decomposition Behaviour of

GdCo5--xMx Pseudo binary Compounds. II.-Decomposition Behaviour”, J. Less-Common

Met., 106(2), 219-228 (1985) (Experimental, Crys. Structure, 46)

[1985Chu2] Chuang, Y.C., Wu, C.H., Chen, B.H., “Structure and Decomposition Behaviour of

GdCo5-xMx Pseudobinary Compounds: I: Structure”, J. Less-Common Met., 106(1), 41-51


[1991Gri] Grieb B., ”Aluminium-Coblt-Gadolinium”, MSIT Ternary Evaluation Program, in MSIT



Assessment, 5)

219


MSIT®

Al–Co–Gd

[1993Wan] Wan, J.L., Bi, Q.H., “Phase Diagram of Gd-CoAl Pseudo-Binary System”, Proc. 7th

National Symposium on Phase Diagrams, 27-30 (1993 (Experimental, Crys. Structure,

Equi. Diagram, #)

[1994Liu] Liu, J.P., Boer, F.R. de, Chatel, P.F. de, Coehoorn, R., Buschow, K.H.J., “On the 4f-3d

Exchange Interaction in Intermetallic Compounds”, J. Magn. Magn. Mater., 132, 159-179

(1994) (Magn. Prop., Review, 64)

[1994Wan] Wan Jinglong, Bi Qinghua, “Gd-CoAl Vertical Section of the Gd-Co-Al Phase Diagram”

(in Chinese), Acta Metall. Sin., 30(5), B204-207 (1994) (Experimental, Equi. Diagram, #, 5)

[1996Tha] Thang, C.V., Brommer, P.E., Colpa, J.H.P., Bruek, E., Menovsky, A.A., Thuy, N.P., Franse,

J.J.M., “Magnetocrystalline Anisotropy and R-Cu Exchange Interaction in Monocrystalline

RCo4Al (R = Y, Gd and Ho)”, J. Alloys Compd., 245, 100-111 (1996) (Experimental, Crys.

Structure, 40)

[1997Che] Cheng, Z.-H., Shen, B.-G., Zhang, J.-X., Liang, B., Guo, H.-Q., Kronmueller, H., “Influence

of Al Substitution on the Structure and Co-sublattice Magnetocrystalline Anisotropy of

Gd2Co17 Compounds”, Appl. Phys. Lett., 70(25), 3467-3469 (1997) (Experimental, Crys.

Structure, Magn. Prop., 8)

[1997Gal] Galatanu, A., Kottar, A., Artigas, M., Plugaru, N., Lazar, D.P., “Effect of Aluminium on

Phase Stability in the Gd3Co11(B,Al)4 System”, J. Alloys Compd., 262-263, 356-362 (1997)


[1999She] Shen, B., Cheng, Z., Zhang, S., Wang, J., Liang, B., Zhang, H., Zhan, W., “Magnetic

Properties of R2Co15Al2 compounds with R = Y, Ce, Pr, Nd, Sm, Gd, Tb, Ho, Er, Tm”,

J. Appl. Phys., 85(5), 2787-2792 (1999) (Experimental, Crys. Structure, Magn. Prop., 43)

[2000Jar] Jarosz, J., Talik, E., Mydlarz, T., Kusz, J., Boehm, H., Winiarski, A., “Crystallographic,

Electronic Structure and Magnetic Properties of the GdTAl; T = Co, Ni and Cu Ternary

Compounds”, J. Magn. Magn. Mater., 208, 169-180 (2000) (Experimental, Crys. Structure,

Magn. Prop., 23)

[2001Gu] Gu, Z.F., Liu, Z.Y., Zeng, D.C., Liang, S.Z., Klaasse, J.C.P., Brueck, E., De Boer, F.R.,

Buschow, K.H.J., “On the Occurence of Spin-Reorientation Transitions in R2Co17-xGax and

R2Co17-xAlx Compounds”, J. Alloys Compd., 319, 37-42 (2001) (Experimental, Crys.


[2001Jar] Jarosz, J., Talik, E., “Electronic Structure and ESR in GdTAl Ternary Compounds; T = 3d,

4d Transition Metals”, J. Alloys Compd., 317-318, 385-389 (2001) (Experimental, Crys.

Structure, Phys. Prop., 7)

[2001Rou] Routsi, Ch., Yakinthos, J.K., “Crystal Structure and Magnetic Properties of R2Co3Al9Compounds (R = Y, Pr, Gd, Tb, Dy, Ho, Er, Tm)”, J. Alloys Compd., 323-324, 427-430

(2001) (Experimental, Crys. Structure, Magn. Prop., 14)

[2002Bod] Bodak, O., “Al-Gd (Aluminum - Gadolinium)” MSIT Binary Evaluation Program,in MSIT

Workplace, Effenberg, G. (Ed.), Materials Science International Services GmbH Stuttgart;

Document ID: 20.12303.1.20 (2002) (Equi. Diagram, Assessment, 15)

[2003Gru] Grushko, B., Cacciamani, G., “Al-Co (Aluminium - Cobalt)”, MSIT Evaluation Program,


GmbH, Stuttgart, to be published (2003) (Equi. Diagram, Assessment, 72)

220


MSIT®

Al–Co–Gd


Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

( Gd)

1313-1200

cF4

Fm3m

Cu

a = 540.5 [Mas2, V-C2]

( Gd)

< 1200

hP2

P63/mmc

Mg

a = 363.3

c = 577.3

[Mas2, V-C2]

( Co)

422-1495

cF4

Fm3m

Cu

a = 354.46 [Mas2]

( Co)

< 422

hP2

P63/mmc

Mg

a = 250.71

c = 406.95

[Mas2]

(Al)

< 660.452

cF4

Fm3m

Cu

a = 404.88 [Mas2]

Co2Al9< 970

mP22

P21/a

a = 855.6

b = 629.0

c = 621.3

= 94.76°

[2003Gru]

O-Co4Al13

< 1080

oP102

Pmn21

O-Co4Al13

a = 815.8

b = 1234.7

c = 1445.2

[2003Gru]

M-Co4Al13

1093-?

mC102

C2/m

Fe4Al13

a = 1517.3

b = 810.9

c = 1234.9

= 107.84°

[2003Gru]

Y

1127-?

oI*

Immm

mC34

C2/m

Os4Al13

a = 1531.0

b = 1235.0

c = 758.0

a = 1704.0

b = 409.0

c = 758.0

= 116.0°

[2003Gru]

Z

< 1158

C-centr.monocl. a = 3984.0

b = 814.8

c = 3223.0

= 107.97°

[2003Gru]

Co2Al5< 1188

hP28

P63/mmc

Co2Al5

a = 767.2

c = 760.5

[2003Gru]

Co1-xAlx< 1640

cP2

Pm3m

CsCl

a = 285.7

a = 286.2

a = 285.9

x = 0.52 [2003Gru]

x = 0.5

x = 0.43

221


MSIT®

Al–Co–Gd

GdAl3< 1125

hP8

P63/mmc

Ni3Sn

a = 633.2

c = 460.0

[2002Bod]

GdCoxAl2-x

< 1520

cF24

Fd3m

MgCu2

a = 790.3

a = 782.8

a = 775.9

x < 0.54

x = 0 [1967Oes]

x = 0.3 [1967Oes]

x = 0.45 [1967Oes]

Gd2Co17-xAlx< 1370

hR57

R3m

Th2Zn17

a = 838.5

c = 1220.8

a = 838.6

c = 1219.5

a = 840.0

c = 1223.2

a = 841.6

c = 1223.9

a = 841.8

c = 1227.2

a = 844.4

c = 1228.0

a = 844.4

c = 1228.0

a = 845.0

c = 1229.5

a = 847.6

c = 1231.3

a = 846.9

c = 1231.6

a = 851.0

c = 1237.2

a = 854.4

c = 1239.7

x = 0 [2001Gu]

x = 0 [1997Che]

x = 1 [2001Gu]

x = 1 [1997Che]

x = 2 [2001Gu]

x = 2 [1997Che]

x = 2 [1999She]

x = 3 [2001Gu]

x = 3 [1997Che]

x = 4 [2001Gu] at 1000°C

x = 4 [1997Che]

x = 5 [1997Che]

GdCo5

1350-850

hP6

P6/mmm

CaCu5

a = 496.0

c = 398.9

a = 498

c = 398

[Mas2, V-C2]

[1970Shi]

Gd2Co7

< 1295

hR54

R3m

Er2Co7

a = 502.4

c = 3632

[Mas2, V-C2]

GdCo3

< 1277

hR36

R3m

NbBe3

a = 502.6

c = 2445.6

[Mas2, V-C2]

GdCo2-xAlx< 1116

cF24

Fd3m

MgCu2

a = 724.9

a = 729.3

a = 732

x = 0 [1967Oes]

x = 0.2 [1967Oes]

x = 0.35 [1967Oes]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

222


MSIT®

Al–Co–Gd


* 1, Gd2Co6Al11 hP38

P63/mmc

Th2Ni17

a = 872.3

c = 893.1

[1978Pop]

* 2, Gd2Co3Al9 oS56

Cmcm

Y2Co3Ga9

a = 1275.7 ± 2

b = 757.0 ± 5

c = 945.0 ± 2

[2001Rou]

* 3, GdCo5-xAlx hP6

P6/mmm

CaCu5

a = 500

c = 399

a = 501

c = 404

a = 505.095

c = 403.958

a = 504

c = 406

a = 505

c = 407

~0.05 x 1.8

x = 0.25 [1970Shi]

x = 1 [1970Shi]

x = 1 [1997Gal]

x = 1.5 [1970Shi]

x = 1.75 [1970Shi]

* 4, GdCo2-xAlx< 1170

hP12

P63/mmc

MgZn2 a = 537.0

c = 857.1

a = 539.1

c = 853.2

a = 544.5

c = 861.7

a = 545.2

c = 861.2

0.98 x 1.46; [1967Oes, 1971Oes,

1993Wan, 1994Wan]

x = 1 [1971Oes]

x = 1 [1993Wan]

x = 1 [2000Jar]

x = 1.4 [1967Oes]

* 5, Gd(Co,Al)1.5

< 860

[1994Wan]


Al Co Gd

L CoAl + 4 1040 e L

CoAl

4

37.25

~49.2

33.3

37.25

~50.3

33.3

25.5

~0.5

33.3

L 4 1170 congruent L, 4 33.3 33.3 33.3

L + 4 5 860 p L

4

5

24

33.3

30

24

33.3

30

52

33.3

40

L 5 + (Gd) 707 e L

5

(Gd)

18.25

30

-

18.25

30

-

63.5

40

100

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

223


MSIT®

Al–Co–Gd

20

40

60

80

20 40 60 80

20

40

60

80

Gd Co


Axes: at.%

GdAl3

GdAl2

Co2Al9

Co2Al5

Co1-xAlx

GdCo2GdCo3

Gd2Co7 Gd2Co17

O-Co4Al13Z

τ1

τ5

τ3

τ2

τ4

(αCo)

Fig. 1: Al-Co-Gd.

Scheme of presumable

phase equilibria at

600°C.

Section GdCo2 - GdAl2according to [1967Oes].

Section CoAl - Gd

according to [1993Wan,

1994Wan]

80 60 40 200

250

500

750

1000

1250

1500

1750

Gd Gd 0.00Co 50.00Al 50.00Gd, mass%

Tem

pera

ture

, °C L+τ4

>1170°C

L+CoAl

CoAl+τ4

(αGd)+τ5

L+τ5

L+(αGd)

L+(βGd)

CoAl

860°C

1640°C

L

1040°C

707°C

1313°C

1235°C

τ5 τ4

Fig. 2: Al-Co-Gd.

Vertical section

Gd - CoAl

[1993Wan,

1994Wan]

224


MSIT®

Al–Co–Hf

Aluminium – Cobalt – Hafnium

Ortrud Kubaschewski, updated by Lazar Rokhlin, Nataliya Bochvar

Literature Data

The present evaluation of the Al-Co-Hf system incorporates and updates the assessment made by

[1991Kub] in the MSIT Evaluation Program, based on data published by [1965Mar, 1969Mar, 1971Bur,

1974Dwi, 1974Mar, 1974Zie]. In all the works crystal structure of the ternary compounds have been

studied, and [1971Bur] in addition investigated the phase equilibria in the area Al-HfAl2-HfCo2-Co.

Further reviews by [1977Abr, 1990Kum] do not really add to the published knowledge, as they merely

describe the Al-Co-Hf phase diagram as presented by [1971Bur] not addressing the inconsistencies with

later data.

In addition to the above investigations of the Heusler phase HfCo2Al published by [1983Bus] are to be

considered, in particular as their measurements of the lattice parameters in HfCo2Al turned out to be close

to those by [1965Mar, 1974Zie]]. The match of the ternary and the edge binary phases needs to be reviewed,

as new critical evaluations of the Al-Co and Co-Hf systems have superseded the binary phase diagrams

published earlier.

Binary Systems

The phase diagram of Al-Hf published in [1981Kub] still reflects the present state of knowledge, whereas

revised binary phase diagrams are available from the MSIT Binary Evaluation Program for Al-Co

[2003Gru] and for Co-Hf [2003Rok]. [2003Gru] shows three different compounds to exist in the vicinity of

Co4Al13 which earlier was considered to be the only compound. The three compounds shown by [2003Gru]

are O-Co4Al13, M-Co4Al13 and Y. The first one is stable down to room temperature, the two others exist

only at higher temperatures. According to [2003Gru] a monoclinic phase designated Z exists in the vicinity

of the composition CoAl3.

Solid Phases

Nine ternary phases were found to exist in the Al-Co-Hf system [1991Kub]. These are HfCoAl4,

Hf6Co7Al16, HfCo2Al, Hf6CoAl2, 1, 2, X, H' and L'. The 1, 2 phases show pronounced ranges of

homogeneity along the section for HfAl2-HfCo2. The 1 phase includes the composition HfCoAl and is

limited in its homogeneity range by the concentrations 33.3Hf-(16.7-49.7)Co(18-50)Al (at.%). The range

of 2 - is significantly less than that of 1 and limited by the concentrations 33.3Hf-(9.7-6.7)Co(57-60)Al

(at.%). Compositions of X, H', L' were established by X-ray measurements and metallographic observations

without determination of their crystal structures. [1971Bur] supposes that the homogeneity range of the

compound HfCo2 expands into the ternary system, up to 10 at.% Al. Crystal structures of the solid phases

are presented in Table 1 with unary and binary phases pertinent to the isothermal section at 800°C.

Isothermal Sections

From the data reported by [1971Bur] and the data from the recently evaluated Al-Co and Co-Hf systems an

amended partial isothermal section can be drawn, in the limits of the area Al-HfAl2-HfCo2-Co. In

accordance with the binary Co-Hf phase diagram the phase Hf6Co23 is stable in the temperature range

1270-950°C and, therefore, is removed from the isothermal section at 800°C [1971Bur]. The phase Hf2Co7,

however, is stable at 800°C and, therefore inserted in the isothermal section. Corrections according to the

accepted binary Al-Co system include replacement of the phases Co4Al13 and CoAl3 with the phases

O-Co4Al13 and Z, respectively.

For a number of other solid phases the range of existence is not firmly established. By lack of information

these phases appear in Fig. 1 as points only, subject to future research.

225


MSIT®

Al–Co–Hf


After annealing at 1000°C for 3 days [1983Bus] found that the Heusler phase HfCo2Al exhibits magnetic

properties with a Curie temperature of 193 K and a saturation magnetic moment of 0.82 at 4.2 K.

Miscellaneous

[1987Kis] successfully applied computer forecasting to retrospectively predict the existence of the Heusler

phase HfCo2Al from semi-empirical and fundamental data.

References

[1965Mar] Markiv, V.Ya., Voroshilov, Yu.V., Kripyakevich, P.I, Cherkashin, E.E., “New Compounds

of the MnCu2Al and MgZn2-types Containing Al and Ga”, Sov. Phys. Crystallogr., 9(5),

619-620 (1965), translated from Kristallografiya, 9, 737-738 (1964) (Crys. Structure,

Experimental, 4)

[1969Mar] Markiv, V.Ya., Burnashova, V.V., “New Ternary Compounds in the (Sc, Ti, Zr, Hf)-(V, Cr,

Mn, Fe, Co, Ni, Cu)-(Al, Ga) Systems” (in Russian), Dop. Akad. Nauk Ukrain. RSR, Ser. A,

Fiz.-Mat. Tekh. Nauki, (5), 463-464 (1969) (Crys. Structure, Experimental, 12)

[1971Bur] Burnashova, V.V., Markiv, V.Ya., Stroganov, G.B., “Study of the Hf-Co-Al System up to

33.3 at.% Hf” (in Russian), Dop. Akad. Nauk Ukr. RSR, Ser. A, Fiz.-Mat. Tekh. Nauki, (12),

1122-1124 (1971) (Crys. Structure, Experimental, Equi. Diagram, #, 20)

[1974Dwi] Dwight, A.E., “Alloying Behaviour of Zr, Hf, and the Actinides in Several Series of

Isostructural Compounds”, J. Less-Common Met., 34, 279-284 (1974) (Crys. Structure,

Experimental, 6)

[1974Mar] Marazza, R., Ferro, R., Rambaldi, G., Mazzjne, D., “On some Ternary Laves Phases in the

Systems of Al and Zr (or Hf) with a Metal of the VIII Group”, J. Less-Common Met., 37,


[1974Zie] Ziebeck, K.R.A., Webster, P.J., “A Neutron Diffraction and Magnetization Study of

Heusler Alloys Containing Co and Zr, Hf, V or Nb”, J. Phys. Chem. Solids, 35, 1-7 (1974)


[1977Abr] Abrikosov, N. Kh., “Phase Diagrams of Aluminium and Magnesium Alloy Systems” (in

Russian), Nauka, Moscow, 22-25 (1977) (Equi. Diagram, Review, 4)

[1981Fer] Ferro, R., Marazza, R., “Crystal Structure and Density Data, Hafnium, Alloys and

Compounds other than Halides and Chalcogenides”, Atom. Energy Rev., Special Issue

No. 8, IAEA, Vienna, 121-250 (1981) (Crys. Structure, Review, 645)

[1981Kub] Kubaschewski von Goldbeck, O.,”Phase Diagram, Hafnium”, Atom. Energy Rev., Special

Issue No. 8, IAEA, Vienna, 57-118 (1981) (Equi. Diagram, Review, 155)

[1983Bus] Buschov, K.H.J., Van Engen, P.G., Jongebreur, R., “Magneto-Optical Properties of Metalic

Ferromagnetis Materials”, J. Magn. Magn. Mater., 38, 1-22 (1983) (Magn. Prop., Optical

Prop., 23)

[1987Kis] Kiseleva, N.N., “Predicting of ABD2 (D=Co, Ni, Cu, Pd) Heusler Phases” (in Russian), Izv.

Akad. Nauk SSSR, Met., (2), 213-215 (1987) (Review, 4)

[1990Kum] Kumar, K.S., “Ternary Intermetallics in Aluminium-Refractory Metal-X Systems (X = V,

Cr, Mn, Fe, Co, Ni, Cu, Zn)”, Int. Mater. Rev., 35(6), 293-327 (1990) (Equi. Diagram,

Review, 158)

[1991Kub] Kubaschewski, O., “Aluminium - Cobalt - Hafnium”, MSIT Ternary Evaluation Program,


GmbH, Stuttgart, Document ID:10.15703.1.20 (1991) (Equi. Diagram, Assessment, Crys.

Structure, #, 9)

[2003Gru] Grushko, B., Cacciamani, G., “Al-Co (Aluminium-Cobalt)”, MSIT Binary Evaluation


226


MSIT®

Al–Co–Hf

Services GmbH, Stuttgart, to be published (2003) (Equi. Diagram, Assessment, Crys.

Structure, 72)

[2003Rok] Rokhlin, L.L., Lysova, E.V., “Co-Hf (Cobalt-Hafnium)”, MSIT Binary Evaluation


Services GmbH, Stuttgart, to be published (2003) (Equi. Diagram, Crys. Structure,

Assessment, 11)


Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

(Al)

< 660.452

cF4

Fm3m

Cu

a = 404.88 pure Al [2003Gru]

dissolves up to 0.186 at.% Hf at 662.2°C

and 0.5 at.% Co at 657°C [Mas2]

( Co)

1495-422

cF4

Fm3m

Cu

a = 354.46 dissolves up to 19.5 at.% Al at 1400°C

[Mas2] and 0.8 at.% Hf at 1100°C

[2003Rok]

( Co)

< 422

hP2

P63/mmc

Mg

a = 250.71

c = 406.86

[Mas2, 2003Rok]

Co2Al9< 970

mP22

P21/a

-

a = 855.6

b = 629.0

c = 621.3

= 94.76

[V-C2, 2003Gru]

O-Co4Al13

<1080

oP102

Pmn21

O-Co4Al13

a = 815.8

b = 1234.7

c = 1445.2

[2003Gru]

M-Co4Al13

1093-?

mC102

C2/m

Fe4Al13

a = 1517.3

b = 810.9

c = 1234.9

= 107.84

[2003Gru]

Y

1124-?

oI*

Immm

-

mC34

C2/m

Os4Al13

a = 1531.0

b = 1235.0

c = 758.0

a = 1704.0

b = 409.0

c = 758.0

= 116.0

[2003Gru]

Z

< 1158

C-centr. monocl. a = 3984.0

b = 814.8

c = 3223.0

= 107.97

[2003Gru]

Co2Al5< 1188

hP28

P63/mmc

Co2Al5

a = 767.2

c = 760.5

a = 767.15

c = 760.85

[2003Gru]

[V-C2]

227


MSIT®

Al–Co–Hf

Co1-xAlx< 1640

cP2

Pm3m

CsCl

a = 285.7

a = 286.2

a = 285.9

a = 286.11

at x = 0.52 [2003Gru]

at x = 0.5 [2003Gru]

at x = 0.43 [2003Gru]

[V-C2]

HfAl3~1590-~650

tI16

I4/mmm

ZrAl3

a = 389 to 401

c = 1714 to 1731

[1981Fer]

HfAl3 650

tI8

I4/mmm

TiAl3

a = 389 to 393

c = 893 to 889

[1981Fer]

HfAl2< 1650

hP12

P63/mmc

MgZn2

a = 523 to 529

c = 865 to 874

[1981Fer]

HfCo7

1255-1050

tP32

-

-

a = 707.0

c = 799.9

at 12.5 at. % Hf [2003Rok, 1981Fer]

Hf6Co23

1275-950

cF116

Fm3m

Mn23Th6

a = 1148.0

a = 1150.2

at 20.7 at.% Hf [2003Rok]

at 1200°C (annealed) [1981Fer]

Hf2Co7

< 1350

o**

-

(Ni7Zr2)

a = 444.4

b = 819.1

c = 1214.0

at 22.2 at.% Hf [2003Rok, 1981Fer]

HfCo2

< 1670

cF24

Fd3m

Cu2Mg a = 689.8 to 692.2

a = 691.2 to 692.2

from at least 28 up to 35 at.% Hf

[2003Rok]

[2003Roc]

[1981Fer]

* HfCo2Al cF16

AlCu2Mn

a = 601.9

a = 600.9

a = 604.5

(+some CoHf2) [1974Zie]

[1965Mar]

[1983Bus]

* ~Hf6Co7Al16 cF116

Fm3m

Th6Mn23

a = 1206 [1969Mar]

* ~HfCoAl4 -

-

(ZrCoAl4)

a = 718

c = 895

[1969Mar]

* Hf6CoAl2 hP9

P62m

Zr6CoAl2

a = 781

c = 328

[1969Mar, 1971Bur]

* 1, Hf(Co1-xAlx)2 hP12

P63/mmc

MgZn2

a = 503 to 518

c = 806 to 848

a = 508.1

c = 819.1

a = 506

c = 802

at 0.25 x 0.75 [1971Bur]

for HfCoAl [1974Dwi]

for HfCoAl [1974Mar]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

228


MSIT®

Al–Co–Hf

* 2, Hf(CoxAl1-x)2 cF24

Fd3m

MgCu2

a = 737.5

0.10 x 0.15 [1971Bur]

at x = 0.15 [1971Bur]

* L'

Hf20Co70Al10

not determined [1971Bur]

* X

Hf4Co22Al74


* H'

Hf30Co52Al18


Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

20

40

60

80

20 40 60 80

20

40

60

80

Hf Co


Axes: at.%

HfCo2 Hf2Co7

(αCo)

L´H'

HfCo2Alλ1

Hf6Co7Al16λ2

HfCoAl4

HfAl2

HfAl3

Co2Al5

ZO-Co4Al13

Co2Al9

L

CoAl

X

Fig. 1: Al-Co-Hf.


800°C

229


MSIT®

Al–Co–Mn

Aluminium – Cobalt – Manganese

Eberhard E. Schmid, Gerhard Schneider, Qingsheng Ran, updated by Andy Watson

Literature Data

The Al-Co-Mn system was first investigated by Köster and Gebhardt [1938Koe1]. They determined seven

temperature-concentration sections and constructed the liquidus surface projection as well as the reaction

scheme in the region between 0 and 50 mass% Al by thermal analysis and microstructural observation. The

materials they used were of technical purities: Co with 1.4 mass% Fe, Mn with 1.4 mass% Si and 0.24

mass% (S+P) and Al with 0.4 mass% (Fe+Si). The solubility limits of Mn in (Mn,Co)Al were determined

by the same authors by magnetic measurement [1938Koe2]. [1942Ven] used the same methods as

[1938Koe1], but with purer materials (Al 99.99%, Mn 99.9% and Co 99.1%) and established liquidus

isotherms and the liquidus surface projection in the Al-corner at compositions of more than 90 mass% Al.

[1944Ray] reported small solubility of Co in MnAl6 by microstructural analysis. [1947Ray] presented the

results of thermal analysis and metallographic observation along three vertical sections and three isothermal

sections, which are in the composition range 0 to 5.6 mass% Mn and 0 to 4.0 mass% Co. The alloys were

prepared from superpure aluminium, aluminium manganese master alloy and aluminium cobalt master

alloy; the impurity levels of the last two alloys being about 0.01 to 0.02 mass%. Using electrolytic Mn and

Co (both 99.9%) and pure Al, [1962Tsu] constructed a partial isothermal section at 900°C using the results

of magnetic measurements but the concentration scale was uncertain. Based on earlier work, using newer

versions of the binary boundary systems and pure materials (99.9% Co, 99.99% Mn and 99.99% Al),

Gödecke and Köster [1972Goe] performed a comprehensive study of the system using thermal analysis and

metallography. The experimental details were not given. Apart from [1938Koe1] and [1942Ven], the above

works agree well or complement each other. However, more recent studies by [1998Kai] indicate that the

phase equilibria in the ternary system are more complex. Previous studies had assumed a continuous solid

solution between the CoAl (B2) phase and the ( Mn) (A2) phase. [1998Kai] prepared diffusion couples that

were annealed in sealed quartz tubes at temperatures between 1000 and 1200°C. Using EDS, the critical

compositions of the A2/B2ordering transition between the two phases were determined from concentration-

penetration curves. They found that both a continuous and a discontinuous transition from A2 to B2 exists

between the two phases, resulting in the presence of an A2+B2 region at certain compositions and

temperatures. Isothermal sections for Al contents less than 50 mole % at 1000, 1050, 1100 and 1200°C and

an isopleth between CoAl-Mn were presented. Several works [1962Tsu, 1971Web, 1981Sol1, 1981Sol2,

1983Kue] contributed to the crystal structure of the Heusler alloy MnCo2Al.

Binary Systems

The Al-Co and Al-Mn binary systems were taken from the MSIT binary evaluation programme, [2003Gru,

2003Pis]. The Co-Mn system was accepted from [Mas2].

Solid Phases

Solid phases are presented in Table 1. These include a ternary phase Mn2Co4Al62 ( ) having a small

homogeneity range [1972Goe]. [1972Goe] had suggested a continuous solid solution between CoAl, and

( Mn) at temperatures greater than 1000°C. However, as CoAl is ordered there must be an order/disorder

transition between CoAl and MnAl and ( Mn) somewhere in the ternary. Such a reaction was discovered

by [1998Kai], between CoAl and ( Mn), but there should also be one between CoAl and MnAl. [1981Sol2]

reports the occurrence of order-disorder transformations in the Heusler alloy MnCo2Al:

cF16 --- (990°C) --- cP2 ----(1250°C) ---- cI2

However, this would not be consistent with the work of [1972Goe] and [1998Kai], where it is suggested

that this composition would most likely result in a two-phase mixture of ( Co) and the cP2 phase. The

230


MSIT®

Al–Co–Mn

Curie temperature of the MnCo2Al alloy was measured to be ~422°C [1983Kue, 1971Web]. A small

solubility of Co in MnAl6 was reported by [1944Ray].


The CoAl-Mn section was reported to be pseudobinary by [1938Koe1]. However, this was found not to be

the case by [1972Goe] and [1998Kai].


A reaction scheme was constructed by [1972Goe] (Fig. 1). Details of the invariant points are listed in Table

2. In order to distinguish between the ordered and disordered variants of the phase, the ordered CoAl based

phase is given as ’. Also, in order to differentiate between the reactions involving the ( Mn) and Mn55Al45

phases in the Al-Mn binary, these phases have been designated as 1 and 2, respectively.

Liquidus Surface

A liquidus surface was constructed by [1972Goe] and is given in Fig. 2. Figure 3 shows an enlarged Al-rich

portion of the liquidus surface.

Isothermal Sections

Isothermal sections for 500, 800 and 900°C are given in Figs. 4-6 taken from [1972Goe]. Figures 7 and 9

show composite isothermal sections for 1000 and 1100°C taken from the work of [1972Goe] for Al contents

greater than 50 mole%, and from [1998Kai] for Al contents less than 50 mole%. Figures 8 and 10 show

partial isothermal sections for 1050 and 1200°C, respectively, for Al contents less than 50 mole%, taken

from [1998Kai]. In all cases, slight adjustments have been made to make the sections consistent with the

accepted binary phase diagrams. It should be noted that [1972Goe] did not distinguish between the M- and

O- modifications of Co4Al13, and hence they appear in the diagrams as the same phase.


Figures 11-15 show isopleths for 25, 40, 70, 85 and 95 mass% Al, respectively, taken from [1972Goe]. A

section at 45 mass% Mn was also presented by [1972Goe], but was found to be incompatible with

[1998Kai], hence, it is omitted here. Figure 16 shows the vertical section from CoAl-Mn taken from

[1998Kai]. Vertical sections were presented in [1938Koe1, 1947Ray, 1978Urs] but were found to be

incompatible with the above.


On investigating the use of thin films of Mn60Al40 as a recording medium, it was found that substituting Mn

with Co increased the saturation magnetization by a factor of up to 2 for Mn55Co5Al40 [1991Mat].

References

[1938Koe1] Köster, W., Gebhardt, E., “The Cobalt - Manganese - Aluminium System” (in German), Z.

Metallkd., 30, 281-286 (1938) (Equi. Diagram, Experimental, 7)

[1938Koe2] Köster, W., Gebhardt, E., “The Magnetic Properties of the Cobalt - Manganese - Aluminium

Alloys” (in German), Z. Metallkd., 30, 286-290 (1938) (Equi. Diagram, Experimental, 7)

[1942Ven] Venturello, G., Predosa, P.B., “The Ternary Aluminium-Cobalt-Manganese System” (in

Italian), Atti Acad. Sci. Tor., Classe Sci. Fis. Mat. Nat., 77, 10-21 (1942) (Equi. Diagram,

Experimental, 19)

[1944Ray] Raynor, G.V., “The Effect on the Compound MnAl6 of Iron, Cobalt and Copper”, J. Inst.

Met., 70, 531-542 (1944) (Equi. Diagram, Experimental, 15)

231


MSIT®

Al–Co–Mn

[1947Ray] Raynor, G.V., “The Constitution of the Aluminium-Rich Aluminium - Manganese - Cobalt

Alloys”, J. Inst. Met., 73, 521-536 (1947) (Equi. Diagram, Experimental, 19)

[1962Tsu] Tsuboya, I., Sugihata, M., “The Magnetic Properties of the K-Phase in Mn-Al-Co System”,

J. Phys. Soc. Japan, 17, 172 (1962) (Equi. Diagram, Crys. Structure, Experimental, 5)


94, 255-258 (1966) (Crys. Structure, Equi. Diagram, Experimental, 9)

[1971Web] Webster, P.J., “Magnetic and Chemical Order in Heusler Alloys Containing Cobalt and

Manganese”, J. Phys. Chem. Solids, 32, 1221-1231 (1971) (Crys. Structure, Experimental,

28)

[1972Goe] Gödecke, T., Köster, W., “The Three Component Cobalt - Manganese - Aluminium

System” (in German), Z. Metallkd., 63, 422-430 (1972) (Equi. Diagram, Experimental, #,

11)

[1978Urs] Ursache, M., “Studies of the Possibilities of Using some Alloys of the Al-Mn-M System of

the Possibilities of Permanent Magnets” (in Romanian), Bul. Inst. Politeh. Bucaresti Chim.

Met., 40, 105-112 (1978) (Equi. Diagram, Experimental, 9)

[1981Sol1] Soltys J., Kozubski, R., “A Simple Model of the Order-Disorder Phase Transitions in

Ternary Alloys and its Application to Several Selected Heusler Alloys”, Phys. Status Solidi

A, 63, 35-44 (1981) (Crys. Structure, Theory, 23)

[1981Sol2] Soltys J., “X-ray Diffraction Research of the Order-Disorder Transitions in the Ternary

Heusler Alloys B2MnAl (B = Cu, Ni, Co, Pd, Pt)”, Phys. Status Solidi A, 66, 485-491 (1981)


[1983Kue] Kübler, T., Williams, A.R., Sommers, C.B., “Formation and Coupling of Magnetic

Moments in Heusler Alloys”, Phys. Rev. B, Condens. Matter., 28, 1745-1755 (1983) (Crys.


[1991Mat] Matsumoto, M., Morisako, A. and Ohshima, J., “Properties of Ferromagnetic MnAl Thin

Films with Additives”, J. Appl. Phys., 69(8), 5172-5174 (1991) (Electr. Prop.,

Experimental, Magn. Prop., Mechan. Prop., 4)

[1996Bur] Burkhardt, U., Grin, J., Ellner, M., Grin, Yu., “Powder Diffraction Data for the Intermetallic



[1996Fre] Freiberg, C., Grushko, B., Wittenberg, R., Reichert, W., “Once More about Monoclinic

Co4Al13”, Mater. Sci. Forum, 228-231, 583-586 (1996) (Crys. Structure, Experimental, 8)

[1996Gru] Grushko, B., Wittenberg, R., Bickmann, K., Freiburg, C., “The Constitution of Aluminium-

Cobalt Alloys between Al5Co2 and Al9Co2”, J. Alloys Compd., 233, 279-287 (1996) (Crys.


[1998Kai] Kainuma, R., Ise, M., Ishikawa, K., Ohnuma, I., Ishida, K., “Phase Equilibria and Stability

of the B2 Phase in the Ni-Mn-Al and Co-Mn-Al Systems”, J. Alloys Compd., 269, 173-180

(1998) (Equi. Diagram, Experimental, #, *, 19)

[1998Mo] Mo, Z.M., Sui, X.L., Kuo, K.H., “Structural Models of 2-Inflated Monoclinic and

Orthorhombic Al-Co Phases”, Metall. Mater. Trans., A29, 1565-1572 (1998) (Crys.


[2003Gru] Grushko, B, Cacciamani, G., “Al-Co (Aluminium - Cobalt)”, MSIT Evaluation Program, in


GmbH, Stuttgart, to be published, (2003) (Equi. Diagram, Crys. Structure, Assessment, 72)

[2003Pis] Pisch, A., “Al-Mn (Aluminium-Manganese)”, MSIT Evaluation Program, in MSIT


Stuttgart, to be published, (2003) (Equi. Diagram, Crys. Structure, Assessment, 40)

232


MSIT®

Al–Co–Mn


Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

( Al) < 660.452

cF4

Fm3m

Cu

a = 404.96 at 25°C [Mas2]

Dissolves 0.62 at.% Mn at 658.5°C

( Al) hP2

P63/mmc

Mg

a = 269.3

c = 439.8

at 25°C, 20.5 GPa [Mas2]

( Co)(h)

1495-422

cF4

Fm3m

Cu

a = 354.46 [V-C2]. Dissolves 59.4 at.% Mn at

1161°C and ~17 at.% Al at 1400°C

( Co)(r)

< 422

hP2

P63/mmc

Mg

a = 250.71

c = 406.95

[V-C2, Mas2]

( Mn)

1138-1100

cF4

Fm3m

Cu

a = 386.2 [Mas2]. Dissolves ~4.5 at.% Co 1145°C

and 9.33 at.% Al at 1073°C.

( Mn)

1100-727

cP20

P4132

Mn

a = 631.52 [Mas2]. Dissolves 45 at.% Co at 546°C

and 41.79 at.% Al at 840°C

( Mn)

< 727

cI58

I3m

Mn

a = 891.26 at 25°C [Mas2].

, (Mn1-y,Coy)1-xAlx

( Mn)

1246-840

Mn55Al45

< 1177

’, CoAl

< 1640°C

cI2

Im3m

W

cP2

Pm3m

CsCl

a = 308.0

a = 306.3

a = 286.2

[Mas2]. Dissolves ~8 at.% Co at 1188°C

and 31.91 at.% Al at 1275°C

[V-C2]. Dissolves 65 at.% Al at 1048°C,

46 at.% Al at 870°C.

~0.2 < x < 0.537 for y = 1

at x = 0.5, y = 1

[1966Rid]

Co2Al5<1188

hP28

P63/mmc

Co2Al5

a = 767.2

c = 760.5

[1996Gru]

[1996Bur]

O-Co4Al13

< 1080

oP102

Pmn21

O-Co4Al13

a = 815.8

b = 1234.7

c = 1445.2

[1996Gru]

[1996Bur]

M-Co4Al13

1093-?

mC102

C2/m

Fe4Al13

a = 1517.3

b = 810.9

c = 1234.9

= 107.84°

[1996Fre]

233


MSIT®

Al–Co–Mn

Z, CoAl3< 1158

mC* a = 3984.0

b = 814.8

c = 3223.0

= 107.97°

[1998Mo] often designated 2-Co4Al13.

Co2Al9 mP22

P121/c1

Co2 Al9

a = 855.65

b = 629.0

c = 621.3

= 94.76°

[V-C2]

MnAl12 cI26

Im3

Wal12

a = 747 [V-C2]

MnAl6< 705

oC28

Cmcm

MnAl6

a = 755.51

b = 649.94

c = 887.24

[V-C2]

, MnAl4< 693

hP586

P63/m

a = 2838.2

c = 1238.9

[2003Pis]

space group does not fit 100%, probably

P63

, MnAl4< 923

hP574

P63/mmc

MnAl4

a = 1998

b = 2467.3

c = 1389.7

[2003Pis]

Mn4Al11(h)

1002 - 916

oP160

Pnma

? [2003Pis]

Mn4Al11(r)

< 916

aP30

P1

Mn4Al11

a = 509.5 ± 0.4

b = 887.9 ± 0.8

c = 505.1 ± 0.4

= 89.35 ± 4°

= 100.47 ± 5°

= 105.08 ± 6°

[V-C2]

1, MnAl2< 1048

? [2003Pis]

2, Mn5Al8< 991

hR26

R3m

Cr5Al8

a = 1273.9

c = 1586.1

at 58 at.% Al [V-C2]

, Mn3Al2< 1312

hP2

P63/mmc

Mg

a = 270.5 to 270.5

c = 436.1 to 438

44.2 - 44.9 at.% Al [2003Pis]

MnCo

< 545°C

cI58

I3m

Mn

a = 628.1 [V-C2]

* , Mn12Co4Al62 oC156

Cmcm

Mn12Ni4Al62

? [1972Goe]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

234


MSIT®

Al–Co–Mn



Al Co Mn

L + ( Co) ’ + ( Mn) 1152 U1 L

( Co)

’

( Mn)

8.0

3.1

12.7

2.5

32.2

39.2

36.8

36.7

59.8

57.7

50.5

60.8

L + Z Co2Al5 + Co4Al13 ~1090 U2 L

Z

Co2Al5Co4Al13

78.5

74.3

71.8

76.5

15.4

25.1

26.2

21.9

6.1

0.6

2.0

1.6

L + Co2Al5 + Mn4Al11(h) 1038 U3 L

Co2Al5Mn4Al11(h)

69.1

53.0

66.9

62.0

6.7

18.7

15.0

9.7

24.2

28.3

18.1

28.3

L + MnAl2 Mn4Al11(h)+

Co2Al5

990 U4 L

MnAl2Mn4Al11(h)

Co2Al5

78.8

69.8

73.0

72.3

1.1

2.1

0.3

3.6

20.1

28.1

26.7

24.1

+ Mn4Al11(h) Co2Al5 +

Mn4Al11(r)

980 U5

Mn4Al11(h)

Co2Al5Mn4Al11(r)

50.8

62.9

67.8

59.0

20.1

8.0

15.5

10.9

29.1

29.1

16.7

30.1

MnAl2 Mn4Al11(h) +

Mn4Al11(r) + Co2Al5

~935 E1 MnAl2Mn4Al11(h)

Mn4Al11(r)

Co2Al5

68.5

72.2

66.3

71.2

2.1

0.6

1.8

6.3

29.4

27.2

31.9

22.5

L + Mn4Al11(h) MnAl4 +

Co2Al5

920 U6 L

Mn4Al11(h)

MnAl4Co2Al5

85.3

76.1

79.5

78.8

0.5

0.4

0.3

1.3

14.2

23.5

20.2

19.9

Mn4Al11(h) + MnAl4Co2Al5 + Mn4Al11(r)

908 U7 Mn4Al11(h)

MnAl4Co2Al5Mn4Al11(r)

74.2

79.1

77.3

73.8

0.9

0.1

1.4

0.3

24.9

20.8

21.3

25.9

L + Co2Al5 + MnAl4 895 P1 L

Co2Al5MnAl4

89.1

78.4

79.6

79.5

0.7

1.7

0.2

1.1

10.2

19.9

20.2

19.4

L + Co2Al5 + Co4Al13 877 U8 L

Co2Al5

Co4Al13

90.6

76.4

78.9

76.9

1.3

4.6

2.2

7.7

8.1

19.0

18.9

15.4

Mn4Al11(h) Co2Al5 +

Mn4Al11(r) + Mn5Al8

868 E2 Mn4Al11(h)

Co2Al5Mn4Al11(r)

Mn5Al8

73.0

73.1

73.8

68.0

0.6

3.5

0.2

0.4

26.4

23.3

26.0

31.6

235


MSIT®

Al–Co–Mn

L + Co4Al13 + Co2Al9 770 U9 L

Co4Al13

Co2Al9

96.2

76.0

78.9

81.5

1.0

12.8

2.8

17.6

2.8

11.2

18.3

0.9

L + MnAl4 + MnAl6 698 U10 L

MnAl4

MnAl6

98.0

79.8

78.9

85.3

0.3

0.6

3.4

0.2

1.7

19.6

17.7

14.5

L + MnAl6 + Co2Al9 680 U11 L

MnAl6Co2Al9

98.3

78.6

85.3

81.9

0.5

3.9

0.2

17.2

1.2

17.5

14.5

0.9

L (Al) + MnAl6 + Co2Al9 652 E3 L

(Al)

MnAl6Co2Al9

98.5

99.4

85.3

81.5

0.7

0.2

0.2

17.6

0.8

0.4

14.5

0.9


Al Co Mn

236


MSIT®

Al–Co–Mn

Fig

. 1

a:

A

l-C

o-M

n.

Rea

ctio

n s

chem

e, p

art

1

l(γ

Co

) +

δ´

1400

e 1

l +

δ1

(βM

n)

1190

p2

l +

δ´

ε1275

p1

Lδ´

+ (β

Mn)

ca.1

150

min

l +

(γC

o)

(βM

n)

1161

p5

l +

δ´

Co

2A

l 5

1188

p3

l +

εδ 2

1177

p4

(γM

n)+

δ 1(β

Mn)

1073

p11

l +

O

Co

2A

l 9

970

p1

5

l +

Z

O

1093

p9

l +

Co

2A

l 5 Z

1158

p6

δ 1+

(βM

n)

(γM

n)

1153

p7

L +

(γC

o)

(βM

n)

+ δ

´1152

U1

δ +

γ 1 C

o2A

l 5+

γ 2980

U5

L +

γ1

Co

2A

l 5+

Mn

4A

l 11(h

)990

U4

L +

δ

Co

2A

l 5+

γ 11038

U3

L +

Z

Co

2A

l 5+

Mca

.10

90

U2

l +

δ2

γ 1

1048

p1

2C

o2A

l 5 +

Z+

M

γ 1C

o2A

l 5+

Mn

4A

l 11(h

)+γ 2

ca.9

35

E1

l +

γ1

Mn

4A

l 11(h

)

1002

p1

3δ

+ C

o2A

l 5+

γ 1

γ 1+

Co

2A

l 5+

γ 2

(βM

n)+

(γC

o)+

δ´

δ+γ 2

+Co

2A

l 5

γ 1+C

o2A

l 5+

Mn

4A

l 11(h

)

δ 2 +

γ1

γ 2

991

p1

4

γ 1γ 2

+ M

n4A

l 11(h

)

957

e 3

Al-

Mn

Al-

Co-M

nC

o-M

nA

l-C

o

(δM

n)

(βM

n)

+ ε

1040

e 2

l +

Mn

4A

l 11(h

)µ

923

p1

6

L +

Mn

4A

l 11(h

)C

o2A

l 5+

µ920

U6

L+

Co

2A

l 5+

Mn

4A

l 11(h

)

Co

2A

l 5+

µ+M

n4A

l 11(h

)L

+C

o2A

l 5+

µ

L+

Co

2Al 5+

M

l +

Z

Y

1127

p8

l +

M

O

1080

p1

0

?

?

Co

2A

l 5+

Mn

4A

l 11(h

)+γ 2

L+

Co

2A

l 5+

γ 1

237


MSIT®

Al–Co–Mn

Fig

. 1b

:

Al-

Co-M

n. R

eact

ion s

chem

e, p

art

2

ε(β

Mn)

+ δ

2

870

e 6

(γC

o)

(εC

o)

+ δ

´

415

e 10

l C

o2A

l 9+

(A

l)

657

e 8

(γC

o)+

(βM

n)

Co

Mn

545

p1

8

δ 2(β

Mn)

+ γ

2

840

e 7

Mn

4A

l 11(h

)+µ

Co

2A

l 5+

Mn

4A

l 11(r

)908

U7

l +

µ

MnA

l 6

705

p1

7

l M

nA

l 6+

(A

l)

508

e 9

Al-

Mn

Al-

Co-M

nC

o-M

nA

l-C

o

Mn

4A

l 11(h

)M

n4A

l 11(r

)+µ

910

e 4

Mn

4A

l 11(h

)γ 2

+M

n4A

l 11(r

)

895

e 5

Mn

4A

l 11(h

)γ 2

+C

o2A

l 5+

Mn

4A

l 11(r

)868

E2

L +

Co

2A

l 5 C

o4A

l 13 +

τ877

U8

L +

Co

4A

l 13

τ

+ C

o2A

l 9770

U9

L +

µτ

+ M

nA

l 6698

U1

0

L +

τ C

o2A

l 9 +

MnA

l 6680

U1

1

L C

o2A

l 9+

MnA

l 6 +

(A

l)652

E3

L +

Co

2A

l 5+

µτ

895

P1

Co

2A

l 5+

µ+τ

µ+C

o2A

l 5+

Mn

4A

l 11(r

)

L+

Co

2A

l 5+

τ

Mn

4A

l 11(h

)+C

o2A

l 5+

Mn

4A

l 11(r

)

L+

Co

4A

l 13+

τ

L +

µ+

τ

Co

4A

l 13

+τ

+ C

o2A

l 9

L+

τ+C

o2A

l 9

τ +

Co

2A

l 9+

MnA

l 6

L +

Co

2A

l 9 +

MnA

l 6

(Al)

+ C

o2A

l 9+

MnA

l 6

γ 2+

Co

2A

l 5+

Mn

4A

l 11(r

)

L +

τ +

MnA

l 6µ+

τ+ M

nA

l 6

Co

2A

l 5+

Co

4A

l 13+

τ

238


MSIT®

Al–Co–Mn

10

20

30

10 20 30

70

80

90

Mn 35.00Co 0.00Al 65.00

Mn 0.00Co 35.00Al 65.00


Axes: at.%

U3

U4

Co2Al5

U6

P1

U8

τ

µ

Mn4Al11(h)

U10

MnAl6

(Al)

E3U11

U9 Co2Al9

U2

Co4Al13 ?

?

e9

p17

p16

p13

p15

p10

p9

p8p6

Z

e8

20

40

60

80

20 40 60 80

20

40

60

80

Mn Co


Axes: at.%

p3

(βMn)

p5

U11175

e1

1400

130012

50

δ1

12751300°C

ε

p2

p1

1250

δ'

1600

150013

50

1300

1200

1150

1125

1100

U9 Co2Al9p15 Co4Al13

p9

p8

p4

U2

Z

Co2Al5

MnAl6µP1p16

Mn4Al11(h)

p13

p12

MnAl2

U3

1025

9501000

1200

1225

p10

p6

1200

(Al)

(γCo)

δ2

Fig. 3: Al-Co-Mn.

Enlargment of the

liquidus surface of the

Al-rich corner

Fig. 2: Al-Co-Mn.

Liquidus surface

239


MSIT®

Al–Co–Mn

20

40

60

80

20 40 60 80

20

40

60

80

Mn Co


Axes: at.%

(αMn)

(αMn)+(βMn)

(βMn)

δ'+(βMn)

(γCo)

(γCo)+δ'

δ'

δ'+Co2Al5

Co2Al5

ZCo4Al13

Co2Al9τ

Co 2Al 5

+γ 2

δ'+γ2

γ2

Mn4Al11(r)

µ

MnAl6λ

MnCo

(Al)

20

40

60

80

20 40 60 80

20

40

60

80

Mn Co


Axes: at.%

(βMn)

(γCo)

(γCo)+δ'

δ'

(βMn)+δ'

δ'+Co2Al5

Co2Al5

γ2+δ'

γ2

Co 2Al 5

+γ 2

Mn4Al11(r)

µ

L

τCo4Al13

Co2Al9

Z

Fig. 4: Al-Co-Mn.


500°C

Fig. 5: Al-Co-Mn.


800°C

240


MSIT®

Al–Co–Mn

20

40

60

80

20 40 60 80

20

40

60

80

Mn Co


Axes: at.%

(γCo)

(βMn) (γCo)+δ'

δ'

MnAl2+δ2

ε

δ'+Co2Al5

Z

Co2Al9

L

Co4Al13

µ

Mn4Al11(h)Mn4Al11(r)

MnAl2

Co2Al5

δ2

(βMn)+δ2

(βMn)+δ´

20

40

60

80

20 40 60 80

20

40

60

80

Mn Co


Axes: at.%

ε

δ'+Co2Al5

γ1

Co2Al5

ZCo4Al13

L

Mn4Al11(h)

(γCo)

(βMn)

δ'

δ2

Fig. 6: Al-Co-Mn.


900°C

Fig. 7: Al-Co-Mn.


1000°C

241


MSIT®

Al–Co–Mn

20

40

60

80

20 40 60 80

20

40

60

80

Mn Co


Axes: at.%

ε

δ2

(βMn)

(γCo)

δ'

δ1

20

40

60

80

20 40 60 80

20

40

60

80

Mn Co


Axes: at.%

ε

δ1

(βMn) (γCo)

ZCo2Al5

δ'+Co2Al5

Y

δ'

δ2

L

L+δ´

(αMn)

Fig. 8: Al-Co-Mn.


1050°C

Fig. 9: Al-Co-Mn.


1100°C

242


MSIT®

Al–Co–Mn

20

40

60

80

20 40 60 80

20

40

60

80

Mn Co


Axes: at.%

ε

δ1

(γCo)

δ'

?

L

10 20 30 40 50500

600

700

800

900

1000

1100

1200

1300

Mn 59.57Co 0.00Al 40.43

Mn 0.00Co 57.86Al 42.14Co, at.%

Tem

pera

ture

, °C

δ'

(βMn)+δ'

L+δ'L

ε

L+ε

δ'+ε

(βMn)+ε+δ'

ε+(βMn)

Fig. 10: Al-Co-Mn.


1200°C

Fig. 11: Al-Co-Mn.

Isopleth at 25 mass%

Al

243


MSIT®

Al–Co–Mn

40 20500

600

700

800

900

1000

1100

1200

1300

Mn 42.40Co 0.00Al 57.60

Mn 0.00Co 40.70Al 59.30Mn, at.%

Tem

pera

ture

, °C

L

L+δ'

L+Co2Al5+δ'

δ'+Co2Al5+γ1

Co2Al5+δ'+γ2

L+δ'+γ1

δ+γ1+γ2

δ2+γ2

δ2

δ'+γ2γ2Co2Al5+δ´

L+δ2

10600

700

800

900

1000

1100

Mn 17.40Co 0.00Al 82.60

Mn 0.00Co 16.40Al 83.60Co, at.%

Tem

pera

ture

, °C

L

L+Co4Al13

L+Co4Al13+Co2Al9

L+Co2Al9

L+Co2Al9+τ

Co2Al9+(Al)+MnAl6

L+Co2Al9+MnAl6τ+Co2Al9+MnAl6

Co2Al9+MnAl6

L+

τ

L+Co2Al5 L+Co2Al5+Co4Al13

L+Co2Al5+Mn4Al11(h)

L+Mn4Al11(h)

L+τ+Co4Al9

µ+MnAl6

MnAl6+τ

τ+λ+MnAl6

L+µ+MnAl6L+µ

L+Co2Al5+τ

L+

τ+µ

680°C

652°C

770°C

877°C

λ+MnAl6

Fig. 12: Al-Co-Mn.


Al

Fig. 13: Al-Co-Mn.


Al

244


MSIT®

Al–Co–Mn

600

700

800

900

1000

Mn 8.00Co 0.00Al 92.00

Mn 0.00Co 7.50Al 92.50Co, at.%

Tem

pera

ture

, °C

Co2Al9+(Al)+MnAl6

(Al)+MnAl6

652°C

680°C

770°C

L+Co2Al9+MnAl6

L+Co2Al9+τ L+Co2Al9

L

L+Co4Al13L+Co4Al13

+Co2Al9L

+τ+

µ

L+Co4Al13+τ

L+τL+µ

L+τ+MnAl6

600

700

800

Mn 2.50Co 0.00Al 97.50

Mn 0.00Co 2.40Al 97.60Co, at.%

Tem

pera

ture

, °C

L

L+τL+Co2Al9

680°C

552°C

Co2Al9+(Al)+MnAl6

(Al)+MnAl6

L+Co2Al9+MnAl6

L+µ

L+τ+µ

L+τ+MnAl6

L+τ+Mn2Al9

Fig. 14: Al-Co-Mn.


Al

Fig. 15: Al-Co-Mn.


Al

245


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Al–Co–Mn

10 20 30 40800

900

1000

1100

1200

1300

Mn Mn 0.00Co 50.00Al 50.00Co, at.%

Tem

pera

ture

, °C

(γMn)

(βMn)

δ'

L

δ1

Fig. 16: Al-Co-Mn.

Vertical section at

Mn-CoAl

246


MSIT®

Al–Co–Ni

Aluminium – Cobalt – Nickel

Tamara Velikanova, Kostyantyn Korniyenko, Vladislav Sidorko

Literature Data

This system is of pronounced industrial and scientific interest because of the mechanical properties of its

alloys [1995Mis, 1998Che, 2000Eda] and the formation of quasicrystalline phases. The relevant literature

has drastically increased by a factor of 8 since [1991Hub] has made the first critical evaluation of this system

under the MSIT Evaluation Program.

Phase equilibria in the range of aluminium content up to 50 at.% were studied by [1941Sch] using thermal

analysis, metallography, X-ray and magnetic techniques. The starting components were Al (99.9 mass%),

Co (97.6 mass%) and Ni (99.9 mass%). The alloys for investigation were prepared using high frequency

induction melting in Fe moulds. The partial liquidus surface, temperature-composition sections at constant

Ni/Co rations of 9/8, 8/2, 5/5, and 2/8 as well as isothermal sections at 1300, 1200, 1100, 1000, 900 and

25°C for the compositional range up to 50 at % Al were presented. The major result of this work was the

verification of a continuous range of solid solutions between the congruent isostructural CoAl and NiAl

phases ( ), which divides the ternary system to Co-CoAl-NiAl-Ni and Al-CoAl-NiAl. [1966Rid] confirmed

the phase by X-ray analysis of alloys along Ni/Co ratios of 8/2, 5/5, and 3/7. The Al-poor boundary of the

phase was determined at room temperature on slowly cooled alloys; its position agrees well with that of

[1941Sch]. The Al-rich corner of the Al-Co-Ni system was studied first by [1947Ray] who determined the

melting points of alloys with more than 95 at.% Al at constant 97.5 mass% (98.8 at.%) Al, the thermal

effects were measured whilst cooling the melts at a rate of 1-2°C·min-1 under simultaneous stirring. Alloys

annealed at 638-639.9, 643, 648.5 and 655°C and quenched were examined by their micrographs, which

established the three-phase solid state equilibrium (Al)+(Co2Al9)+(NiAl3). The temperature of the ternary

eutectic L (Al)+(Co2Al9)+(NiAl3) has been determined in [1976Kov].

The data published up to 1985 have been evaluated by [1991Hub] who presented a number of isothermal

sections, temperature-concentration cuts and the liquidus projection. [1993Pov] investigated phase

equilibria and presented isothermal sections at 1100 and 900°C at the content of Al up to 70 at.%.

Aluminium 99.99, cobalt 99.99, and nickel 99.97 mass% purities were used. The alloys were prepared by

arc melting in argon atmosphere. Specimens containing more than 50 at.% Al were sealed in quartz

ampoules and annealed at 1100°C for 300 h. Preliminary homogenization of other alloys was conducted in

an induction furnace under helium atmosphere at 1300°C for 100 h. Then the specimens were annealed at

1100 and 900°C in the quartz ampoules for 100 and 300 h, respectively, followed by water quenching and

investigated by X-ray diffraction and EMPA. Phase equilibria between (Ni), (Ni3Al) and phases were

investigated by [1994Jia, 1996Kai, 2001Kai] and [2001Oik1]. The alloys were prepared by induction

melting of appropriate mixtures of pure aluminium (99.7 mass%), cobalt (99.9 mass%) and nickel

(99.9 mass%) under an argon atmosphere. Then diffusion couples were made, sealed in evacuated

transparent quartz capsules and annealed at 627 to 1300°C for 1 to 1000 h [2001Kai] or at 800 to 1300°C

for 10 to 1000 h [1994Jia]. Microstructures of the annealed diffusion couples were examined by optical

microscopy and the concentration profiles across the / interface determined by EMPA. [1996Kai]

fabricated the melted ingots by hot-rolling at 1250 to ~1300°C into sheets. The specimens were studied by

optical microscopy, energy dispersion X-ray spectroscopy, transmission electron microscopy as well as

differential scanning calorimetry. [2001Oik1] took small specimens from the ingots and sealed them in

quartz capsules filled with argon. Solution heat treatment at 1300°C for 24 h, and subsequent equilibrating

treatments were carried out at 1100, 1200 and 1300°C for 1 to 24 h before the samples were quenched in

ice water. The samples were examined by metallography, EDX and X-ray diffraction. The tie lines and

phase boundaries at 1300, 1200, 1100, 900 and 800°C by [1994Jia, 2001Oik1], as well as isothermal

sections at 1300, 1100 and 900°C by [1996Kai] in the range of compositions 0-50 at.% Al are reported. The

influence of alloying elements on the morphological stability of the interface between the and phases

was studied at temperatures ranging from 900 to 1300°C [2001Kai].

247


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Al–Co–Ni

The structure and properties of the ternary compounds in the system have been reported starting from

[1989Tsa1, 1989Tsa2] in more than 90 publications. Most of them are dedicated to the structure of the

decagonal phase and its modifications. A great number of results on the investigations of the structure of

the decagonal phase and its modifications were published by [1990Yam, 1991Bur, 1991Hir1, 1991Hir2,

1991Zha, 1992Eda, 1992Eib, 1992Tsa, 1992Zha, 1993Bur, 1993Eda, 1993Fre, 1993Lue, 1993Ste1,

1993Ste2, 1994Est, 1994Gru, 1994Rey, 1995Hra, 1995Qin, 1995Rit, 1995Wue, 1996Rit1, 1996Sch,

1996Tsa, 1996Tsu, 1996Yam, 1997Che, 1997Dug, 1997Feu, 1997Gru1, 1997Gru2, 1997Hra, 1997Kal,

1997Qin, 1997Gru2, 1997Hra, 1997Qin, 1997Sai2, 1997Sai1, 1997Yam, 1997Yok, 1997Zha, 1998Hon,

1998Rit, 1998Sai, 1998Sat, 1998Wid, 1999Fis, 1999Gil, 1999Rit, 1999Wit, 2000Abe, 2000Bee, 2000Cer,

2000Dam, 2000Dro, 2000Doe, 2000Elh, 2000Fre, 2000Gra, 2000Hai, 2000Hra, 2000Kra1, 2000Kra2,

2000Liu, 2000Pra, 2000Rit, 2000Sai, 2000Shi, 2000Ste1, 2000Ste2, 2000Wei, 2000Yan, 2000Yur,

2001Hir1, 2001Hir2, 2001Hir3, 2001Hir4, 2001Hir5, 2001Hir6, 2001Hir7, 2001Tak, 2002Cer, 2002Hir1,

2002Hir2, 2002Kup, 2003Ebe]. The main experimental methods were TEM and HREM. They were applied

to rapidly cooled, as-cast, and annealed alloys. Information concerning the phase composition, phase

transformations, compositional ranges of ternary phases stability is reported by [1991Kek, 1994Eda,

1995Kal, 1995Wue, 1996Gru1, 1996Gru2, 1996Kai, 1997Bau, 1997Gru1].

Four isothermal sections of the Al-CoAl-NiAl subsystem at 1000, 850, 700 and 600°C were suggested by

[1991Kek] based on X-ray diffraction and light optical microscopy data for heat-treated samples. The

re-investigated phase equilibria in the Al-corner of ternary system is given by [1996Goe, 1997Goe1,

1997Goe2, 1997Goe3, 1997Yok, 1998Goe] and [1998Sch]. As starting components, they mostly used

99.999 pure aluminium from Heraeus, 99.9 pure cobalt from Johnson Matthey and 99.98 pure nickel from

Good fellow) The alloys were prepared by melting mixtures of the components in corundum crucibles, put

them into silica ampoules which were closed, evacuated and refilled with argon The specimens were heat

treated under different conditions and investigated by microstructural and X-ray diffraction techniques as

well as by magneto-thermal analysis (MTA) [1996Goe, 1997Goe1, 1997Goe2, 1997Goe3, 1998Goe,

1998Sch]; differential thermal analysis [1996Goe, 1997Goe1, 1997Goe2, 1997Goe3, 1998Sch], TEM

[1997Goe3, 1998Goe] and selected for selected areas by electron diffraction (SED) [1997Goe3]. Liquidus

surface projection of the ternary system in the range of 50-100 at.% Al was plotted by [1997Goe2,

1997Goe3] and [1998Goe]. Reaction scheme of the partial Al-CoAl-NiAl system was reported by

[1997Goe2, 1998Goe]. Isothermal sections at 1050°C in the range of compositions 0-9 at.% Ni and 72-87

at.% Al [1996Goe] as well as at 1150 and 1110°C in the range of cobalt content up to 35 at.% and aluminium

content from 55 to 100 at.% were plotted by [1997Goe2]. Isothermal sections of the Al-CoAl-NiAl

subsystem at 1170, 1100, 1050, 900, 850, 730, and 600°C (also valid for 400°C) are presented by

[1998Goe]. Temperature - composition sections were plotted: at constant Al contents of 57.5, 65, 70, 71.5,

72.5, 75, 78, 80, 85, 92.5, and 97 at.% as well as at constant Ni concentrations of 10, 13, and 19 at.%

[1996Goe, 1997Goe1, 1997Goe2, 1997Goe3] and [1998Sch]. Partial isothermal sections at 927 and 1027°C

including the decagonal 1 phase as well as isopleth along the Co:Ni = 1:1 were determined by [1997Yok].

[1997Yok] prepared alloys in the composition range 3 to 20 at.% Ni or Co by arc-melting in argon

atmosphere followed by annealing in vacuum for 48h just below melting temperature. Pre-alloyed ingots

were heated under flowing argon protection for 1 h at 1123°C, which is about 100 to 200°C above their

melting temperatures. Solidification process from a perfect liquid was examined by DTA and the specimens

were investigated by X-ray diffraction and LOM techniques.

Binary Systems

The Co-Ni system is accepted from [Mas2], Al-Ni from [2003Sal], Al-Co from [2003Gru]. In the Al-Co

phase diagram, according to [2003Gru], two alternative views [1996Goe, 1996Gru1] do exist in the range

of 12 to 34 at.% Co. The results of [1996Goe] are preferred because of the better agreement with the

constitution of the ternary system.

248


MSIT®

Al–Co–Ni

Solid Phases

Crystallographic data on unary and binary phases as well as recently reported ternary ones are listed in Table

1. Two continuous ranges of solid solutions exist in the system, (between the isostructural NiAl and CoAl

phases of the CsCl type) and (between the ( Co) and (Ni) phases) [1941Sch, 1996Kai]. [1998Tia]

clarified the crystallographic properties of strengthening precipitates in the phase which are

supersaturated with Co and Ni. Precipitation was observed in specimens which have been aged at different

aging temperatures. The precipitates was the (Co) phase, but with different crystal structures depending on

the aging temperature. The Co phase has a face centered cubic structure at aging temperature higher than

700°C and its shape was rod-like, with the long axis parallel to the <111> direction of the matrix. At aging

temperatures below 600°C the precipitates of the (Co) phase take a hexagonal close packed structure, again

of rod-like shape with the long axis parallel to the <111> direction of the matrix. More recently [2001Tan]

confirmed the continuity of the solid solution by the measurements of its hardness and lattice parameter.

[1985Mor2] have shown that estimation of Al solubility in the fcc Co-Ni alloys based on semi-empirical

approach of [1985Mor1] developing the method of Darken and Gurry [1953Dar] does not lead to a

satisfactory result. The solubility of Co in Ni3Al increases from 8 at.% at 1300°C to 24 at.% at 900°C

[1996Kai]. The lattice parameter depends weakly on the Co content [1985Mis].

The ’ compound considered in [1980Lu] to be a ternary phase has been concluded in [1997Goe3,

1998Goe] to be the extension of binary Ni3Al4. Its structure is described as a superlattice built up by

stacking together of 54 CsCl type fundamental structural units.

The Co addition stabilizes the NiAl3 solid solution up to 900°C. The (Ni,Co)3Al4 solid solution

demonstrates a similar behavior. On the other hand, for the Y phase, dissolved Ni decreases the temperature

range of existence compared with the binary Al-Co system. So this phase exists in ternary system, as a

ternary phase below 1083°C. Moreover the ternary 2 phase, which possesses a crystal structure close to

that of Y phase, appears at lower temperature when Ni is increased, at constant Al content.

Three ternary phases with crystal structure different from that of the binary intermetallics are reported in the

Al-CoAl-NiAl subsystem. Their structure and specifications as well as their role in various phase reactions

has been subject of many studies in the last two decades.

The stable decagonal 1 phase, usually designated as D in the literature, was first reported by [1989Tsa1,

1989Tsa2] in the Co15Ni15Al70 alloy. The 1 phase is formed below 1175°C [1997Goe3, 1998Sch,

1998Goe] and is stable in a wide composition range from about 5 to 24 at.% Ni and 70 to 73 at.% Al)

[1998Goe, 1996Gru3]. The stability range of D significantly depends on temperature. Several structural

variants of the decagonal phase were reported depending on composition and annealing temperatures

[1992Eda, 1994Eda, 1994Gru1, 1994Hir, 1996Gru1, 1996Gru2, 1996Rit2, 1996Rit3, 1996Tsa, 1997Goe1,

1997Goe2, 1997Goe3, 1997Yam, 1997Zha, 2000Hir, 2001Hir1, 2001Hir2, 2001Hir3, 2001Hir4, 2001Hir5,

2001Hir6, 2001Hir7, 2002Hir2, 2002Hir1, 2002Hir2].

In addition, metastable or stable periodic structures with pseudo-decagonal (PD) symmetry [1998Gru2] and

monoclinic [1990Yam] or orthorhombic [1995Kal, 2002Sug] structures, closely related to the decagonal

phase were observed, too. Such structures commonly are addressed as “approximants”. In a number of

works the alloy phase transformations in the decagonal composition range were studied using in some cases

DTA or DSC methods supported by TEM [1995Kal, 1997Bau, 1998Gru2, 2000Doe, 2002Kup] and others.

The structural relationships in decagonal phase ranges are still not firmly established, in spite of the great

amount of information that has been generated.

The 2 ternary phase based on Co2NiAl9 composition forms at 880°C [1997Goe1]. Its crystal structure was

studied by [1998Gri] on single crystals and by [1999Got] using X-ray powder diffraction technique. It was

concluded that it cannot be considered as an approximant for the decagonal or icosahedral phases because

of the small size of the structural segments with pentagonal antiprisms and because of the absence of atoms

with icosahedral atomic environment.

[1997Goe3] found the ternary 3 phase with composition of Co18.5Ni14.0Al67.5 which forms in the solid

state through the ternary peritectoid reaction at 1002°C. The single phase region of the 3 phase shifts with

decreasing temperature to higher Ni contents. That happens between 1002 and 918°C where the transition

249


MSIT®

Al–Co–Ni

plane in the ternary diagram is. The composition of this phase at low temperatures is far away from its initial

peritectoid composition.


There is the pseudobinary CoAl-NiAl section, which triangulates the ternary diagram into the

Co-CoAl-NiAl-Ni and Al-CoAl-NiAl subsystems.


The reaction scheme in the Co-CoAl-NiAl-Ni subsystem is given in Fig. 1. The invariant quaternary

equilibrium of transition type L+(Ni) Ni3Al+NiAl proposed initially by [1941Sch] is more consistent with

the updated Al-Ni phase diagram [2003Sal] than that in [1991Hub]. The reaction scheme in the

Al-CoAl-NiAl subsystem is presented in Figs. 2a, 2b according to [1997Goe2, 1997Goe3, 1998Goe], the

temperature of the p5 reaction in the Al-Ni system is corrected after [2003Sal].

[1976Kov] confirmed the ternary eutectic by the experiments on directional solidification of the alloy, but

the melting temperature was determined to be 637.4°C. That is lower than that accepted in the present

assessment. Table 2 specifies the invariant equilibria in the investigated range of compositions according to

the data by [1997Goe2] and [1997Goe3] and taking the above corrections into account.

Liquidus Surface

The projection of the liquidus surface of the Co-CoAl-NiAl-Ni subsystem given in Fig. 3 takes into account

the data of [1941Sch, 1991Hub] with minor corrections applied to achieve consistency with the accepted

binary systems. The projection of the liquidus surface of the Al-CoAl-NiAl subsystem is presented in Fig.

4 and as enlargement in Fig. 5. It is based on [1997Goe2], [1997Goe3] and complemented with data from

[1947Ray] for composition range with more than 95 at.% Al.

Isothermal Sections

[1941Sch] published isothermal sections at 1300, 1200, 1100, 1000, 900 and 25°C. Thermodynamic

calculations of isothermal sections of the Al-Co-Ni system have been presented for 1327 and 527°C

[1975Kau], as well as for 1527, 1427, 1327 and 1277°C [1985Bar]. Both calculations are considered as

approximations by their authors. As they deviate from experimental points, the experimental data should be

preferred. The calculated sections at 1327 and 527°C [1975Kau] show identical features. The calculated

isothermal sections from 1527 to 1277°C [1985Bar] also reproduce the general features of the isotherms of

[1941Sch] and confirm the presence of a stable ,Al(Co,Ni) solid solution. The 1427°C section of

[1985Bar] implies that the critical tie line joining the phases (Co,Ni), liquid and ,Al(Co,Ni) forms at a

temperature above 1427°C, which contradicts the experimentally verified liquidus surface.

The isothermal sections of the phase diagram in the vicinity of the Co-Ni edge at 900 and 1100°C were

reinvestigated by [1993Pov, 1996Kai], and at 1300°C by [1996Kai]. The results for the microanalysis of

phase compositions in the above works are in agreement with the metallography data of [1941Sch] and the

data on / equilibria reported by [1994Jia].

Isothermal sections at 1300, 1100, 900°C are presented in Figs. 6, 7, 8 after [1996Kai], whose data are also

consistent with previous results included in [1941Sch, 1994Jia, 1993Pov]. The 25°C isothermal section

published in [1941Sch] is reproduced in Fig. 9. The data are corrected in accordance with the updated binary

phase diagrams.

The isothermal sections in the Al-rich part of the system at 1170, 1100, 1050, 900, 850, 730 and 600°C (the

latter is also valid for 400°C) are given in Figs. 10, 11, 12, 13, 14, 15, 16 after [1998Goe].

Figures 10, 11 exhibit phase equilibria at temperatures close to that of the ternary decagonal phase formation

in result of the quasibinary peritectic reaction at 1175°C. This phase is shown to be in equilibria only with

binary solid phases and liquid up to 1002°C, the temperature of the peritectoid formation of 3. At 900°C

the peritectic melting of the phase, a NiAl3 based solid solution phase, occures. At that temperature the

maximum solubility of Ni in 1 is observed at 70 at.% Al and corresponding to a Ni:Co ratio of 74:26

250


MSIT®

Al–Co–Ni

(atomic ratio) (Fig. 13) [1998Goe], while [1996Gru3] at the practically same aluminium content (71 at.%)

and the same temperature indicates the higher solubility corresponding to the 83:17 Ni:Co ratio. The

addition of Cr stabilizes the solid solution phase in the ternary towards higher temperatures, compared

with the stability in binary alloys. (Ni,Co)3Al4 solid solution demonstrates similar behavior as one can see

in Figs. 14, 15, 16. On the other hand, for the Y phase, dissolved Ni decreases the temperature range of

existence compared with the binary Al-Co system, as one can see in Figs. 12, 13, 14, 15, 16. So this phase

exists in the ternary system, as a ternary phase below 1083°C. Moreover, the ternary 2 phase, which

possesses crystal structure close to that of Y phase, appears at lower temperature when Ni is increased, at

constant Al content (Figs. 14, 15, 16 and Fig. 2).


In Fig. 17 the Co20Ni80-Co11Ni44Al45 isopleth is reproduced from [1991Hub] based on the data for the

liquidus surface and the 1300, 1100, 900 and 25°C isothermal sections from [1941Sch], binaries and the

data from [1966Rid]. The Figs. 18, 19, 20, 21, 22 and 23 after [1997Goe2, 1998Sch] demonstrate the

complicated constitution of the Al-rich part of the Al-Co-Ni phase diagram.

Thermodynamics

[1991Kek] measured partial thermodynamic properties with emphasis on chemical potentials for the first

time for the ordered intermetallic Ni3Al phase with different additions of cobalt. The investigation was

carried out by vaporization measurements using Knudsen effusion mass spectrometry.

[1992Tso] developed a thermodynamic model based on the cluster variation method for the description of

solid phases for ternary systems, with emphasis on the characterizations of ternary ordered phases and

order-disorder transformations in alloys. The model is applied to study the equilibrium between (cF4

disordered phase) and ’ (cP4 ordered phase). It is shown that the present model is valid to describe

accurately the degree of long-range order, thermochemical potentials and phase diagram data within the

same free energy formalism and the same order of approximation.

[1998Bia] determined experimentally the specific heat Cp in the temperature interval from 1.5 to 36 K of

the decagonal Co13Ni16Al71 quasicrystal, which was cut from the Co15Ni15Al70 alloy, rapidly cooled to

room temperature after annealing at 1030°C for 5 d. A conventional relaxation method was used. Graphical

dependence is presented in Fig. 24.

[1998Gru1] measured the enthalpies of formation Hf of the ordered phase of compositions

(Co1-xNix)0.50Al0.50, (Co1-xNix)0.58Al0.42 with 0 x 1 and Co0.15Ni0.30Al0.55 with B2 (cP2) structure at

1073 K using differential solution calorimetry. The values of the enthalpy of formation are given in Table 3.

The authors noted that the composition dependence of the Hf can be described by the disorder model by

Wagner and Schottky.

The melting enthalpies Hfus, temperatures Tfus and entropies Sfus of quasiperiodic and periodic phases

are presented in Table 4 after [1999Hol] (DTA data).

The Bragg-Williams model for describing the composition and temperature dependence of thermodynamic

properties of ternary B2 (cP2) phase has been applied successfully by [2001Bre] for the phase in the

Al-Co-Ni system and boundary binaries Al-Ni and Al-Co. With the activities and the integral enthalpies of

formation as input data, values for the enthalpy and entropy of bonds between atoms were obtained. An

analytical expression was derived for the dependence of the concentration of point defects (vacancies and

antistructure atoms) on the composition and temperature.


Mechanical properties of the Al-Co-Ni alloys are investigated from the end of fifties, in particular,

[1959Gua] investigated the influence of cobalt addition on the structure and hardness of the ’, Ni3Al phase.

The martensitic transformations in the ,Al(Co,Ni) phase in the alloys with aluminium content from 32 to

36 at.% quenched from high temperatures were studied by [1977Lit]. It was shown that introduction of

cobalt at constant aluminium content influences on morphology of martensite like decreasing of aluminium

251


MSIT®

Al–Co–Ni

content, but to a much less degree. [1995Mis] obtained the dependence of the tensile flow stress on the strain

for the Co14Ni56Al30 (at.%). Hot-workability of phase is shown by [1996Kai] to be drastically improved

by the introduction of the phase i.e. the hot workability is significantly related to the phase diagram. It

was established that the temperature of the phase martensitic transformation in the + two-phase alloys

increases with increasing of the annealing temperature. Planar interfaces between ’ and phases in the

ternary Al-Co-Ni diffusional couples annealed at temperatures ranging from 900 to 1300°C were observed

by [2001Kai]. Interdiffusion in the ’ phase alloyed by up to 19 at.% Co was studied by [2002Gaz] in the

sections corresponding to 22 at.% Al, 3.5 or 16 at.% Co at temperatures between 900 and 1200°C. The

relations between the measured interdiffusion coefficients in the ordered ’ phase agree well with literature

data for both the ordered ’ phases and also for the disordered Al-Ni and Co-Ni solid solutions.

Mechanical, electronic, magnetic properties of the decagonal phase, point and other defects and diffusion

in this phase has been extensively studied. The reports are included in a number of monographs and

text books.

The single quasicrystal elastic moduli cij of a decagonal 1 phase were determined by [1998Che] using

resonance ultrasound spectroscopy at selected temperatures in the range between 5 and 290 K. It has been

found to be transversely elastically isotropic to (0.02±0.04) %. There are weak temperature dependences of

elastic moduli. The elastic Debye temperature calculated from cij measured at 5 K agrees well with the

thermodynamic Debye temperature obtained from a low-temperature specific-heat experiment.

Compression experiments were performed by [2000Eda] on an Al-Co-Ni decagonal single quasicrystals

grown by the floating zone method with different orientations of the compression axes: the tenfold direction

(c ), the twofold direction perpendicular to it (c ) and the direction inclined from the tenfold direction by

about 45° (c45°). For the samples inclined from the tenfold direction by about 45° a slip deformation was

observed on the twofold prismatic slip plane and in the tenfold slip direction. Long straight screw

dislocations were observed by TEM in the c45° compressed samples, indicating the existence of deep

Peierls-potential valleys for the dislocation glide. The c and c compressed samples showed slip

deformations along more than two types of pyramidal slip planes.

Data on electrical properties and magnetic behavior of the Al-Co-Ni alloys were obtained by [1991Mar,

1992Poo, 1992Sch, 1993Wan, 1997Goe3, 1998Sch, 1999Cal, 2001Oik1, 2001Oik2, 2002Liu, 2002Mor]

and [2002Mur]. In particularly, while investigating phase equilibria in the Al-CoAl-NiAl subsystem

[1997Goe3] and [1998Sch], performed the magneto-thermal analysis (MTA) by recording magnetic

susceptibility versus temperature using a Faraday type magnetic balance. From the magnetic behavior of

the alloys, the character of order-disorder transformations and the solid state formation of the , Ni3Al4phase was determined and the position of the phase homogeneity region could be clarified. In the

homogeneous region of the 1 phase no simple relationship of magnetic properties and composition is

found. [2001Oik1, 2001Oik2] investigated magnetic properties of the phase, which possesses

ferromagnetism.

Diffusion in the Al-Co-Ni alloys was studied by [2000Kho, 2000Zum, 2001Kai] and [2002Gaz].

Self-diffusion of 57Co in decagonal quasicrystals was investigated as a function of the temperature by

means of the radioactive tracer method [2000Kho]. In combination with serial sectioning, diffusivities were

measured over a large temperature range from 459 to 1000°C. Using the same method, [2000Zum]

measured the diffusion coefficient of 60Co in a single decagonal Co16.0Ni11.8Al72.2 quasicrystal. The results

are discussed together with data on similar diffusion investigations on icosahedral quasicrystals, and a

diffusion mechanism via vacancies is suggested.

Miscellaneous

Partitioning of Co between the , and phases at 800 to 1300°C were studied by [1994Jia] using

diffusion couples. The compositional dependence of the partition coefficients between and phases at

1100°C is shown in Fig. 25 after [1994Jia].

Dependences of the lattice parameters of the ,Al(Co,Ni) solid solutions on the aluminium content is

presented in Fig. 26 after [1966Rid]. The density measurements reveal that the steep drops in lattice

252


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Al–Co–Ni

parameters which take place when the aluminium content exceeds ~50 at.%, are accompanied by the

omission of atoms from the lattice.

[2000Wid] extended the generalized pseudo-potential theory of interatomic potentials in binary

transition-metal aluminides to the ternary system, and applied the first-principle pair potential calculation

to the aluminium-rich corner for Al-Co-Ni alloys. The results reproduce many features of the known phase

diagram, placing known stable and metastable structures on or near the convex hills of the

energy-composition plots.

The generalized vibrational density of states (GVDOS) was determined by [1996Mih] for decagonal

Co15Ni15Al70 using cold neutron inelastic scattering techniques. A computer modeling of the GVDOS was

proposed using realistic pair potentials. [1999Yam] studied the relation between the electron concentration

and anomalous dip appearing on the [110]TA1 phonon branch of the 1 phase with B2 (cP2) structure in

Ni-Al and established that by substituting Ni by Co, the dip-positions shifts toward the Brillouin zone

center. The obtained results indicate clearly that the dip is not any precursor of the martensitic transition but

a reflection of the electronic property in the 1 phase

[2000Elh] analyzed the experimentally measured temperature dependence of the phonon density of states

(DOS) in the decagonal phase obtained by [1997Dug] in the range 27 to 827°C, assuming that the

relationship between the DOS at different temperatures can be expressed in terms of frequency shifts of the

phonon modes. It was concluded that the temperature-dependent frequency shifts are anomalously large at

high temperatures, increasing significantly the vibrational entropy. The authors expect that this contribution

can not be neglected in the competition between quasicrystals and related crystalline phases.

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[1993Wan] Wang, Y., Lu, L., Zhang, D.-L., “Anisotropic Hall Coefficients of Al65Ni20Co15 2D Single

Quasicrystals”, J. Non-Cryst. Solids, 153-154, 361-365 (1993) (Experimental, Phys. Prop.,

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12413-12424 (1994) (Crys. Structure, Equi. Diagram, Experimental, 34)

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a Quantitative Analysis with Decagonal Al70Co15Ni15”, Philos. Mag. Lett., 70(6), 379-384


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Quasicrystals Studied by High-Resolution Electron Microscopy”, Mater. Trans. JIM,


[1994Jia] Jia, C.C., Ishida, K., Nishizawa, T., “Partition Of Alloying Elements Between (A1), '

(L12) and (B2) Phases in Ni-Al Base Systems”, Metall. Mater. Trans. A, 25, 473-485


[1994Mur] Murthy, A.S., Goo, E., “Triclinic Ni2Al Phase in 63.1 at.% NiAl”, Met. Mater., A, 25A (1),


[1995Hra] Hradil, K., Proffen, T., Frey, F., Kek, S., Krane, H.G., Wroblewski, T., “X-ray Diffuse

Scattering in the Decagonal Phases Al70Ni15Co15, Al72.5Ni11Co16.5 and Al62Cu20Co15Si3up to 1150K”, Phil. Mag. B., 71, 955-966 (1995) (Crys. Structure, Experimental, 8)

[1995Kal] M. Kalning, W. Press, S. Kek, “Investigation of a Decagonal Al70Co15Ni15 Single Crystal

by Means of High-Resolution Synchrotron X-ray Diffraction”, Philos. Mag. Lett., 71(6),


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[1995Qin] Qin, Y., Wang, R., Wang, Q., Zhang, Y., Pan, C., “Ar’(+)-Ion-Irradiation-Induced Phase

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83-90 (1995) (Crys. Structure, Experimental, Thermodyn., 21)

[1995Rit] Ritsch, S., Beeli, C., Nissen, H.-U., Lück, R., “Two Different Superstructures of the

Decagonal Al-Co-Ni Quasicrystal”, Philos. Mag. A, 71(3), 671-685 (1995) (Crys. Structure,

Experimental, 21)

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Positron Lifetimes in Quasicrystalline Decagonal and Adjacent Crystalline Phases of

Al-Ni-Co, Al-Cu-Co, and Al-Ni-Fe Alloys”, Phys. Rev. B, 52(9), 6411-6416 (1995) (Equi.


[1995Zha] Zhang, B., Gramlich, V., Steurer, W., “Al13-x(Co1-yNiy)4, a New Approximant of the

Decagonal Quasicrystal in the Al-Co-Ni System”, Z. Kristallogr., 210, 498-503 (1995)


[1996Bur] Burkhardt, U., Ellner, M., Grin Yu., “Powder Diffraction Data for the Intermetallic


11 (2), 123-128 (1996) (Experimental, Crys. Structure, 23)

[1996Fre] Freiburg, C., Grushko, B., Wittenberg, R., Reichert, W., “Once More About Monoclinic

Co4Al13”, Mater. Sci. Forum, 228-231, 583-586 (1996) (Crys. Structure, Experimental, 8)

[1996Goe] Gödecke, T., Ellner, M., “Phase Equilibria in the Aluminium-Rich Portion of the System

Co-Al and in the Cobalt/Aluminium-Rich Portion of the Ternary System Co-Ni-Al”,

Z. Metallkd., 87(11), 854-864 (1996) (Equi. Diagram, Experimental, 36)

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[1996Gru1] Grushko, B., Wittenberg, R., Bickmann, K., Freiburg, C., “The Constitution of

Aluminium-Cobalt Alloys Between Al5Co2 and Al9Co2”, J. Alloys Compd., 233, 279-297

(1996) (Crys. Structure, Equi. Diagram, Experimental, #, *, 18)

[1996Gru2] Grushko B., Holland-Moritz D., Bickmann K., “Decagonal Quasicrystals in Al-Co and

Ternary Aloys Containing Cu and Ni”, J. Alloys Compd., 236, 243-252 (1996) (Equi.


[1996Gru3] Grushko B., Holland-Moritz D., “High-Ni Al-Ni-Co Decagonal Phase”, Scr. Mater.,

35(10), 1141-1146 (1996) (Experimental, Crys. Structure, 19)

[1996Kai] Kainuma, R., Ise, M., Jia, C.C., Ohtani, H., Ishida, K., “Phase Equilibria and

Microstructural Control in the Ni-Co-Al”, Intermetallics, 4, S151-S158 (1996) (Crys.

Structure, Equi. Diagram, Experimental, Mechan. Prop., 20)

[1996Mih] Mihalkovic, M., Dugain, F., Suck, J.-B., “Vibration Density of States Decagonal

Al70Co15Ni15”, J. Non-Cryst. Solids, 205-207, 701-705 (1996) (Crys. Structure,

Experimental, 17)


Ni1+xAl1-x”, Acta Crystallogr., Sect. A: Found. Crystallogr., A52, C319 (1996) (Crys.


[1996Rit1] Ritsch, S., Beeli, C., Nissen, H.-U., Gödecke, T., Scheffer, M., Lück, R., “Highly Perfect

Decagonal Al-Co-Ni Quasicrystals”, Philos. Mag. Lett., 74(2), 99-106 (1996) (Equi.


[1996Rit2] Ritsch, S., Beeli, C., Nissen, H.-U., “One-dimentional Periodic Fivefold Al-Co-Ni

Quasicrystals”, Philos. Mag. Lett., 74(2), 203 (1996) (Crys. Structure, Experimental, 15)

[1996Rit3] Ritsch S., Ph. D. Thesis, ETH Zürich, (1996)

[1996Sch] Schreuer, J., Baumgarte, A., Estermann, M.A., Steurer, W., Reifler, H., “High-Temperature

Furnace for an Imaging-Plate Date-Acquisition System”, J. Appl. Cryst., 29, 365-370


[1996Tsa] Tsai, A.P., Fujiwara, A., Inoue, A., Masumoto, T., “Structural Variation and Phase

Transformations of Decagonal Quasicrystals in the Al-Ni-Co System”, Philos. Mag. Lett.,


[1996Tsu] Tsuda, K., Nishida, Y., Saitoh, K., Tanaka, M., Tsai, A.P., Inoue, A., Masumoto, T.,

“Structure of Al-Ni-Co Decagonal Quasicrystals”, Philos. Mag., A74, 697 (1996) (Crys.


[1996Vik] Viklund P., Haeussermann, U., Lidin, S., “NiAl3: a Structure Type of its Own?”, Acta

Cryst., Sect. A: Found Crystallogr., A52, C-321 (1996) (Crys. Structure, Experimental,

Abstract, 0)

[1996Yam] Yamamoto, A., “Crystallography of Quasiperiodic Crystals”, Acta Crystallogr., Sect. A:

Found. Crystallogr., 52, 509-560 (1996) (Calculation, Crys. Structure, Review, 211)

[1997Alb] Albers,M.; Kath, D.; Hilpert, K., “Thermodynamic Activities and Phase Boundaries for the

Alloys of the Solid Solution of Co in Ni3Al”, Metall. Mater. Trans. A, 28A, 2183-2188

(1997) (Equi. Diagram, Experimental, Thermodyn., 25)

[1997Bau] Baumgarte, A., Schreuer, J., Estermann, M.A., Steurer, W., “X-ray Diffraction Study of

Decaprismatic Al-Co-Ni Crystals as a Fuction of Composition and Temperature”, Philos.

Mag. A, 75(6), 1665-1675 (1997) (Crys. Structure, Experimental, 14)


Liquid Aluminium”, Z. Metallkd., 88 (6), 446-451 (1997) (Thermodyn., Experimental, 15)

[1997Che] Chen, L.F., Wang, L.M., Guo, Y.X., Ewing, R.C., “Ion Irradiation-Induced Phase

Transformation in Al-Cu-Co-Ge Decagonal Quasicrystal”, Nucl. Instr., Meth. Phys. Res. B.,

127/128, 127-131 (1997) (Crys. Structure, Experimental, 14)

[1997Dug] Dugain, F., Mihalkovich, M., Suck, J.-B., “Temperature Dependence of the Generalized

Vibrational density of States of Al70Co15Ni15 and Al62Co15Cu20Si3”, Mater. Sci. Eng. A.,

226/228, 967 (1997) (Experimental, Crys. Structure, 13)

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[1997Feu] Feuerbacher, M., Bartsch, M., Grushko, B., Messerschmidt, U., Urban, K., “Plastic

Deformation of Decagonal Al-Ni-Co Quasicrystals”, Philos. Mag. Lett., 76(6), 369-376


[1997Goe1] Gödecke, T., Ellner, M., “Phase Equilibria in the Al-rich Portion of the Ternary System

Co-Ni-Al at 75 and 78 at.% Al”, Z. Metallkd., 88(5), 382-389 (1997) (Equi. Diagram,

Experimental, Review, 49)

[1997Goe2] Gödecke, T., “Liquidus Surface and Phase Equilibria with Participation of Liquid in the

System Al-AlCo-AlNi” (in German), Z. Metallkd., 88(7), 557-569 (1997) (Equi. Diagram,


[1997Goe3] Gödecke, T., Scheffer, M., Lück, R., Ritsch, S., Beeli, C., “Formation and Phase Bondaries

of (Co,Ni)3Al4 and the Ternary X Phase in the Al-AlCo-AlNi System”, Z. Metallkd., 88(9),


[1997Gru1] Grushko, B., Holland-Moritz, D., “Decagonal Quasicrystals in Al-Co, Al-Ni and their

Ternary Alloys”, Mater. Sci. Eng. A, 226-228, 999-1003 (1997) (Crys. Structure, Equi.


[1997Gru2] Grushko, B., Holland-Moritz, D., “Quasicrystals and Related Structures in Al-Co-Ni”, J.

Alloys Comp., 262-263, 350-355 (1997). (Crys. Structure, Experimental, 34)

[1997Hra] Hradil K., Frey F., Grushko B., “Single Crystal Neutron Diffraction of Decagonal

Al72.5Co11Ni16.5”, Z. Kristallogr., 212, 89-94 (1997) (Crys. Structure, Experimental, 18)

[1997Kal] Kalning, M., Kek, S., Krane, H.G., Dorna, V., Press, W., Steurer, W., “Phason-Strain of the

Twinned Approximant to the Decagonal Quasicrystal Al70Co15Ni15: Evidence for a

One-dimensional Quasicrystal”, Phys. Rev. B, 55(1), 187-192 (1997) (Crys. Structure,

Experimental, 25)


Alloys”, Acta Mater., 45, 2155-2166 (1997) (Experimental, Crys. Structure, 48)

[1997Pot] Potapov, P.L., Song, S.Y., Udovenko, V.A., Prokoshkin, S.D., “X-Ray Study of Phase



[1997Qin] Qin, Y., Wang, R., “Ar Ion Irradiation Effects in an Al70Co15Ni15 Decagonal Quasicrystal”,

Radiat. Eff. Def. Solids, 140, 335-349 (1997) (Crys. Structure, Experimental, Thermodyn.,

21)

[1997Sai1] Saitoh, K., Tsuda, K., Tanaka, M., Kaneko, K., Tsai, A.P., “Structural Study of an

Al72Ni20Co8 Decagonal Quasicrystal Using the High-angle Annular Dark-field Method”,

Jpn. J. Appl. Phys., 36(10B), L1400-L1402 (1997) (Crys. Structure, Experimental, 18)

[1997Sai2] Saitoh, K., Tsuda, K., Tanaka, M., “Structural Models for Decagonal Quasicrystals with

Pentagonal Atom-Cluster Columns”, Philos. Mag., A76, 135-150 (1997) (Crys. Structure,

Experimental, 14)

[1997Yam] Yamamoto, A., Weber, S., “Superstructure and Color Symmetry in Quasicrystals”, Phys.

Rev. Lett., 79(5), 861-864 (1997) (Crys. Structure, Experimental, 20)

[1997Yok] Yokoyama, Y., Note, R., Kimura, S., Inoue, A., Fukaura, K., Sunada, H., “Preparation of

Decagonal Al-Ni-Co Single Quasicrystal by Czochralski Method”, Mater. Trans., JIM, 38,

943-949 (1997) (Crys. Structure, Equi. Diagram, Experimental, 15)

[1997Zha] Zhang, B., Estermann, M., Steurer, W., “The Growth of Decagonal Al-Co-Ni Single

Crystals as a Function of Chemical Composition”, J. Mater. Res., 12(9), 2274-2280 (1997)


[1998Bia] Bianchi, A.D., Bommeli. F., Felder, E., Kenzelmann, M., Chernikov, M.A., Degiorgi, L.,

Ott, R., Edagawa, K., “Low-Temperature Thermal and Optical Properties of Single-Grained

Decagonal Al-Ni-Co Quasicrystals”, Phys. Rev. B, Cond. Matter, 58(6), 3046-3056 (1998)

(Experimental, Optical Prop., Thermodyn., 47)

[1998Che] Chernikov, M.A., Ott, H.R., Bianchi, A., Migliori, A., Darling, T.W., “Elastic Moduli of a

Single Quasicrystal of Decagonal Al-Ni-Co: Evidence for Transverse Elastic Isotropy”,

Phys. Rev. Lett., 80(2), 321-324 (1998) (Calculation, Crys. Structure, 23)

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[1998Goe] Gödecke, T., Scheffer, M., Lück, R., Ritsch, S., Beeli, C., “Isothermal Sections of Phase

Equilibria in the Al-AlCo-AlNi System”, Z. Metallkd., 89(10), 687-698 (1998) (Equi.


[1998Gri] Grin, Yu., Peters, K., “The Structure of the Ternary Phase Co2NiAl9”, Z. Kristallogr., 213,


[1998Gru1] Gruen, A., Henig, E.-T., Sommer, F., “Calorimetric Determination of the Enthalpy of

Formation and the Description of the Constitutional Defects of the Ordered (Ni,Co)1-yAlyPhase”, Z. Metallkd., 89, 591-597 (1998) (Experimental, Thermodyn., 21)

[1998Gru2] Grushko, B., Holland-Moritz, D., Wittmann, R., Wilde, G., “Transition Between Periodic

and Quasiperiodic Structures in Al-Ni-Co”, J. Alloys Compd., 280, 215-230 (1998) (Crys.


[1998Hon] Honal, M., Haibach, T., Steurer, W., “Geometrical Model of the Phase Transformations of

Decagonal Al-Co-Ni to its Periodic Approximant”, Acta Crystallogr., Sect. A: Found.

Crystallogr., A54, 374-387 (1998) (Crys. Structure, Experimental, 24)

[1998Ma] Ma, X.L., Köster, U., Grushko, B., “Al13Os4-type Monoclinic Phase and its Orthorhombic

Variant in the Al-Co System”, Z. Kristallogr., 213, 75-78 (1998) (Experimental, Crys.

Structure, 14)

[1998Mo] Mo, Z.M., Sui, X.L., Kuo, K.H., “Structural Models of 2-Inflated Monoclinic and

Orthorhombic Al-Co Phases”, Metall. Mater. Trans. A,, 29, 1565-1572 (1998)



Vibrational Entropy Difference Between Ordered and Disordered Ni3Al”, Phys. Rev. B,


[1998Rit] Ritsch, S., Beeli, C., Nissen, H.-U., Goedecke, T., Scheffer, M., Lueck, R., “The Existence

Regions of Structural Modifications in Decagonal Al-Co-Ni”, Philos. Mag. Lett., 78(2),


[1998Sai] Saitoh, K., Tsuda, K., Tanaka, M., “New Structural Model of an Al72Ni20Co8 Decagonal

Quasicrystal”, J. Phys. Soc. Jpn., 67(8), 2578-2581 (1998) (Experimental, Crys. Strucrure,

10)

[1998Sat] Sato, T.J., Hirano, T., Tsai, A.P., “Single Crystal Growth of the Decagonal Al-Ni-Co

Quasicrystal”, J. Cryst. Growth, 191, 545-552 (1998) (Crys. Structure, Experimental, 17)

[1998Sch] Scheffer, M., Goedecke, T., Lueck, R., Ritsch, S., Beeli, C., “Phase Equilibria of the

Decagonal AlCoNi Phase”, Z. Metallkd., 89(4), 270-278 (1998) (Equi. Diagram,

Experimental, 16)



558-561 (1998), translated from Neorganicheskie Materialy, 34(6), 684-687 (1998) (Crys.


[1998Tia] Tian W.H., Hibino M., Nemoto M., “Crystal Structure and Morphology of Co Precipitates

in B2-ordered (Ni,Co)Al”, Intermetallics, 6(2), 121-129 (Crys. Structure, Experimentlal)

[1998Wid] Widom, M., Moriarty, J.A., “First-Principles Interatomic Potentials for Transition-Metal

Aluminides. II. Application to Al-Co and Al-Ni Phase Diagram”, Phys. Rev. B, 58(14),

8967-8979 (1998) (Calculation, Crys. Structure, Equi. Diagram, 37)

[1999Cal] Calugaru, G., Craus, M.-L., Hopulele, I., “Structure and Magnetic Properties of Al-Ni-Co

Fine Particles Propduced by Spark Erosion”, Powder Met., 42(4), 367-368 (1999) (Crys.

Structure, Experimental, Magn. Prop., 11)

[1999Fis] Fisher, I.R., Kramer, M.J., Islam, Z., Ross, A.R., Kracher, A., Wiener, T., Sailer, M.J.,

Goldman, A.I., Canfield, P.C., “On the Growth of Decagonal Al-Ni-Co Quasicrystals from

the Ternary Melt”, Philos. Mag. B., B79(3), 425-434 (1999) Experimental, Crys. Structure,

18)

259


MSIT®

Al–Co–Ni

[1999Gil] Gille, P., Dreier, P., Graber, M., Scholpp, T., “Large Single-Grain AlCoNi Quasicrystals

Grown by the Czochralski Method”, J. Cryst. Growth, 207, 95-101 (1999) (Crys. Structure,

Experimental, 14)

[1999Got] Gotzmann, K., Burkhardt, U., Ellner, M., Grin, Y., “Powder Diffraction Data for the

Homeotypic Intermetallic Compounds (Co,Ni)4Al13(h) and Co2NiAl9”, Powder Diffr.,


[1999Hol] Holland-Moritz, D., Lu, I.-R., Wilde, G., Schroers, J., Grushko, B., “Melting Entropy of

Al-Based Quasicrystals”, J. Non-Cryst. Solids, 250-252, 829-832 (1999) (Experimental,

Thermodyn., 17)

[1999Rit] Ritsch, S., Beeli, C., Lueck, R., Hiraga, K., “Pentagonal Al-Co-Ni Quasicrystal with a

Superstructure”, Philos. Mag. Lett., 79, 225-232 (1999) (Crys. Structure, Experimental, 19)

[1999Wit] Wittmann, R., “Comparing Different Approaches to Model the Atomic Structure of a

Ternary Decagonal Quasicrystal”, Z. Kristallogr., 214, 501-505 (1999) (Assessment, Crys.

Structure, 29)

[1999Yam] Yamada, M., Nagasawa, A., Ueno, Y., Morii, Y., “[110]TA1 Phonon Dispersion Relation

of the 1-Phases in Ni-Co-Al Alloys”, J. Phys. Chem. Solids, 60, 1427-1429 (1999) (Crys.


[2000Abe] Abe, H., Tamura, N., Bolloch, D., Moss, S.C., Matsuo, Y., Ishii, Y., Bai, J., “Anomalous

X-Ray Scattering Associated with Short-Range Order in an Al70Ni15Co15 Decagonal

Quasicrystal”, Mater. Sci. Eng. A, 294-296, 299-302 (2000) (Calculation, Crys. Structure,

Experimental, 12)

[2000Bee] Beeli, C., “High-Resolution Electron Microscopy of Quasicrystals”, Mater. Sci. Eng. A,


[2000Cer] Cervellino, A., Haibach, T., Steurer, W., “Modeling Atomic Surfaces for the Al-Ni-Co

Basic Decagonal Phase”, Mater. Sci. Eng. A, 294-296, 276-278 (2000) (Crys. Structure,

Experimental, 11)

[2000Dam] Damson, B., Weller, M., Feuerbacher, M., Grushko, B., Urban, K., “Mechanical

Spectroscopy of i-Al-Pd-Mn and d-Al-Ni-Co”, Mater. Sci. Eng. A, 294-296, 806-809 (2000)


[2000Doe] Döblinger, M., Wittmann, R., Gerthsen, D., Grushko, B., “Structural Relationship and

Mutual Transformation of the Approximants of the Decagonal Al-Co-Ni Phase”, Mater.

Sci. Eng. A, 294-296, 131-134 (2000) (Crys. Structure, Experimental, 9)

[2000Dro] Drobek, T., Heckl, W.M., “Scanning Probe Microscopy Studies of the Surface of Decagonal

Quasicrystals in Ambient Conditions”, Mater. Sci. Eng. A, 294-296, 878-881 (2000) (Crys.


[2000Eda] Edagawa, K., Ohta, S., Takeuchi, S., Kabutoya, E., Guo, J.Q., Tsai, A.P., “Plasticity of

Al-Ni-Co Decagonal Single Quasicrystals”, Mater. Sci. Eng. A, 294-296, 748-752 (2000)


[2000Elh] Elhor, H., Mihalkovic, M., Suck, J.-B., “Temperature Dependence of the Phonon Density

of States in Decagonal Al-Ni-Co”, Mater. Sci. Eng. A, 294-296, 658-661 (2000)


[2000Fre] Frey, F., “Disorder Diffuse Scattering of Decagonal Quasicrystals”, Mater. Sci. Eng. A,


[2000Gra] Graber, M., Barz, R.-U., Dreier, P., Gille, P., “Czochralski Growth and Characterization of

Large Decagonal Al-Co-Ni Quasicrystals”, Mater. Sci. Eng. A, 294-296, 143-146 (2000)


[2000Hai] Haibach, T., Estermann, M.A., Cervellino, A., Steurer, W., “Phase Transition in

Quasicrystals - the Example of Decagonal Al-Co-Ni”, Mater. Sci. Eng. A, 294-296, 17-22


[2000Hir] Hiraga, K., Oshuna, T., Nishimura, S., “An Ordered Arrangement of Atom Columnar

Clusters in a Pentagonal Quasiperiodic Lattice of an Al-Ni-Co Decagonal Quasicrystals”,

Philos. Mag. Lett., 80(9), 653-659 (2000) (Crys. Structure, Experimental, 8)

260


MSIT®

Al–Co–Ni

[2000Hra] Hradil, K., Scholpp, T., Frey, F., Haibach, T., Estermann, M.A., Capitan, M., “Neutron and

X-Ray Investigation of Disordered Quasicrystals”, Mater. Sci. Eng. A, 294-296, 303-307

(2000) (Crys. Structure, Experimental, Phys. Prop., 7)

[2000Kho] Khoukaz, C., Galler, R., Mehrer, H., Canfield, P.C., Fisher, I.R., Feuerbacher, M.,

“Diffusion of 57Co in Decagonal Al-Ni-Co-Quasicrystals”, Mater. Sci. Eng. A, 294-296,

697-701 (2000) (Crys. Structure, Experimental, Phys. Prop., 26)

[2000Kra1] Krajci, M., Hanfer, J., Mihalkovic, M., “Atomic and Electronic Structure of Decagonal

Al-Ni-Co Alloys and Approximant Phases”, Phys. Rev. B, 62(1), 243-255 (2000) (Crys.

Structure, Experimental, Phys. Prop., 57)

[2000Kra2] Krajci, M., Hafner, J., Mihalkovic, M., “Short-Range Order and the Electronic Structure of

Decagonal Al-Ni-Co”, Mater. Sci. Eng. A, 294-296, 548-552 (2000) (Calculation, Crys.


[2000Liu] Liu, Y.C., Yang, G.C., Zhou, Y.H., “Decagonal Quasicrystal Growth in Chill Cast

Al72Ni12Co16 Alloy”, Mater. Res. Bull., 35, 857-866 (2000) (Crys. Structure, Experimental,

13)

[2000Pra] Pramanick, A.K., Mandal, R.K., Sastry, G.V.S., “Effect of Composition on the Streaking

and Diffuse Intensity in Decagonal Phase in Al70-xCo15Cux+yNi15-y System”, Mater. Sci.

Eng. A, 294-296, 173-177 (2000) (Crys. Structure, Experimental, 16)

[2000Rit] Ritsch, S., Radulescu, O., Beeli, C., Warrington, D.H., Lück, R., Hiraga, K., “A Stable

One-Dimensional Quasicrystal Related to Decagonal Al-Co-Ni”, Philos. Mag. Lett., 80(2),


[2000Sai] Saitoh, K., Tanaka, M., Tsai, A.P., Rossouw, J., “ALCHEMI Study of an Al72Ni20Co8

Decagonal Quasicrystal”, J. Phys. Soc. Jpn., 69(8), 2379-2382 (2000) (Crys. Structure,

Experimental, 17)

[2000Shi] Shimoda, M., Guo, J.Q., Sato, T.J., Tsai, A.P., “Surface Structure and Structural Transition

of Decagonal Al-Ni-Co Quasicrystal”, Surf. Sci., 454-456, 11-15 (2000) (Crys. Structure,

Experimental, 15)

[2000Ste1] Steurer, W., “Geometry of Quasicrystal-to-Crystal Transformations”, Mater. Sci. Eng. A,

294-296, 268-271 (2000) (Assessment, Crys. Structure, 12)

[2000Ste2] Steinhardt, P.J., “Penrose Tilings, Cluster Models and the Quasi-Unit Cell Picture”, Mater.

Sci. Eng. A, 294-296, 205-210 (2000) (Calculation, Crys. Structure, Experimental, 31)

[2000Yan] Yan, Y., Pennycook, S.J., “Z-Contrast Imaging of Decagonal Quasicrystals: an Atomistic

Model of Growth”, Mater. Sci. Eng. A, 294-296, 211-216 (2000) (Crys. Structure,

Experimental, 22)

[2000Yur] Yurechko, M., Grushko, B., “A Study of the Al-Pd-Co Alloy System”, Mater. Sci. Eng. A,

294-296, 139-142 (2000) (Crys. Structure, Equi. Diagram, Experimental, 16)

[2000Wei] Weidner, E., Hradil, K., Frey, F., Boissieu, M., Letoublon, A., Morgenroth, W., Krane,

H.G., Capitan, M., Tsai, A.P., “High Resolution X-Ray and Neutron Diffraction of Super-

and Disorder in Decagonal Al-Co-Ni”, Mater. Sci. Eng. A, 294-296, 308-314 (2000) (Crys.


[2000Wid] Widom, M., Moriarty, J.A., “First-Principles Interatomic Potentials for Transition-Metal

Aluminides. III. Extention to Ternary Phase Diagram”, Phys. Rev. B, 62(6), 3448-3457

(2000) (Calculation, Crys. Structure, Equi. Diagram, 47)

[2000Zum] Zumkley, T., Guo, J.Q., Tsai, A.P., Nakajima, H., “Diffusion in Quasicrystalline Al-Ni-Co

and Al-Pd-Mn”, Mater. Sci. Eng. A, 294-296, 702-705 (2000) (Crys. Structure,


[2001Bre] Breuer, J., Sommer, F., Mittemeijer, E.J., “Thermodynamic of B2 Intermetallic Compounds

with triple Defects: a Bragg-Williams Model for (Ni,Co)Al”, Metall. Mater. Trans. A, 32A,

2157-2166 (2001) (Equi. Diagram, Experimental, Thermodyn., 34)

[2001Doe1] Döblinger, M., Wittmann, R., Gerthsen, D., Grushko, B., “A Transition State Between

Quasicrystal and Approximant in the System Al-Ni-Co”, Ferroelectrics, 250, 241-244


261


MSIT®

Al–Co–Ni

[2001Doe2] Döblinger, M., Wittmann, R., Grushko, B., “Metastable Transition States of Decagonal

Al-Ni-Co due to Inhibited Decomposition”, Phys. Rev., B64, 134208 (1-9) (2001) (Crys.


[2001Est] Estermann, M.A., Lemster, K., Steurer, W., Grushko, B., Döblinger, M., “Structure

Solution of a High-order Decagonal Approximant Al71Ni14.5Co14.5 by Maximum Entropy

Patterson Deconvolution”, Ferroelectrics, 250, 245-248 (2001) (Crys. Structure,

Experimental, 10)

[2001Hir1] Hiraga, K., Ohsuna, T., Nishimura, S., Kawasaki, M., “An Ordered Arrangement of

Columnar Clusters of Atoms in a Rhombic Quasiperiodic Lattice in an Al-Ni-Co Decagonal

Phase”, Philos. Mag. Lett., 81(2), 109-115 (2001) (Experimental, Crys. Structure, 15)

[2001Hir2] Hiraga, K., Ohsuna, T., Nishimura, S., “The Structure of an Al-Co-Ni Pentagonal

Quasicrystal Studied by High-Angle Annual Detector Dark-Field Electron, Microscopy”,


[2001Hir3] Hiraga, K., Ohsuna, T., Nishimura, S., “A New Crystalline Phase Related to an Al-Ni-Co

Decagonal Phase”, J. Alloys Compd., 325, 145-150 (2001) (Crys. Structure, Experimental,

17)

[2001Hir4] Hiraga, K., Ohsuna, T., Nishimura, S., “Structure of One-Dimensional Al-Co-Ni

Quasicrystal Studied by Atomic-Scale Transmission Electron Microscopy”, Mater. Trans.,


[2001Hir5] Hirada, K., Ohsuna, T., Yubuta, K., Nishimura, S., “The Structure of an Al-Co-Ni

Crystalline Approximant with an Ordered Arrangement of Atomic Clusters with Pentagonal

Symmetry”, Mater. Trans., 42(5), 897-900 (2001) (Crys. Structure, Experimental, 18)

[2001Hir6] Hiraga, K., Ohsuna, T., Nishimura, S., “The Structure of Type-II Al-Ni-Co Decagonal

Quasicrystal Studied ny Atomic-Scale Electron Microscopic Observations”, Mat. Technol.,


[2001Hir7] Hiraga, K., Sun, W., Ohsuna, T., “Structure of a Pentagonal Quasicrystal in

Al72.5Co17.5Ni10 Studied by High-Angle Annular Detector Dark-Field Scanning

Transmission Electron Microscopy”, Mat. Trans., 42(6), 1146-1148 (2001) (Crys.


[2001Kai] Kainuma, R., Ichinose, M., Ohnuma, I., Ishida, K., “Formation of ´/ Interface

Morphologies in Ni-Al-X Ternary Diffusion Couples”, Mater. Sci. Eng. A, 312, 168-175

(2001) (Equi. Diagram, Experimental, Thermodyn., 21)

[2001Oik1] Oikawa, K., Ota, T., Gejima, F., Ohmori, T., Kainuma, R., Ishida, K., “Phase Equilibria and

Phase Transformations in New B2-Type Ferromagnetic Shape Memory Alloys of Co-Ni-Ga

and Co-Ni-Al Systems”, Mater. Trans., JIM, 42(11), 2472-2475 (2001) (Equi. Diagram,


[2001Oik2] Oikawa, K., Wulff, L., Iijima, T., Gejima, F., Ohmori, T., Fujita, A., Fukamichi, K.,

Kainuma, R., Ishida, K., “Promising Ferromagnetic Ni-Co-Al Shape Memory Alloy

System”, Appl. Phys. Lett., 79(20), 3290-3292 (2001) (Crys. Structure, Magn. Prop., 15)

[2001Tak] Takakura, H., Yamamoto, A., Tsai, A.P., “The Structure of a Decagonal Al72Ni20Co8

Quasicrystal”, Acta Crystallogr., A57(4), 576-585 (2001) (Crys. Structure, Experimental,

38)

[2001Tan] Tan, Y., Shimoda, T., Mishima, Y., Suzuki, T., “Stoichiometry Splitting of Phase in

Ni-Al-Mn, Ni-Al-Co and Ni-Al-Fe Ternary Systems”, Mater. Trans., JIM, 42(3), 464-470

(2001) (Crys. Structure, Equi. Diagram, Experimental, Mechan. Prop., 16)

[2002Cer] Cervellino, A., Haibach, T., Steurer, W., “Structure Solution of the Basic Decagonal

Al-Co-Ni Phase by the Atomic Surfaces Modelling Method”, Acta Crystallogr., 58B, 8-33


[2002Doe] Döblinger, M., Wittmann, R., Gerthsen, D., Grushko, B., “Continuous Transition between

Decagonal Quasicrystal and Approximant by Formation and Ordering of Out-of-phase

Domains”, Phys. Rev., B65, 224201-(1-9) (2002) (Crys. Structure, Experimental, 39)

262


MSIT®

Al–Co–Ni

[2002Gru] Grushko, B., Döblinger, M., Wittmann, R., Holland-Moritz, D., “A Study of High-Co

Al-Ni-Co Decagonal Phase”, J. Alloys Comp., 342, 30-34 (2002) (Crys. Structure,

Experimental, 15)

[2002Gaz] Gazda, A., Rothova, V., Cermak, J., “Interdiffusion in Pseudobinary Sections of Ni3Al-Co

Ternary System”, Intermetallics, 10(9), 859-864 (2002) (Crys. Structure, Equi. Diagram,


[2002Hir1] Hiraga, K., “The Structure of Quasicrystals Studied by Atomic-Scale Observations of

Transmission Electron Microscopy”, Adv. Imag. Electr. Phys., 122, 1-86 (2002)

(Assessment, Crys. Structure, 99)

[2002Hir2] Hirada, K., Ohsuna, T., Sun, W., Sugiuama, K., “The Structural Characteristics of Al-Co-Ni

Decagonal Quasicrystals and Crystalline Approximants”, J. Alloys Compd., 342, 110-114


[2002Kup] Kupsch, A., Meyer, D.C., Gille, P., Paufler, P., “Evidence of Phase Transition and

Measurement of Thermal Expansion in Decagonal Al-Co-Ni at Low Temperatures”,

J. Alloys Compd., 342(1-2), 256-260 (2002) (Crys. Structure, Phys. Prop., 13)

[2002Liu] Liu, C.T., Fu, C.L., Pike, L.M., Easton, D.S., “Magnetism-Induced Solid Solution Effects

in Intermatallic”, Acta Mater., 50, 3203-3210 (2002) (Calculation, Crys. Structure,


[2002Mor] Morito, H., Fujita, A., Fukamichi, K., Kainuma, R., Ishida, K., Oikawa, K.,

“Magnetocrystalline Anisotropy in Single-Crystal Co-Ni-Al Ferromagnetic Shape-Memory

Alloy”, Appl. Phys. Lett., 81(9), 1657-1659 (2002) (Experimental, Magn. Prop., 13)

[2002Mur] Murakami, Y., Shindo, D., Oikawa, K., Kainuma, R., Ishida, K., “Magnetic Domain

Structures in Co-Ni-Al Shape Memory Alloys Studied by Lorentz Microscopy and Electron

Holography”, Acta Mater., 50, 2173-2184 (2002) (Crys. Structure, Experimental, Phys.

Prop., 30)

[2002Sug] Sugiyama, K., Nishimura, S., Hirada, K., “Structure of a W-(AlCoNi) Crystalline Phase

Related to Al-Co-Ni Decagonal Quasicrystals, Studied by Single Crystal X-Ray

Diffraction”, J. Alloys Compd., 342, 65-71 (2002) (Crys. Structure, Experimental, 15)

[2003Ebe] Ebert, Ph., Kluge, F., Yurechko, M., Grushko, B., Urban, K., “Structure and Composition

of Cleaved and Heat-Treated Tenfold Surfaces of Decagonal Al-Ni-Co Quasicrystals”, Surf.

Sci., 523, 298-306 (2003) (Crys. Structure, Experimental, Phys. Prop., 36)

[2003Doe] Doeblinger, M., Wittmann, R., Gerthsen, D., Grushko, B., “Intermediate Stages of a

Transformation between Quasicrystal and an Approximant Including Nanodomain

Structures in the Al-Ni-Co System”, Phil. Mag., 83(9), 1059-1074 (2003) (Crys. Structure,

Experimental, 33)



Services GmbH, Stuttgart, to be published (2003) (Equi. Diagram, Assessment, Crys.

Structure, 72)



International Services GmbH, Stuttgart, to be published, (2003) (Equi. Diagram,

Assessment, Crys. Structure, 164)

263


MSIT®

Al–Co–Ni


Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

(Al)

660.452

CoxNiyAl1-x-y

cF4

Fm3m

Cu

a = 404.88 pure Al, T = 24°C [V-C]

x = 0, y = 0 to 0.004 [2003Sal]

, (Co1-x, Nix)

( Co) (h)

1495 - 422

(Ni)

< 1455

cF4

Fm3m

Cu a = 354.46

a = 352.40

a = 352.32

0 < x < 1

pure Co [V-C]

pure Ni, T = 25°C [1984Och, Mas2]

[V-C]

, (Co) (r)

422

hP2

P63/mmc

Mg

a = 250.71

c = 406.95

[V-C]

Co2Al9< 970

(Co1-xNix)2Al9

mP22

P21/a

a = 855.6

b = 629.0

c = 621.3

= 94.76°

[1950Dou]

5 at.% Ni, T = 850 to 750°C [1998Goe]

O-Co4Al13

< 1092

O-(Co1-xNix)4Al3

oP102

Pnm21

O-Co4Al13

a = 815.8

b = 1234.7

c = 1445.2

[1996Gru1, 1996Bur]

~1.5 at.% Ni, T = 600 to 900°C

M-Co4Al13

< 1090

M-(Co1-xNix)4Al13

mC102

C2/m

Fe4Al13

a = 1517.3

b = 810.9

c = 1234.9

= 107.84°

[1996Fre]

~1.5 at.%Ni, T =600 to 900°C [1998Goe]

Y

1083<T<1127

Y, solid solution

oI96

Immm

mC34

C2/m

Os4Al13

a = 1531.0

b = 1235.0

c = 758.0

a = 1707.1

b = 409.9

c = 749.1

= 116.17°

a = 1704.0

b = 409.0

c = 758.0

= 116.0°

[1998Ma]

[1996Gru1]

[1995Zha]

[1998Ma]

Maximum solubility of Ni is 6.5 at.%

at 850°C [1998Goe]

Z

< 1153

Z, solid solution

C-centred

monoclinic

a = 3984.0

b = 814.8

c = 3223.0

= 107.97°

[1998Mo]

~1.5at.% Ni, T = 600 to 1100°C [1998Goe]

4-5 at.% Ni [2003Gru]

264


MSIT®

Al–Co–Ni

Co2Al5< 1182

(Co1-xNix)2Al5

hP28

P63/mmc

Co2Al5

a = 767.2

c = 760.5

[1996Gru1, 1996Bur]

~5.5 at.% Ni, 750°C [1998Goe]

D2(Al-Co) decagonal n* = 800 ~Co27Al73, metastable [1997Gru1]

, CoAl

< 1640

, NiAl

< 1676

, (Co1-xNix)Al

cP2

Pm3m

CsCl

a = 285.7

a = 286.2

a = 285.9

a = 287.04

a = 287.26

a = 286.0

a = 287.0

a = 288.72(2)

a = 287.98(2)

a = 289.0

a = 289.7

a = 290.4

a = 291.2

a = 291.9

a = 293.2

a = 286.4

a = 287.3

a = 288.1

a = 288.2

a = 287.5

a = 286.8

a = 286.5

a = 286.4

a = 287.1

a = 287.5

a = 286.6

a = 285.6

a = 286.3

a = 286.7

a = 287.1

a = 287.0

a = 285.9

a = 285.5

a = 285.0

a = 290.2

a = 290.9

20 to 54 at.% Al [2003Gru]

52 at.% Al [1966Rid]

50 at.% Al [1966Rid]

43 at.% Al [1966Rid]

42 to 69.2 at.% Ni [Mas2]

57.7 at.% Ni [L-B]

46.6 at.% Ni [L-B]

[1987Kha]

63 at.% Ni [1993Kha]

50 at.% Ni [1996Pau]

54 at.% Ni [1996Pau];

T = 0°C [1971Cli]

T = 200°C [1971Cli]

T = 400°C [1971Cli]

T = 600°C [1971Cli]

T = 800°C [1971Cli]

T = 1000°C [1971Cli]

x = 0 to 1;

in the alloys annealed at T = 1000°C to

1200°C (7 d), slowly cooled to 300°C and

quenched [1966Rid]:

Co12Ni48Al40

Co11Ni44Al45

Co10Ni40Al50

Co9.8Ni39.2Al51

Co9.6Ni38.4Al52

Co9.4Ni37.6Al53

Co29Ni29Al42

Co12Ni48Al40

Co27Ni27Al46

Co25Ni25Al50

Co23Ni23Al52

Co22.5Ni22.5Al55

Co39.2Ni16.8Al44

Co36.4Ni15.6Al48

Co35Ni15Al50

Co34.65Ni14.85Al50.5

Co32.9Ni14.1Al53

Co32.2Ni13.8Al54

Co31.15Ni13.35Al55.5

33 at.% Co, T = 600°C [1971Cli]

33 at.% Co, T = 800°C [1971Cli]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

265


MSIT®

Al–Co–Ni

, NiAl3< 856

, (Ni1-xCox)Al3

oP16

Pnma

NiAl3

oP16

Pnma

CFe3

a = 661.15

b = 736.64

c = 481.18

a = 661.3(1)

b = 736.7(1)

c = 481.1(1)

a = 659.8

b = 735.1

c = 480.2

[L-B]

[1996Vik]

[1997Bou, V-C]

Maximum solubility of Co is ~10 at.%,

at T = 850°C [1998Goe]

, Ni2Al3< 1138

, (NixCo1-x)2Al3

hP5

Pm3m1

Ni2Al3

a = 403.63

c = 490.65

a = 402.8

c = 489.1

36.8 to 40.5 at.% Ni [Mas2]

[L-B]

[1997Bou, V-C]

4.6 at.% Co, T = 1050°C [1998Goe];

20 at.% Co, T = 900°C [1993Pov,

1998Goe];

18 at.% Co, T = 600 to 730°C [1998Goe]

’, Ni3Al4<702

’, (NixCo1-x)3Al4

cI112

Ia3d

Ni3Ga4

a =1140.8(1) [1989Ell, V-C]

Maximum solubility of Co is 22 at.% at

57 at.% Al [1998Goe]

Ni5Al3

<723

oC16

Cmmm

Pt5Ga3

a = 753

b = 661

c = 376

63 to 68 at.% Ni [1993Kha, Mas2];

at 63 at.% Ni [1993Kha]

’, Ni3Al

< 1372

(Ni1-xCox)3Al

cP4

Pm3m

Cu3Au

a = 356.6

a = 357.0

a = 356.77

a = 356.32

a = 357.92

a = 357.1

73 to 76 at.% Ni [Mas2];

[1952Tay],

[1984Och, 1959Gua],

[1986Hua],

disordered [1998Rav],

ordered [1998Rav];

15 at.% Co [1959Gua]

[1996Kai]:

8 at.% Co, T = 1300°C,

20 at.% Co, T = 1100°C,

24 at.% Co, T = 900°C

Ni2Al9 mP22

P21/c

Ni2Al9

a = 868.5(6)

b = 623.2(4)

c = 618.5(4)

= 96.50(5)°

Metastable;

[1988Li, 1997Poh]:

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

266


MSIT®

Al–Co–Ni

NixAl1-x

0.60 < x < 0.68

tP4

P4/mmm

AuCu

m**

a = 383.0

c = 320.5

a = 379.5

c = 325.6

a = 379.5

c = 325.6

a = 379.5

c = 325.6

a = 379.9 to 380.4

c = 322.6 to 323.3

a = 371.7 to 376.8

c = 335.3 to 339.9

a = 378.00

c = 328.00

a = 418

b = 271

c = 1448

= 90°

= 93.4°

= 90°


[1993Kha]

62.5 at.% Ni [1991Kim]

63.5 at.% Ni [1991Kim]

66.0 at.% Ni [1991Kim]

64 at.% Ni [1997Pot]

65 at.% Ni [1997Pot]

[1998Sim]:

[1992Mur]

Ni2Al hP3

P3m1

CdI2

a*126

P1

a = 407

b = 499

a = 1252

b = 802

c = 1526

= 90°

= 109.7°

= 90°

Metastable

[1993Kha]

[1994Mur]

D1(Al-Ni) decagonal n 400 Metastable [1988He, 1988Li], Ni31Al69

[1997Gru1]

D4(Al-Ni) decagonal n 400 Metastable [1988He, 1988Li]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

267


MSIT®

Al–Co–Ni

* 1,

1175

decagonal

P10/mmm,

decagonal

P105/mmc,

decagonal

D1

P10

decagonal

(D1?)

D2

SI

SII

Dbf

Dcf

Dbg

Dag

Dcg

di = 339.3

d5 = 408.07

ij = 60°

i5 = 90°

i, j = 1 to 4

n 400

n 410

d1 = 475

d2 = 336

d3 = 336

d4 = 475

d5 = 817.1

12 = 69.295°

13 = 45°

14 = 41.410°

23 = 90°

24 = 45°

34 = 69.295°

i5=90° (i =1 to 4)

n 820

(Ordered

decagonal)

(Disordered

decagonal

Co-rich)

In Co15Ni15Al70, called as D [1989Tsa1]

Co20Ni10Al70, single-crystal [1990Yam];

the overal composition range Co22Ni5Al73

to Co5.5Ni24.5Al70 [1997Gru1];

Co15Ni15Al70, single-crystal cut from

annealed at 850°C 1 d ingot,

five-dimensional unit-cell parameters

[1993Ste1]:

Co5.5Ni24.5Al70, perfect structure of the

single crystal, 900 to 1100°C [1997Gru1]

Ni-rich, perfect structure of high

temperature modification [1998Rit]

in Co6.7Ni22.7Al70.6 alloy, at room

temperature,

five-dimensional unit cell parameters

[2002Cer]:

Co-rich modification [1998Rit]

Superstructures of D2(?) [1998Rit]

in Co12Ni18Al70 alloy, annealed at 900°C

48 h [2002Hir1], and in Co11Ni16.5Al72.5

alloy, annealed at 900°C (40 h) [2002Hir1];

in Co14.5Ni14.5Al71 alloy, annealed at

1000°C 65 h [2002Hir2];

in Co14.5Ni14.5Al71 alloy, annealed at

900°C 72 h [2002Hir1];

stable variants of decagonal phase in range

9.5 to 16 at.% Ni, 11 to 20 at.% Co, 70 to

72.5 at.% Al, in as-cast and annealed at 800

to 1000°C alloys

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

268


MSIT®

Al–Co–Ni

*n is a parameter of periodicity

< 900°C 1D

PD1

PD2

PD3

PD4

PD5

n = 3070

pseudo-decagonal

a = 3900

b = 800

c = 3800

a = 3900

b = 800

c = 3800

a = 3900

b = 800

c = 3800

a = 3900

b = 800

c = 3800

a = 3900

b = 800

c = 3800

one-dimensional quasicrystal, in range 18

to 22 at.% Co, 70-71.5 at.% Al;

in range 9.5 to 16 at.% Ni, 11 to 20 at.%

Co, 70 to 72.5 at.% Al in as-cast and

annealed at 800 to 1000°C alloys

[1998Gru2]

* 2,

< 880

oI96

Immm

a = 1206.46

b = 755.53

c = 1535.3

a = 1252

b = 802

c = 1526

Co2NiAl9, called as Y2 [1998Gri];

6 to 8.5 at.% Ni, 75 at.% Al [1998Goe];

Co17Ni8.2Al74.8, quenched after annealing

at 850°C 3 d [1998Gri]

Co19Ni6Al75, quenched after annealing at

600°C (30 d) [1998Gri]

* 3,

< 1002

orthorhombic (?)

triclinic d1 = 735

d2 = 583

d3 = 364

d1^d2 = 74.3°

d2^d3 = 80.5°

Co18.5Ni14.0Al67.5, called as X

[1991Kek], the overall composition range:

7 to 16 at.% Ni, 69 to 69.5 at.% Al

[1998Goe];

[1991Kek];

[1997Goe3]

“W-CoNiAl” Cm a = 3966.8

b = 815.8

c = 2339.2

= 90.05°

in Co20Ni7.5Al72.5 alloy annealed at 950°C

20 d [2002Sug]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

269


MSIT®

Al–Co–Ni

Table 2: Invariant Equilibria in the Al-CoAl-NiAl Subsystem


Al Co Ni

L + 1 1175 p3(max) L

1

72

55

71

25

35

26

~3

10

~3

L + Co2Al5 + 1 1160 U2 L

Co2Al5

1

76.0

55.0

72.0

71.5

23.5

35.5

26.0

25.0

1.5

9.5

2.0

3.5

L + Co2Al5 Z + 1 1136 U3 L

Co2Al5Z

1

77.5

72.0

74.8

73.0

21.5

26.0

24.5

22.5

1.0

2.0

0.7

4.5

L + Z Y + 1 1080 U4 L

Z

Y

1

79.0

74.5

75.0

73.0

18.0

24

23.5

22.0

3.0

1.5

1.3

5.0

L + + 1 1048 U5 L

1

76.0

56.5

59.5

69.5

5.0

12.5

10.0

9.5

19.0

31.0

30.5

21.0

+ Co2Al5 + 1 3 1002 P1

Co2Al5

1

3

55

72.0

71.5

69.5

22.5

26.0

23.0

23.5

22.5

2

5.5

7.0

L + O-Co4Al13 Y + Co2Al9 950 U6 L

O-Co4Al13

Y

Co2Al9

87.5

76.0

75.5

82.0

9.5

22.5

22.0

16.5

3

1.5

2.5

1.5

+ 2 3 + 918 U7

1

3

56.0

70.0

69.5

59.5

13.5

14.0

15.0

9.5

30.5

16.0

15.5

31.0

L + Y 1 + Co2Al9 906 U8 L

Y

1

Co2Al9

85.0

75.5

73.5

82.0

6.7

18.0

16.0

13.0

8.3

6.5

10.5

5.0

L + + 1 900 P2 L

1

84.0

63.0

70.0

75.0

1.0

1.5

6.5

2.4

15.0

35.5

23.5

22.6

L + 1 Co2Al9 + 888 U9 L

1

Co2Al9

85.0

73.0

82.0

75.0

2.5

13.5

13.5

5.6

12.5

13.5

4.5

19.0

270


MSIT®

Al–Co–Ni

Table 3:Enthalpies of Formation Hf of the Ordered phase with Compositions (Co1-xNix)0.50Al0.50,

(Co1-xNix)0.58Al0.42 with 0 x 1 and Co0.15Ni0.30Al0.55 with B2 (cP2) Structure at 1073 K,

Referred to Solid Ni (Nis), Solid Co (Cos) and Liquid Al (All), [1998Gru1]

Y + 1 + Co2Al9 2 880 P3 Y

1

Co2Al9

2

75.5

73.0

82.5

75.0

18.0

16.5

13.0

16.5

6.5

10.5

4.5

8.5

1 + Co2Al9 2 + 860 U10 1

Co2Al9

2

73.0

82.5

75.0

75.0

14.0

13.0

16.0

10.0

13.0

4.5

9.0

15.0

+ 3 + ’ 850 P4

3

’

56.0

69.0

60.0

57.0

13.5

15.1

9.0

13.0

30.5

16.0

31.0

30.0

+ 3 Co2Al5 + ’ 750 U11

3

Co2Al5’

56.5

69.0

71.5

60.0

22.0

20.5

23.0

20.0

21.5

10.5

5.5

20.0

L Co2Al9 + (Al) + 643 E1 L

Co2Al9(Al)

97.3

91.8

99.6

75.2

0.2

13.0

0.1

0.4

2.5

5.2

0.2

24.4

Composition of the phase (B2) HfB2 [kJ mol-1] Reaction of formation

Co0.50Al0.50

Co0.42Ni0.08Al0.50

Co0.38Ni0.20Al0.42

Co0.29Ni0.29Al0.42

Co0.25Ni0.25Al0.50

Co0.20Ni0.38Al0.42

Co0.17Ni0.33Al0.50

Co0.15Ni0.30Al0.55

Co0.13Ni0.37Al0.50

Co0.08Ni0.42Al0.50

Ni0.50Al0.50

66.05 ± 0.05

66.31 ± 0.10

54.25 ± 0.08

55.10 ± 0.15

67.24 ± 0.06

57.39 ± 0.14

68.48 ± 0.06

66.73 ± 0.07

66.65 ± 0.32

70.04 ± 0.12

71.27 ± 0.13

Cos + All B2

Cos + Nis + All B2

Cos + Nis + All B2

Cos + Nis + All B2

Cos + Nis + All B2

Cos + Nis + All B2

Cos + Nis + All B2

Cos + Nis + All B2

Cos + Nis + All B2

Cos + Nis + All B2

Nis + All B2


Al Co Ni

271


MSIT®

Al–Co–Ni

Table 4: Melting Enthalpies Hfus, Melting Temperatures Tfus and Melting Entropies Sfus of

Quasiperiodic and Periodic Phases [1999Hol]

Alloy Composition Heat Treatment Phase Hfus [kJ mol-1] Tfus [K (°C)] Sfus [J mol-1 K-1]

Co21.8Ni5.5Al72.7

Co18Ni9.5Al72.5

Co14.5Ni14.5Al71

Co18Ni7Al75

Co21Ni5Al74

1373 K (1100°C),

24 h

1273 K (1000°C),

119 h

1073 K (800°C),

75 h

1148 K (875°C),

90 h

1173 K (900°C),

190 h

D

D

D

Y

Z

13.1 ± 0.4

10.4 ± 0.3

10.3 ± 0.3

14.2 ± 0.4

14.4 ± 0.4

1440 ± 5

(1167 ± 5)

1383 ± 5

(1110 ± 5)

1400 ± 5

(1127 ± 5)

1368 ± 5

(1095 ± 5)

1405 ± 5

(1132 ± 5)

9.1 ± 0.6

7.5 ± 0.5

7.4 ± 0.5

10.4 ± 0.7

10.3 ± 0.8

Al-Co

l γ + β1400 e

1

Al-Co-Ni

L + γ β + γ´1369<T<1372 U1

Al-Ni

l + γ γ´

1372 p1

l γ + γ´

1369 e2

β + γ + γ´

Fig. 1: Al-Co-Ni.

Reaction scheme in

the partial Co - CoAl

- NiAl - Ni system

272


MSIT®

Al–Co–Ni

Fig. 2a: Al-Co-Ni. Reaction scheme in the Al - CoAl - NiAl subsystem

L + β τ1

1175 p3(max)

β + Co2Al

5+ τ

1τ3

1002 P1

Al-Co Al-Co-Ni Al-Ni

l + β δ1138 p

5

L + Y O-Co4Al13

1092 p7

l + Ζ Y

1127 p6

l + (Co2Al

5) Z

1153 p4

l + β Co2Al

5

1182 p2

L + Co2Al

5 Z + τ

11136 U

3

L + Z Y + τ1

1080 U4

β + τ1

τ3 + σ918 U

7

L + β δ + τ1

1048 U5

L + O-Co4Al

13Y + Co

2Al

9950 U

6

L + β Co2Al

5 + τ

11160 U

2

L + Y τ1 + Co

2Al

9906 U

8

L + O-Co4Al

13Co

2Al

9

970 p8

L + β τ1

L + β τ1

L Co2Al

5+ τ

1

β + Co2Al

5 + τ

1

L Z + τ1

Co2Al5 + Z + τ

1

Z + Y + τ1

L + Y τ1

L β + τ1β + δ + τ

1

β + τ1 + τ

3

Co2Al

5 + τ

1 + τ

3

β + Co2Al

5 + τ

3

L Y + Co2Al

9O-Co

4Al

13 + Y + Co

2Al

9

τ1 + τ

3+ δβ + τ

3+ δ

Y + τ1 + Co

2Al9 L τ

1 + Co

2Al

9

273


MSIT®

Al–Co–Ni

Fig. 2b: Al-Co-Ni. Reaction scheme in the Al - CoAl - NiAl subsystem

β + τ3 + δ β´850 P

4

Al-Co Al-Co-Ni Al-Ni

L+τ1

Co2Al9+ε888 U

9

Y+τ1+Co

2Al9

τ2

880 P3

L Co2Al

9+ (Al) + ε643 E

1

τ1+Co

2Al

9τ2+ε860 U

10

β + τ3 Co

2Al

5+ β´750 U

11

L + δ + τ1

ε900 P2

L + O-Co4Al

13Co

2Al

9

970 p8

L + τ1

ε

L + τ1

Co2Al

9

τ1 + Co

2Al

9 + ε

Y + τ1 + τ

2

β + τ3 + β´

τ3 + δ + β´

β + δ + β´

τ3 + Co

2Al

5+ β´ β + β´ + Co

2Al

5

Co2Al

9 + (Al) + ε

l (Al) + ε644 e

4

β + δ β´

702 p10

L + δ ε856 p

9

δ + τ1 + ε L + δ ε

Y + τ2 + Co

2Al

9

τ1

+ Co2Al

9+ τ

2

L Co2Al9

+ ε

τ1 + τ

2+ ε τ

2 + Co

2Al

9+ ε

274


MSIT®

Al–Co–Ni

20

40

60

80

20 40 60 80

20

40

60

80

Co Ni


Axes: at.%

1460

1440

1420 14001380

1480

e1

1400

e2

1360

1440

14801520

p1

γ

β

εU1

10

20

30

10 20 30

70

80

90

Co 38.00Ni 0.00Al 62.00

Co 0.00Ni 38.00Al 62.00

Data / Grid: at.%

Axes: at.%

τ1

β

Co2 A

l9

ε

(Al)

Y

δ

O

mCo2Al5

p8

p7

p6p4

p2

P3

U6

U8

U9 P2

p9

p5

U5

U4

U3

U2

e4

E1

e3

700

750

800850

900

950

9501000

105011001150

1500

14001300

1200

1500

1400

1300

1150 1100

1250

1050

1000

950

Al

Fig. 3: Al-Co-Ni.

Liquidus surface of

the partial

Co-CoAl-NiAl-Ni

system with less than

35 at.% Al

Fig. 4: Al-Co-Ni.

Liquidus surface of

the partial

Co-CoAl-NiAl

system

275


MSIT®

Al–Co–Ni

Co 5.00Ni 0.00Al 95.00

Co 0.00Ni 5.00Al 95.00

Data / Grid: at.%

Axes: at.%

Co2Al9

(Al)

E1

e3

e4

ε

Al

20

40

60

80

20 40 60 80

20

40

60

80

Co Ni


Axes: at.%

β

γ

γ´

γ´+β

γ+β

γ+γ´

β,NiAlβ,CoAl

Fig. 5: Al-Co-Ni.

Liquidus surface of

the Al-corner with

more than 95 at.% Al

Fig. 6: Al-Co-Ni.


the Co-CoAl-NiAl-Ni

partial system at

1300°C

276


MSIT®

Al–Co–Ni

20

40

60

80

20 40 60 80

20

40

60

80

Co Ni


Axes: at.%

β β,NiAlβ,CoAl

γ

γ´

γ´+β

γ+γ´

γ+β

Fig. 7: Al-Co-Ni.


the Co-CoAl-NiAl-Ni

partial system at

1100°C

20

40

60

80

20 40 60 80

20

40

60

80

Co Ni


Axes: at.%

β

γ

γ´+β

γ´

γ+γ´

γ+β

β,NiAlβ,CoAl

Fig. 8: Al-Co-Ni.


the Co-CoAl-NiAl-Ni

partial system at

900°C

277


MSIT®

Al–Co–Ni

20

40

60

80

20 40 60 80

20

40

60

80

Co Ni


Axes: at.%

γ

β,NiAlββ,CoAl

γ´

γ+β β+γ´

γ+β+γ´

γ+γ´

30

40

10 20

60

70

Co 50.00Ni 0.00Al 50.00

Co 20.00Ni 30.00Al 50.00

Co 20.00Ni 0.00Al 80.00 Data / Grid: at.%

Axes: at.%

L

β

Co2Al5

τ1

Co2Al5+β L+βL+β

τ1+β

L+β+Co2Al5

L+Co2Al5

L+τ1

Fig. 9: Al-Co-Ni.

Diagram of phase

compositions of the

Co-CoAl-NiAl-Ni

alloys slowly cooled

to room temperature

Fig. 10: Al-Co-Ni.


the Al-CoAl-NiAl

partial system at

1170°C

278


MSIT®

Al–Co–Ni

10

20

30

40

10 20 30 40

60

70

80

90

Co 50.00Ni 0.00Al 50.00

Co 0.00Ni 50.00Al 50.00

Data / Grid: at.%

Axes: at.%

L

τ1

β

δ

L+δτ

1+β

L+τ1

Co2Al5+β

OM

ZCo2Al5

Y

β+δ

Al

10

20

30

40

10 20 30 40

60

70

80

90

Co 50.00Ni 0.00Al 50.00

Co 0.00Ni 50.00Al 50.00

Data / Grid: at.%

Axes: at.%

τ1

L

β

δ

L+δ

L+β

L+τ1

YZ

Co2Al5

Co2Al5+βτ

1+β

L+Y

Al

Fig. 12: Al-Co-Ni.


the Al-CoAl-NiAl

partial system at

1050°C

Fig. 11: Al-Co-Ni.


the Al-CoAl-NiAl

partial system at

1100°C

279


MSIT®

Al–Co–Ni

10

20

30

40

10 20 30 40

60

70

80

90

Co 50.00Ni 0.00Al 50.00

Co 0.00Ni 50.00Al 50.00

Data / Grid: at.%

Axes: at.%

Y

L

τ1

τ3

Co2Al9

OMZ

Co2Al5

L+Co2Al9

L+τ1

β

β+Co2Al5

β+τ3

δ

β+δ

ε

τ1+δ

L+δ

P2

Al

10

20

30

40

10 20 30 40

60

70

80

90

Co 50.00Ni 0.00Al 50.00

Co 0.00Ni 50.00Al 50.00

Data / Grid: at.%

Axes: at.%

L

δ

β+δ

τ1

Yε

L+ε

ε+δ

L+Co2Al9

Co2Al9

OM

ZCo2Al5

Co2Al5+βτ

3+β

τ3

τ2

τ1+ε

P4

β

Al

Fig. 13: Al-Co-Ni.


the Al-CoAl-NiAl

partial system at

900°C

Fig. 14: Al-Co-Ni.


the Al-CoAl-NiAl

partial system at

850°C

280


MSIT®

Al–Co–Ni

10

20

30

40

10 20 30 40

60

70

80

90

Co 50.00Ni 0.00Al 50.00

Co 0.00Ni 50.00Al 50.00

Data / Grid: at.%

Axes: at.%

τ1

τ3

L

Co2Al9

OMZ

Co2Al5

L+C

o 2A

l 9

ε

L+Co2Al9+ε

δ

ε+δ

Y

β

β´

τ3+β´

β+Co2Al5

τ1+ε

τ1 +δ

τ2

Al

10

20

30

40

10 20 30 40

60

70

80

90

Co 50.00Ni 0.00Al 50.00

Co 0.00Ni 50.00Al 50.00

Data / Grid: at.%

Axes: at.%

ε

τ1

δ

β´

Y

Co2Al9

OMZ

Co2Al5

τ3

τ2

Co2Al9+(Al)+ε

ε+δ

β

Co2Al5+βτ

3+β´

τ1+ε

Co 2

Al 9+(

Al)

τ1+ε+δ

τ3+δ+β´

δ+β´

(Al)Al

Fig. 15: Al-Co-Ni.


the Al-CoAl-NiAl

partial system at

730°C

Fig. 16: Al-Co-Ni.


the Al-CoAl-NiAl

partial system at

600°C

281


MSIT®

Al–Co–Ni

10 20 30 400

250

500

750

1000

1250

1500

Co 20.00Ni 80.00Al 0.00

Co 11.00Ni 44.00Al 45.00Al, at.%

Tem

pera

ture

, °C

βγγ+β

γ´+β

γ´

γ+γ´

L

600

700

800

900

Co 3.00Ni 0.00Al 97.00

Co 0.00Ni 3.00Al 97.00Ni, at.%

Tem

pera

ture

, °C

L+Co2Al9

L+(Al)+Co2Al9

E1,643

L

e4

(Al)+ε

e3

(Al)+Co2Al9(Al)+Co2Al9+ε

L+Co2Al9+εL+(Al)

L+(Al)+ε

Fig. 17: Al-Co-Ni.

Polythermal section

within the Co:Ni =

20:80 atomic ratio in

Co-Ni edge of the

ternary system

Fig. 18a:Al-Co-Ni.

Polythermal section

of the Al-AlCo-AlNi

partial system at 97

at.% Al

282


MSIT®

Al–Co–Ni

600

700

800

900

Co 7.50Ni 0.00Al 92.50

Co 0.00Ni 7.50Al 92.50Co, at.%

Tem

pera

ture

, °C

L+Co2Al9

(Al)+Co2Al9

E1,643

(Al)+Co2Al9+ε

e3

e4

L

L+εL+Co2Al9+ε

(Al)+ε

L+(Al)+ε

2.0 4.0 6.0

10600

700

800

900

1000

1100

1200

Co 15.00Ni 0.00Al 85.00

Co 0.00Ni 15.00Al 85.00Ni, at.%

Tem

pera

ture

, °C

(Al)+Co2Al9+ε

L+Co2Al9L+Co2Al9+ε

e4

e3 E1,643

(Al)+ε

L+ε

L+(Al)+ε

(Al)+Co2Al9

L

p8

L+O

L+O+Y

L+Y

L+O+Co2Al9

L+Y+Co2Al9

Fig. 18b:Al-Co-Ni.

Polythermal section

of the Al-AlCo-AlNi

partial system at 92.5

at.% Al

Fig. 19a:Al-Co-Ni.

Polythermal section

of the Al-AlCo-AlNi


at.% Al

283


MSIT®

Al–Co–Ni

10600

700

800

900

1000

1100

1200

Co 20.00Ni 0.00Al 80.00

Co 0.00Ni 20.00Al 80.00Ni, at.%

Tem

pera

ture

, °C

τ2+Y+

τ1+Y+

(Al)+Co2Al9+ε

Co2Al9

Co2Al9+τ1+ε

τ 2+ε+

L+τ1+ε

Co2Al9+τ1

L+Co2Al9+τ1 L+δ

L+ε+δ

L+ε

e4

ε+Co2Al9

U9,888

900

L+ZL+Z+Y

L+Y

U6,950

L+Y+τ1

U10

860P3,880

E1,643

L+Y+Co2Al9p8

p7

P2p9

U8,906

Co2Al9

τ1+τ2+Co2Al9

Y+Co2Al9

τ2+Co2Al9

O+Co2Al9

O+Y+Co2Al9

L+O+Y

L+OL+τ1 L+τ1+δ

L+Co2Al9+ε

p6

L

Co2Al9

10 20600

700

800

900

1000

1100

1200

1300

Co 25.00Ni 0.00Al 75.00

Co 0.00Ni 25.00Al 75.00Ni, at.%

Tem

pera

ture

, °C

L+Co2Al5+βL+Z+τ1

Co2Al9+τ2+τ1

L+ L+δ

L+δ+βL+τ1+β

Co2Al9+τ1

Co2Al9+ε+τ1

τ2+ε+

τ1+τ2+ετ2+ε

U10,860

L+β

L+Y+τ1

Z+Y+mτ2+Co2Al9

Y+τ2+

Y+τ1

Y+τ1+τ2

p2p4p6

Y+τ2

P2,900

τ1+δ

L

U5,1048

U9,888P3,880

U8,906

ε

L+τ1+ε

Y

Co2Al9

Z+Y

Z+m

L+Co2Al9+τ1

Co2Al9+Y+τ1

p7 1080

U3,1136

L+β+τ1

L+β

U4

L+ε+δ

L+τ1

Co2Al9

p9

Fig. 20a:Al-Co-Ni.

Polythermal section

of the Al-AlCo-AlNi


at.% Al

Fig. 19b:Al-Co-Ni.

Polythermal section

of the Al-AlCo-AlNi


at.% Al

284


MSIT®

Al–Co–Ni

10 20600

700

800

900

1000

1100

1200

1300

Co 22.00Ni 0.00Al 78.00

Co 0.00Ni 22.00Al 78.00Ni, at.%

Tem

pera

ture

, °C

L

L+τ1

L+ε+τ1

L+δ

L+Co2Al9+Y

L+Co2Al9+τ1

L+ε

L+ε+Co2Al9

Co2Al9+ετ2+ε+Co2Al9Co2Al9+Y

Y+Co2Al9+τ2

L+Z

L+Z+τ1

e4

p9

E1,643

(Al)+ε+Co2Al9

P2,900

U10,860

U8,906

U9,888P3,880

τ2+Co2Al9

τ1+ε+Co2Al9

Co2Al9+τ1+τ2

Co2Al9+Y+τ1

L+Y+τ1

Co2Al9+τ1

L+Y

Co2Al9+O+YCo2Al9+O

L+δ+τ1L+O

L+O+Y

p8

p7

U6,950

U4,1080

p6

10 20600

700

800

900

1000

1100

1200

1300

Co 30.00Ni 0.00Al 70.00

Co 0.00Ni 30.00Al 70.00Ni, at.%

Tem

pera

ture

, °C

L+β

L+β+δ

L+δ

L+ε+δ

L+τ1+δ

τ1+ε+δ

β+τ1

τ1+β+τ3

τ1+τ3

β+τ1+Co2Al5

L+β+Co2Al5

1160

L+β+τ1

1048

P2,900

τ1+τ3+ε

τ1+ε

+τ3+β

Co2Al5+β

U2

L+β+τ1

U5

L+τ1

τ1+τ3+

β+β'

Co2Al5+β'

τ3+β'+

U11

p5

p2

p9

P1,1002

τ1

750

τ3+Co2Al5

Co2Al5

Co2Al5

Co2Al5+

Co2Al5

L

p3,1175

ε+δ

Fig. 21a:Al-Co-Ni.

Polythermal section

of the Al-AlCo-AlNi


at.% Al

Fig. 20b:Al-Co-Ni.

Polythermal section

of the Al-AlCo-AlNi


at.% Al

285


MSIT®

Al–Co–Ni

10 20600

700

800

900

1000

1100

1200

1300

Co 28.50Ni 0.00Al 71.50

Co 0.00Ni 28.50Al 71.50Ni, at.%

Tem

pera

ture

, °C

L+β

L+β+Co2Al51160

L+β

L+β+δ

L+β+τ1

U4,1048 L+δ

L+ε+δ

L+τ1+δ

L+τ1+ε

τ1+ε+δ

τ1+ε

P2,900

1002

τ3+Co2Al5τ1+τ3+

Co2Al5+τ3+β

Co2Al5+β'Co2Al5+β+β'

Co2Al5+τ3+β'U11

Co2Al5 P1

p3 L+β+τ1

L

L+τ1

p9

p7

p2

750

τ1+τ3

τ1

Co2Al5

U2

β+τ1

β+τ1+Co2Al5β+

ε+δ

β+τ1+τ3

10 20600

700

800

900

1000

1100

1200

1300

Co 27.50Ni 0.00Al 72.50

Co 0.00Ni 27.50Al 72.50Ni, at.%

Tem

pera

ture

, °C

τ1

L

L+τ1

L+β

1048

P2,900

p9

p2

p4p5

L+β+τ1L+β+δ

1136

Z+Co2Al5 τ1+Z

τ1+Z+

τ1+ε τ1+ε+δ

L+βL+Co2Al5

L+β+Co2Al5

L+β+τ1

L+τ1+Co2Al5

L+τ1+ε

L+ε+δ

L+δ

U5

U2,1160

U3

L+τ1+δ

Co2Al5 ε+δ

Fig. 22: Al-Co-Ni.

Polythermal section

of the Al-AlCo-AlNi


at.% Al

Fig. 21b:Al-Co-Ni.

Polythermal section

of the Al-AlCo-AlNi


at.% Al

286


MSIT®

Al–Co–Ni

60 70 80600

700

800

900

1000

1100

1200

1300

Co 40.00Ni 10.00Al 50.00

Co 0.00Ni 10.00Al 90.00Al, at.%

Tem

pera

ture

, °C

L+β+τ1

L+τ1

Y+τ1+Co2Al9

β+τ1+Co2Al5

Co2Al5+β

Co2Al5+β+β'Co2Al5+β'

Co2Al5+τ3+β'

Co2Al5+τ3Co2Al5+τ1+τ3

Co2Al5+τ1

U11

P1,1002

τ1+Co2Al9+ε

Co2Al9+ετ2+Co2Al9+ε

L+Co2Al9+ε

(Al)+ε+Co2Al9

L+τ1+Co2Al9

L+Y+τ1

β+τ1

τ1

τ3+βCo2Al5+τ3+β

τ2+ε

τ1+τ2

τ2+τ1

L+Co2Al9

τ1+Y

τ1+τ2+Co2Al9750

τ1+τ3+β

L+β

τ1+Co2Al9

τ1+τ2+Y

L+ε

L

β

+ε

60 70 80600

700

800

900

1000

1100

1200

1300

Co 33.00Ni 13.00Al 54.00

Co 3.00Ni 13.00Al 84.00Al, at.%

Tem

pera

ture

, °C

L+β+τ1

β+τ1

τ1+τ3+β

τ3+β

τ3+β+β'

τ3+β´

Co2Al5+τ3+β'

Co2Al5+β+β'

Co2Al5+β'

Co2Al5+β

τ1+β+Co2Al5

U11,750

860

L+Co2Al9+ε

(Al)+ε+Co2Al9

τ1+ε

τ2+ε

τ1+τ2+ε

P1,1002

U9,888

E1,643

L+τ1

L+τ1+ετ1+Co2Al9+ε

P3,880Co2Al9+ε

Co2Al9+

L+β

L

τ1+τ3

τ1

τ3

Co2Al5+τ3+β

+ε+τ2

β

Fig. 23b:Al-Co-Ni.

Polythermal sections

of the Al-AlCo-AlNi


at.% Ni

Fig. 23a:Al-Co-Ni.

Polythermal sections

of the Al-AlCo-AlNi


at.% Ni

287


MSIT®

Al–Co–Ni

1 3 10 30

10-3

10-2

10-1

100

T(K)

Cp(JmolK)

-1-1

0 2 4 6 8 10

0.60

0.65

0.70

0.75

T2 2(K )

Cp

/T(mJmolK)

-1-2

Fig. 24b:Al-Co-Ni.

Specific heat of

decagonal

Al71Ni16Co13

quasicrystal vs

temperature;

between 1.5 and 3 K

[Cp/T vs T2]; after

[1998Bia]

Fig. 24a:Al-Co-Ni.

Specific heat of

decagonal

Al71Ni16Co13

quasicrystal vs

temperature; between

1.5 and 36 K [Cp vs

T(K)]; after [1998Bia]

288


MSIT®

Al–Co–Ni

0.4

0.6

0.8

1.0

1.3

0 2 4 6 8

0.2

0

-0.2

-0.4

-0.6

-0.8

Co, at.%

Partitioncoefficient,Kxg/

g´

lnKxg/

g´

40 42 44 46 48 50 52 54 56

285

286

287

288

289

Latticespacing,pm

Al, at.%

Co Al

Ni Co = 37

Ni Co = 11

Ni Co = 41

Ni Al

Fig. 25: Al-Co-Ni.

Partition coefficient

between and

phases vs Co content

at 1100°C after

[1994Jia]

Fig. 26: Al-Co-Ni.

Partition coefficient

between and

phases vs Co content

at 1100°C after

[1994Jia]

289


MSIT®

Al–Co–Ti

Aluminium – Cobalt – Titanium

Kazuhiro Ishikawa, Ryosuke Kainuma and Kiyohito Ishida

Literature Data

This evaluation updates and modifies in parts the thoroughly made critical evaluation by [1991Sch] in the

same MSIT Ternary Evaluation Program. The Al-Co-Ti system was first investigated by [1966Mar], who

prepared 110 alloys, melted from iodide titanium (99.97%), cobalt (99.9%) and aluminum (99.997%) under

helium in an arc furnace with W-electrode, using a water cooled copper mould. The whole ternary system

was determined by thermal, X-ray, and dilatometric analysis together with hardness and specific electrical

resistivity measurements (only for Ti-rich alloys). The samples were annealed at 800°C and 600°C for 1

month in evacuated silica ampoules containing Ti-chips. The authors found two ternary phases: TiCo2Al

and another one called Ti2CoAl2, reported with a small range of homogeneity. The samples annealed at

600°C had compositions identical to those annealed at 800°C. The phase TiCo2Al is a Heusler phase

[1962Mar, 1963Gla, 1967Hof], the phase Ti2CoAl2 is of the Th6Mn23 type [1969Mar], the latter paper

gives an approximate composition TiCoAl2. A Japanese group [1967Tsu, 1968Tsu] studied the equilibria

in the Ti-rich corner (more than 80 mass% Ti) between 1100 and 600°C. Commercially pure Ti-sponge

(99.8%), Co (99.54%) and Al (99.99%) were melted in an argon arc furnace. Alloys with more than 85

mass% Ti were hot rolled between 1000 and 800°C to eliminate the as-cast structure. The specimens for

microscopic examination were heat treated in argon filled silica capsules and subsequently quenched in

water. Annealing times: 8 h at 1100°C, 1 day at 1050°C or 1 week at 1000°C. The specimens quenched from

below 950°C were cooled in stages from 1000°C to the annealing temperature, being held for 1 week at

1000°C and then 1 week at 950°C, then 2 weeks at 900°C and 950°C and 1 month at 800, 750, 700, 650 and

600°C. For X-ray diffraction the specimens were heated in vacuum for 1 h to the required temperature and

quenched [1967Tsu]. Eleven isothermal sections and nine isopleths of the Ti-rich corner with more than 80

mass% Ti were constructed [1968Tsu]. The paper [1967Tsu] is a short version of [1968Tsu] with five

isothermal and four vertical sections. In two further papers [1969Tsu1, 1969Tsu2] the investigations were

extended to 70 mass% Al+Co. In [1972Tsu] these two papers are combined in an English translation

containing the same diagram and micrographs. From 111 alloys, most of them chemically analyzed, the

liquidus surface as well as 6 isothermal sections were constructed, covering the partial system with less than

50 mass% Al and more than 30 mass% Ti. The authors reported a continuous solid solution (Ti,Al)Co

between TiCo and AlCo although the reported alloys cover only part of this range. The three phase fields

L+(Ti,Al)Co+ 2 and L+ 2+TiAl have maxima with the reactions L+(Ti,Al)Co 2 and L 2+TiAl

respectively. Phase equilibria in the Al-Ti portion were determined by [2000Kai]. The alloys prepared by

arc melting were equilibrated at 1300°C for 1 day, 1200°C for 7 days and 1000°C 7 days in a evacuated

quartz tube back-filled with Ar with Ti filings as getters. The equilibrium compositions were determined by

EPMA with standard calibration method. The phase equilibria in the Co-Ti portion were investigated by

[2001Ish]. Twenty six alloys were prepared with pure elements by arc melting under an Ar atmosphere. The

alloys were sealed in a quartz tube with a titanium getter and equilibrated at 1100°C for 7 days, 1000°C for

14 days and 900°C for 21 days. The equilibrium compositions were determined by energy dispersive

spectroscopy (EDS) using standard calibration method. The phase 2, contrary to [1966Mar], is assumed to

have a large range of homogeneity by Ti to Al exchange. Six invariant four-phase reactions were found. By

X-ray diffraction it is not possible to distinguish between the hexagonal ( Ti) phase and Ti3Al which is

ordered. Therefore no ordering reflections were observed by [1972Tsu]. By thermal analysis, X-ray

diffraction reflections and metallography of 16 as-cast alloys [1979Sei] constructed the whole liquidus

surface. It was stated that the results of [1967Tsu] and [1972Tsu] were used to construct the phase diagram,

but the lines of double saturation in this diagram differ significantly from those of [1972Tsu], although the

alloys reported are not at all sufficient to prove these differences. The Al-rich part was not assessed but

estimated to be similar to the Al-Fe-Ti system, assessed in the same paper and to match the known binary

systems. Three ternary phases 1-TiCo2Al, 2-Ti1-xCoAl2-x and 3-Ti8Al22Co3 were found by [1979Sei].

290


MSIT®

Al–Co–Ti

She indicated a field of primary crystallization of the Heusler-cF16 type phase TiCo2Al, which implies that

there is no continuous solid solution between CoAl and TiCo in contradiction to [1969Tsu1, 1969Tsu2,

1972Tsu] and [1986Zas]. Several works [1962Mar, 1963Gla, 1967Mar, 1967Hof, 1973Web, 1984End,

1993Nak] contributed to the crystal structure and the lattice parameter of the Heusler phase TiCo2Al. The

phase equilibria in the TiCo-TiCo2Al-CoAl pseudo-binary section (Co = 50 at.%) were determined by

[2002Ish1] using the diffusion couple method. The TiCo/TiCo2Al and TiCo2Al/CoAl couples were

equilibrated for 2 days at 1300°C, 14 days for 1200°C and 21 days at 1100°C. From the

concentration-penetration profiles obtained by EDS analysis, it was confirmed in the TiCo-CoAl

pseudo-binary section that a continuous ordering from the CsCl (B2) type to Heusler (L21) phase exist on

both the TiCo and CoAl sides. The phase equilibria in the TiCo-TiCo2Al section (Co = 52 at.%) were also

investigated by [2003Kaw] correlating microstructures and mechanical properties. Their alloys were

prepared by arc melting and homogenized in a vacuum at 1200°C for 2 days, then annealed at 700 - ~900°C.

Transmission electron microscopic observation was carried out to detect the anti-phase domain structure

introduced during the ordering reaction in the as-quenched alloys. These studies also confirmed the

continuous ordering reaction in the TiCo-TiCo2Al section.

A detailed refinement of the crystal structure of the 2 phase has been performed by [2003Gry] employing

X-ray single crystal- and neutron powder diffraction as well as electron diffraction.

Binary Systems

The binary systems Al-Co and Co-Ti compiled by [Mas] are used as boundary systems. The Al-Ti system

[1989Pri] is based on the critical assessment of Murray [1987Mur], but corrected with the results

[1989McC] for the range of 40 to 55 at.% Al and [1989Kal] for the range of 65 to 75 at.% Al. This phase

diagram is shown in Fig. 1.


The TiCo-CoAl section is reported by [2002Ish1] and [2003Kaw] to be a pseudobinary one and shown in

Figs. 12 and 13 by dashed lines.

Solid Phases

The reported binary phases and the ternary phases are represented in Table 1. The solid solubility of Co in

(Ti) and Ti3Al is less than 5 at.% Co at 800°C [1966Mar]. There are conflicting assumptions on the solid

solution between TiCo and CoAl and the observation of the ternary Heusler phase TiCo2Al, which is an

ordered form of the CsCl-solid solution “Co(Ti,Al)”. Complete solid solubility is claimed by [1972Tsu],

although the experimental points cover only the Co-rich part. An enthalpy vs concentration curve of the

CoAl-TiCo section which shows no interruption by a two phase field was reported by [1986Zas]. Since the

Heusler phase is a superstructure of the CsCl type, the distinction between both phases was possibly not

well established. The ternary phase 3 [1979Sei] was not found by [1966Mar] and is outside the ranges

investigated by other authors. But since similar phases exist in Al-Ni-Ti and Al-Cu-Ti [1965Ram], its

existence is very probable. The solvus of the ( Ti) phase was determined by [1967Tsu], it is shown in Fig. 2.

The refinement of the crystal strucure of the 2 phase gives as formula: Ti27.5Co23.4Al49.1 , its structure type

has been determined as Mg6Cu16Si7, a filled variant of the Th6Mn23 type.


The partial reaction scheme after [1972Tsu], corrected to the accepted binaries, is given in Fig. 3. A reaction

scheme given by [1979Sei] is partially in contradiction to that of [1972Tsu] and to the accepted Al-Ti binary

system. In the reaction scheme in Fig. 3 a continuous solid solution (Ti,Al)Co is assumed, from which the

Heusler phase TiCo2Al may form at lower temperatures.

291


MSIT®

Al–Co–Ti

Liquidus Surface

The liquidus surfaces given by [1972Tsu] and [1979Sei] disagree in many details. That of [1972Tsu] is

based on many more alloys and therefore is preferred in the construction of the liquidus surface in Fig. 4.

The remaining parts given by [1979Sei] are based on so few alloys that they can be taken only as very

tentative. Furthermore the phases TiCo3 and the two different modifications of TiCo2 are neglected in

[1979Sei].

Isothermal Sections

The isothermal sections of 1300, 1200, 1100, 1000, 900, 800 and 600°C in the Ti-rich part by [1972Tsu],

the Al-Ti corner by [2000Kai] and the Co-Ti by [2001Ish] are integrated in Figs. 5, 6, 7, 8, 9, 10 and 11,

respectively. Because of the discrepancy between [1967Tsu, 1972Tsu, 1979Sei] and [1966Mar], the

isothermal section of [1966Mar] at 800°C is not shown. For the same reason, the isothermal section at

1000°C by [1972Tsu] was replaced by one constructed on the basis of recent data [2000Kai, 2001Ish].


Nine vertical sections were constructed by [1968Tsu] in the Ti-corner.

Thermodynamics

Enthalpies of formation by solution calorimetry in liquid Al for five alloys of the section Ti1-xCoAlx were

determined by [1986Zas]. The entropies of alloys of the Ti1-xCoAlx section were determined by [1987Kra]

using low temperature (78 to 273 K) heat capacity measurements.


Magnetic measurements on the Heusler phase TiCo2Al were made by [1973Web, 1983Bus, 1984End]. For

alloy concentrations of Ti1-xCoAlx with x > 0.6 the ferromagnetic behavior changes to paramagnetic. The

Curie temperature for the TiCo2Al compound is determined as 134 K in [1983Bus] on a sample annealed

at 527°C for 14 days.

The characteristic of the electrical resistivity of the Ti32Co22Al46 compound is typical metalic and the

temperature dependence follows the Bloch-Grüneisen relation with a Debye temperature of ~300

K [2003Gry]. The residual resistivity for the Ti32Co22Al46 compound is 0.97 m cm [2003Gry].

The Ti47Co28Al25 compound can absorb up to 0.8 wt.% hydrogen (8.57 mg) [2003Gry].

Miscellaneous

The stability of the Heusler phase TiCo2Al up to the liquidus surface (1750°C) is described by [1979Sei].

The phase stability of the L21 phase in the TiCo-TiCo2Al-CoAl quasibinary section was reported by

[2002Ish2]. There, the (metastable) critical temperature of B2/L21 order-disorder transition of

stoichiometric TiCo2Al was given as 1827°C and the two tri-critical temperatures of the B2+L21

decompositions were estimated as about 1127°C. The critical compositions of the continuous ordering

evaluated by [2002Ish2] are shown in Fig. 12 superimposed on the stable melting equilibria (dashed lines).

Also shown are the assumed limits of both B2+L21 two-phase fields [2002Ish2]. [2003Kaw] describes the

ordering temperature vs composition for continuous ordering on the TiCo rich side of the section at 52 at.%

Co from ~1300 down to 600°C but does not recognize the separation into two phases B2+L21, see Fig. 13.

Note added in press

Phase equilibria at 950°C has been reported by [2000Din] based on EPMA, quantitative X-ray diffraction

and optical microscopy data for arc-melted samples annealed at 950°C for 240 hours. Note: In this work the

existence of the 3 phase has been confirmed in as-cast and annealed samples.

292


MSIT®

Al–Co–Ti

References

[1962Mar] Markiv, V.Ya., Teslyuk, M.Y., “Crystal Structure of Ternary Compounds TiCo2Al,

MgNi2Zn, TlNi2Zn and TiCu2Zn” (in Russian), Dop. Akad. Nauk Ukr. RSR, (12),

1607-1609 (1962) (Crys. Structure, 7)

[1963Gla] Gladyshevskij, E.I., Markiv, V.Ya., Kuz’ma, Yu.B., Cherkashin, E.E., “Crystal Structure of

Some Ternary Intermetallic Compounds of Titanium” (in Russian), Titan. Splavy. Izv. Akad.

Nauk SSSR, Moskva, 10, 71-73 (1963) (Crys. Structure, 10)

[1965Ram] Raman, A, Schubert, K., “On the Structure of Some Alloy Phases Related to TiAl3. III.

Investigations in Several T-Ni-Al and T-Cu-Al Alloy Systems (T = Transition Element)”

(in German), Z. Metallkd., 56, 99-104 (1965) (Experimental, Crys. Structure, 14)

[1966Mar] Markiv, V.Ya., “Phase Equilibrium in the Ti-Co-Al System”, Izv. Akad. Nauk SSSR, Met.,

(1), 156-158 (1966) (Experimental, Crys. Structure, Equi. Diagram, #, 10)

[1967Hof] Hofer, G., Stadelmaier, H.H., “Cobalt-, Nickel- and Copper-Phases of the Ternary

MnCu2Al Type” (in German), Monatsh. Chem., 98, 408-411 (1967) (Experimental, Crys.

Structure, 9)

[1967Mar] Markiv V.Ya., Kripyakevich, P.I., “Compounds of the Type R(X’,X’’)2 in Systems with

R=Ti, Zr, Hf, X’=Fe, Co, Ni, Cu and X’’=Al, Ga and their Crystal Structures”, Sov. Phys. -

Crystallogr., 11, 733-738 (1967), translated from Kristallografiya, 11, 859-865 (1966)

(Crys. Structure, 25)

[1967Tsu] Tsujimoto, T., Adachi, M., “The Titanium-Rich Corner of the Ternary Ti-Al-Co System”,

J. Inst. Met., 95, 146-151 (1967) (Experimental, Equi. Diagram, 8)

[1968Tsu] Tsujimoto, T., Adachi, M. “The Titanium-Rich Corner of the Ternary Ti-Al-Co System”,

Trans. Nat. Res. Inst. Met. (Jpn.), 10, 325-343 (1968) (Experimental, Equi. Diagram, 8)

[1969Mar] Markiv, V.Ya., Burnashova, V.V., “New Ternary Compounds in the (Sc, Ti, Zr, Hf)-(V, Cr,

Mn, Fe, Co, Ni, Cu)-(Al, Ga) Systems” (in Ukrainian), Dop. Akad. Nauk Ukr. RSR, A, (5),

463-464 (1969) (Crys. Structure, 12)

[1969Tsu1] Tsujimoto, T., Adachi, M., “Reactions with the Melt in the Titanium-Rich Region of the

Ternary Titanium-Aluminium-Cobalt System” (in Japanese), Nippon Kinzoku Gakkaishi,

33, 606-611 (1969) (Experimental, Equi. Diagram, Crys. Structure, #, 19)

[1969Tsu2] Tsujimoto, T., Adachi, M., “Reactions in the Solid State in the Titanium-Rich Region of the

Ternary Titanium-Aluminium-Cobalt System” (in Japanese), Nippon Kinzoku Gakkaishi,

33, 612-617 (1969) (Experimental, Equi. Diagram, 6)

[1972Tsu] Tsujimoto, T., Adachi, M., “The Titanium-Rich Region of the Ternary Ti-Al-Co System”,

Trans. Nat. Res. Inst. Met. (Jpn.), 14, 178-188 (1972) (Experimental, Equi. Diagram, Crys.

Structure, #, *)

[1973Web] Webster, P.J., Ziebeck, K.R.A., “Magnetic and Chemical Order in Heusler Alloys

Containing Cobalt and Titanium”, J. Phys. Chem. Solids, 34, 1647-1654 (1973) (Crys.

Structure, 26)

[1979Sei] Seibold, A., “Determination of Ternary and Quaternary Systems of Titanium for the

Development of Technical Appliable Casting Alloys” (in German), Thesis, Univ.

Erlangen-Nürnberg, (1979) (Experimental, Equi. Diagram, #, 70)

[1983Bus] Buschow, K.H.J., van Engen, P.G., Jongebreur, R., “Magneto-Optical Properties of Metallic

Ferromagnetic Materials”, J. Magn. Magn. Mater., 38, 1-22 (1983) (Magn. Prop., Optical

Prop., 23)[1984End] Endo, K., Shinogi, A., Ooiwa, K., Date, M., Hiramoto, K., “The Transitions from

Nonmagnetic State to Ferromagnetic State of Co is a Pseudobinary Alloy CoTi1-xAlx”,

J. Phys. Soc. Jpn., 53, 1487-1494 (1984) (Experimental, 12)

[1986Zas] Zasypalov, Yu.V., Kiselev, O.A., Mogutnov, B.M., “The Enthalpies of Formation of

Intermetallic Compounds CoTi1-xAlx and TiNi1-xCox (0 x 1)” (in Russian), Dokl. Akad.

Nauk SSSR, 287, 158-161 (1986) (Thermodyn., 9)

293


MSIT®

Al–Co–Ti

[1987Kra] Krasheninnikova, N.G., Mogutnov, B.M., Tomilin, I.A., Shaposhnikov, N.G.,

“Thermodynamic Properties of the Intermetallic Compounds (Ni0.5Ti0.5)x(Co0.5Ti0.5)1-x

and (Co0.5Ti0.5)x(Co0.5Al0.5)1-x at Low Temperatures”, Russ. J. Phys. Chem., 61,

1627-1630 (1987), translated from Zh. Fiz. Khim., 61, 3089-3093 (1987) (Experimental,

Thermodyn., 10)

[1987Mur] Murray, J.L., “Phase Diagrams of Binary Titanium Alloys” in “Series on Alloy Phase

Diagrams”, ASM Metals Park Ohio, (1987) (Equi. Diagram, Crys. Structure, Review, #, 93)

[1989Kal] Kaltenbach, K., Gama, S., Pinatti, D.G., Schulze, K., “A Contribution to the Al-Ti Phase

Diagram”, Z. Metallkd., 80, 511-514 (1989) (Experimental, Equi. Diagram, Crys. Structure,

#, 14)

[1989McC] McCullough, C., Valencia, J.J., Levi, C.G., Mehrabian, R., “Phase Equilibria and

Solidification in Ti-Al Alloys”, Acta Metall., 37, 1321-1336 (1989) (Experimental, Equi.

Diagram, Crys. Structure, #, 25)

[1989Pri] Prince, A., “The Al-Ti Binary Phases Diagram”, private communication (1989) (Equi.

Diagram, Review)

[1991Sch] Schmid, E.E., “Aluminium-Cobalt-Titanium”, MSIT Ternary Evaluation Program, in MSIT


Stuttgart; Document ID: 10.10909.1.20, (1991) (Equi. Diagram, Crys. Structure,

Assessment, 21)

[1993Nak] Nakayama, Y., Mabuchi, H., “Formation of Ternary L1(2) Compounds in Al3Ti-Base

Alloys”, Intermetallics, 1, 41-48 (1993) (Crys. Structure, Experimental, Equi. Diagram, 40)

[2000Din] Ding, J.J., Rogl, P., Schmidt, H., Podloucky, R., “Structure Chemistry and Constitution in

TiAl-Based Intermetallics”, Visn. L’viv. Univ., Ser. Khim, (39), 136-141 (2000) (Crys.

Structure, 12)[2000Kai] Kainuma, R., Fujita, Y., Mitsui, H., Ohnuma, I., Ishida, K., “Phase Equilibria Among

(hcp), (bcc) and (L10) Phases in Ti-Al Base Ternary Alloys”, Intermetallics, 8, 855-867


[2001Ish] Ishikawa, K., Himuro, Y., Ohnuma, I., Kainuma, R., Aoki, K., Ishida, K., “Phase Equilibria

in the Co-Ti Portion of the Co-Al-Ti Ternary System”, J. Phase Equilib., 22, 219-226

(2001) (Experimental, Equi. Diagram, #, 10)

[2002Ish1] Ishikawa, K., Mitsui, H., Ohnuma, I., Kainuma, R., Aoki, K., Ishida, K., “Ordering and

Phase Separation of BCC Aluminides in (Ni, Co)-Al-Ti System”, Mat. Sci. Eng. A, 329-331,


[2002Ish2] Ishikawa, K., Kainuma, R., Ohnuma, I., Aoki, K., Ishida, K., “Phase Stability of the X2AlTi

(X: Fe, Co, Ni and Cu) Heusler and B2-Type Intermetallic Compounds”, Acta Mater., 50,


[2003Gry] Grytsiv, A., Ding, J.J., Rogl, P., Weill, F., Chevalier, B., Etourneau, J., Andre, G., Bouree,

F., Noel, H., Hundegger, P., Wiesinger, G., “Crystal Chemistry of the G-Phases in the

Systems Ti-{Fe, Co, Ni}-Al with a Novel Filled Variant of the Th6Mn23-Type”,

Intermetallics, 11, 351-359 (2003) (Experimental, Crys. Structure, 26)

[2003Kaw] Kawai, H., Kaneko, Y., Yoshida, M., Takasugi, T., “Microstructures and Mechanical

Properties of CoTi(B2)-Co2AlTi (L21) Pseudo-Binary Intermetallic Compounds”,

Intermetallics, 11, 467-473 (2003) (Experimental, Equi. Diagram, Mechan. Prop., 17)

294


MSIT®

Al–Co–Ti


Phase /

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

(Al )

< 660

cF4

Fm3m

Cu

a = 404.88 24°C [V-C]

( Co)(h)

1495-422

cF4

Fm3m

Cu

a = 354.46 [V-C]

( Co)(r)

< 422

hP2

P63/mmc

Mg

a = 250.71

c = 406.95

[V-C]

( Ti)(h)

1670-882

cI2

Im3m

W

a = 330.65 [V-C]

( Ti)(r)

< 882

hP2

P63/mmc

Mg

a = 295.08

c = 468.55

[V-C]

Ti2Co

< 1058

cF96

Fd3m

Ti2Ni

a = 1130 [V-C]

TiCo2(c)

< 1235

cF24 a)

Fd3m

MgCu2

a = 669.2 [V-C],

homogeneity range 66.5 to 67 at.% Co

[Mas]

TiCo2(h) hP24 a)

P63/mmc

MgNi2

a = 473

c = 1541

[V-C],

homogeneity range 68.75 to 72 at.% Co

[Mas]

TiCo3

1190

cP4

Pm3m

CuAu3

a = 361.4 [V-C]

Co2Al5< 1172

hP28

P63/mmc

Co2Al5

a = 767.15

c = 760.85

[V-C]

Co4Al13

1100

mC100

Cm

Co4Al13

a = 1518.3

b = 812.2

c = 1234.0

=107.9°

[V-C]

Co2Al9< 944

mP22

P21/a

Co2Al9

a = 855.6

b = 629.0

c = 621.3

= 94.76°

[V-C]

TiAl3< 1395

tI8

I4/mmm

TiAl3

a = 384.9

c = 861

[1989Kal]

295


MSIT®

Al–Co–Ti

a) Possibly only one of the two TiCo2 based Laves phases is a stable phase [Mas]

Ti9Al23

780

a = 384.3

c = 3346.4

superstructure of TiAl3 [1989Kal]

, TiAl2.4(h)

1415-990

tI16

I4/mmm

ZrAl3

a = 391.7

c = 1652.4

[1989Kal]

TiAl2< 1175

tI24

I41/amd

HfGa2

a = 397.6

c = 2436

[1989Kal]

TiAl

< 1447

tP4

P4/mmm

CuAu

a = 401.1

c = 406.9

a = 398.8

c = 408.1

at 46 at.% Al [1989Kal]

at 62 at.% Al

Ti3Al

1180

hP8

P63/mmc

Ni3Sn

a = 578.2

c = 462.9

[V-C]

(Ti1-xAlx)Co

TiCo

< 1325

CoAl

< 1648

cP2

Pm3m

CsCl

a = 299.5

a = 286.11

0 x 1

[V-C]

[V-C]

* 1, TiCo2Al cF16

Fm3m

BiF3

a = 584.7

a = 584.8

[1962Mar], [1979Sei]

[V-C]

* 2, Ti1+xCoAl2-x cF116

Fm3m

Th6Mn23

Mg6Cu16Si7

a = 1193

a = 1193.56 ± 0.03

0 x 1 [1972Tsu]

TiCoAl2 [1969Mar]

Ti27.5Co23.4Al49.1 [2003Gry]; a filled

variant of the Th6Mn23-type

* 3, Ti8Co3Al22 cF4 a = 395 Cu3Au-like [1979Sei]

Phase /

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

296


MSIT®

Al–Co–Ti

80

90

10 20

10

20

Ti Ti 70.00Co 30.00Al 0.00

Ti 70.00Co 0.00Al 30.00 Data / Grid: at.%

Axes: at.%

1100

1050

950

900

850

800

750 700

950

1100

1050

1000

°C

80 60 40 20600

700

800

900

1000

1100

1200

1300

1400

1500

1600

1700

1800

Ti AlTi, at.%

Tem

pera

ture

, °C

14751447

1415 1395

L

665

(βTi)

~1118

Ti3Al(αTi) TiAl

Ti 9Al 23

TiAl2

990

ξ

1175

TiA

l3

882°C

1670°C

Fig. 2: Al-Co-Ti.

Solvus lines of the

( Ti) phase field

[1967Tsu]

Fig. 1: Al-Co-Ti.

Acceped Al-Ti phase

diagram

297


MSIT®

Al–Co–Ti

Co-Ti

l+TiCo Ti2Co

1057 p4

l TiAl + τ2

e1(max)

Al-Co-Ti

L+TiAl (αTi)+τ2

1270 U1

Al-Ti

l+(βTi) (αTi)

1475 p1

l (βTi)+Ti2Co

1020 e4

(βTi) (αTi)+Ti2Co

685 e5

l+(αTi) TiAl

1447 p2

(αTi) Ti3Al+TiAl

1118 e2

(βTi)+Ti3Al (αTi)+Ti

2Co775 U

6

(βTi)+τ2

Ti3Al+Ti

2Co1003 U

5

L (βTi)+Ti2Co+τ

21005 E

2

L+(Ti,Al)Co τ2+Ti

2Co1040 U

4

l+(Ti,Al)Co τ2

p3(max)

(αTi)+τ2

(βTi)+Ti3Al U

3

(αTi) Ti3Al+TiAl+τ

2E1

(αTi) Ti3Al+τ

2

e3(max)

L+(αTi) (βTi)+τ2

1240 U2(αTi)+TiAl+τ

2

Ti3Al+TiAl+τ

2

(Ti,Al)Co+τ2+Ti

2Co L+τ

2+Ti

2Co

(βTi)+τ2+Ti

2Co

τ2+Ti

3Al+Ti

2Co

(βTi)+Ti3Al+Ti

2Co

(αTi)+Ti3Al+Ti

2C

(αTi)+(βTi)+τ2

L+(βTi)+τ2

(βTi)+τ2+Ti

3Al

(αTi)+(βTi)+Ti3Al

L+(αTi)+τ2

20

40

60

80

20 40 60 80

20

40

60

80

Ti Co


Axes: at.%

ξ

TiAl

(αTi)

(βTi)(Ti,Al)Co

(γCo)

τ2

Ti2Co

U1

U2

U4

p3max

e4p4

p1

p2

E2

Fig. 4: Al-Co-Ti.

Liquidus surface

Fig. 3: Al-Co-Ti. Reaction scheme

298


MSIT®

Al–Co–Ti

20

40

60

80

20 40 60 80

20

40

60

80

Ti Co


Axes: at.%

TiAl

(αTi)

(βTi) L

Fig. 5: Al-Co-Ti.


1300°C

20

40

60

80

20 40 60 80

20

40

60

80

Ti Co


Axes: at.%

(βTi)

(αTi)

TiAl

τ2

L

Fig. 6: Al-Co-Ti.


1200°C

299


MSIT®

Al–Co–Ti

20

40

60

80

20 40 60 80

20

40

60

80

Ti Co


Axes: at.%

L(βTi)

Ti3Al

TiAl

τ2

TiCo (γCo)

TiCo2(c) TiCo2(h) TiCo3

TiC

o 2A

l

AlCo

Fig. 7: Al-Co-Ti.


1100°C

20

40

60

80

20 40 60 80

20

40

60

80

Ti Co


Axes: at.%

TiCo

Ti2Co

(βTi)

(αTi)

Ti3Al

TiAl

τ2

TiC

o 2A

l

AlCo

(γCo)


Fig. 8: Al-Co-Ti.


1000°C

300


MSIT®

Al–Co–Ti

20

40

60

80

20 40 60 80

20

40

60

80

Ti Co


Axes: at.%

(βTi)

(αTi)

Ti3Al

TiAl

τ2

TiCo

Ti2Co

(γCo)


TiC

o 2A

l

AlCo

Fig. 9: Al-Co-Ti.


900°C

20

40

60

80

20 40 60 80

20

40

60

80

Ti Co


Axes: at.%

(αTi)

Ti3Al

TiAl

Ti2Co

τ2

TiCo+τ2

TiCo(βTi)

τ2+TiAl

τ2+Ti3Al

Fig. 10: Al-Co-Ti.


800°C [1972Tsu]

301


MSIT®

Al–Co–Ti

20

40

60

80

20 40 60 80

20

40

60

80

Ti Co


Axes: at.%

(αTi)

Ti3Al

TiAl

Ti2Co

τ2

TiCo

Fig. 11: Al-Co-Ti.


600°C [1972Tsu]

10 20 30 40500

750

1000

1250

1500

1750

2000

Ti 50.00Co 50.00Al 0.00

Ti 0.00Co 50.00Al 50.00Al, at.%

Tem

pera

ture

, °C

TiCo TiCo2Al CoAl

L

1325°C

1640°C

Fig. 12: Al-Co-Ti.

TiCo - CoAl

pseudobinary section

[2002Ish1]

302


MSIT®

Al–Co–Ti

10 20600

700

800

900

1000

1100

1200

1300

1400

Ti 48.00Co 52.00Al 0.00

Ti 23.00Co 52.00Al 25.00Al, at.%

Tem

pera

ture

, °C

TiCo TiCo2Al

Fig. 13: Al-Co-Ti.

Part of the

TiCo - TiCo2Al

pseudobinary section

(Co = 52 at.%)

[2003Kaw]

303


MSIT®

Al–Co–Y

Aluminium – Cobalt – Yttrium

Oksana Bodak

Literature Data

A critical analysis of the literature data on the Al-Co-Y system was made by [1991Gri] based on articles

published in the period 1971 to 1990. These investigations have generated isothermal sections of the phase

diagram [1971Ryk] and determined compositions and crystal structures of 4 ternary compounds: YCoAl4-x,

YCoAl2, YCoAl and ~YCo2Al7 by [1971Ryk, 1972Ryk]. Several papers were devoted to alloys from the

solid solution regions based on binary compounds of the Co-Y system: Y2(Co1-xAlx)17 in papers by

[1971Ryk, 1974Ham, 1985Mod] and Y(Co1-xAlx)5 by [1971Ryk, 1982Chu1, 1982Chu2, 1985Yos]. During

the last 15 years 10 more articles on this system were published with focus on the crystal structure and alloys

from the solid solution regions as well as on the ternary compounds. [1992Gla] re-assessed the composition

and structure of the YCoAl4 phase to be: Y2Co3Al9; and in [2001Rou] its magnetic properties were

examined. The interest in the properties of the alloys from the solid solution regions remains:

Y2(Co1-xAlx)17 [1997Zha, 1999She], Y(Co1-xAlx)5 [1996Tha, 2002Zlo] and Y(Co1-xAlx)2 [1993Tov,

1998Got, 1991Gab, 1999Mus, 2000Mus].

The samples usually were prepared by arc melting high purity metals under argon atmosphere. Then they

were heat treated at various temperatures and investigated both in annealed and in as cast state,

predominantly using X-ray methods. Magnetic properties were examined using SQUID magnetometer in a

temperature range of 2-300 K and in magnetic fields up to 7 T. Neutron diffraction was applied by

[2002Zlo]. Single crystal of the YCo4Al composition has been successfully grown in a tri-arc Czochralski

apparatus by [1996Tha] and sizable single crystals of Y2(Co,Al)17 were produced by [1985Mod] in

Bridgman technique.

Binary Systems

Co-Y binary system was taken from [Mas2]. Al-Co system was accepted according to [2003Gru] and Al-Y

as published by [2003Cor].

Solid Phases

Four ternary compounds were found and stability regions and structure of YCoAl compound was

determined in [1971Ryk, 1972Ryk]. The complete determination of YCoAl2 crystal structure is due to

[1971Ryk, 1973Ryk]. The composition of ~YCoAl4 phase was re-assessed as being Y2Co3Al9 and its

structure completely calculated by [1992Gla]. The structural symmetry and lattice parameters of ~YCo2Al7is available from [1971Ryk], but the structure itself is still unknown. The change of the lattice parameters

in the homogeneity region of the Y(Co1-xAlx)2 solid solution is shown in Fig. 1 according to the data by

[1985Yos, 1999Mus]. For alloys in the Y2(Co1-xAlx)17 solid solution, annealed at 1150°C, the change of

lattice parameters with changing Co/Al concentration is given in the Fig. 2 [1974Ham].

[1997Zha] and co-authors reported the crystal structures for Y2Co17-xAlx (x = 2, 3) and have found that

samples of such compositions, annealed for 3 weeks at 900°C, are single phase and belong to the Th2Zn17

type structure. Lattice parameters were not presented. Table 1 summarizes the composition and structure

data of the solid phases in the system Al-Co-Y.

Isothermal Sections

Phase configurations at 600°C in the partial isothermal section, Fig. 3, are drawn to merge consistently the

data from [1971Ryk] with the newly evaluated data on the Al-Co system and the re-assessed compositions

of the compounds. Both groups of authors, [1971Ryk, 1996Tha, 2002Zlo] investigating the YCo5-xAlxregion and [1971Ryk, 1974Ham, 1999She] investigating the Y2Co17-xAlx solid solutions reported the

presence of the phases with CaCu5 and Th2Ni17 type structures, which is in conflict with the binary Co-Y

304


MSIT®

Al–Co–Y

data. At that point it is not clear whether these results are more correct than the information presented in

[Mas2], because the temperature for the polymorphic transformation Y2Co17 Y2Co17 is not well

defined as is the decomposition temperature of YCo5.


Weakly itinerant ferromagnetism has been found in the magnetically dilute system Y(Co1-xAlx)2 (x = 0.13

~ 0.19) [1985Yos]. The temperature dependence of the first magneto-crystalline anisotropy constant K1 has

been deduced for Y(Co0.85Al0.15)2 samples [1993Tov]. The magnitude of K1 is equal to 7.6×104 erg cm-3

at T = 7 K and falls rapidly with increasing temperature. K1 has a negative sign over the temperature range

investigated from 7 to 20 K, i.e. below TC = 25 K [1993Tov]. In the concentration region 0.12 < x < 0.15 a

meta-magnetic transition from the weakly developed ferromagnetic to a stronger ferromagnetic was

observed by [1998Got]. The critical field of this transition BC was found to increase with pressure at a rate

of dBC/dP = 7.8 GPa-1 for x = 0.075. For x = 0.09 BC increases at a rate of dBC/dP = 7.4 GPa-1. The initial

volume compressibility amounts up to 8.7×10-3 GPa-1 at 77 K [1999Mus].

The magnetic properties of alloys from the Y2(Co1-xAlx)17 phase field were investigated by [1974Ham,

1997Zha, 1999She]. When the Al content increases the Curie temperature and saturation magnetization

decrease [1974Ham, 1999She]; also the magneto-crystalline anisotropy reverses from easy-plane to

easy-axis anisotropy for higher Al concentration [1997Zha]. In the Y(Co1-xAlx)5 solid solution, similarly to

Y2(Co1-xAlx)17, the Co substitution of Co by Al reduces the Curie temperature, saturation magnetization

and changes the magneto-crystalline anisotropy [2002Zlo]. The single crystal investigation of YCo4Al

shows that Al substitution also leads to a large decrease of the Co magnetic moment compared with YCo5

[1996Tha]. A magnetization anisotropy of 3.4% has been found for YCo4Al [1996Tha]. Y2Co3Al9compound is a Pauli paramagnet [2001Rou].

References

[1971Ryk] Rykhal’, R.M., Zarechnyuk, O.S., “Y-Co-Al Ternary System in the Region 0-33.3 at.% Y”

(in Ukrainian), Dop. Akad. Nauk Ukr. RSR A, Fiz-Mat. Tekh., 33, 854-956 (1971)

(Experimental, Equi. Diagram, Crys. Structure, #, 10)

[1972Ryk] Rykhal, R.M., “Crystal Structures of the Ternary Compounds YFeAl and YCoAl” (in

Russian), Vestn. L’vov. Univ. Khim., 13, 11-14 (1972) (Experimental, Crys. Structure, 4)

[1973Ryk] Rykhal’, R.M., Zarechnyuk, O.S., Pyshchik. G.V., “New Representatives of the MgCuAl2and YNiAl4 Types of Structure” (in Ukrainian), Dop. Akad. Nauk Ukr. RSR A, Fiz-Mat.

Tekh., (6), 568-570 (1973) (Experimental, Crys. Structure, 2)

[1974Ham] Hamano, M., Yajima, S., Umebayashi, H., “Magnetocrystalline Anisotropy Measured on

Single Crystal Y2(Co1-xAlx)17 Intermetallics”, Proc. Rare-Earth Research Conference,

11th, 477-486 (1974) (Experimental, Crys. Structure, Magn. Prop., 17)

[1982Chu1] Chuang, Y.C., Wu, C.H., Chang, Y.C., “An Investigation of the Metastable Character of

Y(Co,M)5 Compounds”, J. Less-Common Met., 83(2), 235-241 (1982) (Experimental,

Equi. Diagram, 8)

[1982Chu2] Chuang, Y.C., Wu, C.H., Chang,Y.C. “Structure and Magnetic Properties of Y(Co1-xMx)5

Compounds”, J. Less-Common Met., 84, 201-213 (1982) (Experimental, Crys. Structure,

Magn. Prop., 37)

[1985Mod] Modrzejewski, A., Warchol, S., Slepowronski, M., “Growth of Rare-Earth - Transition

Metal Single Crystal Compounds” (in German), Akad. Wiss. DDR, 6th Int. Sym. High P. M.,

(1985) (Experimental, Magn. Prop., 2)

[1985Yos] Yoshimura, K., Nakamura,Y., “New Weakly Itinerant Ferromagnetic System, Y(Co,Al)

(Y(Co1-xAlx)2)”, Solid State Commun., 56, 767-771 (1985) (Experimental, Crys. Structure,

20)

[1991Gab] Gabelko, I.L., Levitin, R.Z., Markosyan, A.S., Silant’ev, V.I., Snegirev V.V., “Influence of

the d-Electron Concentration on the Itinerant Electron Metamagnetism and Ferromagnetism

305


MSIT®

Al–Co–Y

in M(Co1-xAlx)2 Systems (M = Y, Lu, Ce)”, J. Magn. Magn. Mater., 94(3), 287-292 (1991)

(Magn. Prop., 15)

[1991Gri] Grieb, B., “Aluminium-Cobalt-Yttrium”, MSIT Ternary Evaluation Program, in MSIT



Assessment, 8)

[1992Gla] Gladyshevskii, R.E., Cenzual, K., Parthe, E., “Y2Co3Al9 with Y2Co3Ga9 Type Structure:

an Intergroeth of CsCl- and Th3Pd5-Type Slabs”, J. Alloys Compd., 182, 165-170 (1999)


[1993Tov] Tovstolytkin, A.I., Belous, N.A., Zorin, I.A., Lezhnenko, I.V., “Magnetocrystalline

Anisotropy in Y(Co0.85Al0.15)2 with the C15 Cubic Laves Phase Structure”, J. Phys.:

Condensed Matter, 5, 7009-7012 (1993) (Experimental, Magn. Prop., 10)

[1996Tha] Thang, C.V., Brommer, P.E., Colpa, J.H.P., Bruek, E., Menovsky, A.A., Thuy, N.P., Franse,

J.J.M., “Magnetocrystalline Anisotropy and R-Co Exchange Interaction in Monocrystalline

RCo4Al (R = Y, Gd and Ho)”, J. Alloys Compd., 245, 100-111 (1996) (Experimental, Crys.

Structure, 40)

[1997Zha] Zhang, D., de Groot, C.H., de Boer, F.R., Buschow, K.H.J., “Magnetic Properties of

Pr2Co17-xAlx and Y2Co17-xAlx”, J. Alloys Compd., 259, 42-46 (1997) (Experimental, Crys.

Structure, 8)

[1998Got] Goto, T., Bartashevich, M.I., “Magnetovolume Effects in Metamagentic Itinerant-Electron

Systems Y(Co1-xAlx)2 and Lu(Co1-xGax)2”, J. Phys.: Condensed Matter, 10(16), 3625-3634

(1998) ( Experimental, Crys. Structure, Magn. Prop., 28)

[1999Mus] Mushnikov, N.V., Goto, T., “Itinerant Electron Metamagnetism of Y(Co1-xAlx)2 Under

High Pressure and Magnetic Fields”, J. Phys.: Condens. Matter, 11, 8095-8101 (1999)


[1999She] Shen, B., Cheng, Z., Zhang, S., Wang, J., Liang, B., Zhang, H., Zhan, W., “Magnetic

Properties of R2Co15Al2 Compounds with R= Y, Ce, Pr, Nd, Sm, Gd, Tb, Ho, Er, Tm”, J.

Appl. Phys., 85(5), 2787-2792 (1999) (Experimental, Crys. Structure, Magn. Prop., 43)

[2000Mus] Mushnikov, N.V., Andreev, A.V., Goto, T., “Effects of Substitution of Uranium for Yttrium

on Band Metamagnetism of Y(Co0.92Al0.08)2”, J. Alloys Compd., 298, 73-76 (2000)


[2001Rou] Routsi, Ch., Yakinthos, J.K., “Crystal Structure and Magnetic Properties of R2Co3Al9Compounds (R = Y, Pr, Gd, Tb, Dy, Ho, Er, Tm)”, J. Alloys Compd., 323-324, 427-430

(2001) (Experimental, Crys. Structure, Magn. Prop., 14)

[2002Zlo] Zlotea, C., Isnard, O., “Structural and Magnetic Properties of RCo4Al Compounds (R = Y,

Pr)”, J. Magn. Magn. Mater., 242-245, 832-835 (2002) (Experimental, Crys. Structure,

Magn. Prop., 15)

[2003Cor] Cornish, L., Cacciamani, G., Saltykov, P., “Al-Y (Aluminium-Yttrium)”, MSIT Binary


International Services, GmbH, Stuttgart; to be published, (2003) (Crys. Structure, Equi.




Services GmbH, Stuttgart; to be published, (2003) (Crys. Structure, Equi. Diagram,

Assessment, 71)

306


MSIT®

Al–Co–Y


Phases/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

(Al)

< 660.452

cF4

Fm3m

Cu

a = 404.88 [Mas2]

( Co)

422-1495

cF4

Fm3m

Cu

a = 354.46 [Mas2]

( Co)

< 422

hP2

P63/mmc

Mg

a = 250.71

c = 406.95

[Mas2]

Co2Al9< 970

mP22

P21/a

...

a = 855.6

b = 629.0

c = 621.3

= 94.76°

[2003Gru]

O-Co4Al13

< 1080

oP102

Pmn21

O-Co4Al13

a = 815.8

b = 1234.7

c = 1445.2

[2003Gru]

M-Co4Al13

1093-?

mC102

C2/m

Fe4Al13

a = 1517.3

b = 810.9

c = 1234.9

= 107.84°

[2003Gru]

Y

1127-?

oI*

Immm

or

mC34

C2/m

Os4Al13

a = 1531.0

b = 1235.0

c = 758.0

a = 1704.0

b = 409.0

c = 758.0

= 116.0°

[2003Gru]

Z

< 1158

C-centr.monocl. a = 3984.0

b = 814.8

c = 3223.0

= 107.97°

[2003Gru]

Co2Al5< 1188

hP28

P63/mmc

Co2Al5

a = 767.2

c = 760.5

[2003Gru]

Co1-xAlx< 1640

cP2

Pm3m

CsCl

a = 285.7

a = 286.2

a = 285.9

x = 0.52 [2003Gru]

x = 0.5

x = 0.43

YAl3< 645(?)

hP8

P63/mmc

Ni3Sn

a = 627.6 ± 2

c = 458.2 ± 1

[2003Cor]

Metastable phase

YAl3980-655

hP36

R3m

BaPb3

a = 620.4 ± 2

c = 2118.4 ± 2

[2003Cor]

307


MSIT®

Al–Co–Y

Y(CoxAl1-x)2

< 1485

cF24

Fd3m

MgCu2

a = 785.5 ± 7

a = 784

a = 788 to 786

a = 771

x = 0 [2003Cor]

x = 0 [1971Ryk]

supersaturated

x = 0.3 [1971Ryk]

Y2Co17

< 1300

hP57

R3m

Th2Zn17

a = 835.6

c = 1220

[Mas2, V-C2]

Y2(Co1-xAlx)17

1357-1300

hP38

P63/mmc

Th2Ni17

a = 835.5

c = 812.8

a = 836

c = 816

a = 835

c = 812

a = 839.6

c = 818.5

a = 838

c = 819

x = 0 [Mas2, V-C2]

x = 0, at 600°C [1971Ryk]

x = 0, at 1500°C [1974Ham]

x = 0.11 (Y2Co15Al2) annealed at

1000°C [1999She]

x = 0.11 (Y2Co15Al2),

at 600°C [1971Ryk]

Y(Co1-xAlx)5

< 1345

hP6

P6/mmm

CaCu5

a = 495.1

c = 397.5

a = 500

c = 400

a = 498.5

c = 401.9

a = 499.8 ± 1

c = 401.9 ± 1

a = 498.3 ± 5

c = 402.4 ± 5

a = 504

c = 404

x = 0 [Mas2, V-C2]

x = 0, at 600°C [1971Ryk]

x = 0.2 (YCo4Al) [1996Tha]

x = 0.2 (YCo4Al) [2002Zlo]

x = 0.2 (YCo4Al) at 2 K [2002Zlo]

x = 0.36 (YCo3.2Al1.8),

at 600°C [1971Ryk]

Y2Co7

< 1320

hP54

R3m

Er2Co7

a = 500

c = 3615

[Mas2, V-C2]

YCo3

< 1308

?

hP36

R3m

NbBe3

hP24

P63/mmc

CeNi3

a = 502.0

c = 2440

a = 501.5

c = 1628

[Mas2, V-C2]

[V-C2]

Y(Co1-xAlx)2

< 1154

cF24

Fd3m

MgCu2

a = 721.8

a = 722

a = 728

x = 0 [Mas2, V-C2]

x = 0 [1971Ryk]

x = 0.1 [1971Ryk]

1, YCo2Al7 orthor. a = 410

b = 1690

c = 1195

[1971Ryk]

Phases/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

308


MSIT®

Al–Co–Y

2, Y2Co3Al9 oC56

Cmcm

Y2Co3Ga9

a = 1276

b = 739

c = 939

a = 1274.0 ± 2

b = 746.35 ± 9

c = 932.1 ± 1

a = 1274.0 ± 5

b = 752.3 ± 8

c = 941.1 ± 3

[1971Ryk]

[1992Gla]

[2001Rou]

3, YCoAl2 oC16

MgCuAl2

a = 408

b = 1015

c = 706

[1971Ryk, 1973Ryk]

4, YCo1+xAl1-x hP12

P63/mmc

MgZn2

a = 539

c = 867

a = 536

c = 863

x = 0 (YCoAl) [1971Ryk, 1972Ryk]

x = 0.35 (YCo1.35Al0.65)

[1971Ryk]

Phases/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

0

834 810

812

814

816

818

820

836

838

840

842

844

0.04 0.08 0.12 0.16

x in Y (Co Al )2 1- 17x x

Latticeparameters,and

(pm)

ac

a

c

a cFig. 1: Al-Co-Y.

Concentration de-

pendence of the lat-

tice constant of

Y2(Co1-xAlx) at

1500°C [1974Ham]

309


MSIT®

Al–Co–Y

0.00

720

722

724

726

728

730

732

734

736

0.05 0.10 0.15 0.20 0.25

Latticeconstant,

(pm)

a

[1999Mus]

[1985Yos]

x in Y(Co Al )1- 2x x

Fig. 2: Al-Co-Y.

Concentration de-

pendence of the lat-

tice constant of

Y(Co1-xAlx)2

[1999Mus]

20

40

60

80

20 40 60 80

20

40

60

80

Y Co


Axes: at.%

Co2Al9

O-Co4Al13

Co2Al5

Co1-xAlx

YCo2 YCo3 YCo5 ?Y2Co17

YAl3

YAl2

Z

τ3

τ4

τ1

τ2

(αCo)

Fig. 3: Al-Co-Y.


600°C

310


MSIT®

Al–Cr–Cu

Aluminium – Chromium – Copper

Gautam Ghosh

Literature Data

Earlier investigations [1960Zol, 1967Zar] of the phase equilibria were restricted to the Al-corner only.

[1960Zol] reported the effect of up to 2% Cr on the liquidus and solidus temperatures of Al-rich alloys.

[1967Zar] reported a partial isothermal section at 400°C. [1979Dri] presented a review of these results.

[1972Pre] reported the solid state phase equilibria of the entire ternary system at 600 and 800°C. They

prepared more than 100 ternary alloys in an arc furnace under purified Ar using the elemental metals of

following purity: 99.98 mass% Al, 99.9 mass% Cr and 99.99 mass% Cu. The alloys were sealed in

evacuated quartz tubes and annealed at 600°C for 400 h or at 800°C for 200 h, followed by quenching in

cold water. Phase identification was carried out by means of X-ray diffraction. Later, [1981Che] reported

the phase equilibria of the ternary system at room temperature. They investigated 407 ternary alloys which

were prepared, using 99.9 mass% elemental metals, in an induction furnace under vacuum or under Xe

atmosphere. The alloys were sealed in evacuated quartz tubes and were subjected to two different heat

treatment schedules: (i) annealing at 330°C for 30 days followed by slow cooling to room temperature or

(ii) annealing at 800°C for 1h followed by quenching in ice water and subsequently annealing between 340

to 350°C for 126 days followed by slow cooling to room temperature. The phase identification was

performed by means of the X-ray powder diffraction method. These results were assessed by [1991Gho].

Binary Systems

The Al-Cr binary phase diagram is accepted from [Mas]; the Al-Cu binary phase diagram is accepted from

the assessment of [2003Gro], and the Cr-Cu binary phase diagram is accepted from [2003Ans].

Solid Phases

[1958Kho] reported the solid solubility of Cr and Cu in (Al). The solubility isotherms are plotted in Fig. 1.

Recent investigations [1972Pre] and [1981Che] suggest that, in the ternary regime, the solid solubilities of

Cr in (Cu) and Cu in (Cr) are much higher than those in the binary alloys (for example see Fig. 3 and Fig.

4). These data differ with those reported by [1939Ale].

Based on the wet chemical analysis of extracted particles, [1960Zol] reported that CrAl7 dissolves at least

1.04 at.% Cu. [1972Pre] reported four ternary phases, which are designated here as 1, 2, 3 and 4, as

existing at 600°C. They can be represented as Cr23Cu20Al57, Cr20Cu10Al70, Cr15Cu13Al72 and

Cr15Cu18Al67, respectively. 3 and 4 are not stable at 800°C or above. Except for the 2 phase, other ternary

phases have nominal solid solubility. The authors [1972Pre] reported the crystal structure of the 2 phase

only. [1981Che] reported the existence of five ternary phases at room temperature, which are designated as

5, 6, 7, 8 and 9. The 5 phase has a small region of homogeneity and can be represented as

Cr4.5Cu31Al64.5. Its crystal structure was reported to be orthorhombic. The other ternary phases have solid

solubility ranges, but their crystal structures were not reported by [1981Che]. In the absence of the crystal

structure data of all the ternary phases, it is difficult to conclude whether all of them are different phases or

whether some of them are the same.

The details of the crystal structures, lattice parameters, etc. of the binary and ternary phases are listed in

Table 1.

Liquidus Surface

Experimental data on the melting equilibria of the ternary system is very meager. Figure 2 shows the

liquidus surface of the Al corner [1943Mon] which exhibits the presence of a U type and a E type invariant

reactions. Limited data of [1933Roe] and [1941Kna] suggest the ternary eutectic reaction as

L (Al)+CuAl2+Cr7Al45. Also, the vertical section reported by [1982Lit] and the observation of the

311


MSIT®

Al–Cr–Cu

(Al)+CuAl2+Cr7Al45 three-phase field at the 400°C isothermal section [1967Zar] confirm the above

eutectic reaction. The ternary eutectic occurs at about 28.5 mass% Cu, 1.5 mass% Cr, with a melting point

of about 545°C [1982Lit]. However, [1943Mon] reported that the transition reaction

L+Cr7Al45 CrAl5+(Al) followed by the presence of Cu hinders the formation of the Cr7Al45 phase, and

accordingly he proposed the transition reaction L+Cr7Al45 CrAl5+(Al) followed by the ternary eutectic,

L (Al)+CuAl2+CrAl5 for which there is no experimental evidence so far.

Isothermal Sections

The isothermal section of the Al-Cr-Cu system at 600°C [1972Pre] is shown in Fig. 3. The doubtful portion

of this diagram is shown as dotted. Except for the absence of the 3 and 4 phases, the phase boundaries at

800°C essentially remain the same as those at 600°C [1972Pre]. Figure 4 shows the isothermal section at

room temperature [1981Che]. After very slow cooling of the binary and ternary alloys, [1981Che] did not

observe the 2 phase (of the Al-Cu binary system) at room temperature. According to [1981Che], and

phases of the Al-Cr system form a solid solution ( ') well within the ternary regime, whereas they are

immiscible in ternary alloys close to the binary edge. Such a situation is quite unlikely and further

investigation in this composition range is needed. Also, the above feature was not observed in the 600°C

isothermal section by [1972Pre]. In both Figs. 3 and 4, the results along the Cu2Al-Cr2Al section are

consistent with those reported by [1964Ram] and [1965Ram]. Minor adjustments have been made in Figs. 3

and 4 in order to comply with the accepted binary phase diagrams. The doubtful portions of the phase

diagrams are shown by dashed lines.

[1967Zar] reported an isothermal section of the Al corner at 400°C. In the composition range of

Al-12.5Cr-33.3Cu (at.%), they observed an (Al)+Cr7Al45+CuAl2 three-phase field and the corresponding

two-phase fields.


Figure 5 shows the vertical section from Al to 2.5 mass% Cr [1982Lit]. Addition of Cr to Al-Cu alloys

increases the (Cu)+ 1 transformation temperature [1969Hor].

Thermodynamics

Experimental thermodynamic data and CALPHAD modeling of phase equilibria are known only for the

relevant binary systems.


[2000Grz] investigated the effect of 1.65 at.% Cr on the properties of Al-9.9Cu (at.%) alloy. They found

that Cr addition reduces phase coarsening at high temperature and refines 2 lamellae in the eutectoid

microstructure. The quenched microstructure consists of fine acicular ’+ ’1 martensite. Refinement of

microstructure leads to significant increase in strength without any significant change in ductility, both in

annealed and quenched conditions.

[1983Sid] determined the resistivity and the temperature coefficient of resistivity of vapor deposited

thin-film, Cu-rich ternary alloys.

Miscellaneous

Recently, the ternary system has received renewed interest because of the ability to synthesize quasicrystals

in Al-rich compositions. In particular, compositions around Cr15Cu20Al65 [1988Tsa, 1991Eba, 1992Sel,

1995Kha, 1997Kha, 1999Qi, 2001Pon], Cr20Cu10Al70 [1992Oka], Cr15CuxAl85-x (0 x 20) [1993Sel]

have been investigated extensively. The quasicrystals are mainly two types: icosahedral and decagonal. A

lower e/a ratio favors the former while a higher e/a favor the latter. The stability [1999Qi] and bulk modulus

[2001Pon] of the quasicrystals is also related to the e/a ratio.

312


MSIT®

Al–Cr–Cu

[1988Tsa] rapidly solidified the alloy Cr15Cu20Al65 and showed that a quasi-crystalline icosahedral phase

forms. For compositions Cr15CuxAl85-x a quasi-crystalline phase forms on rapid solidification of alloys with

x = 0 and 5. For x = 10 and 15, a mixture of CuAl2 and a quasi-crystalline phase is formed. At x = 20 only

the quasi-crystalline phase forms. On heating at 40 K min-1 up to 600°C the Cr15Cu20Al65 quasi-crystalline

phase showed no exothermic effects. The high thermal stability, as confirmed by unpublished work,

indicates the formation of a thermodynamically stable quasi-crystalline phase in conventionally solidified

material. [1992Oka] observed that the decagonal quasicrystal in Cr20Cu10Al70 is stable up to 1000°C. It is

worth noting that the 4 phase [1972Pre] is close in composition to the alloy Cr15Cu20Al65.

A detailed description of these quasicrystals can be found in the comprehensive review by [1996Yam].

References



[1933Roe] Röntgen, P., Koch, W., “Influence of Heavy Metals on Aluminium Alloys” (in German),

Z. Metallkd., 25, 182-185 (1933) (Equi. Diagram, Experimental, *, 8)

[1937Bra] Bradley, A.J., Lu, S.S., “An X-Ray Study of the Chromium-Aluminium Equilibrium

Diagram”, J. Inst. Met., 60, 319-337 (1937) (Crys. Structure, Experimental, Equi. Diagram,

8)

[1939Ale] Alexander, W.O., “Annealing Characteristics and Solid Solubility Limits of Copper and

Copper Alloys Containing Chromium”, J. Inst. Met., 64, 93-112 (1939) (Equi. Diagram,

Experimental, *, 11)

[1941Kna] Knappwost, A., Nowotny, H., “Magnetic Investigation of Aluminium - Chromium - Copper

System” (in German), Z. Metallkd., 33, 153-157 (1941) (Equi. Diagram, Experimental, #, *,

27)

[1943Mon] Mondolfo, L.F., “Aluminium - Chromium - Copper” in “Metallography of Aluminium

Alloys”, New York, 69-70 (1943) (Equi. Diagram, Review, 2)

[1958Kho] Khokhlev, V.M., “Physicochemical Investigation of the Joint Solubility of Cu and Cr in Al”

(in Russian), Izv. V.U.Z. Tsvetn. Met., (4), 136-141 (1958) (Equi. Diagram, Experimental,

#, *, 7)

[1960Zol] Zoller, H., “The Influence of Zn, Mg, Si, Cu, Fe, Mn and Ti on the Primary Crystallisation

of Al7Cr” (in German), Schweiz. Arch. Angew. Wiss. u. Techn., 26, 478-491 (1960) (Equi.

Diagram, Experimental, *, 33)

[1963Koe] Koester, W., Watchel, E., Grube, K., “Structure and Magnetic Properties of

Aluminium-Chromium Alloys” (in German), Z. Metallkd., 54, 393-401 (1963) (Equi.

Diagram, Crys. Structure, Thermodyn., Magn. Prop., Experimental, 33)

[1964Ram] Raman, A., Schubert, K., “The Occurrence of Zr2Cu- and Cr2Al-type Intermetallic

Compounds” (in German), Z. Metallkd., 55, 798-804 (1964) (Crys. Structure, Experimental,

23)

[1965Ram] Raman, A., Schubert, K., “On the Crystal Structure of some Alloy Phases Related to TiAl3.

III. Investigation in Several T-Ni-Al and T-Cu-Al Systems” (in German), Z. Metallkd., 56,


[1967Zar1] Zarechnyuk, O.S., Malinkovich, A.N., Lalayan, E.A., Markiv, V.Ya., “X-Ray Investigation

of Aluminium-Rich Alloys of the Ternary Al-Cu-Cr, Al-Cu-Zr and Al-Cr-Zr Systems and

the Quaternary Al-Cu-Cr-Zr System”, Russ. Metall. (Engl. Transl.), 6, 105-107 (1967)


[1969Hor] Hori, M., “On the Effects of Cr and Ti on the Eutectoid Transformation of Cu-Al Binary

Alloys” (in Japanese), J. Japan Inst. Metals, 33, 1073-1077 (1969) (Equi. Diagram,


[1972Pre] Prevarsky, A.P., Skolozdra, R.V., “The Cr-Cu-Al System” (in Russian), Izv. Akad. Nauk

SSSR, Met., (1), 193-195 (1972) (Equi. Diagram, Experimental, #, *, 14)

313


MSIT®

Al–Cr–Cu

[1977Bra] Brandon, J.K., Pearson, W.B., Riley, P.W., Chieh, C., Stokhuyzen, R., “ -Brasses with R

Cells”, Acta Crystallogr., 3B, 1088-1095 (1977) (Crys. Structure, Experimental, 16)

[1977Vis] Visser J.W., “On The Structure of Chromium-Aluminum (Cr5Al8) 26r A Correction”, Acta

Crystallogr., Sect. B, 33B(1), 316 (1977) (Experimental, Crys. Structure)


Turkina, N.I., “Cu-Al-Cr” (in Russian) in “Binary and Multicomponent Copper-Base

Systems”, Nauka, Moskow, 82-83 (1979) (Equi. Diagram, Review, 2)

[1981Che] Chen, R.-Z., Lin, C.-J., Li, D.-X., Zheng, J.-X., “The Room-Temperature Section of the

Phase Equilibrium Diagram of the Al-Cr-Cu Ternary System” (in Chinese), Acta Phys. Sin.

(Chin. J. Phys.), 30(4), 555-558 (1981) (Equi. Diagram, Experimental, #, *, 9)

[1982Lit] Litvin, B.N., Zinkovskii, G.V., “Effect of Transition Elements on the Aluminium - Copper

Phase Diagram” (in Russian), Elek. Svoist. Tverd. Tel i Preva., Saransk, 124-128 (1982)

(Equi. Diagram, Experimental, #, *, 3)

[1983Sid] Sidorenko, S.I., Kotenko, I.E., Lysova, E.V., Bochvar, N.R., “Electrophysical Properties

and Phase Composition of Cu-Cr-Al Condensates” (in Russian), Izv. Akad. Nauk SSSR,

Met., (3), 189-192 (1983) (Equi. Diagram, Experimental, 6)

[1985Mur] Murray, J.L., “The Aluminium - Copper System”, Int. Met. Rev., 30, 211-233 (1985) (Equi.

Diagram, Review, #, *, 230)

[1988Tsa] Tsai, A.-P., Inoue, A., Masumoto, T., “New Quasicrystals in Al65Cu20M15 (M = Cr, Mn or

Fe) Systems Prepared by Rapid Solidification”, J. Mater. Sci. Lett., 7, 322-326 (1988)


[1989Ell] Ellner, M., Braun, J., Predel, B., “X-Ray Investigations on Cr-Al Phases of the W-Family”

(in German), Z. Metallkd., 80, 374-383 (1989) (Equi. Diagram, Crys. Structure,

Experimental, 38)

[1991Gho] Ghosh, G., “Aluminium-Chrmium-Copper”, MSIT Ternary Evaluation Program, in MSIT


Stuttgart; Document ID: 10.16050.1.20 (1991) (Equi. Diagram, Review, #, *, 17)

[1991Eba] Ebalard, S., Spaepen, F., “Approximants to the Icosahedral and Decagonal Phases in the

Al-Cu-Cr System”, J. Mater. Res., 6(8), 1641-1649 (1991) (Crys. Structure, Experimental,

15)

[1992Oka] Okabe, T., Furihata, J.-I., Morishita, K., Fujimory, H., “Decagonal Phase and

Pseudo-Decagonal Phase in the Al-Cu-Cr System”, Philos. Mag. Lett., 66(5), 259-264


[1992Sel] Selke, H., Vogg, U., Ryder, P.L., “Approximants of the Icosahedral Phase in as-cast

Al65Cu20Cr15”, Philos. Mag. B, 65(3), 421-433 (1992) (Calculation, Crys. Structure, Equi.


[1993Sel] Selke, H., Ryder, P.L., “Decomposition of Icosahedral Quasicrystals in Al-Cu-Cr Alloys”,

Mater. Sci. Eng. A, 165, 81-87 (1993) (Crys. Structure, Equi. Diagram, Experimental, 22)

[1994Mur] Murray, J.L., “Al-Cu (Aluminium - Copper)” in “Phase Diagrams of Binary Copper

Alloys”, ASM, Subramanian, P.R. (Eds), 18-42 (1994) (Calculation, Crys. Structure, Phys.

Prop., Theory, 65)

[1995Kha] Khare, V., Lalla, N.P., Tiwari, R.S., Srivastava, O.N.,“On the New Structural Phases in

Al65Cu20Cr15 Quasicrystalline Alloy”, J. Mater. Res., 10(8), 1905-1912 (1995) (Crys.


[1996Yam] Yamamoto, A., “Crystallography of Quasiperiodic Crystals”, Acta Crystallogr., Sect. A:

Found. Crystallogr., 52, 509-560 (1996) (Calculation, Crys. Structure, Review, 211)

[1997Kha] Khare, V., Tiwari, R.S., Srivastava, O.N., “On the Curious Structural Phases in Al-Deficient

(Al62Cu23Cr15) and Al-Rich (Al68Cu17Cr15) Quasicrystalline Alloys”, Cryst. Res.

Technol., 32(4), 545-552 (1997) (Crys. Structure, Experimental, 9)

[1998Mur] Murray, J.L., “The Al–Cr (Aluminium–Chromium) System”, J. Phase Equilib., 19(4),

368-375 (1998) (Equi. Diagram, Assessment, Calculation, Review, #, *, 43)

314


MSIT®

Al–Cr–Cu

[1999Qi] Qi, Y.H., Zhang, Z.P., Hei Z. K., Dong, C., “The Microstructure Analysis of Al-Cu-Cr

Phases in Al65Cu20Cr15 Quasicrystalline Particles/Al Base Composition”, J. Alloy. Compd.,


[2000Grz] Grzegorzewicz, T., Kuznicka, B., Krajczyk, L., “Modifying Effect of Zirconium on an

Aluminium-Chromium Bronze”, Z. Metallkd., 91(6), 489-493 (2000) (Equi. Diagram,


[2001Pon] Ponkratz, U., Nicula, R., Jianu, A., Burkel, E., “In Situ High Pressure X-ray Diffraction

Study of Icosahedral Al-Cu-TM (TM = V, Cr, Mn) Alloys”, J. Phys., Condens. Matter, 13,



System”, Abstr. VIII Int. Conf. ”Crystal Chemistry of Intermetallic Compounds”,


[2003Ans] Ansara, I., Ivanchenko, V., “Cr-Cu (Chromium-Copper)”, MSIT Binary Evaluation


Services GmbH, Stuttgart, to be published, (2003) (Equi. Diagram, Assessment, 29)

[2003Cor] Cornish, L., Saltykov, P., Cacciamani, G., Velikanova, T., “Al-Cr (Aluminum -

Chromium)”, MSIT Binary Evaluation Program, in MSIT Workplace, Effenberg, G. (Ed.),

MSI, Materials Science International Services GmbH, Stuttgart, to be published, 2003

(Equi. Diagram, Review, 51)



Stuttgart, to be published, (2003) (Equi. Diagram, Review, 68)


Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group

Prototype

Lattice Parameters

[pm]

Comments/References

(Al)

< 660.452

cF4

Fm3m

Cu

a = 404.96 [Mas2], pure Al at 24°C

(Cr)

< 1863

cI2

Im3m

W

a = 288.4 [V-C], pure Cr at 27°C

(Cu)

< 1085

cF4

Fm3m

Cu

a = 361.48 [V-C], pure Cu at 25°C

CrAl7(Cr2Al13)

mC104

C2/m

V7Al45

a = 2519.6

b = 757.4

c = 1094.9

= 128.7

at room temperature 13.5 at.% Cr

[2003Cor]

315


MSIT®

Al–Cr–Cu

Cr2Al11

(CrAl5)

Orthorhombic

oC584

Cmcm

a = 1240

b = 3460

c = 2020

a = 1252.1

b = 3470.5

c = 2022.3

a = 1260

b = 3460

c = 2000

quenched from 920°C

16.9 to 19.2 at.% Cr;

[2003Cor]

single crystal

“ CrAl4”

[2003Cor]

“ CrAl4” [2003Cor]

, CrAl4< 1031

hP574

P63/mmc

MnAl4

a = 1998

c = 2467

a = 2010

c = 2480

at room temperature,

20.9 ± 0.3 at.% Cr [2003Cor]

20.6 to 21.2 at.% Cr [2003Cor];

22.3 ± 0.1 at.% Cr

at Cr-rich border at 1000°C [2003Cor]

Cr4Al9 cI52

I43m

Cu4Al9

a = 912.3 ~31 to 45 at.% Cr quenched from liquid

[1941Kna, Mas2];

29 at.% Cr at Al-rich border at 920°C

[2003Cor]

Cr4Al9< 700 (?)

hR52

R3m

Cr4Al9

a = 1291

c = 1567.7

32.8 to 35 at.% Cr

[Mas2, 2003Cor]

, Cr4Al9 1060

---

---

---

--

---

---

Cr5Al8 1100 (?)

cI52

I43m

Cu5Zn8

a = 910.4 to 904.7 30 to 42 at.% Cr, quenched from liquid

[1989Ell]

Cr5Al8 1100 (?)

hR26

R3m

Cr5Al8

a = 1271.9

c = 793.6

a = 1272.8

c = 794.2

a = 1281.3

c = 795.1

[1977Vis, Mas2]

[1977Bra]

[1989Ell]

, Cr2Al

< 910

tI6

I4/mmm

MoSi2

a = 300.45

c = 864.77

a = 300.5 to 302.8

c = 864.9 to 875.5

~65.5 to ~71.4 at.% Cr

[1937Bra, 1963Koe, 1998Mur]

[1989Ell]

1 cF16

Fm3m

BiF3

a = 585 Metastable, supercell of [1994Mur]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group

Prototype

Lattice Parameters

[pm]

Comments/References

316


MSIT®

Al–Cr–Cu

2, Cu1-xAlx< 363

-

long period

superlattice

TiAl3)

a = 366.6

c = 367.5

a = 366.8

c = 367.7

a = 366.8

c = 368.0

[1985Mur], at 77.9 at.% Cu

[1985Mur], at 77.2 at.% Cu

[1985Mur], at 76.4 at.% Cu

solid solubility ranges from 76.5 to 78.0

at.% Cu

, Cu1-xAlx1037-964

cI2

Im3m

W

- [1985Mur], solid solubility ranges from

67.6 to 70.2 at.% Cu

0, Cu2Al

1037-800

cI52

I43m

Cu5Zn8

- [1985Mur], solid solubility ranges from

59.8 to 69.0 at.% Cu

1, Cu9Al4 890

cP52

P43m

Cu9Al4

a = 871.32 [V-C], at 69.23 at.% Cu


at.% Cu

, Cu1-xAlx< 686

hR*

R3m

a = 1226

c = 1511

[1985Mur, V-C], at 61.6 at.% Cu


at.% Cu

1, Cu1-xAlx958-848

cubic(?) - [1985Mur], solid solubility

ranges from 59.4 to 62.1 at.% Cu

2, Cu2-xAlx850-560

hP6

P63/mmc

Ni2In

a = 414.6

c = 506.3

[V-C], at 57.5 at.% Cu


at.% Cu

1, Cu47.8Al35.5(h)

590-530

oF88 - 4.7

Fmm2

Cu47.8Al35.5

a = 812

b = 1419.85

c = 999.28

55.2 to 59.8 at.% Cu [Mas2, 1994Mur]


2, Cu11.5Al9(r)

< 570

oI24 - 3.5

Imm2

Cu11.5Al9

a = 409.72

b = 703.13

c = 997.93

55.2 to 56.3 at.% Cu [Mas2, 1985Mur]


1, CuAl(h)

624-560

o*32 a = 408.7

b = 1200

c = 863.5

49.8 to 52.4 at.% Cu

[V-C2, Mas2, 1985Mur]


2, CuAl(r)

< 560

mC20

C2/m

CuAl(r)

a = 1206.6

b = 410.5

c = 691.3

= 55.04°

[1985Mur], unknown composition,


at.% Cu

, CuAl2< 591

tI12

I4/mcm

Al2Cu

a = 606.3

b = 487.2


at.% Cu [V-C]

* 1, Cr23Cu20Al57

< 800

? - [1972Pre], nominal solid solubility

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group

Prototype

Lattice Parameters

[pm]

Comments/References

317


MSIT®

Al–Cr–Cu

* 2, Cr20Cu10Al70

< 800

? - [1972Pre], Al varies from 70 to 75 at.%

and Cu varies from 5 to 10 at.%

* 3, Cr15Cu13Al72

< 800

? - [1972Pre], nominal solid solubility

* 4, Cr15Cu18Al67 hP* a = 1282.0

c = 1271.0

[1972Pre], nominal solid solubility

* 5, Cr4.5Cu31Al64.5 oP* a = 409.04

b = 349.82

c = 290.28

[1981Che], nominal solid solubility

* 6, Cr17Cu8Al75 ? - [1981Che], Cr varies from 16.2 to 18.0

at.% and Cu varies from 5.2 to 8.6 at.%







Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group

Prototype

Lattice Parameters

[pm]

Comments/References

Cr 2.50Cu 0.00Al 97.50

Cr 0.00Cu 2.50Al 97.50


Axes: at.%

200300

400

500

Fig. 1: Al-Cr-Cu.

Solvus surface of the

(Al) phase

318


MSIT®

Al–Cr–Cu

10

20

10 20

80

90

Cr 25.00Cu 0.00Al 75.00

Cr 0.00Cu 25.00Al 75.00


Axes: at.%

CrAl5

CuAl2

E

(Al)

Cr7Al45

0.2 at.%1.1 at.%

Fig. 2: Al-Cr-Cu.

Liquidus surface of

the Al-corner

20

40

60

80

20 40 60 80

20

40

60

80

Cr Cu


Axes: at.%

(Cu)

β

γ1

δ

ε2

η1

L

(Al)

CrAl7

µαCr4Al9

βCr4Al9

αCr5Al8

η

(Cr)(Cu)+β+(Cr)

γ1+η+(Cr)

η+γ1+αCr5Al8

τ1

τ2 τ4

τ3

β+γ1+(Cr)

(Cr)+(Cu)

Fig. 3: Al-Cr-Cu.Isothermal section at

600°C

319


MSIT®

Al–Cr–Cu

20

40

60

80

20 40 60 80

20

40

60

80

Cr Cu


Axes: at.%

(Cr)

η

αCr5Al8

βCr4Al9

αCr4Al9

µ

CrAl7

(Al)

η2

µ2

δγ1

(Cu)

τ8

τ9

τ7

τ6

τ5

(Cr)+(Cu)

(Cr)+γ1

η+γ1+αCr5Al8

θ

80 90400

500

600

700

800

Cr 1.70Cu 22.40Al 75.90

Cr 1.30Cu 0.00Al 98.70Al, at.%

Tem

pera

ture

, °C

(Al)+Cr7Al45+CuAl2

(Al)+Cr7Al45

L+(Al)+Cr7Al45

L+Cr7Al45

L+CuAl2+Cr7Al45

L

L+CrAl5+Cr7Al45

L+CrAl5

Fig. 4: Al-Cr-Cu.


room temperature

Fig. 5: Al-Cr-Cu.

Vertical section at

2.5 mass% Cr

320


MSIT®

Al–Cr–Fe

Aluminium – Chromium – Iron

Gautam Ghosh, updated by Tamara Velikanova, Kostyantyn Korniyenko, Vladislav Sidorko

Literature Data

Although the Al-Cr-Fe system has undergone many investigations, the Al-Cr-Fe equilibrium diagram has

not been determined in the whole composition range. After assessment of [1991Gho] in accordance with

which there are no ternary phases in the system, many reports with data on ternary phases in the Al-rich part

of phase diagram appeared. The major part of the earlier work has been done by Kornilov [1940Kor1,

1940Kor2, 1945Kor, 1946Kor] and Kozheurov [1970Koz1] and [1970Koz2]. Kornilov used Armco grade

Fe (0.25 mass% C, 0.05 mass% Si and traces of Mn), Al pigs (0.1 mass% Si, 0.1 mass% Cu), Al powder

(0.1 mass% Si, 0.1 mass% Cu), chromium oxide of unspecified purity and analytically pure iron oxide. The

Fe and Cr rich alloys were prepared by the aluminothermic process, which was also used by other

investigators [1932Tai1, 1932Tai2, 1943Mon, 1951Pra, 1953Cas, 1954Chi, 1955Tag] and [1958Chu].

Thermal analysis was performed to monitor the solidification process in an induction furnace in insulated

corundum crucibles and under an inert atmosphere of He-Ar. [1932Tai1] and [1932Tai2] used Armco grade

Fe (0.14 mass% Si), Al (0.17 mass% Si, 0.6 mass% Fe), and the liquidus surface was determined by thermal

analysis. Atomic ordering and lattice parameters of Cr1-xFexAl alloys were studied by [1969Kal] using

neutron diffraction. [1951Pra] have experimentally determined two isothermal sections at 425 and 600°C,

in the Al-rich corner. [1958Chu] determined isothermal sections using high-purity Al (99.994 mass%),

iodide Cr (99.988 mass%), and electrolytic Fe (99.994 mass%) having extremely low contents of interstitial

elements C, H, O, and N. Alloys were prepared by arc melting, followed by homogenizing treatment at

1000°C for 100 h. Final heat treatments were done under an argon atmosphere in silica capsules with

subsequent quenching into water. Phase analysis was carried out by optical metallography, X-ray

diffraction, and hardness testing. [1955Tag] and [1958Tag] studied the effect of Al addition to Cr-Fe binary

alloys on the formation of the phase by means of optical microscopy, X-ray diffraction and hardness

measurements. The effect of Cr on the stability of 1Fe3Al and 2FeAl and the transition from ( Cr), ( Fe)

or 1 to 2 has been studied by X-ray diffraction, dilatometry [1968Bul, 1969Bul1] and [1969Bul2] and

also by high-temperature X-ray diffraction [1969Sel]. The details of the ordering nature in the ternary

(Cr,Fe)3Al alloys have been studied by X-ray and neutron diffraction [1972Kaj, 1974Niz, 1975Lit] and

[1977Tys]. [1982Yea] investigated Al-based alloys of four compositions prepared by extrusion at 260°C

and annealed at 400°C for 100 h. [1997Pal] reported an isothermal section in the Al-rich corner at 1000°C

established by metallography, EMPA and X-ray investigations of quenched samples. [1997Pal] used iron

99.97, aluminium 99.99, and chromium 99.53 mass% with 0.35 mass% iron as a main impurity. Alloys of

18 compositions with more than 50 at.% Al were prepared by levitation melting and annealed at 1000°C for

100 h followed by quenching in ice brine. [1988Ten, 1989Law1, 1989Law2, 1992Don, 1995Sui, 1995Zha,

1997Sui, 1998Lia, 1999Sui, 2000Mo, 2000Dem, 2001Dem, 2002Dem1] and [2002Dem2] reported ternary

phases of monoclinic, orthorhombic as well as hexagonal structures found in alloys in the range of

compositions 65 to 81 at.% Al and 6 to 15 at % Cr, which were under investigation. Initial Al used in these

studies was of 99.99 or higher purity, Fe 99.5, Cr 99.9 mass%. The alloys were prepared by either arc

melting [1995Sui, 1997Sui, 1998Lia, 1999Sui] or induction levitation melting under pure helium

atmosphere [2000Dem, 2001Dem, 2002Dem1, 2002Dem2] and investigated in the as-cast or annealed state.

[2001Dem, 2002Dem2] annealed the samples at temperatures in the range 900 to 1050°C for 20 h

depending on the alloy and cooled at a conventional rate. TEM, HREM, at a SEM-(EDX, WLDX), XRD

were used for investigation of alloys. [2000Mo] established the crystal structure of the hexagonal ternary

Cr11Fe8Al81 phase, labelled by him as , using TEM, HREM and X-ray diffracton methods. The alloy of

the nominal composition Cr2FeAl12 was prepared by induction melting a mixture of high-purity Al

(99.9999 mass%), Fe (99.5 mass %), and Cr (99.9 mass %) and cooled in a sand bath. The chemical

composition of a hexagonal needle-like single crystal of the Cr11Fe8Al81 phase selected in the cavities of

the cast ingots was determined by electron microprobe analysis. The hexagonal phase is supposed to have

321


MSIT®

Al–Cr–Fe

the largest cell among intermetallics. The icosahedral ternary i phase in coexistence with the Al solid

solution was found by [1995Zia] and [1995Sta] in Cr-3.1Fe-94.7Al and Cr-8Fe-86Al (at.%) alloys,

respectively. The alloys were prepared by induction melting followed by centrifugal atomization after

heating at 1200°C and then degassed at 330°C for 3 h [1995Zia] and by arc melting followed by a spinning

process [1995Sta]. As-cast and annealed alloys were investigated by TEM, SEM-EDX, X-ray, convergent

beam technique (CBT), DSC [1995Zia] and XRD, DSC, Moessbauer spectroscopy and magnetic

susceptibility [1995Sta].

Binary Systems

The Al-Cr and Al-Fe systems are accepted from [2003Cor] and [2003Pis], respectively. Data concerning

the Cr-Fe system are from [Mas2, 1982Kub].

Solid Phases

Crystallographic data on the known unary and binary phases as well as recently reported ternary ones are

listed in Table 1. Seven ternary phases with crystal structures different from those of the binary

intermetallics are reported in the ternary Al rich alloys solidified and consequently (directly or after

homogenization) cooled at conventional rate. One of them, Cr11Fe8Al81, can be believed to be a stable

ternary compound at high temperature. This hexagonal phase investigated by [2000Mo] was found in the

CrFe2Al12 alloy by [1999Sui] as the main phase together with orthorhombic “O-CrFeAl” and monoclinic

“M-CrFeAl”. Body centered orthorhombic phase, labelled as “O-CrFeAl” was observed in Al rich as-cast

alloys (prepared by arc melting) by [1995Sui, 1996Ros, 1997Sui, 1998Lia] and also [2000Dem]. Found

together with O phase, C-centered monoclinic ternary phase “M-CrFeAl” has a structure which is

considered a superstructure of “O-CrFeAl”. The lattice correspondence between the lattice parameters of

the M- and O-phases are as follows:

am = co bo (am = co /sin ),

bm = ao

cm = 2bo

Three orthorhombic phases “O-CrFeAl”, “O1-CrFeAl” and “C3.1-CrFeAl” additionally to Al-solid solution

were found by [2000Dem] in as-cast alloy of Cr11Fe8Al81 nominal composition, prepared by levitation

melting. Phases with the same crystal structure as the two latter ones, O1- and the O3.1-, earlier were

observed in Al-Cr-Cu-Fe by [1992Don], as well as in Al-Mn-Ni and Al-Pd-Ru by [1988Ten] and

[1995Zha], respectively. A new “O2-CrFeAl” phase together with orthorhombic phases “O-CrFeAl”,

“O1-CrFeAl” as well as Al8Cr5, which is isostructural with -brass, were obtained by [2001Dem] in alloys

of the compositions (at.%): Cr-6.0Fe-77.5Al (O+O1+hexagonal phase type), Cr-8.0Fe-72.5Al

O+O2+hexagonal type), Cr-6.0Fe-72.5Al (O1+O), as well as Cr-9.1Fe-67.6Al (hexagonal type). The

alloys after induction melting were annealed in the range 900 to 1050°C for 20 h. The O2-phase is for the

first time observed in this system, but a phase with the same structure was identified before in Al-Cr-Cu-Fe

by [1992Don, 1995Li]. The orthorhombic O1 and O2 phases were observed by [2002Dem1, 2002Dem2] in

the alloy of Cr-6.0Fe-77.5Al (at.%) composition, prepared by induction melting, subsequently crushed and

pressed in a graphite mold and then sintered at 980 and 1060°C. In the alloy of the same composition which

was annealed at 900 to 1050°C for 20 h directly after melting the O1- and O-phases coexist. Both

[2002Dem1] and [2002Dem2] found a -brass-like phase in the Cr-7Fe-65Al (at.%) alloy as single phase

with somewhat shorter lattice parameters. The last fact, which is in agreement with data of [1997Pal] for

1000°C, demonstrates the high solubility of Fe in the Cr8Al5(r) phase, and supports the results concerning

orthorhombic phases. As one can see, most of the investigated alloys were not in an equilibrium state.

Quenching experiments were not made. Except for the Cr11Fe8Al81, the composition of the reported

ternary phases are unknown. The latter may be either ternary compounds or stable or unstable

polymorphous modifications of the binary intermetallics because of their close structural relationship to

each other.

There is a body centred cubic continuous solid solution (Fe,Cr,Al) in the system and a wide field of

ordered phases 2 (FeAl) and 1 (Fe3Al) based on the b.c.c. lattice. FeAl dissolves more than 30 at.% Cr at

322


MSIT®

Al–Cr–Fe

600°C at the equiatomic Al/Fe ratio according to [1991Tre, 1997Pal]. Fe3Al can dissolve a considerable

amount of Cr (more than 26%) [1968Bul, 1969Bul1] and [1969Bul2], which leads to some increase in both

Fe3Al FeAl and FeAl ( Fe) transition temperatures [1969Bul2] and [1969Sel]. [1972Kaj] suggested that

at certain compositions Fe occupies one sublattice while Cr and Al occupy the other. [1993Kni] found that

the alloys on the basis of Fe3Al with 2 and 5 mass% Cr (about 1.3 and 3.3 at.% Cr, respectively) have an

equilibrium structure of the BiF3 type (cF16) at low temperatures which transforms to the CsCl type

structure (cP2) above 500°C. The crystal structures of alloys in a similar range of compositions were

investigated also by [1999Wit]. [1976Vla] studied the decomposition behavior of a Cr-68.3Fe-10.4Al

(at.%) alloy after quenching from 750°C and subsequent annealing at 490°C for up to 200 h by means of

Mössbauer spectroscopy, low-angle X-ray scattering and TEM. Though no ternary phase was detected upon

annealing, the authors observed phase separation into two isomorphous solid solutions which were depleted

or enriched with Cr. Coordinates of the (( Fe)+( Fe))/( Fe) surface of the ( Fe)-loop in the Al-Cr-Fe

system are given in Table 2 based on the microstructural, hardness, electrical resistivity, and dilatometry

results on eight ternary alloys heat treated between 800 and 1300°C [1946Kor].

All binary intermetallics of the ternary system dissolve the third component. Cr2Al is reported by [1969Kal]

to dissolve Fe up to x = 0.25 replacing Cr atoms in the lattice. Data on the lattice parameters of (Cr1-xFex)2Al

as a function of x are listed in Table 1. [1951Pra] reported that the extracted crystals of (Cr2Al13) and

(Cr2Al11) (from alloys cooled slowly to room temperature from the liquid phase) dissolved iron. The

observed compositions of Cr2Al13 and Cr2Al11 at maximum Fe solubilities were Cr-5.49Fe-75.05Al

(mass%) Cr-3.02Fe-85.48Al (at.%)) and Cr-13.47Fe-67.96Al (mass%) Cr-7.73Fe-80.81Al (at.%)),

respectively. [1960Zol1] and [1960Zol2] also analyzed Cr2Al13 crystals from alloys with various Fe

contents. The solid solubility data of [1960Zol1] and [1960Zol2] showed a lower Fe solubility in Cr2Al13

of 2.36 mass% (1.3 at.%) Fe, but it was not certain to be a maximum value. The data of [1951Pra] show that

the replacement of Cr for Fe deviates from a simple one-to-one atomic substitution scheme, but that in

[1960Zol1] and [1960Zol2] is somewhat closer to one-to-one atomic replacement. Solution of Fe in Cr2Al13

is reported to cause a reduction in the lattice parameter of the Cr2Al13 phase [1960Zol1] and [1960Zol2].

FeAl3 is reported to dissolve some Cr, and the FeAl3 composition, according to chemical analysis data, is

Cr-39.89Fe-56.17Al (mass%) (Cr-24.87Fe-72.49Al (at.%)) [1951Pra]. But the value 2.64 at.% for Cr

solubility in FeAl3 can not be accepted as maximal, because according to [1997Pal], the solid solubility of

Cr in FeAl3 at 1000°C is considerably higher - about 6.4 at.%. All Al-rich phases that are in a solid state at

1000°C (based on FeAl3, Fe2Al5, FeAl2, Cr4Al9 and Cr5Al8) extend deep into the ternary system. The

maximum solubilities of the third component at 1000°C are observed for the Cr5Al8 and Cr4Al9 phases -

32.5 and 9.6 at.% Fe, respectively. The lattice parameters of the, Cr5Al8 (r) ( 2) phase versus Fe content are

presented in Fig. 1. [1990Ioa] found that the rapidly solidified alloy Cr-1Fe-95Al (mass%)

(Cr-0.5Fe-97.37Al at.%)) exhibits a mixed microstructure composed of featureless and cellular

morphologies. According to X-ray data, the equilibrium Cr2Al13 phase coexists in the alloy with the

aluminium matrix and an unknown phase. Taking into account the data of [1995Zia] and [1995Sta], the

latter could be a ternary quasicrystalline phase with an icosahedral symmetry, see Table 1. [1995Zia] found

the i phase, named Q by him, in the Cr3FezAlx (z = 0, 1 or 3 at.%) alloys, using X-ray diffraction. The

accepted composition of the phase Cr12±1Fe12±1Al75±0.5, was established using chemical microanalysis.

During the “low” temperature sequences of the rapidly solidified alloys, the Q phase reacts with the Al

matrix giving rise to the non-equilibrium and equilibrium phases: (Al)+Q FeAl6+Cr2Al13+FeAl3. At

higher temperatures (450 to 550°C), the quasicrystal transforms directly into the stable phases, by-passing

the step of the metastable FeAl6 phase formation. At the quasicrystal/matrix interface the orthorhombic

phase was observed. According to EDX analysis, the ratio (Al)/(Cr+Fe) is equal to 3.1 ± 0.1 and the content

of Cr << 1 at.%. [1995Zia] concludes that this phase is the allotropic variant of FeAl3, which is monoclinic

in the binary system. The structure of the i phase, found in a melt spun alloy of Cr8Fe6Al86 (at.%)

composition, is reported by [1995Sta] as simple icosahedral type with the value of the six-dimensional

hypercubic lattice constant a6D = 654.2 ± 0.02 pm. In a rapidly solidified alloy, the i phase coexisted with

the Al-solid solution. This mixture transformed to a mixture of stable phases Cr2Al13+FeAl3 after 5 min.

heating at 580 or 635°C. Earlier a metastable icosahedral ternary phase was also reported by [1987Wou,

1988Man, 1989Man, 1988Sch, 1989Law1, 1989Law2].

323


MSIT®

Al–Cr–Fe


Figure 2 gives the tentative invariant equilibria for the Al-rich corner. The equilibrium L+Cr2Al11+FeAl3within the ternary is not known, while equilibrium L+Cr2Al13+FeAl3 is unquestioned because the existence

of the three-phase equilibrium Cr2Al13+FeAl3+(Al) is established well at temperatures close to the solidus:

500°C [1995Zia] and 635°C [1995Sta]. [1943Mon] suggested that the invariant U1 reaction takes place at

Cr-4.2Fe-93.7Al (mass%), but the temperature was not given. Careful thermal analysis data of [1932Tai1]

and [1932Tai2] show the presence of a ternary eutectic E at Cr-2Fe-97Al (mass%). On the other hand,

[1943Mon] and [1976Mon] suggested that E takes place at Cr-1.70Fe-97.95Al (mass%), to which there is

no experimental evidence. It remains inconclusive whether the ternary eutectic reaction E exists or not.

Thermodynamic calculations of the Al-rich corner of the Al-Cr-Fe system by Saunders [1987Sau] suggest

that the reaction E is unlikely and instead he predicted a ternary transition U1 reaction

L+Cr2Al11 Cr2Al13+FeAl3 at 709°C (0.63 mass% (0.33 at.%) Cr, 3.09 mass% (1.52 at.%) Fe) followed by

the ternary transition U2 reaction L+Cr2Al13 (Al)+FeAl3 at 654.5°C (0.19 mass% (0.10 at.%) Cr, 2.02

mass% (0.99 at.%) Fe). The latter shows a good agreement with the findings of [1960Zol2] and [1973Wil]

showing no ternary eutectic reaction at 640°C, but a transition reaction at 655°C. Because of this

uncertainty, alternative paths for E and U are given by broken lines in Fig. 2.

Liquidus Surface

Figures 3 and 4 show two versions for the liquidus surface of the Al corner. Fig. 3 is presented after

experimental data [1932Tai1, 1932Tai2] and [1943Mon]. The melting troughs separate 4 different areas of

primary crystallization. Ternary alloys from 100 to about 94 at.% Al have been investigated by different

authors [1932Tai1, 1932Tai2, 1951Pra, 1954Chi, 1960Zol1, 1960Zol2], and no ternary compound has been

reported by them in this composition range. The presence of the ternary eutectic E is concluded from

thermal analysis data of [1932Tai1] and [1932Tai2], even though limited thermal analysis results of

[1960Zol1] and [1960Zol2] failed to confirm it. Figure 4 is the calculated liquidus surface of the Al corner

after [1987Sau], showing the presence of the transition invariant reaction U2 instead of ternary eutectic

reaction. [1951Pra] failed to observe the (Cr2Al11) phase in binary and ternary alloys either slowly-cooled

or quenched from 730 to 765°C. In accordance with the old version of the Al-Cr binary phase diagram

adopted by [1951Pra], in which a reaction L+ takes place at 755°C instead of 790°C in the presently

accepted binary phase diagram, the obtained result seems to reject the existence of the stable Cr2Al11

compound. Nevertheless, these data are in good agreement with the Al-Cr phase diagram accepted in this

assessment. But there is no confidence that the equilibrium L+ +FeAl3 exists. It can be prevented by

possible formation of high-temperature incongruently melting ternary compounds with aluminium content

less than 94 at.%. Therefore the monovariant curves in the vicinity of U1 are dotted. The liquidus surface in

Fig. 5, after [1945Kor], shows a melting trough defining the primary crystallization field of (Cr, Fe).

Approximate isotherms at 50 K intervals are also shown. [1935Gru] reported the melting point of a

Cr-64.6Fe-5.3Al (mass%) Cr-59.86Fe-10.17Al (at.%)) alloy which agrees reasonably well with Fig. 5.

[1970Koz1] and [1970Koz2] compared the calculated and experimental results for liquidus points for

compositions from the Cr corner to about 70 mass% Fe and 40 mass% Al. The experimental values were

always 30 to 40 K lower than calculated ones, which was attributed to undercooling. Nevertheless, the

isotherms between 1500 and 1800°C agree well with those of [1945Kor]. The original publications

[1940Kor1, 1940Kor2, 1945Kor, 1946Kor] show the liquidus surface of (Cr, Fe) as terminated by the

uninterrupted monovariant curve p1p2, corresponding to the equilibrium of liquid with the (Cr, Fe) phase

and assumed continuous solid solution of the binary 1 and phases. There is reason to believe that the 1

phase has a cubic structure. If the cubic phase is isomorphous with 1, the continuous cubic solid solution

in the ternary system is possible at high temperatures. But until now the existence of a ( , ) continuous

series has not been established.

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Isothermal Sections

Figure 6 shows the isothermal section at 1150°C based on data of [1945Kor, 1946Kor] and [1991Tre,

1997Pal]. In the original paper [1946Kor], the two-phase “ 3+ 3” field is not very clear. Even though “ 3”

is the ternary (Cr, Fe) solid solution and 3 is the or phase, the authors made very little investigation of

the “ 3” phase and they interpreted it as a continuous solid solution between (Fe2Al3) and 1 (Cr5Al8)(h)

[1946Kor]. Since the crystal structure of is unknown, better evidence for the existence of a continuous

solid solution between (Fe2Al3) and 1 (Cr5Al8)(h) is required. On the other hand, [1997Pal] established

a large extension of 2 into the ternary system - up to 32.5 at.% Fe at about 48 at.% Al at 1000°C. The 2/

transition of the second order is shown according to the binary Al-Fe system and data of [1991Tre] on an

FeAl-Cr polythermal section. Figures 7, 8, 9, 10, and 11 show isotherms at 900, 750, 700, 650, and 600°C,

respectively, after [1958Chu], with correction in the range of the ordering of the phase according to the

experimental data of [1991Tre]. Phase equilibria between the -brass type phases are assumed by taking

into account the data of [1997Pal] for 1000°C. Phase equilibria in the Al-corner are presented after data of

[1951Pra, 1961Phi, 1995Zia, 1995Sta]. Annealing times for different alloys used by [1958Chu] are listed

in Table 3. More than 50 ternary alloys were studied by [1958Chu], most of them near the region of phase

formation. As one can see in the isothermal sections at 750, 700, 650, and 600°C, the extent of the phase

field decreases with increasing Al content. This is in agreement with the results of [1945Kor]. Even though

the phase (Cr2Al) is stable up to 911°C according to the accepted Al-Cr binary phase diagram, this phase

does not appear in the isothermal section at 900°C shown in Fig. 7. Such a difference of 11 K is not

unreasonable when comparing data from different sources [1980Riv]. In his original paper, Chubb

[1958Chu] presented a wide two-phase 2+ field in all isothermal sections of the ternary system, as well

as two three-phase ( Fe)+FeAl 2+Cr2Al( ) and FeAl 2+Cr2Al( )+Cr4Al9( ) ones, the latter two being

contiguous, which is not likely. The existence of the wide 2+ field, because of very narrow (to 1 or 2 at.%

Cr) 2 region shown by [1958Chu], is rather doubtful when the data of [1991Tre] and [1997Pal] are taken

into account. FeAl dissolves at 1000°C about 30 at.% Cr at 45 at.% Al after [1997Pal]. In agreement with

the above mentioned data, [1991Tre] showed that the extension of 2 in the FeAl-Cr section increases with

decreasing temperature down to about 28 at.% Cr at 36 at.% Al at 1000°C. The phase transition / 2 of the

second order in binary Al-Fe at high temperatures becomes first order below 665°C [1993Oka, 2003Pis]. A

rise in the / 1 temperature with increasing Cr content is reported by [1968Bul, 1969Bul1] and [1969Bul2].

The influence of Cr on the type of the ordering transition / 2/ 1 in ternary solid solution has not been

studied in detail. In the isothermal sections at 900, 750, 700, 650, and 600°C, phase ordering is presented

based on binary Al-Fe as well as on the compared data of [1991Tre, 1997Pal]. There is some contradiction

between the results of [1958Chu] and those of [1955Tag] and [1958Tag] as far as the formation of the

phase in the ternary alloys is concerned. Based on the purity of the material, heat treatment regime and

number of alloys used, the results of [1955Tag] and [1958Tag] seem to be more reliable than those of

[1958Chu]. The results of [1955Tag] and [1958Tag] on phase formation in alloys containing up to 32

mass% Al are in accordance with those of [1958Chu], but they disagree with [1958Chu] for ternary alloys

containing 35 mass% Cr. It should be emphasized that the formation of the phase is reported to be

sensitive to non-equilibrium factors arising from impurities in ternary alloys [1955Tag, 1969Mue]. Phase

equilibria above 50 at.% Al proposed in Figs. 7 to 11 are based on significant solubility of Fe in ( ) phases

at 1000°C found by [1997Pal]. A very strong temperature dependence of the solubility of Fe in and

phases can be assumed taking into account the low thermodynamic stability of the binary phase, which

coexists in equilibrium with and is stable only within close limits of the equilibrium parameters at high

temperature. It is seen in the isothermal sections. The isothermal section at 1000°C for Al content greater

than 50 at.% is presented in Fig. 12 according to [1997Pal]. The data presented by [1997Pal] for the ternary

alloys fit well to those for Al-Fe [Mas2] and Al-Cr [1992Cos, 1995Aud], respectively, as accepted in the

[2003Cor] assessment of Al-Cr. The Al solubility within the ternary Fe based solid solutions is near to that

for 1150°C but higher than reported for 900°C by [1958Chu]. While no ternary intermetallic phases have

been found at 1000°C in this work, in contradiction to above mentioned observation of the ternary phases,

the solubility of the third component in the Al-Cr and Al-Fe binary phases in some cases is very high.

Solubility of Fe in the 2 phase reaches about 30 at.% at 10 at.% Cr and 60 at.% Al. Fe stabilizes the 2

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Al–Cr–Fe

structure so that at a content higher than about 13 at.% Fe only the 2 phase (but not 1) is reported to

participate in phase equilibria at temperatures under investigation. The solubility of Cr in the Al-Fe binary

phases is less than that of Fe in the binary Al-Cr phases as seen in Table 1. When the aluminium content

exceeds 80 at.%, the liquid and liquid-solid regions appear. Fig. 13 shows the partial isothermal section for

the Al corner at 600°C, according to the data of [1951Pra, 1961Phi]. [1951Pra] reported that undercooling

suppresses the reaction L+Cr2Al11 Cr2Al13 in both binary and ternary alloys. In the composition range

shown in Fig. 13, no ternary phase has been reported and the phase fields remain the same at 425°C with a

small shift in the phase boundaries [1951Pra]. Saunders [1987Sau] calculated the isothermal sections of the

Al-rich corners at 600 and 425°C. The agreement between the calculated (presented by dashed line in Fig.

13) and the experimental (Al)+Cr2Al13/(Al)+Cr2Al13+FeAl3 phase boundary accepted by [1951Pra] was

reported to be very good, whereas that for the (Al)+FeAl3/(Al)+Cr2Al13+FeAl3 boundary was less

satisfactory. After [1995Zia, 1995Sta], in ternary alloys at Al contents greater than 94 at.% at 635°C and

below, only (Al), Cr2Al13 and FeAl3 phases coexist in equilibrium, in agreement with [1951Pra, 1961Phi]

and [1987Sau]. The sections through the surface (( Fe)+( Fe))/( Fe) of the -loop in the ternary system

are given in Fig. 14. Further work is necessary to clarify the phase equilibria in the Al corner of the system.


Figure 15 shows the polythermal FeAl-Cr section of the phase diagram according to [1991Tre]. The alloys

containing up to 70 at.% Cr were prepared by arc melting from aluminium (99.5 mass% purity), electrolytic

chromium and carbonyl iron. The annealings were carried out at 1200°C and 1300°C for 70 h each. As can

be seen from Fig. 15, the temperature of the 2 transformation decreases with increasing the chromium

content. The 2 field extends to about 28 at.% Cr at 1000°C. Fig. 16 shows the variation in the

order-disorder reaction temperature as a function of the Cr content along the Fe3Al-CrFe3 section. In the

Fe3Al-CrFe3 isopleth taken from [1969Bul1], additional dashed boundaries are given approximately

according to the phase transformations in Fe75Al25 (at.%) by [1993Oka]. The partial isopleth along

Fe3Al-Cr3Al [1969Bul1] is in poor agreement with the general data set discussed above and is not

considered here.

[1946Kor] gave four isopleths at constant mass ratios Cr/Fe. These diagrams partially contradict the

isothermal sections shown in Figs. 6, 7, 8, 9, 10, 11, 12 and therefore are not reproduced here.

Thermodynamics

Information on thermodynamic properties of the Al-Cr-Fe alloys is incomplete. [1975Kau] used a simple

thermodynamic model to calculate the phase boundaries between liquid and (Cr, Fe) at 1747, 1647, 1547

and 1527°C. In general, there is a substantial disagreement between the calculated [1975Kau] and the

experimental phase boundaries [1970Koz2]. Applying a defect model, [1988Hoc] calculated the activity of

Cr in FeAl, assuming that FeAl is either a compound or a solid solution. The calculated results do not show

a significant discrepancy and both cases suggest complete solid solubility between Cr and FeAl. [1992Hil]

studied the vaporization of the alloy Cr-75.4Fe-4.8Al (mass%) (Cr-70.72Fe-9.32Al (at.%)) using Knudsen

effusion mass spectrometry in the temperature range 1313-1556 K. This composition virtually agrees with

those of the commercial Aluchrom and MA956 alloys. The obtained thermodynamic data are presented in

Tables 4 and 5. The heat capacities of the Fe3Al-based compound with a Cr content of 5 at.% have been

measured in the temperature range from 20 to 700°C by [1997Rud]. The results of the Cp(T) measurement

are shown in Fig. 17. [2000Sub] have reported a thermodynamic assessment of the Al-Cr-Fe system, which

was performed applying the standard CALPHAD methodology. There the old version of the Al-Cr phase

diagram [Mas2] was accepted, and no ternary phases have been assumed. A four-sublattice model for the

-brass type phases was developed. [2001Sch] calculated isopotential curves of the thermodynamic forces

for ternary diffusion as a function of composition for the Al-Cr-Fe system at 1073 and 1273 K.

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Al–Cr–Fe


Mechanical properties of the Al-Cr-Fe alloys were investigated by [1982Nao, 1991Pra, 1991Sik1,

1991Sik2 1993Kni, 1996Jim, 1998Su] and [2000Spi]. In particular, [1982Nao] obtained the ductile

supersaturated ferrite solid solution with high hardness and strength by the rapid quenching technique. The

range of its formation is limited to less than about 35 at.% Cr and 23 at.% Al. The hardness, yield strength

and tensile fracture strength increase with increasing amounts of chromium and aluminium. [1991Pra]

studied mechanical properties of ordered alloys in the composition range 50 to 80 at.% Fe, 0 to 20 at.% Cr,

that were rapidly solidified by melt spinning. An increasing preponderance of cleavage fracture with

increasing ternary substitution for iron was observed. Mechanical properties of Fe3Al-based alloys were

investigated by [1991Sik1, 1991Sik2] and [1993Kni]. According to [1991Sik1], room-temperature tensile

ductility of the samples with 2 to 5 mass% Cr (1.3 and 3.3 at.%, respectively) approach 20%, which should

be acceptable for many practical applications, and [1993Kni] established that increasing the Cr content from

2 to 5 mass% has a small effect on the ductility of the alloys based on Fe3Al. The tensile properties of the

Cr-65Fe-30Al (at.%) alloy in air and in vacuum were investigated by [1998Su]. The yield strength of the

Fe3Al alloy was reduced by the addition of 5 at.% Cr, indicating a softening with the addition of chromium,

but the ultimate tensile strength (UTS) was increased slightly. [1996Jim] studied the creep behavior of

several Al-Cr-Fe alloys ranging in aluminium from 21.7 to 48 at.% and established that the ternary alloys

exhibit an improvement in strength under high temperature compressive creep. The microstructure of four

Al-Cr-Fe alloys containing 9.3 to 18.0 at.% Cr and 7.6 to 25.5 at.% Al was investigated by [2000Spi] using

TEM after different heat treatments and different degrees of compressive deformation. The maximum of

the work-hardening curves is found to be shifted to higher strains with increasing aluminium concentration.

At a deformation temperature of 400°C dynamic strain aging occurs. [1976Vla] investigated three alloys

(mass%): Cr-7Fe-92Al, Cr-7.0Fe-92.5Al and Cr-7.0Fe-91.5Al (in at.%: Cr-3.5Fe-95.9Al, Cr-3.5Fe-96.2Al

and Cr-3.5Fe-95.7Al) designed to be used at elevated temperatures. Extrusion bars were made from

powders. The as-extruded and annealed at 482°C alloys, investigated by optical microscopy, TEM and

XRD, had a microstructure consisting of equiaxed grains of aluminium matrix and two types of precipitates,

namely (Cr,Fe)Al3 and a metastable (Cr,Fe)Al6 phase.

Data on the magnetic behavior of the Al-Cr-Fe alloys were obtained by [1969Kal, 1974Niz, 1975Lit,

1983Bus, 1985Okp, 1995Sta] and [1997Sat]. [1969Kal] studied the antiferromagnetic behavior and Neel

temperature of ternary alloys based on the (Cr2Al) phase. [1974Niz] and [1975Lit] reported the magnetic

atomic moment, Curie temperature, temperature dependence of magnetic coercivity and susceptibility in the

temperature range from 627 to -196°C. [1983Bus] obtained the values of Curie temperature, saturation

moment at 4.2 K and Kerr rotation angle for the CrFe2Al alloy annealed at 800 K (527°C) for 11 d.

[1985Okp] studied the ferromagnetism of ternary alloys based on FeAl, with Cr contents up to 50 at.%,

quenched from 830°C. Ferromagnetism was observed in alloys with Cr contents no less than 35 at.%.

[1995Sta] investigated magnetic susceptibility of the Cr8Fe6Al86 (at.%) alloy solidified by melt spinning,

of the phase content i+ +FeAl3+(Al). The icosahedral symmetry was concluded not to produce any

magnetic properties in the studied alloy. [1997Sat] determined the magnetic moment of chromium in

Fe3Al-based alloys with chromium content up to 15 at.% in the temperature range 10 to 300 K. The overall

moment was found to be small and that of neighboring iron atoms was reduced by about 0.1 B per Cr atom.

[1982Nao] reported that the room temperature electric resistivity of the alloys with less than about 35 at.%

Cr and less than 23 at.% Al increases with increasing chromium and aluminium contents and reaches a

maximum value for the Cr30Fe50Al20 (at.%) alloy. The temperature coefficient of resistivity in the

temperature range between room temperature and 500°C decreases with increasing chromium and

aluminium contents and becomes zero in the vicinity of 20 to 30 at.% Cr and 15 at.% Al. The influence of

aluminium on the kinetics of phase formation in alloys at the equiatomic Cr/Fe ratio with fine- and

coarse-grained structures was studied by [2000Bla] using 57Fe Mössbauer spectroscopy. It was found that

the addition of 0.2 at.% Al slightly accelerated the kinetics in the coarse-grained samples, and practically

did not affect in the fine-grained samples. On the other hand, doping with 1 at.% Al resulted in a significant

retardation of the phase formation both in the fine-grained samples as well as in the coarse-grained

samples. [2001Dem] presented the results of surface oxidation studying on the alloys containing the

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O1-(CrFeAl) and O2-(CrFeAl) phases. It was found that under mild conditions only aluminium oxidizes,

but under extreme conditions (water immersion at room temperature, or oxygen exposure at high

temperatures), chromium oxidizes as well. [2001Rod] obtained a nanocomposite with an amorphous matrix

containing metallic nanocrystals through the controlled crystallization of an amorphous Cr-5Fe-90Al (at.%)

alloy. Milling of this alloy for 60 h resulted in the formation of amorphous and nanocrystalline regions and

the crystallization temperatures for the primary and intermetallic phases occurred with an interval of 50°C.

The effect of heat treatment and grain size on the damping capacity of the Cr-70Fe-5Al (mass%)

(Cr-63.4Fe-12.3Al (at.%)) has been investigated by [2002Zho]. It has been shown that annealing

temperature and grain size have a significant influence on the damping capacity and strain amplitude

dependence of this alloy. It has a rather low damping capacity after being water quenched or cold worked

due to a high internal stress in the structure. [2002Dem2] studied the optical conductivity of the ternary

phases and interpreted the obtained data on the basis of a tunneling transition. Good agreement between the

obtained results and a theoretical approach developed for aperiodic intermetallics assuming an anomalous

diffusion of the electron wavepacket was found.

Miscellaneous

[1970Koz3] reported the solubility of C in liquid Al-Cr-Fe alloys at different temperatures. [1974Vya] used

the “simplex lattice method” to construct the liquidus and solidus surfaces and reported a good agreement

with data of [1970Koz1].

References

[1932Tai1] Taillandier, M.CH., “Contribution to Al-Fe-Cr Alloys, Part I” (in French), Rev. Metal., 29,

315-325 (1932) (Equi. Diagram, Experimental, #, *, 8)

[1932Tai2] Taillandier, M.CH., “Contribution to Al-Fe-Cr Alloys, Part II” (in French), Rev. Metall., 29,

348-356 (1932) (Experimental, 19)

[1934Osa] Osawa, A., “X-Ray Analysis of Fe-Al Alloys. The 2nd Report”, Metals & Alloys, 5, 154

(1934) (Crys. Structure, Review)

[1935Gru] Grunert, A., Hesselbruch, W., Schistal, K., “On the High Heat-Resistant Cr-Al-Fe Alloys

with and without Cobalt” (in German), Electrowaerme, 5, 131-132 (1935) (Experimental, 2)


Diagram”, J. Inst. Met., 60, 319-337 (1937) (Equi. Diagram, Crys. Structure, Experimental,

8)

[1940Kor1] Kornilov, I.I., Mikheev, V.S., Kornenko-Gracheva, O.K., “Equilibrium Diagram of the

Ternary Fe-Cr-Al System (Preliminary Communication)” (in Russian), Stal', (5/6), 57-59

(1940) (Equi. Diagram, Experimental, #, *, 3)

[1940Kor2] Kornilov, I.I.V, “New Heat-Resistant Fe-Cr-Al Alloys with High Electrical Resistance” (in

Russian), Izv. Akad. Nauk SSSR, Ser. Khim., (5), 751-757 (1940) (Experimental, 15)

[1943Mon] Mondolfo, L.F., “Al-Cr-Fe”, in “Metallography of Aluminum Alloys”, John Wiley & Sons

Inc., New York, 70-71 (1943) (Equi. Diagram, Review, #, *, 1)

[1945Kor] Kornilov, I.I., “Alloys of Fe-Cr-Al” in “Iron Alloys” (in Russian), Vol. 1, Akad. Nauk

SSSR, Leningrad, Moscow (1945) (Equi. Diagram, Experimental, #, *)

[1946Kor] Kornilov, I.I., Mikheeva, V.S., Konenko-Gracheva, O.K., Mints, R.S., “Equilibrium

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[1951Pra] Pratt, J.N., Raynor, G.V., “The Al-Rich Alloys of the System Al-Cr-Fe”, J. Inst. Met., 80,


[1953Cas] Case, S.L., van Horn, K.R., “The Constitution of Binary and Complex Fe-Al Alloys”, in

“Aluminium in Iron and Steel”, John Wiley & Sons Inc., New York, 265-278 (1953) (Equi.

Diagram, Review, #, 19)

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[1953Sch] Schubert, K., Roesler, U., Kluge, M., Anderko, K., Haerle, L., “Crystallographical Results

on Phases with Penetration Bonding” (in German), Naturwissenschaften, 40, 437 (1953)

(Crys. Structure)

[1954Chi] Chinetti, J., “Research on the Formation of Coarse Precipitates in Light Alloys Containing

Cr” (in French), Metaux, 29, 151-161 (1954) (Experimental, 8)

[1955Bla1] Black, P.J., ”The Structure of FeAl3.I”, Acta Crystallogr., 8, 43-48 (1955) (Crys. Structure,

Experimental, 17)

[1955Bla2] Black, P.J., “The Structure of FeAl3.I“, Acta Crystallogr., 8, 175-182 (1955) (Crys.


[1955Tag] Tagaya, M., Nenno, S., “The Effect of Al on the Formation in Fe-Cr System”, Technol.

Repts., Osaka Univ., (5), 149-152 (1955) (Experimental, 4)

[1958Chu] Chubb, W., Alfant, S., Bauer, A.A., Jablonowski, E.J., Schober, F.R., Dickenson, R.F.,

“Constitution, Metallurgy and Oxidation Resistance of Fe-Cr-Al Alloys”, Battelle

Memorial Institute, Columbus, (1958) (Equi. Diagram, Experimental, #, *, 66)

[1958Tag] Tagaya, M., Nenno, S., Kawamoto, M., “Effect of Al on Formation in the Fe-Cr System”

(in Japanese), Nippon Kinzoku Gakkai Shi, 22, 387-389 (1958) (Experimental, 4)

[1958Tay] Taylor, A., Jones, R.M., “Constitution and Magnetic Properties of Iron-Rich

Iron-Aluminium Alloys”, J. Phys. Chem. Solids, 6, 16-37 (1958) (Crys. Structure,

Experimental)

[1960Zol1] Zoller, H., “The Influence of Zn, Mg, Si, Cu, Fe, Mn, Ti on the Primary Crystallisation of

Al7Cr” (in German), Schweiz. Arch. Angew. Wiss. u. Techn., 26, 437-448 (1960)


[1960Zol2] Zoller, H., “The Influence of Zn, Mg, Si, Cu, Fe, Mn, Ti on the Primary Crystallisation of

Al7Cr” (in German), Schweiz. Arch. angew. Wiss. u. Techn., 26, 478-491 (1960) (Equi.


[1961Lih] Lihl, F., Ebel, H., ”X-Ray Examination of the Constitution of Iron-Rich Alloys of the

Iron-Aluminium Systems” (in German), Arch. Eisenhuettenwes., 32, 483-487 (1961) (Crys.

Structure, Experimental)

[1961Phi] Phillips, H.W.L., “Al-Cr-Fe”, in “Equilibrium Diagrams of Aluminium Alloy Systems”,

Aluminium Development Association, London, 1-78 (1961) (Equi. Diagram, Review, 1)

[1968Bul] Bulycheva, Z.N., Tolochko, M.N., Svezhova, S.I., Kondrat'ev, V.K., “Influence of Cr on the

Ordering of Fe-Al Alloys” (in Russian), Akad. Nauk Ukr. SSR, Met., 20, 120-124 (1968)

(Experimental, 9)

[1969Bul1] Bulycheva, Z.N., Tolochko, M.N., Svezhova, S.I., Kondrat'ev, V.K., “Change in the

Ordering Temperature of Fe3Al on Adding a Third Element” (in Russian), Ukrain. Fiz.

Zhur., 14, 1706-1708 (1969) (Equi. Diagram, Experimental, #, *, 5)

[1969Bul2] Bulycheva, Z.N., Kondrat'ev, V.K., Pogosov, V.Z., Svezhova, S.I., Tolochko, M.N., “The

Effect of Cr and Co on the Structure and Properties of Ordered Fe-Al Alloys” (in Russian),

Sb. Tr. T. N.- Inst. Chern. Met. (Moscow), 71, 55-62 (1969) (Equi. Diagram, Experimental,

#, *, 7)

[1969Kal] Kallel, A., “Antiferromagnetic Order in the Alloys AlCr2-xFex” (in French), Compt. Rend.

Acad. Sci., Paris, 268B, 455-458 (1969) (Experimental, 8)

[1969Mue] Müller, F., Kubaschewski, O., “The Thermodynamic Properties and Equilibrium Diagram

of the System Cr-Fe”, High Temp.-High Pres., 1, 543-551 (1969) (Equi. Diagram, Review,

34)

[1969Sel] Selissky, Ya.P., Tolochko, M.N., “High-Temperature X-Ray Diffraction Study of Fe-Al-Cr,

Fe-Al-Mo and Fe-Al-W Alloys” (in Russian), Ukrain. Fiz. Zhur., 14, 1692-1694 (1969)

(Equi. Diagram, Experimental, #, *, 7)

[1970Koz1] Kozheurov, V.A., Ryss, M.A., Pigasov, S.E., Antonenko, V.I., Kuznetsov, Yu.S.,

Mikhailov, G.G., Pashkeev, I.Yu., “The Fe-Cr-Al Phase Diagram” (in Russian), Sb.

Nauchn. Tr. Chel. Polit. Inst., 78, 3-15 (1970) (Equi. Diagram, Experimental, Theory, #, *,

2)

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[1970Koz2] Kozheurov, V.A., Ryss, M.A., Pigasov, S.E., Antonenko, V.I., Kuznetsov, Yu.S.,

Mikhailov, G.G., Pashkeev, I.Yu., “The Phase Diagram of Fe-Cr-Al in the Region of

Crystallisation of the Solid Solution from the Melt” (in Russian), Sb. Chelyab. Elektromet.

Kombinata, 2, 69-79 (1970) (Equi. Diagram, Experimental, Theory, #, *)

[1970Koz3] Kozheurov, V.A., Ryss, M.A., Pigasov, S.E., Antonenko, V.I., “Solubility of Carbon in

Melts of Fe-Cr-Al System” (in Russian), Sb. Chelyab. Elektromet. Kombinata, 2, 62-68

(1970) (Experimental, Thermodyn., 9)

[1972Kaj] Kajzar, F., Lesniewska, B., Niziol, S., Oles, A., Pacyna, A., Tucharz, Z., “Neutron

Diffraction Study of Ordered Arrangement of Fe-Cr-Al Alloys”, Inst. Tech. Jad., AGH

Rep., No. 22/PS, Institute of Nuclear Physics, Cracow (1972) (Crys. Structure,

Experimental)

[1973Cor] Corby, R.N., Black, P.J., “The Structure of FeAl2 by Anomalous Dispersion Methods”, Acta

Cryst. B, 29, 2669-2677 (1973) (Crys. Structure, Experimental, 31)

[1973Wil] Willey, L.A., “Al-Cr-Fe Aluminum-Chromium-Iron)” in “Metal Handbook”, 8th Edition,

ASM, Metals Park, OH, 382 (1973) (Equi. Diagram, Review, *, 3)

[1974Niz] Niziol, S., Oles, A., Tucharz, Z., Tyszko, Z., “Crystallographic Ordering and Magnetic

Properties of Alloys” (in Russian), Trans. Internat. Conf. on Magnetism, 1973, 2, Nauka,

Moscow, 227-231 (1974) (Experimental, Crys. Structure, Magn. Prop., 10)

[1974Vya] Vyatkin, G.P., Mishchenko, V.Ya., Povolotskii, D.Ya., “Using the Simplex-Lattice Method

for Calculating the Equilibrium Diagram of the Fe-Cr-Al System” (in Russian), Izv. VUZ

Chern. Metall., 8), 9-12 (1974) (Equi. Diagram, Thermodyn., Theory, 4)

[1975Kau] Kaufman, L., Nesor, H., “Calculation of Superalloy Phase Diagrams: Part IV”, Met. Trans.,

6A, 2123-2131 (1975) (Equi. Diagram, Thermodyn., Theory, 38)

[1975Lit] Litinska, L., Niziol, S., “Crystallographic Structure and Magnetic Properties of (FeCr)3Al

Type Phases in Iron-Chromium-Aluminium (Fe0.67Cr0.08Al0.23) Alloys”, Inst. Tech. Jad.,

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330


MSIT®

Al–Cr–Fe

Studied by Means of Transmission Electron Microscopy and Diffraction. II. Discovery of a

New Phase”, Phys. Status Solidi A, 67, 233-248 (1981) (Equi. Diagram, Experimental, 2)

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331


MSIT®

Al–Cr–Fe

[1990Ioa] Ioannidis, E.K, Sheppard, T., “Powder Metallurgy Aluminium Alloys: Characteristics of an

Al-Cr-Fe Rapidly Solidified Alloys”, J. Mater. Science, 25, 3965-3975 (1990)

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Al86Cr8Fe6 Alloy”, Philos. Mag. B, 71(2), 221-238 (1995) (Crys. Structure, Experimental,

67)

332


MSIT®

Al–Cr–Fe

[1995Sui] Sui, H.X., Liao, X.Z., Kuo, K.H., “A Non-Fibonacci Type of Orthorhombic Decagonal

Approximant”, Philos. Mag. Lett., 71, 139 (1995) (Crys. Structure, Experimental, 18)

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Decagonal Quasicrystal in the Al-Co-Ni System”, Z. Krist., 210, 498-503 (1995) (Crys.


[1995Zia] Ziani, A., Michot, G., Pianelli, A., Redjaimia, A., Zahra, C.Y., Zahra, A.M.,

“Transformation of the Quasicrystalline Phase Al-Cr-Fe Induced By Rapid Solidification”,

J. Mater. Sci., 30, 2921-2929 (1995) (Crys. Structure, Equi. Diagram, Experimental, 27)

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Alloys”, Mater. Sci. Eng. A, A220, 93-99 (1996) (Experimental, Phys. Prop., 18)

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corner of the Al-Cr-Ni system”, J. Alloys Compd., 233, 246-263 (1996) (Crys. Structure,


[1997Kog] Kogachi, M., Haraguchi, T., “Ordered In Vacansies in B2-Structured Intermetallic

Compound Feal”, Mater. Sci. Eng. A, A230, 124-131 (1997) (Crys. Structure,

Experimental, 231)

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Alloys Compd., 252, 192-200 (1997) (Equi. Diagram, Experimental, 41)

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Compound and Thermal Diffusivity Anomaly in D03 Phase”, Mater. Res. Bull., 32(4),

441-449 (1997) (Experimental, Thermodyn., 15)

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Brueckel, Th., Schaerpf, O., Blonowski, K., “Structural and Magnetic Properties of

Fe-Cr-Al Alloys with Do3-Type Structure”, J. Magn. Magn. Mater., 169, 240-252 (1997)

(Crys. Structure, Experimental, Magn. Prop., 29)

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Orthorhombic Non-Fibonacci Approxi,Mant in the Al12Fe2Cr Alloy”, Acta Crystallogr.,

Sect. B: Struct. Crystallogr. Crys. Chem., B53, 587-595 (1997) (Crys. Structure,

Experimental, 41)

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Al-Fe Phases Forming in Direct-Chill (Dc)-Cast Aluminium Alloy Ingots”, Calphad, 22,


[1998Lia] Liao, X.Z., Sui, H.X., Kuo, K.H., “A New Monoclinic Approximant of the Decagonal

Quasicrystal in Al-Co-Cu-W and Al-Fe-Cr Alloys”, Philos. Mag. A, 78(1), 143-156 (1998)


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[1999Wit] Wittmann, R., Spindler, S., Fischer, B., Wagner, H. Gerthsen, D., Lange, J., Brede, M.,

Kloewer, J., Schunk, P., Schimmel, T., “Transmission Electron Microscopic Investigation

of the Microstructure of Fe-Cr-Al Alloys”, J. Mater. Sci., 34, 1791-1798 (1999) (Equi.

Diagram, Experimental, Crys. Structure, 26)

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- Phase Transformation in an Al-Doped Fe-Cr Alloy”, J. Alloys Compd., 313, 182-187

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in Al-Cr-Fe”, Mater. Sci. Eng. A, 294-296, 79-81 (2000) (Crys. Structure, Experimental, 13)

333


MSIT®

Al–Cr–Fe

[2000Mah] Mahdouk, K., Gachon, J.-C., “Thermodynamic Investigation of the Aluminium-Chromium

System”, J. Phase Equilib., 21(2), 157-166 (2000) (Equi. Diagram, Thermodyn.,


[2000Mo] Mo, Z.M., Zhou, H.Y., Kuo, K.H., “Structure of Nyu-Al80.61Cr10.71Fe8.68, a Giant

Hexagonal Approximant of a Quasicrystal Determined by a Combination of Electron

Microscopy and X-Ray Diffraction”, Acta Crystallogr., Sect. B: Struct. Crystallogr. Crys.

Chem., 56, 392-401 (2000) (Crys. Structure, Experimental, 16)

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Acta Mater., 48, 3671-3685 (2000) (Crys. Structure, Experimental, 39)

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Rapidly Solidified Cr-40 at.% Al Alloy”, Philos. Mag. Lett., 80(11), 703-710 (2000) (Crys.


[2000Spi] Spindler, S., Wittmann, R., Gerthsen, D., Lange, J., Brede, M., Kloewer, J., “Dislocation

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Reassessment of the Al-Cr System”, Proc. Disc. Meet. Thermodyn. Alloys, 42 (2000)

(Thermodyn.)

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Alloys”, J. Magn. Magn. Mater., 225, 346-350 (2001) (Crys. Structure, Experimental,

Moessbauer, 21)

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Thiel, P.A., Dubois, J.M., “Surface Oxidation of Al-Cr-Fe Alloys Characterized by X-Ray

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Experimental, 30)

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Eng. Mater., 189-191, 573-578 (2001) (Crys. Structure, Experimental, 10)

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Role of Second-Order Boundaries”, J. Phase Equilib., 22(3), 287-290 (2001) (Calculation,

Equi. Diagram, Thermodyn., 9)

[2002Dem1] Demange, V., Machizaud, F., Dubois, J.M., Anderegg, J.W., Thiel P.A., Sordelet, D.J.,

“New Approximants in the Al-Cr-Fe System and their Oxidation Resistance”, J. Alloys

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“Optical Conductivity of Al-Cr-Fe Approximant Compounds”, Phys. Rev. B, 65, 144205-1

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Damping Capacity of an Fe-Cr-Al Alloy”, Phys. Status Solidi A, 191(1), 89-96 (2002)

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MSI, Materials Science International Services GmbH, Stuttgart, to be published, (2003)

(Equi. Diagram, Assessment, 51)

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Stuttgart, to be published, (2003) (Equi. Diagram, Assessment, 58)

334


MSIT®

Al–Cr–Fe


Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

(Al)

660.452

CrxFeyAl1-x-y

cF4

Fm3m

Cu

a = 404.88 pure Al, T = 24°C [V-C]

x = 0 to 0.00375 [2003Cor]

y = 0 to 0.004 [2003Pis]

(Cr)

1863

, ( Fe)(r)

912

, CrxFe1-x-yAly

cI2

Im3m

W

a = 288.4

a = 286.65

a = 286.60

a = 287.67

a = 288.55

a = 289.2

a = 289.99

a = 288.13

a = 288.96

a = 289.43

a = 289.59

a = 2912.0

a = 2971.4

pure Cr, T = 27°C [V-C ]

x = 0 to 0.46 [V-C2]

pure Fe, T = 27°C [V-C]

pure Fe, room temperature [1961Lih,

1993Oka]

x = 0, y = 0 to 0.46 [1980Sch]

x = 0, y = 0.06 [1961Lih, 1993Oka]

x = 0, y = 0.105 [1961Lih, 1993Oka]

x = 0, y = 0.155 [1961Lih, 1993Oka]

x = 0, y = 0.19 [1961Lih, 1993Oka]

Quenched from 250°C [1958Tay,

1993Oka]:

x = 0, y = 0.0985

x = 0, y = 0.141

x = 0, y = 0.177

x = 0, y = 0.188

Quenched from 1000°C (100 h)

[1997Pal]:

x = 0.028, y = 0.444

x = 0.556, y = 0.444

( Fe)(h2)

1538 - 1394

cI2

Im3m

W

a = 293.80 [1993Oka]

( Fe)(h1)

1394 - 912

, Fe1-xAlx, CryFe1-y

, CrxFe1-x-yAly

cF4

Fm3m

Cu

a = 366.60

a = 364.67

pure Fe, T = 1167°C [1993Oka]

T = 915°C [Mas2]

x = 0 to 0.013 [1993Oka]

y = 0 to 0.119 [Mas2]

y = ~0.04 at x = 0.083, T = 1200°C

[1946Kor]

y = 0.06 at x = 0.083, T = 1100°C

[1946Kor]

y = 0.077 at x = 0.082, T = 1000°C

[1946Kor]

335


MSIT®

Al–Cr–Fe

2, FeAl

1310

2, Fe1-xAlx

2,

(Fe,Cr,Al)1(Al,Cr,Fe)1

cP8

Pm3m

CsCl a = 289.48

a = 289.60

a = 289.86

a = 290.50

a = 290.9

a = 289.81

a = 291.01

a = 289.53

a = 289.66

a = 289.77

a = 290.17

a = 291.9

a = 291.7

x = 0.22 at T = 600°C to x = 0.545 at T =

1102°C [1993Oka]

x = 0.345 [1961Lih, 1993Oka]

x = 0.389 [1961Lih, 1993Oka]

x = 0.422 [1961Lih, 1993Oka]

x = 0.475 [1961Lih, 1993Oka]

x = 0.5 [1958Tay, 1993Oka]

Quenched from T = 500°C [1997Kog]:

x = 0.397

x = 0.509

Quenched from T = 250°C [1958Tay]:

x = 0.362

x = 0.383

x = 0.409

x = 0.438

30 at.% Cr, 40 at.% Fe [2001Alo]

35 at.% Cr, 35 at.% Fe [2001Alo]

1, Fe3Al

547

1, Fe1-xAlx

1,

(Fe,Cr,Al)3Al,Cr,Fe)1

cF16

Fm3m

BiF3

a = 579.23

a = 579.30

a = 579.28

a = 579.30

a = 579.24

a = 578.92

a = 579.30

a = 579.28

a = 579.18

a = 579.30

a = 579.32

a = 579.38

a = 579.32

a = 579.06

a = 578.94

a = 578.96

a = 578.86

a = 578.86

x = 0.225 to 0.365 [V-C]

x = 0.25 [V-C]

x = 0.247 [1961Lih, 1993Oka]

x = 0.263 [1961Lih, 1993Oka]

x = 0.28 [1961Lih, 1993Oka]

x = 0.307 [1961Lih, 1993Oka]

x = 0.317 [1961Lih, 1993Oka]

Quenched from T = 250°C [1958Tay,

1993Oka]:

x = 0.231

x = 0.237

x = 0.243

x = 0.254

x = 0.261

x = 0.272

x = 0.283

x = 0.295

x = 0.315

x = 0.34

x = 0.35

CrFe2Al alloy, annealed at T = 527°C

[1983Bus]

, Fe2Al31232 -1102

, Fe1-xAlx

cI16 (?)

-

a = 598.0

x 0.58 to 0.65 [1993Oka]

x = 0.61 [1934Osa]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

336


MSIT®

Al–Cr–Fe

FeAl2 1156

Fe1-xAlx

(CryFe1-y)Al2

aP18

P1

FeAl2

A-base-centred

pseudomono-

clinic

Triclinic P1

Triclinic P1

a = 488

b = 646

c = 880

= 91.70°

= 73.3°

= 96.90°

a = 487.8

b = 646.1

c = 880.0

= 91.75°

= 73.27°

= 96.89°

a = 759.4

b = 1688.6

c = 486.2

= 89.55°

= 122.62°

= 90.43°

a = 487.8

b = 646.1

c = 880.0

= 91.75

= 73.27

= 96.89

a = 486.3

b = 645.4

c = 880.1

= 91.92

= 72.95

= 96.87

x = 0.655 to 0.670 [V-C]

T = 900°C [V-C]

x = 0.669; = 4200 kg·m-3 [1973Cor]

[1978Bas]

x = 0.666, quenched from T = 1000°C

(100 h) [1997Pal]

y = 0 to 0.045, T = 1000°C [1997Pal]

y = 0.045, quenched from T = 1000°C

(100 h) [1997Pal]

Fe2Al5 1169

Fe1-xAlx

(CryFe1-y)2Al5

oC24

Cmcm a = 767.5

b = 640.3

c = 420.3

a = 765.73

b = 640.87

c = 422.65

a = 765.59

b = 641.54

c = 421.84

a = 767.5

b = 640.3

c = 420.3

a = 769.4

b = 644.3

c = 422.7

x = 0.70 to 0.73 [1993Oka]

x = 0.72 [1953Sch]

x = 0.7145 [1986Gri]

x = 0.715 [1994Bur]


(100 h) [1997Pal]

y = 0 to 0.062, T = 1000°C [1997Pal]

y = 0.062, quenched from T = 1000°C

(100 h) [1997Pal]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

337


MSIT®

Al–Cr–Fe

FeAl3 1160

Fe1-xAlx

(Fe,Cr,Al)1(Al,Cr,Fe)3

mC102

C2/m

orthorhombic,

A2mm or Amm2

or A2/mA2/mA2/m

a = 1548.7

b = 808.4

c = 1248.8

= 107.99°

a = 1548.3

b = 807.9

c = 1250.9

= 108.11°

a = 1548.9

b = 808.31

c = 1247.6

= 107.72°

a = 1550.4

b = 807.0

c = 1247.2

= 107.71°

a = 1549.2

b = 807.8

c = 1247.1

= 107.69°

a = 1550.9

b = 806.3

c = 1247.7

= 107.74°

a = 1551.3

b = 805.1

c = 1248.6

= 107.80°

a = 1552.7

b = 803.5

c = 1244.9

= 107.70°

a = 1548.9

b = 808.3

c = 1247.6

= 107.72°

a = 1554.3

b = 802.9

c = 1245.0

= 107.47°

a = 640

b = 840

c = 620

x = 0.745 to 0.766 [1993Oka]

Sometimes called Fe4Al13 in the

literature

x = 0.767 [1986Gri]

x = 0.7665 [1986Gri]

x = 0.766, single crystal

[1955Bla1, 1955Bla2]

x = 0.7602 [1986Gri]

x = 0.76 [1994Gri]

x = 0.7594 [1986Gri]

x = 0.7463 [1986Gri]

x = 0.7416 [1986Gri]


(100 h) [1997Pal]

From 0 to 3 at.% Cr, at 600°C [1951Pra]

From 0 to 6.4 at.% Cr, from 22 to 25

at.% Fe, at 1000°C [1997Pal]

6.4 at.% Cr, 21.1 at.% Fe, quenched from

1000°C (100 h) [1997Pal]

<< 1 at.% Cr at 23.3 at.% Fe; in the

alloys (at.%) Cr3Al97, Cr3FeAl96 and

Cr3Fe3Al94 prepared by hot extrusion of

rapidly solidified powder, followed

annealing at 400°C [1995Zia]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

338


MSIT®

Al–Cr–Fe

Fe2Al9 mP22

P21/c

Co2Al9

a = 869

b = 635

c = 632

= 93.4°

Metastable

81.8 at.% Al [1977Sim, 1993Oka]

FeAl6 oC28

Cmc21

FeAl6

a = 744.0

b = 646.3

c = 877.0

a = 744

b = 649

c = 879

Metastable

85.7 at.% Al [1993Oka]

[1998Ali]

FeAl4+x t**

a = 884

c = 2160

Metastable, 0 < x < 0.4

[1998Ali]

, Cr2Al13

791

,

(Cr,Fe,Al)2(Al,Cr,Fe)13

mC104

C2/m

V7 Al45

a = 2519.6

b = 757.4

c = 1094.9

= 128.7°

Room temperature, 13.5 at.% Cr

[1975Ohn, 1995Aud, 2003Cor]

Sometimes called CrAl7 in the literature

From 0 to 3.2 at.% Fe;

11.5 at.% Cr at 3.2 at.% Fe; cooled

slowly from the liquid state [1951Pra]

, Cr2Al11

941

,

(Cr,Fe,Al)2Al,Cr,Fe)11

oC584

Cmcm

a = 1240

b = 3460

c = 2020

a = 1260

b = 3460

c = 2000

16.9 to 19.2 at.% Cr [1995Aud,

2000Mah, 2003Cor]


Quenched from 920°C, 16.9 to 19.2 at.%

Cr [1995Aud, 2000Mah, 2003Cor]

“ CrAl4” [1992Wen]

From 0 to 7.74 at.% Fe; 11.45 at.% Cr at

7.74 at.% Fe; cooled slowly from the

liquid state, in equilibrium with FeAl3[1951Pra]

, CrAl4 1031

, Cr1-xAlx

,

(Cr,Fe,Al)1Al,Cr,Fe)4

hP574

P63/mmc

MnAl4a = 1998

c = 2467

a = 2010

c = 2480

a = 2146.9

c = 1634

a = 2165.1

c = 1644.9

x = 0.78 to 0.80 [2003Cor]

y = 0.788 to 0.794, at 800°C [1995Aud]

x = 0.791 ± 0.003

[1995Aud, 2000Mah, 2003Cor]

y = 0.777 ± 0.001, quenched from

1000°C [2000Mah, 2003Cor]

From 0 to 11.9 at.% Fe, T = 1000°C

[1997Pal]

at 10.9 at.% Fe, 19.1 at.% Cr, quenched

from 1000°C (100 h) [1997Pal]

The Cr19.9Fe75.0Al5.1 sample quenched

from 1000°C (100 h) [1997Pal]

i, CrAl4(or CrAl5)

icosahedral In melt spun alloys Al-Cr at 8 to 13 at.%

Cr; by decomposition of amorphous of

20 at.% Cr, metastable [1998Mur]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

339


MSIT®

Al–Cr–Fe

1, Cr4Al9 (h)

1, Cr1-xAlx

cI52

I43m

Cu4Al9

a = 912.3

x 0.55 to 0.69 [Mas2]

x = 0.71 at Al-rich limit, quenched from

T = 920°C [1995Aud]

2, Cr4Al9 (r)

2, Cr1-xAlx

2,


hR52

R3m

Cr4Al9

a = 1291

c = 1567.7

a = 1284.7

c = 1545.9

x = 0.650 to 0.672 [Mas2]

In the alloy Cr15Fe15Al70 quenched from

1000°C (100 h) [1997Pal]

From 29 to 39 at.% Cr, from 0 to 9.6

at.% Fe (or to 12.5 at.% Fe estimated),

T = 1000°C [1997Pal]

29 at.% Cr, 9.6 at.% Fe, quenched from

1000°C (100 h) [1997Pal]

1, Cr5Al8(h)

1100 (?)

cI52

I43m

Cu5Zn8

a = 904.7 to 910.4 30.0 to 42.0 at.% Cr, quenched from

liquid [1989Ell]

2, Cr5Al8(r)

1100(?)

2, Cr1-xAlx

2,


hR26

R3m

Cr5Al8

a = 1271.9

c = 793.6

a =1276.5 to 1271.5

c = 795.4 to 782.8

a = 1272.8

c = 794.2

a = 1267.0

c = 790.0

a = 1258.4

c = 785.0

a = 1255.4

c = 783.0

a = 1254.0

c = 782.0

a = 1253.0

c = 779.0

[1994ICD], No. 29-15]

x = 0.58 to 0.65 [1989Ell]

[1977Bra]

37 to 40 Cr, 0 to 32.5 Fe (at.%)

T = 1000°C [1997Pal]

6 at.% Fe, quenched from 1000°C (100h)

[1997Pal

18.5 at.% Fe, quenched from 1000°C

(100 h) [1997Pal]

24 at.% Fe,quenched from 1000°C

(100h) [1997Pal]

25.5 at.% Fe, quenched from 1000°C

(100 h) [1997Pal]

5 at.% Fe, quenched from 1000°C (100h)

[1997Pal]

, Cr2Al

< 910

, (Cr1-xFex)2Al

tI6

I4/mmm

MoSi2

a = 300.45

c = 864.77

a = 300.5 ± 0.1

c = 864.9 ± 0.1

a = 300.1 to 299.0

c = 864.7 to 865.9

a = 299.5

c = 865.8

a = 298.8

c = 867.1

a = 298.4

c = 867.5

a = 298.0

c = 867.6

a = 297.7

c = 868.0

~65.5 to 71.4 at.% Cr [1998Mur]

[1937Bra, 1998Mur]

[1989Ell]

0 x 0.25, annealed at 700 to 1000°C

[1969Kal]

x = 0.025

x = 0.045

x = 0.075

x = 0.085

x = 0.120

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

340


MSIT®

Al–Cr–Fe

X

400

Cr5Al3 or

Cr3Al

superlattice

Possibly metastable [1998Mur]

~75 to ~80 at.% Cr [1981Bro, 1981Ten]

T In quenched alloys Cr-Al at 60 to 100

at.% Cr, like metastable Ti in Ti alloys

[2000Sha1, 2000Sha2]

, CrFe

830-440

tP30

P42/mnm

CrFe

a = 879.95

c = 454.42

44.5 to 50.0 at.% Cr [V-C]

* P63/m a = 4068.0±0.07

c = 1254.6±0.01

atoms/cell =

1184.56

a = 4000

c = 1240

Cr10.71Fe8.68Al80.61 single crystal,

elicited from ingot after inductive

melting followed cooling in sand bath

[2000Mo].

Sometimes called “H-(CrFeAl)”.

Cr11Fe8Al81 together with -(CrFeAl) in

as-cast CrFe2Al12 alloy [1999Sui]

* ” -(CrFeAl)” hexagonal,

-Cr18Ni6Al76

In as-cast CrFe2Al12 alloy together with

[1999Sui]

* ”O-(CrFeAl)” orthorhombic

body-centered

a = 1230

b = 1240

c = 3070

In as-cast Cr11Fe8Al81 alloy together

with O1-(CrFeAl) and C3,1-(CrFeAl)

[2000Dem].

In as-cast Cr2FeAl12 alloy together with

H-(CrFeAl) and M-(CrFeAl) [1997Sui,

1999Sui.

In as-cast CrFe2Al12 alloy [1998Lia]

* ”O1-(CrFeAl)” orthorhombic

base-centered or

primitive

a = 3250

b = 1220

c = 2360

In as-cast Cr11Fe8Al81, Cr16.5Fe6Al77.5

and Cr21.5Fe6Al72.5 alloys together with

O-(CrFeAl) and C3,1-(CrFeAl)

[2000Dem, 2001Dem]

* ”O2-(CrFeAl)” orthorhombic a = 1990

b = 1240

c = 2320

In as-cast Cr19.5Fe8Al72.5 alloy together

with O-(CrFeAl) [2001Dem]

* C3,1-(CrFeAl)” orthorhombic

primitive

[1988Ten]

a = 3270

b = 1250

c = 2380

In as-cast Cr11Fe8Al81 alloy together

with O1-(CrFeAl) [2000Dem]

* ”M-(CrFeAl)” monoclinic a = 3310

b = 1230

c = 2480

= 112°

-

In as-cast CrFeAl12 alloy [1998Lia]

In as-cast alloy Cr2FeAl12 together with

O-(CrFeAl) and H-(CrFeAl) [1997Sui,

1999Sui]

* i simple

icosahedral-type

-

a6D= 654.2(2)

Cr12±1Fe12±1Al75±0.5, rapid

solidification by centrifugal atomization

followed extrusion at 340°C [1995Zia]

In Cr8Fe6Al86, rapid solidification by

melt spinning [1995Sta]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

341


MSIT®

Al–Cr–Fe

Table 2: Coordinates of the (( Fe)+ Fe))/( Fe) Surface of the -loop [1946Kor, 1991Gho]

Table 3: Heat Treatment Schedule for Different Alloys by [1958Chu]

Table 4: Partial Pressures of Cr, Fe and Al over the Alloy Cr-75.4Fe-4.8Al (mass%) and Temperature

Range of the Measurements T [1992Hil]. Errors of A and B values are standard deviations. Errors

of pi values are probable overall errors

Table 5: Chemical Activities ai, Excess Chemical Potentials iE, and Partial Excess Enthalpies Hi

E of the

Components in the Alloy Cr-75.4Fe-4.8Al (mass%) for a Temperature of 1500 K [1992Hil]. Errors

are probable overall errors

Temperature [°C] Al Cr

(mass%) (at.%) (mass%) (at.%)

1200

1100

1000

1.7

2.2

3.0

2.9

3.9

1.9

3.8

3.4

4.4

6.0

5.8

7.7

3.8

7.5

4.0

4.0

8.0

4.0

8.0

12.0

4.0

4.2

4.2

8.3

4.2

8.2

12.5

4.1

Alloys with > 50 mass% Fe Alloys with > 10 mass% Al

Temperature [°C] Time [h] Temperature [°C] Time [h]

750

700

650

600

500

480

720

1000

720

720

2000

2200

900

750

700

650

600

500

100

200

500

250

250

1200

Gaseous

species i

pi [Pa]

at 1500 K

T [K] ln pi = –A·104/T+B

A B

Cr

Fe

Al

1.6·10-2 ± 14 %

7.5·10-3 ± 15 %

4.5·10-3 ± 43 %

1313-1556

1313-1556

1313-1556

4.298 ± 0.015

4.622 ± 0.022

4.501 ± 0.071

24.51 ± 0.05

25.92 ± 0.12

24.50 ± 0.56

Alloy Component i ai (at 1500 K) iE (at 1500 K) [kJ·mol-1] Hi

E (at 1450 K) [kJ·mol-1]

Cr

Fe

Al

0.28 ± 0.04

0.50 ± 0.07

(3.3 ± 1.4)·10-3

4.3 ± 1.9

–4.4 ± 2.0

–42.0 ± 7.0

27.6 ± 8.8

13.7 ± 7.5

–66.0 ± 8.6

342


MSIT®

Al–Cr–Fe

35302520151050

1272

1270

1268

1266

1264

1262

1260

1258

1256

1254

1252

latticeconstant

,pm

a0

Fe, at.%

Fig. 1a: Al-Cr-Fe.

Lattice constant a0 of

the Cr5Al8(r) phase vs

Fe content. Al content

is 55 to 58 at.%

35302520151050

790

788

786

784

782

780

792

794

778

Fe, at.%

latticeconstant,pm

c0

Fig. 1b: Al-Cr-Fe.

Lattice constant c0 of

the Cr5Al8(r) phase vs

Fe content. Al content

is 55 to 58 at.%

343


MSIT®

Al–Cr–Fe

Fig. 2: Al-Cr-Fe. Partial reaction scheme of the Al-rich alloys

Al-Cr

l + ρ θ790 p

3

Al-Cr-Fe

L + ρ θ + FeAl3

709 U1

Al-Fe

l FeAl3 + (Al)

655 e1

l + θ (Al)

661.5 p4

L + θ FeAl3 + (Al) 655 U

2

L θ + FeAl3 + (Al) 640 E

1

L + ρ + FeAl3

L + θ + FeAl3

θ + FeAl3 + (Al)

ρ + θ FeAl3

or

either

Cr 4.00Fe 0.00Al 96.00

Cr 0.00Fe 4.00Al 96.00


Axes: at.%

(Al)

FeAl3

U1

E1

e1

p4

p3

θ1,Cr2Al13

ρ,Cr2Al11

Fig. 3: Al-Cr-Fe.

Liquidus surface

projection of the

Al-corner

344


MSIT®

Al–Cr–Fe

20

40

60

80

20 40 60 80

20

40

60

80

Cr Fe


Axes: at.%

1800

1750

1700

1650

1600

15501500

1450

1400

1300

p1,~1350°C

p2,1232°C

(Cr,αFe)

1350

Cr 4.00Fe 0.00Al 96.00

Cr 0.00Fe 4.00Al 96.00


Axes: at.%

e1

U2

U1

FeAl3

(Al)

700

750

800

850

p4

p3

ρ,Cr2Al11

θ1 ,Cr

2 Al

13

Fig. 5: Al-Cr-Fe.

Partial liquidus

surface projection

Fig. 4: Al-Cr-Fe.

Calculated liquidus

surface of the

Al-corner

345


MSIT®

Al–Cr–Fe

20

40

60

80

20 40 60 80

20

40

60

80

Cr Fe


Axes: at.%

(Cr,αFe)

ζ1,Cr4Al9(h)

γ,Cr5Al8

FeAl3Fe2Al5

ε+α2

α2

γ2+α γ2+α2

γ2ε

L

(γFe)

20

40

60

80

20 40 60 80

20

40

60

80

Cr Fe


Axes: at.%

(Cr,αFe)

α2

γ2

η,Cr2Al

ρ,Cr2Al11µ,CrAl4

ζ1,Cr4Al9(h)

γ2,(Cr5Al8)(r)

FeAl3Fe2Al5

FeAl2

(γFe)

ν

γ2+α

γ2+α2

L

Fig. 6: Al-Cr-Fe.


1150°C

Fig. 7: Al-Cr-Fe.


900°C

346


MSIT®

Al–Cr–Fe

20

40

60

80

20 40 60 80

20

40

60

80

Cr Fe


Axes: at.%

σ

σ+(Cr,αFe)

(Cr,αFe)

η+α

η,Cr2Al

α2

θ,Cr2Al13

µ,CrAl4

ζ1,Cr4Al9(h)

γ2,Cr5Al8(r)

FeAl3Fe2Al5

FeAl2

L

η+α2+γ2γ2+α2

γ2

η+α2

ν

20

40

60

80

20 40 60 80

20

40

60

80

Cr Fe


Axes: at.%

σ

σ+(Cr,αFe)

(Cr,αFe)

η+α2+γ2

α2

θ,Cr2Al13

µ,CrAl4

ζ1,Cr4Al9(h)

γ2,Cr5Al8(r)

η,Cr2Al

Fe2Al5

FeAl3

FeAl2

ν

γ2+α2

γ2

η+α2

η+α

L

Fig. 8: Al-Cr-Fe.


750°C

Fig. 9: Al-Cr-Fe.


700°C

347


MSIT®

Al–Cr–Fe

20

40

60

80

20 40 60 80

20

40

60

80

Cr Fe


Axes: at.%

σ

σ+(Cr,αFe)

(Cr,αFe)

η+α2+γ2

α2

θ,Cr2Al13

µ,CrAl4

ζ1,Cr4Al9(h)

γ2,Cr5Al8(r)

η,Cr2Al

Fe2Al5

FeAl3

FeAl2

ν

γ2+α2

γ2

η+α2

η+α

(Al)

ζ2, Cr4Al9(r)

20

40

60

80

20 40 60 80

20

40

60

80

Cr Fe


Axes: at.%

σ

σ+(Cr,αFe)

(Cr,αFe)

η+α2+γ2

α2

θ,Cr2Al13

µ,CrAl4

ζ2, Cr4Al9(r)

γ2, Cr5Al8(r)

η, Cr2Al

Fe2Al5

FeAl3

FeAl2

ν

γ2 +FeAl

2 +α2

γ2

η+α2

η+α

(Al)

ζ1, Cr4Al9(h)

Fig. 10: Al-Cr-Fe.


650°C

Fig. 11: Al-Cr-Fe.


600°C

348


MSIT®

Al–Cr–Fe

20

40

20 40

60

80

Cr 60.00Fe 0.00Al 40.00

Cr 0.00Fe 60.00Al 40.00


Axes: at.%

µ,CrAl4

ζ2 ,Cr

4Al9(r)

γ2,Cr5Al8(r)

Fe2Al5

FeAl2

γ2+α2

ζ2+µ

L+µ

γ2+Fe2Al5

α2+FeAl2

L+FeAl

3

γ2+αα2

ζ2+γ2

L

FeAl3

α

Cr 4.00Fe 0.00Al 96.00

Cr 0.00Fe 4.00Al 96.00


Axes: at.%(Al)

FeAl3+(Al)

calculated

(Al)+θ+FeAl3θ,C

r 2A

l 13+(

Al)

Fig. 12: Al-Cr-Fe.

Partial isothermal

section at 1000°C

Fig. 13: Al-Cr-Fe.

Partial isothermal

section of the

Al-corner at 600°C

349


MSIT®

Al–Cr–Fe

10

90

10

Cr 20.00Fe 80.00Al 0.00

Fe

Cr 0.00Fe 80.00Al 20.00 Data / Grid: at.%

Axes: at.%

1000°C

1100°C

1200°C

20 40 60 801000

1250

1500

1750

2000

Cr 0.00Fe 50.00Al 50.00

CrCr, at.%

Tem

pera

ture

, °C

L

(Cr,αFe)

α2

1863°C

Fig. 14: Al-Cr-Fe.

Isotherms of the

surface ((γFe)+αFe))/

(αFe) of the γ-loop in

the ternary system

Fig. 15: Al-Cr-Fe.

Polythermal section

FeAl - Cr

350


MSIT®

Al–Cr–Fe

400

500

600

700

800

Cr 0.00Fe 75.00Al 25.00

Cr 6.00Fe 75.00Al 19.00Cr, at.%

Tem

pera

ture

, °C

α1

α1+α

α2+α

α2 α

2.00 4.00

Fig. 16: Al-Cr-Fe.

Variation of

order-disorder

reaction temperature

as a function of the Cr

content along the

Fe3Al-CrFe3 section

1200

1000

800

600

400

100 200 300 400 500 600 7000

T[°C]

C[J

kg

K]

p-1

-1×

×

Fig. 17: Al-Cr-Fe.

Temperature

dependence of the

heat capacity Cp of

the FeAl3-based

compound with

chromium content

5 at.%

351


MSIT®

Al–Cr–Mg

Aluminium – Chromium – Magnesium

Peter Rogl, Sibylle Stiltz and Fred Hayes, updated by Andriy Grytsiv

Literature Data

Information about the phase equilibria in the aluminium-rich region are due to the results obtained by

different investigators [1940Erd, 1940Hof, 1943Mon, 1948Lit, 1956Vul, 1960Zol1, 1960Zol2, 1973Ohn1,

1973Ohn2]. [1940Erd] was the first to examine the phase relations in the Al-rich corner within the range of

0 to 23 mass% Cr and 0 to 37 mass% Mg by means of thermal analysis (±0.5°C, 60 grams of alloy) and

optical metallography of a total of 140 alloys. A liquidus projection was established for the Al-rich and

Cr-poor region (3 mass% Cr and 35 mass% Mg, see also [1941Han]). All samples were prepared by melting

the Al in a graphite crucible internally-lined with sintered Al2O3 prior to adding the proper amounts of Cr

in the form of an Al-10 mass% Cr master alloy followed by the Mg. To prevent oxidation, a protective layer

of Hydrasal was used and, due to a retarded solubility of Al-Cr crystals, the melts had to be kept for

prolonged periods at temperature. Starting materials were 99.99 % Al and Mg and 99.86 % pure electrolyte

Cr containing 0.095 mass% H, 0.03 % Fe, 0.01 % Si, 0.01 % Cr and 0.003 % S. To avoid separation by

gravity, melts were cast in flat 10 × 15 mm thin-walled iron molds. Phases were specified by selective

etching using NaOH (1 %) at 50°C for CrAl7 (15-45 s, brown, no attack on Cr2Al11 and T), and HNO3

(20 %) at 70°C for Mg2Al3 (dark brown, no attack on Al). For an isothermal section at 400°C, the alloys

were sealed in silica ampoules under 1 bar of air with addition of Mg filings as a getter material, and heat

treated for 720 h at 400°C. Solid solubility limits of a series of alloys (1.96 to 2.07 mass% Mg, 0.12 to 1.6

mass% Cr, balance Al) have been derived at three different temperatures (400, 500 and 600°C) from

electrical resistivity measurements and by X-ray examination [1940Hof]; alloys were prepared by casting

into thick-walled brass crucibles, annealing at 600 to 620°C for 48 h and subsequently hot drawing (at 420

to 450°C) into a wire of 4 mm diameter, quenching, sealing in silica capsules and finally annealing at 400,

500 and 600°C, respectively. The results of [1940Erd], in particular the existence of a ternary phase T, were

essentially confirmed by [1948Lit] in a reinvestigation of the ternary system in the region of 0 to 20 mass%

Mg and 0 to 10 mass% Cr on a series of more than 60 samples which were prepared by melting Al and

proper amounts of an Al-8.6 mass% Cr master alloy in fluorspar-lined Al2O3 crucibles before adding the

Mg. The reguli were then sealed in evacuated hard glass tubes, annealed for 380 to 720 h at 460°C and

examined by chemical analysis (some), by optical metallography and by X-ray analysis and a partial

isothermal section at 460°C was established. Etchants used were hot alkaline permanganate solutions at 60

to 70°C. T was generally outlined by a 1 min swab etch with aqueous hydrofluoric acid. In contradiction to

these observations by [1940Erd], [1941Han] and [1948Lit], the ternary phase T was considered by

[1943Mon] to constitute a solid solution of Mg in binary Cr2Al11 (in this assessment called CrAl5) rather

than a true ternary compound - as a consequence the primary field of the T phase is eliminated in the liquidus

projection and the primary field of CrAl7 will extend further up to 20 mass% of Mg; similarly, the

isothermal section proposed by [1943Mon] for a temperature of 447°C is without a ternary compound. In a

later review by [1952Han], Mondolfo's version of the phase diagram was rejected on the basis of significant

differences between T and the proposed solution of Mg in Cr2Al11 as seen under polarized light.


knowledge.

Binary Systems

The binary system Al-Cr was accepted after [Mas2]. The binary Al-Cr compounds CrAl7 and Cr2Al11 are

called here and , respectively. The new version of the Al-Mg binary system was accepted after

[1998Lia]. It is modified according to the documented homogeneity range of the phase [1997Su], which

was not taken into account by the calculation. The small homogeneity range of the phase [1997Su] is not

well established. The Al-Mg phase diagram is accepted from [2003Luk].

352


MSIT®

Al–Cr–Mg

Solid Phases

Despite arguments by [1943Mon] (see above) the ternary compound originally labeled T (“CrMgAl8”) by

[1940Erd] and [1941Han] has been confirmed by [1948Lit, 1952Han, 1956Vul, 1973Ohn1] and

[1973Ohn2] and an extended homogeneous range was indicated from X-ray and chemical analysis on

electrochemically extracted single crystals, then revealing a Cr content of about 11.8 to 12.6 mass% Cr; a

tie line construction furthermore resulted in a Mg content varying from 8.2 to 13.5 mass% Mg

(“Cr2Mg3-4Al24-25”) [1948Lit]. The large lattice parameter, as observed by [1953Lit] for “Cr2Mg3Al25”

confirms the existence of an extended homogeneous range towards compositions richer in Mg than

Cr2Mg3Al18, as was also indicated from the investigation by [1948Lit]. Assuming complete occupation of

all atom sites in the unit cell, and taking further into account the various results obtained from chemical

analyses [1940Erd, 1948Lit], the homogeneous range, however, appears to be at higher Cr contents as

indicated by [1948Lit], and thus might be represented by the formula: Cr2Mg4Al17 to Cr2Mg2Al19 (see also

Fig. 6). In contrast to a preliminary X-ray investigation by [1953Lit], a complete determination of the crystal

structure by means of single crystal X-ray Weissenberg photographs revealed cubic symmetry Fd3m due to

observed extinctions (hhl) for h+l=2n+1 [1954Sam, 1958Sam]. At a reliability factor of R = 0.116 the atom

parameters were (origin of cell at 1/8 1/8 1/8 from 1): Al1 in 96 g (0.0666(3), 0.0666, 0.2998(4)), Al2 in 48

f (0.1407(6), 0, 0), Mg1 in 16 d (5/8, 5/8, 5/8), Mg2 in 8 b (1/2, 1/2, 1/2) and Cr in 16 c (1/8, 1/8, 1/8))

[1958Sam]. The crystal structure was confirmed using X-ray powder data [1973Ohn1, 1987Ker]. Besides

the existence of T (Cr2Mg3Al18) the formation of at least one further ternary phase (denoted Tx) was

claimed by [1940Erd], but no details were given. Solid solubility of Mg in CrAl7 and in Cr2Al11 were

observed to be very small [1940Erd] or negligible [1960Zol2]. Solid solubility limits for Cr and Mg in (Al)

as derived by [1940Hof] were: 0.56 Cr mass% at 0.0 mass% Mg, 600°C, and 0.38 mass% Cr at 2.0 mass%

Mg, 600°C; 0.3 mass% Cr at 0.0 mass% Mg, 500°C and 0.2 mass% Cr at 2.0 mass% Mg, 500°C. These data

and later observations by [1948Lit] at 460°C (0.3 mass% Cr at 1.1 mass% Mg) are slightly higher than the

more recent findings by [1973Ohn1] and [1973Ohn2] at 400, 450 and 550°C, respectively. Crystallographic

data of the solid phases appearing in the diagrams are listed in Table 1.


Four ternary invariant equilibria were reported by [1940Erd] and [1941Han] in the Al-rich region of the

system ( 35 mass% Mg, 3 mass% Cr; see Table 2): eutectic decomposition of the liquid at 447.3 ± 0.5°C

and three transition type reactions U1, U2, U3, for which a reaction temperature was measured only for U2

at 632.7°C. The compositions of the liquids are given explicitly [1940Erd, 1941Han], those of the solid

phases are corrected in view of later investigations by [1948Lit] and [1973Ohn1, 1973Ohn2] (see also

section Isothermal Sections). The anomalous nature of the ternary eutectic was also discussed by [1960Spe].

Based on the information by [1940Erd] on the formation of at least two ternary phases T and Tx, the reaction

scheme (Fig. 1) and a projection of the invariant equilibrium planes and the connecting lines of double

saturation (Fig. 2) are presented for the Al-rich region of the Al-Cr-Mg system. Due to the lack of detailed

information, however, the diagram is partly estimated.

Liquidus Surface

Figure 3 shows some isotherms of the liquidus surface and the melting grooves separating five areas of

primary crystallization in the Al-rich region of the system: , , , , T. Figure 3 is essentially based on the

experimental results of [1940Erd] and [1960Zol2]. In contrast to [1940Erd], and based on liquid extraction

experiments on a series of alloys with constant Mg contents of 1.5, 2.0 and 3.0 mass%, the experiments of

[1960Zol2] revealed that with increasing Mg content up to 7 mass% Mg, the field of primary

crystallization contracts.

Isothermal Sections

Figures 4, 5 and 6 reveal the isothermal sections in the Al-rich region at 550, 450 and 400°C according to

[1973Ohn1] and [1973Ohn2]. The phase field distribution at 400°C is mainly based on [1940Erd] with

353


MSIT®

Al–Cr–Mg

minor corrections regarding the position and homogeneous range of the ternary T phase [1958Sam] which

was found from the 460°C section by [1948Lit]. Furthermore, according to the investigations by [1948Lit]

and [1973Ohn1, 1973Ohn2], the vertex of the three phase field + +T is generally located at smaller Mg

and Cr contents, as also suggested by [1952Han] in view of the earlier data by [1940Hof].


[1952Han] and [1956Vul] report on the hardness of the ternary compound T in comparison with binary

Cr-aluminides. Whereas [1952Han] measured 540 kg·mm-2, the variation of the microhardness of

“CrMg2Al12” was given as 461 kg·mm-2 at 20°C (30 s), 402 kg·mm-2 at 300°C (30 s) and 358 kg·mm-2 at

300°C after 60 min [1956Vul]. Furthermore, the influence of “Cr2Mg4Al24” (Cr2Mg4Al17) on the heat

resistance of aluminium alloys was investigated at 300°C. The fatigue limit 100 at 300°C for the alloy

containing 0.63 mass% Cr and 2.30 mass% Mg was found to be 4.7 kg·mm-2 [1956Vul].

Structure and mechanical properties of rapidly solidified Al-(3-6)Mg-(0-9)Cr (at.%) alloys were

investigated by [1994Abr]. Authors report that Al-Cr-Mg alloys exhibit higher strength and hardness

(Table 3) comparing with corresponding values of binary Al-Cr alloys. However, the use of magnesium as

alloying element produced a drastic reduction in tensile ductility.

References

[1940Erd] Erdmann-Jesnitzer, F., “The Al Corner of the Al-Mg-Cr Ternary System” (in German),

Alum. Arch., 29, 1-15 (1940) (Crys. Structure, Equi. Diagram, Experimental, 11)

[1940Hof] Hofmann W., Herzer, R.W., “The Solid Solubility of Cr in Al with up to 2 mass% Mg” (in

German), Metallwirtschaft, 191, 141-143 (1940) (Equi. Diagram, Experimental, 7)

[1941Han] Hanemann, H., Schrader, A., “On the Al Ternary Systems” (in German), Z. Metallkd., 33,

20-21 (1941) (Review, 3)


London, Chapman and Hall Ltd., London, 71-73 (1943) (Equi. Diagram, Review, 1)

[1948Lit] Little, K., Axon, H.J., Hume-Rothery, W., “The Constitution of Aluminium-

Magnesium-Zinc-Chromium Alloys at 460°C”, J. Inst. Met., 75, 39-50 (1948-49) (Crys.


[1952Han] Hanemann, H., Schrader, A., “Ternary Aluminium Alloys” in “Atlas Metallogr. III”, (in

German), 2, Verlag Stahleisen GmbH, Dusseldorf, 66-69, Tables 4, 5 (1952) (Equi.

Diagram, Review, 4)

[1953Lit] Little, K., “The Ternary Compound E in the System Aluminium-Chromium- Magnesium”,

J. Inst. Met., 82, 463-464 (1953) (Crys. Structure, Experimental, 5)

[1954Sam] Samson, S., “Crystal Structure of the Intermetallic Compound Mg3Cr2Al18”, Nature, 173,


[1956Vul] Vul'f, B.K., Chernov, M.N., “The Effect of Ternary Metallic Compound E (AlCrMg) on

Heat Resistance of Aluminium Alloys”, Russ. J. Inorg. Chem., 1(1), 163-168 (1956),

translated from Zh. Neorg. Khim., 1(1), 158-162 (1956) (Experimental, 11)

[1958Sam] Samson, S., “The Crystal Structure of the Intermetallic Compound Mg3Cr2Al18”, Acta

Crystallogr., 11, 851-857 (1958) (Crys. Structure, Experimental, 23)

[1960Spe] Spengler, H., “The Importance of Research on Eutectics and its Applications to Ternary

Eutectic Aluminium Alloys” (in German), Metall, 14, 201-206 (1960) (Review, 11)

[1960Zol1] Zoller, H., “The Influence of Zn, Mg, Si, Cu, Fe, Mn and Ti on the Primary Crystallization

of Al7Cr” (in German), Schweiz. Arch. angew. Wiss. u. Techn., 26, 437-448 (1960) (Equi.


[1960Zol2] Zoller, H., “The Influence of Zn, Mg, Si, Cu, Fe, Mn and Ti on the Primary Crystallization

of Al7Cr” (in German), Schweiz. Arch. Angew. Wiss. u. Techn., 26, 478-491 (1960) (Equi.


[1968Sam] Samson, S., Gordon, E.K., “The Crystal Structure of Mg23Al30”, Acta Crystallogr., B24,


354


MSIT®

Al–Cr–Mg

[1973Ohn1] Ohnishi, T., Nakatani, Y., Shimizu, K., “Phase Diagrams and Ternary Compounds of the

Al-Mg-Cr and the Al-Mg-Mn Systems in the Al-rich Side” (in Japanese), J. Jpn. Inst. Light

Met., 23, 202-209 (1973) (Crys. Structure, Equi. Diagram, Experimental, 16)

[1973Ohn2] Ohnishi, T., Nakatani, Y., Shimizu, K., “Phase Diagram in the Al-rich Side of the Al-Mg-Cr

Quaternary System” (in Japanese), J. Jpn. Inst. Light Met., 23, 437-443 (1973) (Equi.


[1981Sch] Schürmann, E., Voss, H.J., “Investigation of the Equilibrium Containing Liquid of

Mg-Li-Al Alloys” (in German), Giessereiforschung, 33, 43-46 (1981) (Equi. Diagram,


[1987Ker] Kerimov, K.M., Dunaev, S.F., Sljusarenko, E.M., “Investigation of the Structure of Ternary

Phases in Al-Mg-Ti, Al-Mg-V and Al-Mg-Cr Systems”, J. Less-Common Met., 133,


[1994Abr] Abramov, V.O., Sommer, F., “Structure and Mechanical Properties of Rapidly Solidified

Al-(Fe,Cr) and Al-Mg-(Fe,Cr) Alloys”, Mater. Lett., 20, 251-255, (1994) (Experimental,

Mechan. Prop., Crys. Structure, 6)

[1997Su] Su, H.-L., Harmelin, M., Donnadieu, P., Baetzner, C., Seifert, H. J., Lukas, H. L., Effenberg,


Al”, J. Alloys Compd., 247, 57-65 (1997) (Equi. Diagram, Experimental, 20)


Seifert, H. J., Lukas, H.-L., Aldinger, F., “Experimental Investigation and Thermodynamic

Calculation of the Central Part of the Mg-Al Phase Diagram”, Z. Metallkd., 89, 536-540

(1998) (Equi. Diagram, Thermodyn, Experimental, Theory, Calculation, 33)



MSI, Materials Science International Services GmbH, Stuttgart, to be published, 2003

(Equi. Diagram, Review, 51)





Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

, (Al)

< 660.452

cF4

Fm3m

Cu

a = 404.96 at 25°C [Mas2]

, (Mg)

< 650

hP2

P63/mmc

Mg

a = 320.94

c = 521.07

at 25°C [Mas2]

, Mg2Al3< 452

cF1168

Fd3m

Mg2Al3


[2003Luk]

60-62 at.% Al [1997Su]

, Mg23Al30

410-250

hR159

R3

Mg23Al30

a = 1282.54±0.03

c = 2174.78±0.09

[V-C, 1968Sam, 1981Sch]


[2003Luk]

355


MSIT®

Al–Cr–Mg

a Earlier denoted as “Al8CrMg” by [1940Erd] or as E by [1948Lit] who, from X-ray powder and single crystal

oscillation photographs, reported Fm3m as the most probable space group due to the lack of extinctions observed for the (hhl)-reflections.

b Assuming complete occupation of all atom sites in the structure, the large lattice parameter of [1953Lit] suggests an extended homogeneity range towards compositions richer in Mg than Al18Cr2Mg3. Taking further into account the

various results obtained from chemical analysis [1940Erd, 1948Lit] the homogeneity range might be Al17 19Cr2Mg4 2 (this range is assumed in Fig. 6).

, Mg17Al12

< 458

cI58

I43m

Mn

a = 1054.38

a = 1048.11

a = 1053.05

a = 1057.91

[V-C], x = 2.068 Mg·m-3

52.58 at.% Mg [L-B]

56.55 at.% Mg [L-B]

60.49 at.% Mg [L-B]

, Cr2Al11

940oC584Cmcm a = 1240

b = 3460

c = 2020

a = 1252.1

b = 3470.5

c = 2022.3

a = 1260

b = 3460c = 2000

[2003Cor]


16.9 to 19.2 at. % Cr;

single crystal ”εCrAl4”

”εCrAl4”

, CrAl7 790

mC104

C2/m

Al45V7

a = 2519.6

b = 757.4

c = 1094.9

= 128.80°

obs = 2.78 Mg·m-3 at

13.2 at.% Cr [V-C]

* Ta b, Cr2MgAl18 cF184

Fd3m

Al18Cr2Mg3

a = 1455

a = 1453±1

a = 1468

[1958Sam], sp. group Fd3m

x = 2.86 Mgm-3 [1954Sam]

exp = 2.80 Mgm-3 [1954Sam]

[1987Ker]

[1948Lit, 1953Lit] for “Al2Cr2Mg3”

converted from kX-units

* Tx unknown structure - [1940Erd]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

356


MSIT®

Al–Cr–Mg


Table 3: Mechanical Properties of Al-Cr-Mg and Al-Cr Alloys [1994Abr]


Al Cr Mg

L + + T ~ 750 U1 L1

1

1

T1

84.9

84.6

87.2

78.3

1.2

15.4

12.8

8.7

13.9

0.0

0.0

13.0

L + + T 633 U2 L2

2

2

T2

85.0

87.5

97.5

81.3

0.9

12.5

0.3

8.6

14.1

0.0

2.2

10.1

L + Tx + T 448 U3 L3

Tx3

3

T3

64.6

unknown

60.5

74.0

1.1

0.0

8.7

34.3

39.5

17.3

L + + T 447 E L4

4

4

T4

65.5

85.6

61.5

78.6

0.9

0.0

0.0

8.4

33.6

14.4

38.5

13.0

Composition (at.%) Yield strength

[MPa]

UTS [MPa] Elongation (%) Hardness

[MPa]Al Cr Mg

99.5

98.5

98.0

92.0

0.5

1.5

2.0

2.0

0

0

0

6.0

185

233

241

498

198

235

257

520

16.5

8.5

8.0

4.0

566

755

950

1610

357


MSIT®

Al–Cr–Mg

10

20

30

40

10 20 30 40

60

70

80

90

Mg 50.00Cr 0.00Al 50.00

Mg 0.00Cr 50.00Al 50.00


Axes: at.%

Tx3

Tx3

T3

T

U3

E

β3

β4

U1

U2

η

Θ

η1

Θ1

Θ2

T2

T1

T4

α2

595.5

557

542

524.5

506.1

α4

α

e

Tx3

p2p1

Fig. 2: Al-Cr-Mg.

Invariant equilibrium

planes

l + η Θ790 p

1 L + η + T

l + Θ α661.5 p

2

L + η Θ + Tca.750 U1

L + Θ α + T633 U2

L α + β + T447 E

α + β + T

L + Tx

β + T448 U3

l α + β450.5 e

L + Θ + T η + Θ + Τ

α + Θ + Τ

L + α + T

L + β + T

T + Tx + β

L + β + Tx L + T + T

x

Fig. 1: Al-Cr-Mg. A partial reaction scheme

Al-Cr Al-MgAl-Cr-Mg

358


MSIT®

Al–Cr–Mg

0 1 2 3 4 5

0

2

4

6

8

10

Mg, mass%

Cr,mass%

a + Q

a +T + Q

� + Ta

Fig. 4: Al-Cr-Mg.

Phase equilibria in

the Al corner at

550°C

10

20

30

40

10 20 30 40

60

70

80

90

Mg 50.00Cr 0.00Al 50.00

Mg 0.00Cr 50.00Al 50.00


Axes: at.%

T

U3

E

β

U1

U2

η

Θα2

595.5

557

542

524.5

506.1

α

α

e

p2p1

Fig. 3: Al-Cr-Mg.

Liquidus projection

of the Al-rich region

359


MSIT®

Al–Cr–Mg

10

20

30

10 20 30

70

80

90

Mg 40.00Cr 0.00Al 60.00

Mg 0.00Cr 40.00Al 60.00


Axes: at.%

α+T

α+T+β

T

η+Θ+TΘ

η

α+Θα

α+Θ+T

β

Fig. 6: Al-Cr-Mg.

Partial isothermal

section at 400°C

0 2 4 6 8 10 12 140

1

2

3

4

5

6

� + T + Q

�

� + �

Mg, mass%

Cr,mass%

Fig. 5: Al-Cr-Mg.

Phase equilibria in

the Al corner at

450°C

360


MSIT®

Al–Cr–Nb

Aluminium – Chromium – Niobium

Volodymyr Ivanchenko

Literature Data

Forty-six ternary alloys located in the Nb-NbCr2-NbAl3 portion of the ternary system have been

investigated by means of metallography and X-ray diffraction analysis by [1964Sve]. The alloys were

prepared by arc melting under purified Ar using 99.99 mass% Al, 99.95 mass% Cr and 99.4 mass% Nb (0.4

mass% Ta, 0.06 mass% Ti, 0.06 mass% Si and 0.07 mass% Fe). Annealing was carried out under purified

Ar for 17 to 30 h at 1500°C and for 105 h at 1200°C. The samples were cooled after annealing at 100°C per

minute.

[1968Hun] used 22 alloy compositions to determine the constitution of the Nb-Cr-NbAl3 portion of the

ternary system at 1000°C. Alloys were arc melted under Ar using 99.999 Al and Cr and 99.9 mass% Nb.

Samples were annealed for 168 h at 1000°C in evacuated quartz capsules and subsequently air-cooled. Only

X-ray diffraction analysis was used to establish a tentative section at 1000°C. Within the MSIT Evaluation

Program [1991Gam] made a critical review of the data published until the year 1986.

Because of the serious discrepancies between the results of [1964Sve] and [1968Hun], [2001Mah]

performed a new study of the Al-Cr-Nb ternary system, combining X-ray diffraction and electron probe

microanalysis together with direct reaction calorimetry. Powders (99.5 Al, 99.5 Cr and 99.8 mass% Nb) of

the components of the alloy were mixed together at room temperature in the right proportions, inside a glove

box under purified Ar. The mixture was compressed in order to make small pellets of about 30-150 mg,

which were loaded in an argon tight sample dispenser. Then, the dispenser was connected to the calorimeter

and the samples were dropped, one after the other, from room temperature into the crucible of the

calorimeter. The calorimeter temperature was high enough to ensure a quick diffusion of the elements into

each other, but lower than the melting point or peritectic temperature of the compound. Some binary and

ternary compounds were synthesized in this way whilst determining their enthalpies of formation.

[1986Bla, 1985Tho] examined the 66.67 at.% Cr section. Six alloy compositions were arc melted under

gettered Ar using only 99 mass% Al with 99.2 mass% Cr and 99.5 mass% Nb. Samples were annealed for

a minimum of 170 h at temperatures in the range 800-1200°C and presumably air-cooled.

[1977Ale] determined the limit of solubility of Cr in Nb3Al along the constant Al section by X-ray

diffraction analysis. Samples were homogenized for 5 h at 1650°C and the annealed for 250 h at 700°C. The

solubility of Cr in Nb3Al was found to be 4.5 at.% Cr. The lattice parameter of Nb3Al is reduced by only

0.47 pm per at.% Cr.

[1975Sha] reported the same data as [1977Ale]. These results are almost the same as received by

[2001Mah].

In a cursory examination of the Al-Cr-Nb system, [1964Ram] studied the phases present in three alloys after

annealing for 80 h at 700°C. They detected NbCr2(h) as one of the phases in all three alloys.

Computer calculated isothermal sections were reported by [1973Kau] for temperatures 2000, 1800, 1700,

1600, 1500, 1400, 1200 and 1000°C. A calculated liquidus projection was also given. [1978Cha] reported

a calculated 1500°C section.

[1975Tho] arc melted 9 alloy compositions in the vicinity of the predicted ternary eutectic of [1973Kau].

Alloys were arc melted under Ar using 99.95 Al, 99.99 Cr and 99.8 mass% Nb.

Some problems related to the mechanical properties of intermetallics in the Al-Cr-Nb system have been

examined by [1990Kum, 1996Mac].

Binary Systems

The accepted Al-Cr phase diagram is taken from [2003Cor]. The Al-Nb binary system is taken from

[2003Vel]. The Cr-Nb phase diagram is taken from [2003Iva].

361


MSIT®

Al–Cr–Nb

Solid Phases

Solid phases observed in this system are given in Table 1.

Liquidus Surface

[1973Kau] predicted a pseudobinary saddle point on the Cr5Al8 - NbAl3 section at 1375°C and 30 Cr, 7 at.%

Nb. A ternary eutectic at 1317°C was calculated to occur at 34 Cr, 12 at.% Nb. [1975Tho] checked the

results of this calculation and showed that the predicted ternary eutectic contained NbAl3 primary crystals

with eutectic after slow cooling from the melt. It appears that the alloy with 34 Cr and 12 at.% Nb lies on a

monovariant eutectic curve that descends towards the pseudobinary eutectic between Cr5Al8 and NbAl3. It

should be noted that the liquidus projection calculated by [1973Kau] disagrees with the calculated 1500°C

isothermal section. The isothermal section does not show any evidence of the transition reaction at 1500°C

indicated on the liquidus projection.

Isothermal Sections

There are substantial differences between the 1200°C section of [1964Sve] and the 1000°C section of

[2001Mah] at one side, and the 1000°C section of [1968Hun] with respect to another. According to

[1968Hun], the Nb3Al phase extends into the ternary along the line of constant Nb content as opposed to

that given by [1964Sve] and [2001Mah]. It should be noted, that the location of the Nb3Al phase field given

by [1968Hun] is similar to that proposed by [1989Sub], who investigated two alloys by XRD and EPMA:

Al-15Nb-25Cr and Al-25Nb-12.5Cr (at.%) annealed at 1300°C. Based on his own data and that of

[1968Hun] it was suggested that Cr substitutes preferentially for Al with constant Nb content. At the same

time, [1989Sub] showed that Fe, Mo and W substituted for Nb with constant Al content on dissolving in

Nb3Al. This result may be regarded as argument in favor of the [1964Sve] and [2001Mah] data. The

homogeneity region of Nb2Al was shown by [1968Hun] as having considerably more solubility for Cr than

indicated by [1964Sve, 2001Mah]. The NbCr2(h) phase is stable at 1000°C. But the homogeneity range

presented by [1968Hun] included higher Nb contents than shown by [1964Sve] and [2001Mah] whose

results are very similar.

X-Ray diffraction analysis performed by [1986Bla] showed that alloys containing 0-20 at.% Al were single

phase with a NbCr2(h) structure. This result disagrees with the 1000°C data of [1964Sve, 2001Mah]. Since

[1964Sve] shows a wide NbCr2(h) region along the section NbCr2-NbAl3 at 1200°C, it is difficult to accept

that the NbCr2(h) region will have an extension along a constant Cr content as shown by [1986Bla].

[1973Kau] compared their calculated isothermal sections with the 1000°C section of [1968Hun] and with

a 1500 and 1200°C sections that are probably data from [1964Sve]. The calculated 1500°C isothermal

section does not indicate Cr5Al8-NbAl3 to be a stable join although the experimental data of [1964Sve]

suggested it to be so.

The isothermal sections at 1500 and 1200°C are presented in Fig. 1 and Fig. 2 taken from [1964Sve]. The

isothermal section at 1200°C is presented in accordance with the accepted Al-Nb binary system. The

isothermal section at 1000°C is presented in Fig. 3 taken from [2001Mah]. It has been slightly modified in

accordance with assessed Al-Cr and Al-Nb systems and reflects the existence of a two-phase region

between NbCr2(h) and NbCr2(r). The three new three-phase regions are marked by dashed lines. The

compositions of the phases in equilibrium at 1000°C are presented in Table 2 in accordance with [2001Mah]

considering the width of homogeneity regions of Cr4Al9 and Cr5Al8 compounds.

Slight discrepancies between location of phase boundaries in the accepted Al-Cr phase diagram and data

presented by [2001Mah] exist because of Nb solubility. It should be noted that compositions of the

(Nb,Cr)Al3 phase in equilibria 3, 4 and 5 do not allow correct connections of the tie-triangles with the

single-phase field of (Nb,Cr)Al3, therefore these compositions have been changed slightly in the diagram

presented in Fig. 3.

362


MSIT®

Al–Cr–Nb

Thermodynamics

The enthalpies of formation of (Nb,Cr)3Al, Nb2(Cr,Al), (Nb,Cr)Al3, Nb(Cr,Al)2 as a function of

composition have been measured by [2001Mah] and are presented in Table 3.


The solubility of Cr in Nb3Al lowered the critical temperature of the transition to the superconductive state.

The concentration dependence of Tc is Tc = 18.6 - 0.74 (at.% Cr) K [1977Ale].

The Nb(Cr,Al)2 phase has high hardness and high brittleness. The substitution of Cr for Al in Nb(Cr,Al)2

lowered the microhardness of the C14 high temperature Laves phase from 9.32 GPa to 8.47 GPa.

[1990Kum] found that the brittle to ductile transition temperature of Nb3Al occurred around 1200 K.

[1996Mac] investigated various Al containing ternary Laves phases having the hexagonal C14 structure. It

was shown that NbCrAl phase had very low thermal shock resistance. After arc melting + levitation

remelting the specimen was cracked severely and could not be used for mechanical testing.

References

[1963Koe] Köster, W., Watchel, E., Grube, K., “Structure and Magnetic Properties of



[1964Ram] Raman, A., Schubert, K., “The Occurence of Zr2Cu- and Cr2Al-Type Intermetallic

Compounds”, Z. Metallkd., 55, 798-804 (1964) (Experimental, 23)

[1964Sve] Svechnikov, V.N., Shurin, A.K., Dimitrieva, G.P., “Investigation of Alloys in the System

Nb-NbCr2- NbAl3” (in Russian), Issled. Stalei i Splavov, 104-107 (1964) (Crys. Structure,

Equi. Diagram, Experimental, Kinetics, Mechan. Prop., #, 19)

[1968Hun] Hunt, C.R.Jr., Raman, A., “Alloy Chemistry of ( ,U)-Related Phases. I. Extens Ion of

- and Occurrence of ’-Phases in the Ternary Systems Nb (Ta)-X-Al (X= Fe, Co, Ni, Cu,

Cr, Mo)” Z. Metallkd., 59 (9), 701-707 (1968) (Crys. Structure, Equi. Diagram, 14)

[1973Kau] Kaufman, L., Nesor, H., “Theoretical Approaches to the Determination of Phase

Diagrams”, Annu. Rev. Mater. Sci., 3(1), 1-30 (1973) (Equi. Diagram, Theory, 148)

[1975Ohn] Ohnishi, T., Nakatani, Y., Okabayashi, K. Bull. Univ. Osaka Prefect., 24, 183-191 (1975)

(Equi. Diagram, Crys. Structure, Experimental) quoted by [1998Mur]

[1975Sha] Shamrai, V.F., Postnikov, A.M., “Study of Some Ternary Solid Solutions Based on the

Compound Nb3Al”, Dokl. Akad. Nauk SSSR, 224, 1130-1133 (1975) (Crys. Structure,

Experimental, 8)

[1975Tho] Thomas, M.K., “Undirectional Solidification of a Cr/Nb/Al Eutectic Alloy”, Conf. Situ

Composites - II, Lake George, N.Y., Jackson, M.R., Walter, J.L., Hertzberg, R.W., (Eds.),

Xerox Individualised Publ. 37-47 (1975, Publ.1976 ) (Experimental, 19)

[1977Bra] Brandon, J.K., Pearson, W.B., Relay, P.W., Chieh, C., Stokhuyzen, R., “ -Brasses with

R Cells”, Acta Crystallogr., 3B, 1088-1095 (1977) (Crys. Structure, Experimental, 16)

[1977Ale] Alekseyevskiy, N.Y., Ageev, N.V., Shamrai, V.F., “Superconductivity of Some

Three-Component Solid Solutions Based on the Compound Nb3Al”, Fiz. Met. Metalloved.,

43, 29-35 (1977) (Crys. Structure, Equi. Diagram, Experimental, Magn. Prop.,

Superconduct., 14)

[1978Cha] Chart, T.G., “The Calculation of Multicomponent Alloy Phase Diagrams at the National

Physical Laboratory” in “Application of Phase Diagrams in Metallurgy and Ceramics”,

NBS Special Publ., 496(2), 1186-1199 (1978) (Equi. Diagram, Thermodyn., Theory, 26)

[1981Bro] den Broeder, F.J.A., van Tendeloo, G., Amelinckx, S., Hornstra, J., de Ridder, R., van

Landuyt, J., van Daal, H.J., “Microstructure of Cr100-xAlx Alloys (10 at.% < x < 33 at.%)

Studied by Means of Transmission Electron Microscopy and Diffusion. II. Discovery of a

New Phase”, Phys. Stat. Sol. (A), 67, 233-248, (1981) (Equi. Diagram, Experimental, 2)

363


MSIT®

Al–Cr–Nb




Phys. Stat. Sol. A, 67A, 217-232 (1981) (Equi. Diagram, Experimental, 10)

[1985Tro] Trojko, R., Blazina, Z., “Metal-Metalloid Exchange in Some Friauf-Laves Phases

Containing Two Transition Metals”, J. Less-Common Met., 106, 293-300 (1985) (Crys.


[1986Bla] Blazina, Z., Trojko, R., “Structural Investigations of the Nb(1-x)SixT2 and Nb1-xAlxT2

(T=Cr, Mn, Fe, Co, Ni) Systems”, J. Less-Common Met., 119, 297-305 (1986) (Crys.


[1989Ell] Ellner, M., Braun, J., Predel, B., “X-Ray Study on Cr-Al Phases of the W-Family” (in

German), Z. Metallkd., 80(5), 374-383 (1989) (Crys. Structure, Equi. Diagram,


[1989Sub] Subramanian, P.R., Simmons, J.P., Mendriatta, M.G., Dimiduk, D.M., “Effect of Solutes on

Phase Stability in Al3Nb”, Mat. Res. Symp. Proc., 133, 51-56, (Experimental, Equi.

Diagram, Mechan. Prop., 12)


Cr, Mn, Fe, Co, Ni, Cu, Zn)”, Int. Mater. Rev., 35(6), 293-327 (1990) (Crys. Structure, Equi.


[1991Gam] Gama, S., “Aluminium - Chromium - Niobium”, MSIT Ternary Evaluation Program, in

MSIT Workplace, Effenberg, G. (Ed.), MSI, Materials Science International Services GmbH


Assessment, 11)

[1992Tho] Thoma, D.I., Perepezko, I.H., “An Experimental Evaluation of the Phase Relationships and

Solubilities in the Nb-Cr System”, Mater. Sci. Eng. A, 156(1), 97-108 (1992) (Equi.


[1992Wen] Wen, K.Y.; Chen, Y.L.; Kuo K.H., “Crystallographic Relationships of the Al4Cr Crystalline

and Quasicrystalline Phases”, Metatt. Trans. A, 23A, 2437-2445 (1992) (Crys. Structure,

Experimental, 36)

[1993Bar] Barth, E.P., Sanchez, J.M., “Observation of a New Phase in the Niobium-Aluminium

System”, Scr. Metall. Mater., 28, 1347-1352 (1993) (Crys. Structure, Equi. Diagram,

Experimental, 9)

[1994Sel] Selke, H., Vogg, U., Ryder, P.L., “New Quasiperiodic Phase in Al85Cr15”, Phys. Status

Solidi A, 141(31), 31-41 (1994) (Crys. Structure, Experimental, 19)

[1995Aud] Audier, M., Duranr-Charre, M., Laclau, E., Klein, H., “Phase Equilibria in Al-Cr System”,

J. Alloys Compd., 220, 225-230 (1995) (Crys. Structure, Experimental, *, 17)

[1996Mac] Machon, L., Sauthoff, G., “Deformation Behaviour of Al-Containing C14 Laves Phases

Alloys”, Intermetallics, 4, 469-481 (1996) (Equi. Diagram, Experimental, 41)

[1997Li] Li, X.Z., Sugiyama, K., Hiraga, K., Sato, A., Yamamoto, A., Sui, H.X, Kuo, K.H., “Crystal

Structure of Orthorhombic -Al4Cr”, Z. Kristallogr., 212, 628-633 (1997) (Crys. Structure,

Experimental, 17)

[1998Li] Li, X.Z., Sui, H.X., Kuo, K.H., Sugiyama, K., Hiraga, K., “On the Structure of the Al4Cr

Phase and its Relation to the Al-Cr-Ni Phase”, J. Alloys Compd., 264, L9-L12 (1998)



368-375 (1998) (Equi. Diagram, Assessment, Calculation, Review, 43)



Experimental, 26)

[2000Sha1] Shao, G., Tsakiropoulos, P., “On the Phase Formation in Cr-Al and Ti-Al-Cr Alloys”,


364


MSIT®

Al–Cr–Nb

[2000Sha2] Shao, G., Nguen-Manh, D., Pettifor, D.G., Tsakiropoulos, P., “ -Phase Formation in a

Rapidly Solidified Cr-40 at.% Al Alloy”, Philos. Mag. Lett., 80(11), 703-710 (2000) (Crys.


[2001Mah] Mahdouk, K., Gachon, J.-C., “A Thermodynamic Study of the Al-Cr-Nb Ternary System”,

J. Alloys Compd., 321(2), 232-236 (2001) (Equi. Diagram, Experimental, Thermodyn., #, 7)

[2003Cor] Cornish, L., Saltykov, P., Cacciamani, G., Velikanova, T., “Al-Cr

(Aluminium-Chromium)”, MSIT Binary Evaluation Program, in MSIT Workplace,

Effenberg, G. (Ed.), MSI, Materials Science International Services GmbH, Stuttgart; to be

published, (2003) (Crys. Structure, Equi. Diagram, Review, 51)

[2003Iva] Ivanchenko, V., “Cr-Nb (Chromium-Niobium)”, MSIT Binary Evaluation Program, in


GmbH, Stuttgart; to be published, (2003) (Crys. Structure, Equi. Diagram, Review, 32)

[2003Vel] Velikanova, T., Ilyenko, S., “Al-Nb (Aluminium-Niobium)”, MSIT Binary Evaluation


Services GmbH, Stuttgart; to be published, (2003) (Crys. Structure, Equi. Diagram, Review,

81)


Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

( Al) hP2

P63/mmc

Mg

a = 269.3

c = 439.8

at 25°C, 20.5 GPa [Mas2]

( Al)

< 660.452

cF4

Fm3m

Cu

a = 404.96 at 25°C [Mas2]

(Cr)

< 1863

cI2

Im3m

W

a = 288.48

a = 290.01 ± 0.17

a = 289.70 ± 0.51

a = 289.43 ± 0.30

a = 289.20 ± 0.18

a = 288.80 ± 0.12

Pure Cr at 25°C, [Mas2]

5.59 ± 0.31 at.% Nb at 1668°C,

[1992Tho]

97.54 ± 0.32 at.% Cr, cooled from

1400°C, [1992Tho]


1300°C, [1992Tho]


1200°C, [1992Tho]


1100°C, [1992Tho]


950°C, [1992Tho]

365


MSIT®

Al–Cr–Nb

(Nb)

< 2469

cI2

Im3m

W

a = 330.04

a = 325.95 ± 0.89

a = 326.27 ± 0.35

a = 327.21 ± 0.51

a = 328.08 ± 0.75

a = 328.89 ± 0.31

Pure Nb at 25°C, [Mas2]

<24.42 ± 0.88 at.% Cr at 1703


1400°C, [1992Tho]

12.53 ± 075 at.% Cr, cooled from

1300°C, [1992Tho]


1200°C, [1992Tho]


1100°C, [1992Tho]

9.44 ± 0.31 at.% Cr, cooled from 950°C,

[1992Tho]

NbCr2(h)

1730 - 1585

hP12

P63mmc

MgZn2

a = 493.1

c = 812.3

at 25°C, 66.7 at.% Cr, [1986Bla]

NbCr2(l)

< 1625

cF24

Fd3m

MgCu2

a = 702.25 ± 0.26

to 699.50 ± 0.12

a = 701.81 ± 0.22

to 700.02 ± 0.12

a = 701.56 ± 0.24

to 700.96 ± 0.39

a = 701.02 ± 0.16

to 699.67 ± 0.22

a = 700.53 ± 0.33

to 699.49 ± 0.22

63.59 ± 0.27 - 68.04 ± 0.53 at.% Cr,

cooled from 1400°C, [1992Tho]

63.99 ± 0.43 - 67.95 ± 0.40 at.% Cr,


64.51 ± 0.32 - 67.79 ± 0.45 at.% Cr,


65.73 ± 0.41 - 67.49 ± 0.27 at.% Cr,


63.57 ± 0.46 - 68.27 ± 0.32 at.% Cr,


Nb3Al

< 2060

cP8

Pm3n

Cr3Si

a = 518.6 [V-C2]

18.6 to 25 at.% Al [Mas2]

Nb2Al

< 1940

tP30

P42/mnm

CrFe

a = 994.3

c = 518.6

[V-C2]

30 to 42 at.% Al [Mas2]

NbAl3< 1680

tI8

I4/mmm

Al3Ti

a = 384.1 ± 1

c = 860.9 ± 2

[V-C2]

Nb3Al2< ~1450

tP20

P42/mnm

Al2Zr3

a = 707 ± 8

c/a ~ 0.05

[1993Bar]

42.4 at.% Nb

CrAl7 (Cr2Al13)

< 790

mC104

C2/m

V7Al45

a = 2519.6

b = 757.4

c = 1094.9

= 128.7


[1995Aud, 1998Mur]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

366


MSIT®

Al–Cr–Nb

Cr2Al11 (CrAl5)

< 940

Orthorhombic

oC584

Cmcm

a = 1240

b = 3460

c = 2020

a = 1252.1

b = 3470.5

c = 2022.3

a = 1260

b = 3460

c = 2000


16.9 to 19.2 at.% Cr;

[1995Aud, 2000Mah]

single crystal

“ CrAl 4"

[1997Li, 1998Li]

“ CrAl 4"

[1992Wen]

CrAl4< 1030

hP574

P63/mmc

MnAl4

a = 1998

c = 2467

a = 2010

c = 2480


20.9 ± 0.3 at.% Cr

[1995Aud, 2000Mah]

20.6 to21.2 at.% Cr [1995Aud];

22.3 ± 0.1 at.% Cr

at Cr-rich border at 1000°C [2000Mah]

Cr4Al9< 1060

cI52

I43m

Cu4Al9

a = 912.3 ~31 to 45 at.% Cr quenched

from liquid [Mas2];


[1995Aud]

Cr4Al9< 700

hR52

R3m

Cr4Al9

a = 1291

c = 1567.7

32.8 to35 at.% Cr

[Mas2]

Cr5Al8~ 1350 - 1110

cI52

I43m

Cu5Zn8

a = 910.4 to 904.7 30 to42 at.% Cr, quenched from liquid

[1989Ell]

Cr5Al8< ~1150

hR26

R3m

Cr5Al8

a = 1279.9

c = 793.6

a = 1272.8

c = 794.2

a = 1281.3

c = 795.1

[Mas2]

[1977Bra]

[1989Ell]

Cr2Al

< 910

tI6

I4/mmm

MoSi 2

a = 300.45

c = 864.77

a = 300.5 to 302.8

c = 864.9 to 875.5

~65.5 to ~ 71.4 at.% Cr

[1963Koe, 1998Mur]

[1989Ell]

X

400

Cr5Al3 or Cr3Al

superlattice

~75 to ~80 at.% Cr [1981Bro, 1981Ten];

possibly metastable [1998Mur]

’CrAl4 Pmcm in as-cast alloy 15 at.% Cr, lattice

parameters are the same as for

“ CrAl 4” metastable [1994Sel]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

367


MSIT®

Al–Cr–Nb

Table 2: Compositions of the Phases in Equilibrium, at 1000°C, in the Al-Cr-Nb System, [2001Mah]

* values is brackets show compositions presented in the diagram Fig. 3.

iCrAl4 icosahedral in spinning alloy of 8 to 13 at.% Cr; by

decomposition of amorphous 20 at.%

Cr, metastable [1998Mur]

dCrAl4 decagonal 19 at.%, 4 at.% Si [1994Sel]

T in quenched alloy of 60-100 at.% Cr,

like metastable Ti [2000Sha1,

2000Sha2]

Domain number in

Figure 3

Phases involved in the

equilibrium

Composition of phases by EPMA (at.%)

Al Cr Nb

1 Nb2(Cr,Al)

(Nb,Cr)3Al

(Nb)

25.5

19

7

8

4.4

5.2

66.5

76.6

87.8

2 Nb2(Cr,Al)

(Nb)

NbCr2(h)

24.4

9.7

14

10.7

11.5

49.7

64.9

78.8

36.3

3 (Nb,Cr)Al3Nb2(Cr,Al)

NbCr2(h)

73.8 (73.97)*

37.6

44.4

0.2 (0.48)*

2.7

21.3

26 (25.55)*

59.7

34.3

4 (Nb,Cr)Al3NbCr2(h)

(Cr)

73.9 (73.6)*

38.4

30

0.9 (1.4)*

27.4

69.4

25.2 (25.0)*

34.2

0.6

5 (Nb,Cr)Al3Cr5Al8(Cr)

72.8 (73.6)*

57.4

39.3

1.3 (2.2)*

42.4

60.6

25.9 (24.2)*

0.2

0.1

6 (Nb,Cr)Al3CrAl4Cr4Al9

74.3

77.8

69.9

10.8

22.1

29.9

14.9

0.1

0.2

7 (Nb,Cr)Al3CrAl4Liquid

75.5

79.5

86.2

3.7

20.4

13.6

20.8

0.1

0.2

8 Cr4Al9Cr5Al8(Nb,Cr)Al3

~66

~64

~73.4

~33.9

~35.9

~7.09

~0.1

~0.1

19.51

9 (Nb)

NbCr2(h)

NbCr2(l)

~6

~10

~7.4

~12

~54

~55.8

~82

~36

~36.8

10 (Cr)

NbCr2(h)

NbCr2(l)

~12

~10.5

~8

~87.5

~57

~59

~0.5

~32.5

~33

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

368


MSIT®

Al–Cr–Nb

Table 3:Enthalpies of Formation of Some Binary and Ternary Compounds in the Al-Cr-Nb System,

Referred to Al (liq), Cr (bcc) and Nb (bcc) at T

Alloy Composition Calorimeter

Temperature [°C]

Enthalpy of Formation,

fH [kJ mole-1 of atoms]

References

Al0.61Cr0.39 (Al8Cr5) 1203 - 23.5 ± 0.5 [2001Mah]

Al0.61Cr0.39 (Al8Cr5) 1010 -23.7 ± 0.4 [2001Mah]

Al0.69Cr0.31 (Al9Cr4) 940 -24.8 ± 0.5 [2001Mah]

Al0.805Cr0.195 (Al4Cr) 921 -24.8 ± 0.8 [2001Mah]

Al0.84Cr0.16 (Al11Cr2) 843 -20.05 ± 0.4 [2001Mah]

Al0.87Cr0.13 (Al7Cr) 710 -22.6 ± ? [2001Mah]

Nb0.80 Al0.20 1426 - 19.7 ± 2.3 [2001Mah]

Nb0.79Cr0.02Al0.19 1428 - 17.2 ± 1.0 [2001Mah]

Nb0.77Cr0.04Al0.19 1423 - 12.3 ± 1.8 [2001Mah]

Nb0.67 Al0.33 1426 - 29.8 ± 1.0 [2001Mah]

Nb0.67Cr0.05Al0.28 1387 - 27.7 ± 1.0 [2001Mah]

Nb0.63Cr0.04Al0.33 1450 - 30.2 ± 1.2 [2001Mah]

Nb0.26 Al0.74 1001 - 54.6 ± 0.9 [2001Mah]

Nb0.24Cr0.02Al0.74 1000 - 52.55 ± 1.2 [2001Mah]

Nb0.22Cr0.04Al0.74 1001 - 50.6 ± 1.8 [2001Mah]

Nb0.20Cr0.06Al0.74 1001 - 49.0 ± 0.8 [2001Mah]

Nb0.18Cr0.08Al0.74 1000 - 46.9 ± 0.95 [2001Mah]

Nb0.16Cr0.10Al0.74 1001 - 45.2 ± 0.8 [2001Mah]

Nb0.333Cr0.567Al0.10 1485 - 11.6 ± 1.4 [2001Mah]

Nb0.333Cr0.467Al0.20 1485 - 20.3 ± 0.4 [2001Mah]

Nb0.333Cr0.367Al0.30 1485 - 26.5 ± 0.8 [2001Mah]

Nb0.333Cr0.267Al0.40 1485 - 34.9 ± 1.4 [2001Mah]

369


MSIT®

Al–Cr–Nb

20

40

60

80

20 40 60 80

20

40

60

80

Nb Cr


Axes: at.%

NbAl3

βNbCr2(h)

Nb2Al

Nb3Al

(Nb)αNbCr2(l)

? Nb3Al2

Fig. 1: Al-Cr-Nb.


1500°C [1964Sve]

20

40

60

80

20 40 60 80

20

40

60

80

Nb Cr


Axes: at.%

NbAl3

Nb2Al

Nb3Al

(Nb)

βNbCr2(h)

αNbCr2(l)

Nb3Al2

Fig. 2: Al-Cr-Nb.


1200°C [1964Sve]

370


MSIT®

Al–Cr–Nb

20

40

60

80

20 40 60 80

20

40

60

80

Nb Cr


Axes: at.%

(Cr)

NbAl3

Nb2Al

Nb3Al

(Nb)

Cr4Al9

CrAl4

L

7

6

5

43

21

Nb3Al2

βNbCr2(h)

8

910

Cr5Al8

αNbCr2(l)

Fig. 3: Al-Cr-Nb.


1000°C [2001Mah]

371


MSIT®

Al–Cr–Ni

Aluminium – Chromium – Nickel

Tamara Velikanova, Kostyantyn Korniyenko, Vladislav Sidorko

Literature Data

The Al-Cr-Ni system has been investigated in many works, however Al-Cr-Ni equilibrium diagram has not

been determined in the whole composition range so far. After assessments of [1984Mer1] and [1991Rog],

in accordance with which there are no ternary phases in the system, several reports with data on the ternary

phases in Al-rich part of phase diagram have appeared. The major part of the earlier works had been

dedicated to the Cr-Ni edge of the system. The present evaluation updates work of [1991Rog] and considers

all data available.

Besides the early cursory study [1933Roe], summarized by [1943Mon], dealing with the influence of Cr

and Ni additions on the (Al) solid solution, the first detailed investigation of the NiAl-Ni-Cr50Ni50

subsystem, including a series of isothermal sections at 750, 850, 1000 and 1150°C as well as tentative

mapping of the fields of primary crystallization, was done by [1952Tay2]. The alloys, usually weighing

50 g, were prepared by induction melting of the high purity constituting elements (impurities not given) in

alumina-lined crucibles under a low pressure of hydrogen. The alloys were studied in the as-cast state as

well as after annealing at various temperatures: 750°C (500 h), 850°C (500 h), 1000°C (100 h) and 1150°C

(48 h) employing X-ray powder techniques on filings along with optical microscopy for the alloys cooled

from 750, 850°C. Phase relations at higher temperatures were derived by microoptical analysis only. A

homogenizing step at 1150 to 1250°C for 100 h was introduced prior to the final annealing procedure.

Further studies of partial isothermal sections and reaction isotherms were performed by [1958Bag1] and

[1958Bag2] (1150, 1200°C), and by [1982Tu, 1983Lan, 1983Ofo, 1984Car, 1985Ofo, 1987Ofo] and

[1989Hon] in the temperature range from 950 to 1200°C. Whereas the latter group of authors mainly

employed DTA, EMPA, SEM-EDX techniques to derive precise data for the location of the phase

boundaries, diffusion experiments were used by [1984Car, 1987Nes1, 1987Nes2, 1987Nes3] and

[1984Mer2] and the work of [1983Ofo, 1985Ofo] and [1987Ofo] involved Knudsen cell mass spectroscopy.

The alloys of [1987Nes1, 1987Nes2, 1987Nes3] and [1989Hon] were prepared by arc melting the high

purity elements under argon followed by subsequent annealing for 140 h at 1250°C in evacuated silica tubes

[1989Hon] or in molybdenum cans [1987Nes1, 1987Nes2, 1987Nes3] with final quenching in water. The

diffusion couples, used by [1987Nes1, 1987Nes2] and [1987Nes3] were fabricated from flat polished discs

cut from the pre-alloyed and homogenized samples and were further heated in Mo containers at either 1100

or 1200°C for 100 h. A second set of diffusion-bounded couples was prepared by hot-pressing in a stainless

steel mixture at 1100°C in vacuum for 1 h under 20 MNm-2 pressure. These couples were then sealed in

evacuated silica capsules, backfilled with Ar, and annealed at 1095 and 1205°C for 100, 300 and 500 h. A

similar preparation technique was adopted by [1984Mer2]. The diffusion couples were then sectioned,

polished and examined by EMPA. [1983Ofo, 1985Ofo] and [1987Ofo] studied 16 binary and 9 ternary

alloys by means of X-ray diffraction, microscopic analysis, Knudsen cell mass spectroscopy and EMPA.

The alloys were prepared by melting high purity metals in a vacuum furnace under argon, keeping the melt

for some time at certain temperature, followed by chill casting into ingots of 2.5 cm diameter and 15 cm

height. For heat treatment, the samples were placed inside an Al2O3 tube contained in a sealed evacuated

silica tube and annealed for 100 to 200 h; Cr-rich alloys were annealed for 400 h. The more ductile samples

were given a 50% hot compression and heat treated at 1250°C for 240 h with 100 extra hours at 1150°C.

All samples used in the 1150°C isothermal section were quenched and their composition was checked by

chemical analysis. The use of phase diagram information in the understanding of the multi-element

diffusion and the correlation of coating/substrate compositions, microstructures and behavior has been

demonstrated by [1977Jac1] on Al-Cr-Ni coatings of superalloys prepared by pack aluminization, and a

series of isothermal sections around 1000°C have been proposed based on X-ray diffraction, microscopical,

chemical and microprobe analysis of the aluminized structures. A large number of experimental

investigations are concerned with the constitution of alloys on and in vicinity of the section NiAl-Cr

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[1953Kor, 1952Tay2, 1958Bag1, 1958Bag2, 1992Gor] and [1993Cot1], which is not quasibinary if the

reported data on directions of tie-lines in ( Cr)+( NiAl) field [1982Tu, 1985Ofo] are taken into account,

and the other results generalized in the thermodynamic assessment [2001Dup]. This conclusion agrees with

[2001Com] who reported that the maximum temperature on invariant line L + [2001Com] was shifted

to Al corner. Liquidus surface projection of the NiAl-Cr-Ni subsystem was presented by [1991Rog] having

generalized the data of [1952Tay2, 1954Kor, 1955Kor2, 1958Kor]. Using the elemental metals and 25 or

54.2 at.% Al-Ni master alloys of various purities (99.96 mass% Cr or 97 mass% Cr containing 2.5 mass%

Al, 0.3 mass% Si and 0.5 mass% Fe), the alloys (50 g each) were prepared by high frequency melting in

alumina crucibles either under a 48Al2O3-7MgO-45CaO flux [1954Kor] and [1955Kor2] or under argon

[1958Bag1]. The microstructure, hardness and temperature coefficient of resistivity were investigated after

quenching from 1200°C in water and after slow cooling; thermal expansion and heat resistance were studied

on 1200°C annealed alloys. In the range of compositions near NiAl-Cr section (with chromium content up

to 5 at.%) liquidus and solidus surfaces were plotted and phase composition of alloys slowly cooled from

1400°C was presented by [1993Cot1]. [1993Cot1] produced the alloys using nonconsumable arc melting of

constituent elements (99.999 mass% Al, 99.99 mass% Cr, 99.95 mass% Ni) in a water-cooled copper

crucible under argon gas. Then homogenization was carried out in commercial purity argon gas for 24 h at

1400°C, using heating and cooling rates of 0.083 K/s. DTA was employed using samples prepared by

pulverizing ~10 to 50 g of each homogenized casting to powder. Investigation of the NiAl-Cr eutectic alloys

was conducted by [1978Vol], and also by [1992Gor] in the composition range 12 to 33 at.% Al. [1992Gor]

investigated also eutectic alloys Cr- Ni in the range of 0 to 15 at.% Al. Directional eutectic crystallization

was performed by [1970Cli, 1970Wal, 1971Cli, 1973Wal, 1978Vol, 1986Gor] and [1996Ros] on NiAl-Cr

alloys produced in an arc furnace, cast into rods in an induction furnace, followed by directional

crystallization by the Bridgman method in a vertical furnace. The phases with crystal structure different

from one of the binary phases were revealed and investigated by [1982Tu, 1989Zho, 1990Col, 1996Ros,

1997Li, 1997Sat, 2000Uch] and [2001Com]. For the first time the existence of a ternary phase in Al-Cr-Ni

has been reported by [1982Tu]. The phase was found in a sample pack-aluminized at 900°C and then it was

prepared as single phase (according to metallography) of Cr15Ni10Al75 composition. The structure was not

determined. A ternary phase with the same composition and four more ones were obtained by [1996Ros] in

as-cast and annealed Al-rich alloys. The aspect of the phase diagram concerned and investigated to

liquid-solid equilibria in the subsection AlCr-AlNi-Al was investigated by [1996Ros] and [2001Com]. The

alloys by both [1996Ros] and [2001Com] were prepared by melting of high purity (99.9 mass%) constituent

Al, Cr and Ni. But [1996Ros] carried out the melting process in an inductive cold crucible under an argon

atmosphere as well as by the addition of chromium and aluminium to prealloyed NiAl3 or Ni2Al3compounds, just as [2001Com] used arc melting under an argon atmosphere. The alloys were investigated

in as-cast state [2001Com] or in addition after quenching from selected temperature in the DTA experiment

process. Compositions of the phases were determined using SEM-EDX [1996Ros, 2001Com], EDS (Link

AN10000 system) and EMPA (on a Cameca SX50 microprobe) [1996Ros]. Phase structures were identified

by TEM [1996Ros]. The transformation temperatures in alloys were measured by DTA on samples of about

1 g masses using the cooling and heating rates 5K min-1 or less, however, the fields of primary

crystallization are given without direction of temperature change. This was also shown on liquidus surface

projection of the AlCr-AlNi-Al subsystem by [2001Com], where the temperatures of the invariant equilibria

are also not indicated.

The crystal structure of the ternary phases obtained by rapid solidification and in conditions of conventional

cooling rate were investigated by [1989Zho, 1997Li, 1997Sat], and [2000Uch] using SEM-EDX, TEM, and

HREM, and modeling. Accurate determination of lattice parameters was used by a series of investigators

for a precise characterization of the extent of the mutual solid solution behavior in the Al-Cr-Ni ternary

[1952Tay2, 1955Kor1, 1955Kor2, 1958Bag2, 1959Gua, 1960Kor, 1961Ham, 1961Pry, 1963Arb,

1964Ram, 1965Ram, 1971Cli, 1972Sch, 1976Low, 1983Och, 1984Och1, 1984Och2, 1985Mis, 1996Ros,

1997Kre, 1999Zak, 1999Zya] and [2001Com]. Samples were generally prepared by melting under argon

followed by various heat treatments under argon in sealed silica capsules. [1960Kor] and [1961Pry]

annealed their alloys for 200 h at 1200°C and 100 h at 1000°C in evacuated silica tubes followed by a water

quench. Samples of [1961Ham] were prepared by high frequency melting in vacuum, then homogenized for

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4 h at 1260°C and hot rolled whereby the material was reheated five times to 1260°C for 10 min. These

specimens were then aged at selected temperatures for 12 to 24 h and quenched in iced brine. Whereas

[1952Tay2, 1955Kor1, 1955Kor2, 1958Bag2, 1960Kor, 1964Ram, 1965Ram, 1971Cli, 1972Sch,

1976Low, 1984Och1, 1984Och2, 1985Mis] and [1999Tia, 2002Fis] deal with the extent of the NiAl and

(Ni) phase regions, the problem of Cr substitution in ' Ni3Al is treated by [1952Tay2, 1959Gua,

1961Ham, 1963Arb, 1966Arb, 1984Och1, 1984Och2] and [1985Mis]. In search for a MgCu2 type phase,

[1964Ram] and [1965Ram] studied two alloys: Cr25Ni13Al6 (arc melted, as-cast) which was a

homogeneous Cr5Al8 type, and Cr33Ni33Al34 which, as-cast and/or after 85 h at 700°C, revealed a CsCl

type phase in accordance with the 750°C isothermal section of [1952Tay2]. Based on earlier investigations

by [1959Gua, 1963Arb] and [1966Arb], the extent of the 'Ni3Al phase field on alloying with Cr as well as

the mode of atom substitution has been investigated by [1983Och, 1984Och1, 1984Och2] and [1985Mis]

by means of X-ray diffractometry and metallography, assisted by hardness measurements from [1959Gua]

and [1963Arb]. Three series of alloys, CrxNi3Al1-x, CrxNi3-xAl and Crx(CryNi1-y)3Al1-x, were prepared by

[1983Och, 1984Och1, 1984Och2] and [1985Mis], who essentially confirmed earlier data [1966Arb] with

Cr replacing Al in CrxNi3Al1-x while in general Cr was found to substitute for both lattice sites in

Crx(CryNi1-y)3Al1-x.

Binary Systems

The Cr-Ni system is adopted according [Mas2]. The Al-Cr and Al-Ni systems are accepted from [2003Cor]

and [2003Sal], respectively.

Solid Phases

Data on the solid phases are presented in Table 1. For the Al-poor range of compositions below the

Cr5Al3-Ni2Al3 tie-line, no ternary phases are found. In the Al-rich corner several ternary phases have been

found in as-cast (or annealed and cooled at conventional rate) alloys. Also a hexagonal metastable phase in

the rapidly solidified Cr0.5Ni0.5Al6 alloy together with decagonal and icosahedral quasicrystals was found

by [1989Zho]. It appears during the quasicrystal-to-crystal transition and its structure closely resembles that

of the decagonal quasicrystal and stable orthorhombic phases because of the presence of icosahedral

subunits. The hexagonal phase after heating up to 300°C transforms into an orthorhombic structure.

Monoclinic 1, orthorhombic 2, and hexagonal 3, 4, 5 phases reported by [1996Ros] and [1997Li,

1997Sat] are of own crystal structure types. The structure of 1 and 2 are rather complicated, each of them

exhibits very large cell parameters and different polytypes and superordering. The high temperature

rhombohedral 3 and hexagonal 4 phases are found to be of related structure. The orthorhombic 1'

polytype forms because of a periodic multiple (100) twinning of 1. The orientational relationships between

the 1 monoclinic and its orthorhombic polytype structure are as follows:

(010)monocl. || (001) orthor.

(001)monocl. || (010) orthor.

(100)monocl. || (100)orthor.

and relation between the cell parameters is: amonocl. = (corthor · sin-1 )/2, bmonocl. = aorthorh., cmonocl. =

borthor. The a and b parameters of 2 appear to correspond to those of the 1' phase, which is an orthorhombic

polytype of 1. This is confirmed by the orientational relationships between the orthorhombic 1 and

orthorhombic 2 phases. They are as follows:

(100) 1 || (001) 2

(001) 1 || (100) 2

(010) 1 || (010) 2

and relation between the cell parameters is:

a 2 = b 1, b 2 = a 1, c 2 = (7a 1·sin 1)/6.

Triclinic superstructure of 2 ( 2’) is supposed by [1996Ros], with cell parameters being equal:

atricl. = 2a 2, btricl. = b 2 , ctricl. = 2c 2, or orthorhombic polytype with cell parameters two times larger than

those of 2. The orientational relationships between the two structures of 3 and 4 are as follows:

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Al–Cr–Ni

(III) || (000I)

(II0) || (I2I0)

(II2) || (I0I0) and 4 = 2a 3,rhomb. · sin( /2). These two phases ( 3 and 4) are considered to be high

temperature ones. The 5 phase is reported as stable at low temperature, and forming through reaction

between 3 and 4. The structure of the 3, 4 and 5 phases is very close to that of CrAl4. However

substitution of Al or Cr atoms by Ni atoms in the CrAl4 structure does not occur or is very small.

[2001Com] claimed that they confirmed the phases described by [1996Ros] with the microstructure and the

composition measurements. But there are some dissensions in the results of [1996Ros] and [2001Com]

concerning phase compositions. The phases considered by [1997Li, 1997Sat] and [2000Uch] are the same

as 4 (h) of [1996Ros]. The latter is shown to be related to icosahedral quasicrystals, and to have a large unit

cell with 222 atoms, with transition metals Cr and Ni co-occupying the same positions [1997Li, 1997Sat].

[2000Uch] proposed a new interpretation of this phase structure as modulated one instead of generally

accepted description in terms of the aggregations of clusters. The proposed modulated structure is basically

composed of close-packed layers with ordered atomic vacancies owing to the occurrence of

charge-density waves.


There is no pseudobinary section in the Al-Cr-Ni system. But the pseudobinary eutectic exists within an

isopleth shifted to the Al corner and its temperature is somewhat higher compared with the accepted one by

[1984Mer1, 1991Rog] for the radial Cr - Ni0.5Al0.5 section. This displacement may be attributed to the

experimental observation of [2001Com] and was shown in thermodynamic assessment of [2001Dup]. There

is no special investigation concerning the location of the tie-line with maximal temperature in the two-phase

( Cr)+NiAl1±x field.


Seven ternary invariant equilibria in ternary system are reported (Table 2): maximum decomposition of the

liquid e1 at temperature of about 1445°C (see section Pseudobinary Systems) within maximal tie-line

Cr-NiAl1+x; eutectic decomposition of the liquid E1 at 1300±20°C, which is the average of the data of

1320±10°C [1952Tay2], 1300°C reported by [1955Kor2], and the calculated ternary eutectic at 1288°C by

[1981Sto] as well as at 1280°C by [2001Dup]; a transition type reaction U1 at 1350°C [2001Dup] which is

in a reasonable agreement with value of 1340 ± 10°C reported by [1952Tay2] which, due to the mode of

formation of the ' phase, was slightly altered by [1984Hil, 1988Bre], and two more transition reactions, U2

and U3, involving the binary Ni2Al3 and Cr5Al8 phases. These reactions were already postulated by

[1984Mer2] in the proposed partial reaction scheme for the Al-Cr-Ni system. The solid state transition

reaction U4 at 996°C after [2001Dup] is in a good agreement with a value of 990 ± 3°C [1982Tu], which

was earlier proposed at 1000°C by [1952Tay2]. The eutectic four-phase invariant reaction E2 exists at

634°C [1996Ros], and one of the preceding processes of crystallization, with participation of the phase

and aluminium, being incongruent in the binary Al-Cr system, l+ (Al), in the ternary system changes the

character to congruent one: L (Al)+ . The compositions of the phases in U1, E1, and U4 equilibria are

given by [2001Dup]. The compositions of the other liquid phases are given explicitly by [1952Tay2] and

[1955Kor2], and those of the solid phases are constructed by extrapolation from EMPA data given by

various research teams [1991Rog]. A partial reaction scheme is presented in Fig. 1.

Liquidus Surface

The liquidus projection, as shown in Fig. 2, is essentially based on the early data by [1952Tay2, 1954Kor,

1958Bag1] and [1993Cot1] followed by critical discussion by [1982Wes, 1984Mer1] and [1991Rog].

Additionally to the isotherms corrected slightly by [1991Rog] with respect to the accepted boundary

systems and the melting point of Cr at 1863°C the isotherms based on [2001Dup, 1993Cot1] data are

proposed in Fig. 2. Figures 3 and 4 present calculated liquidus surface by [2001Dup] and the ,NiAl phase

liquidus surface in vicinity of Ni0.5Al0.5 composition after [1993Cot1]. The liquidus surface projection in

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the Al-rich corner is not established. The experimental data of [1996Ros] and [2001Com] concerning the

map of the liquidus surface in the Al-rich corner disagree with each other, although the phases in the as-cast

alloys were the same according to [2001Com]. Neither the direction of the monovariant temperatures nor

the invariant temperatures are given by [1996Ros]. And the relative dislocation of the primary fields and

ternary phase compositions given by [2001Com] are inconsistent with each other from the view point of

geometrical thermodynamics and with the shown temperature change direction along the monovariant lines.

Isothermal Sections

The earlier published information [1952Tay2, 1958Bag1, 1958Bag2, 1958Kor, 1982Tu, 1984Mer2,

1983Lan, 1983Och, 1985Ofo, 1987Nes1, 1987Nes2] and [1989Hon], assessed by [1991Rog], and

[1992Gor, 1993Cot1, 1994Jia, 1999Tia] is concerned with the NiAl-Cr-Ni subsystem covering the

temperature range from ~600°C to solidus. [2001Dup] thermodynamic assessment covered many of the

mentioned and recent publications [1990Dav, 1990Kek, 1994Yeu, 1996Wu, 1999Sun]. Generally a good

agreement between calculated and experimental data for investigated temperature and composition ranges

was obtained. Both, experimental and calculated isothermal sections are presented in Figs. 5 to 16. Figure

17 demonstrates phase solidus surface in the vicinity of its equiatomic composition. The main

characteristic is the increase in the Cr solubility in the ' phase field with decreasing temperature. Phase

relations at 750 and 850°C in the Ni-rich corner for more than 50 at.% Ni are due to [1952Tay2] and

presented in Fig. 15 and Fig. 13 with minor adaptation to the accepted binaries [1991Rog]. Isoparametric

lines for the size of the unit cell within the and ' phase fields reveal the difficulties in the X-ray resolution

of the two bcc-phases in a certain restricted composition range, where the exact overlap of the X-ray high

angle reflections tends to mask the duplex structure. Whereas fcc-fcc precipitation usually occurs on the

(111) planes, [1952Tay2], in the region with equal lattice parameters of the and ' phases, a preference of

the '-precipitates for the rectangular-cubic to the usual spheroidal shape growing on the (100) planes is

observed. Phase relations, as found in slowly-cooled samples, were reported to essentially correspond to the

750°C isothermal section [1952Tay2]. [1952Tay2] was first to observe the + + ' transition reaction,

which was attributed to the 1000°C isothermal section. Later thermal analysis by [1982Tu] gave a value of

990 ± 3°C for the four-phase reaction isotherm. The effects of alloying on the temperature of the + + '

transition reaction were studied by [1976Jac]. Employing EMPA, [1982Tu] provided a phase triangulation

in the ternary up to 60 at.% Al at 1025°C, which is presented in Fig. 10a. The tip of the ' phase field has

been accurately re-determined by [1983Lan] overcoming the matrix effects of [1982Tu] in the EMPA

analysis of the ' precipitates. Some controversies exist between the phase relations at temperatures around

1025°C according to [1982Tu, 1983Lan] and the isothermal sections designed by [1977Jac1] and

[1977Jac2] for the temperature range ~950 to ~1100°C. The discrepancies mainly concern the postulated

+ equilibrium, which is in contradiction to the findings of [1982Tu, 1983Lan] and [1985Ofo]. A second

argument concerns the curvature of the phase boundary in the ternary, which in the original paper by

[1977Jac1] was shown with a negative curvature with respect to the Al-Cr boundary, but was later corrected

by [1977Jac2] to be consistent with the experimental findings of [1958Bag1, 1982Tu, 1983Lan] and

[1985Ofo]. Figure 7a gives the phase relation at 1150°C as determined by [1952Tay2] and [1958Bag1] and

by a more complete and herein accepted EMPA study by [1985Ofo]: inconsistencies mainly concern the

extensions and widths of the , and ' phase fields. Whereas [1952Tay2] arrived at a rather exaggerated

Cr-solubility in the phase, the data by [1985Ofo] seem to support earlier results by [1958Bag1] revealing

a maximum solubility of 10 at.% Cr at 30 at.% Al. Agreements exist on the maximum Cr solubility in the

' phase of 8 at.% Cr at 22 at.% Al [1952Tay2, 1958Bag1] and [1985Ofo]. The form and extension of the

field [1985Ofo] (Fig. 7a), however, need further investigation. Unlike [1985Ofo], [2001Com] in as-cast

alloys found the content of Ni in phase to be equal 3.3 at.% only and Ni decreases slightly the content of

Al in . This finding agrees with [1982Tu, 1983Lan] data for 1025°C (Fig. 10a).

Replotting the lattice parameter values obtained by [1952Tay2], [1955Kor1] showed a partially linear

variation of the lattice parameters of the (Cr, Ni, Al) solution at 20 at.% Cr up to 10 at.% Al. Similarly,

based on X-ray and metallographic analysis, hardness measurements and electrical resistivity data,

[1960Kor] and [1961Pry] showed a linear variation of the lattice parameters of the (Cr, Ni, Al) solid

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Al–Cr–Ni

solution at 11.1 at.% (10 mass%) Cr up to 16.9 at.% Al (at 1200°C) and up to 13.2 at.% Al (at 1000°C),

respectively. The / ' phase boundary as a function of temperature, as assessed by [1961Ham] from

extensive metallographic studies by electron microscopy and high temperature X-ray diffractometry in the

range from 750 to 1200°C and within the vertical section Ni3Al-CrNi3, reveals slight deviations from the

values obtained by [1952Tay2]. The / ' solvus boundary [1961Ham] tends to show larger Al solubility in

the phase at lower temperatures, but smaller Al contents at temperatures above 1000°C. The data of

[1961Ham] are, however, in a good agreement with the EMPA studies of [1982Tu, 1983Lan, 1984Car] and

[1985Ofo]. The / '-solvus lines at 827, 927, 1027 and 1127 were obtained by employing DTA with

support from energy dispersive X-ray spectroscopy combined with SEM-ELY. Their results, on the

contrary, show slightly smaller Al solubilities in the phase with respect to [1961Ham]. Therefore, the data

of [1952Tay2] are accepted for the 750 and 850°C isothermal sections, whereas the outline of the field at

1025 and 1150°C is accepted according to the measurements by [1982Tu, 1983Lan, 1984Car] and

[1985Ofo], despite the fact that their curvature of the Al-rich / ' boundary is opposite to [1989Hon].

Isothermal sections above 1150°C are primarily concerned with the + + and the + + ' equilibria

[1958Bag1 and 1958Kor], and [1987Nes1], and [1987Nes2]. Solubility data [1958Bag1] and [1958Kor] are

listed in Table 2. An estimated phase field distribution at 1200°C is given by [1987Nes1]. His investigation,

however, mainly concerns the / + boundary ranging from 57 at.% Ni at 10 at.% Al to 72 at.% Ni

at 15 at.% Al.

The calculated by [2001Dup] partial isothermal sections at 750, 800, 850, 900, 1000, 1025, 1100, 1150,

1200 and 1300°C are presented in Figs. 5 to 15. As one can see, the calculation showed a smaller solubility

of Cr in and phases compared with the experimental data [1952Tay1] and [1952Tay2] at 750 and

850°C, and uncommon form of phase solvus as well as a negative curvature of Cr solvus isotherm at

1150°C. The calculated smaller solubility of Cr in ’ at temperatures lower than 1000°C was confirmed in

experiments of [1983Och], who dealt with longer heat treatment time of alloys at 1000°C and their higher

purity than [1952Tay2]. These data well agree with calculated isothermal section. Elevated solubility value

reported in earlier works could be due to not fully equilibrated samples or due to the poor sensitivity of the

experimental methods. The minimal solubility of Cr in the equiatomic NiAl phase according to the

calculation [2001Dup] shown in Figs. 7b, 10b, 13b, 15b is supported by experimental points of [1982Tu] in

the isothermal section at 1025°C (Fig. 10a), although approximation made by [1983Lan] does not cover

these experimental points.

[1999Tia] found by TEM that the solubility of Cr in NiAl at Al contents of 48 to 50 at.% is not more than

8 at.% for alloys annealed for 74 h at 1290°C and quenched; and it is less than 2 at.% in the range of 700

to 800°C. These data were obtained on alloys of high purity: starting materials were 99.9 mass% Ni, 99.99

mass% Al and 99.8 mass% Cr. The same result was obtained by [2002Fis] for 550°C using atom probe field

ion microscopy. Data of [1993Cot1] concerning solubility of Cr in NiAl at low temperature shown in Fig.

16 are in a good agreement with [1999Tia] and [2002Fis]. [1997Sch] reported the solubility of Al in in

+ equilibria at 600°C to be less than after [1952Tay2] for 2 to 3 at.% within the whole phase boundary

extension. The results were obtained by both three-dimensional atom probe and TEM technique on aged

low supersaturated alloy 5.2 Al 14.7 Cr (at.%). Isothermal sections at 750, 1000, 1227, 1327, 1427, 1527,

1627, and 1727°C earlier have been calculated by [1974Kau] with some shortcomings in so far as the

bcc-phase was calculated to be stable for the entire solution range and no quasibinary behavior along the

NiAl-Cr section was revealed. These features have mainly been overcome in the later calculations of the

isothermal sections at 1027, 1127, 1227, 1327, 1427 by [1980Cha] and [1985Bar].


Early thermal and microscopic investigations along the vertical Cr-NiAl section by [1953Kor],

complemented by hardness and resistivity measurements, revealed a binary eutectic at 1445°C and

33.6Cr-33.2Ni-33.2Al (at.%). This shows a rather restricted solid solubility of the two and bcc type

phases. [1952Tay2] determined the eutectic + at 30Ni-30Al (at.%), whereas the findings of [1958Bag1]

and [1958Bag2] resulted in 37.4 to 28.2 at.% Cr. More recent studies by [1978Vol] located the binary

eutectic in the vertical section Cr-NiAl at 32.5Ni-32.5Al (at.%) and further studies by [1970Cli, 1970Wal,

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Al–Cr–Ni

1971Cli, 1973Wal] and [1984She] arrived at 34Cr-33Ni-33Al (at.%). The microstructure of melt-spun

ribbons of the NiAl-Cr eutectic composition (34 at.% Cr) has been studied by optical and TEM microscopy

[1984She]. At 1200°C the Cr phase contains 20.6 mole% NiAl, whereas for the ,NiAl phase a Cr content

of about 8 at.% was estimated by [1984She, 1999Tia]. X-ray diffraction patterns of the CsCl and bcc lattices

were said to be indistinguishable. The EMPA data on the mutual solid solubilities within Cr-NiAl section

reveal consistently a much larger solid solubility at 1025, 1150 and 1200°C, than earlier reported by

[1953Kor, 1958Bag1] and [1958Bag2]. For 1025°C these data are reported by [1982Tu, 1983Lan, 1984Car,

1983Ofo]; for 1150°C - by [1985Ofo]; for 1200°C - by [1984She]. The authors [1953Kor, 1958Bag1] and

[1958Bag2] considered the Cr-NiAl section as a quasibinary system, and [1991Rog] presented it in such a

way essentially based on [1953Kor, 1958Bag1, 1958Bag2] and [1982Tu, 1984Car, 1983Ofo, 1985Ofo,

1987Ofo]. But the solidus temperature in the + phase field is not available and there is no evidence that

1445°C is a maximum solidus temperature of this phase field, which is a necessary condition for the

quasibinary section. There are wide ranges of ( Cr) and NiAl solid solutions based on congruent phases

coexisting in equilibria in this ternary system. In such a kind of systems, deviation of the quasibinary section

from the connected line is a common feature. Therefore it is not surprising that thermodynamic calculations

of both [1974Kau] and [2001Dup] revealed no quasibinary behavior along the Ni-AlCr section. This result

seems to be confirmed by the experimental points for the set of tie-lines given by [1982Tu, 1983Lan] for

1025°C.

Polythermal Cr-NiAl section according to [2001Dup] is given in Fig. 18. The calculated liquidus and

solidus of phase is in a complete agreement with data [1993Cot1] and -solvus is in agreement with

[1958Bag, 1953Kor]. The Ni3Al-Ni3Cr section has been investigated by [1952Tay2, 1953Kor] and

[1961Ham]. The experimental isopleth after [1952Tay] is reproduced in Fig. 19a from [1961Ham], who

confirmed data [1952Tay2], and calculated by [2001Dup] one is given in Fig. 19b. The isopleth sections

53Cr47Ni - 40Cr45Ni15Al and 49Cr43Ni18Al - 34Cr33Ni33Al, which are close to the monovariant L

curves of the L ( Cr)+ and L ( Cr)+ Ni eutectics, are given in Figs. 20, 21 according to [1992Gor] data

after minor correction in liquidus-solidus ranges taking into account the ternary system liquidus

constitution.

Thermodynamics

The thermodynamic activities of Al in the ternary system for the Cr0.0838Ni0.9162-Al section with

aluminium content from 0 to 21 at.% have been determined by [1966Mal] and [1968Mal] using the emf

method. The measurements were conducted at temperatures of 1045, 1090, 1135, and 1180 K. The obtained

values of excess integral Gibbs energies and entropies of formation of ternary alloys from solid components,

as well as activity coefficients at 1045 and 1180 K are presented in Table 3. Because the values of fSex

were determined using the fSex = ( GT1

ex - GT2ex)/(T2 - T1) formula, and T1 and T2 are minimum and

maximum values (772 and 907°C, respectively), the obtained values of fSex can be considered rough. The

excess integral Gibbs energies of the ’ phase containing 21 at.% Al are -24.27 kJ·mol-1 and -24.77 kJ·mol-1

at 772 and 907°C, respectively. The thermodynamic activities of Al, Cr, Ni at 1423 K in the binaries as well

as in the Al-Cr-Ni ternary have been determined by [1983Ofo] and [1985Ofo] using Knudsen cell mass

spectroscopy. Some difficulty was experienced with alloys exhibiting high Al vapor pressures, which

caused rapid deterioration of the thermocouples and the tantalum used in the construction of the Knudsen

cell furnace. The obtained data are presented in Table 4. With applying a defect model, [1988Hoc]

calculated the activity of Cr in (NiAl) assuming that NiAl is a compound or a solid solution. The calculated

results do not show significant discrepancy. [1990Kek] measured the enthalpy of formation of ternary alloys

Cr-72Ni-23Al, Cr-70Ni-22Al and Cr-67Ni-21Al (at.%) at room temperature by solution calorimetry. It was

reported that the alloys were of ’ single-phase, according to X-ray and metallographic examination results.

The temperature of heat treatment, however, was not given. The enthalpies of formation of these three alloys

at 298 K are 36.7 ± 1.4 kJ·mol-1, 35.2 ± 1.4 kJ·mol-1 and 36.7 ± 1.4 kJ·mol-1, respectively. [1992Hil] studied

the vaporization of the Ti-1.85Ta-3.9W-2.05Mo-14.9Cr-70.3Ni-4.5Al (mass%) alloy using Knudsen

effusion mass spectrometry in the temperature range 1393-1562 K. The partial pressures of Cr, Ni and Al

were determined in this temperature range (Table 5). Chemical activities and excess chemical potentials

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were evaluated from these pressures for a temperature of 1500 K (Table 6). [2000Sal] determined the partial

and the integral enthalpies of mixing of liquid constituent ternary alloys along four isopleths xCr/xNi,

namely, 0.18, 0.43, 1.00 and 4.00, by high temperature isoperibolic calorimetry at 1454 ± 5°C. The results

were analytically described by the thermodynamically adapted power series according to the Kohler

interpolation geometry and to a regular association model (RAM). The maximal discrepancies between

experimental and calculated values do not exceed 1 kJ·mol-1, which is within the confidence bands of the

data measured. On the basis of data on phase equilibria and thermodynamic properties, a new

thermodynamic description was developed by [1999Hua] by thermodynamic modeling. The liquid, bcc, and

fcc phases were modeled as substitutional solutions. No ternary phases were included. The comparison

between the calculation and experimental data are presented. The calculated and experimentally determined

activity data of Cr, Ni and Al at 1150°C [1983Ofo, 1985Ofo] as well as the enthalpies of formation of series

of the alloys at 25°C [1990Kek] are in a good agreement. Thermodynamic modeling of the ternary system

was done by [2002Bro] using Thermo-Calc software package. Two different sets of thermodynamic

parameters of Al-Cr-Ni system for two types of thermodynamic models were published for the first time in

the literature. The comparison shows acceptable agreement between the calculated and experimental data.


[1960Kor] showed an increase in hardness values for Al-10 mass% Cr-Ni alloys from 1300 MN·m-2 at 3

mass% Al to 2500 MN·m-2 at 8 mass% Al. Hardness-temperature curves have been measured by [1959Gua]

on Ni3Al-2.5 and 7.5 at.% Cr alloys. [1999Tia] studied the hardness variations during aging of phases

based alloys using a micro-Vickers hardness tester. It was established that typical age-hardening and

over-age softening occur by fine precipitation of Cr in NiAl under aging after quenching from high

temperatures. The degree of age hardening of stoichiometric NiAl in which equal amounts of Ni and Al are

replaced by Cr is smaller than that obtained in off-stoichiometric NiAl. [1983Dan] investigated the

influence of the microstructure in the cast 70 AlCrNi alloy on its ductility during deformation and

[2001Com] investigated the effect of alloys microstructure on Vicker’s microhardness in the

aluminium-rich corner. Compression creep behavior was investigated in ternary single crystals

containing Cr with stress axes parallel to the crystallographic orientation near [001] [1991Fie]. Some

mechanical properties of the intermetallics based alloys were investigated by [1991Miu, 1993Cot2,

2002Guo]. [1987Nes1, 1987Nes2] and [1987Nes3] studied interdiffusion in Ni-rich Al-Cr-Ni alloys at 1100

and 1200°C. Concentration dependent ternary interdiffusion coefficients were derived from EMPA studies

of / and / + diffusion couples, and a ternary finite-difference interdiffusion model was employed to

predict concentration profiles, which at 1100 and 1200°C were in a good agreement with the measurements.

[1997Kai] investigated pseudo-interface formation as well as diffusion behavior in the B2 phase region of

NiAl-based diffusion couples (concentration ranges 30-60 at.% Al, 0-10 at.% Cr) using EMPA. Also the

isoactivity lines for alloying elements in the B2 phase were calculated. In the CALPHAD summary

[1999Kau], results of studying diffusion couples at 1200°C combined with calculations based on

thermo-calc and DICTRA Programs are presented. Assessments of diffusional mobilities were carried for

face-centered cubic alloys [1996Eng] and for Ni-base superalloys [2002Cam]. Models for simulating

diffusion in multiphase dispersion were applied by [1997Eng] and [1998Mat] to multiphase diffusion

couples at 1200°C. A general equation for the effective diffusivity (Deff) in a two-phase + region was

derived by [1999Che] based on the assumption that the second phase can be treated as a point source or sink

of solute. The variation of Deff in the + region was calculated and shown to be up to 70 %.

[1978Vol] and [1986Gor] examined the possibility of obtaining a directionally crystallized eutectic,

whereas the effect of alloy additions on the rod-plate transition in the directionally solidified NiAl-Cr

eutectic was studied by [1970Cli] and dislocation networks at the interface between phases were studied by

[1971Cli]. The rod-plate transition was observed to occur near the composition for zero lattice mismatch.

The average coefficient of thermal expansion of NiAl was 1.4 10-5 and that of Cr was 1.1 10-5 as obtained

from X-ray diffraction in the temperature range from room temperature to 1000°C [1970Cli]. Similar

investigations concern the effect of solidification rate on structure and high temperature strength

[1970Wal], on the stability of the directionally solidified Cr-NiAl eutectic [1973Wal] as well as the effect

379


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Al–Cr–Ni

of rapid solidification rate on the microstructure and phase solubility in Cr-NiAl eutectic [1985Boe]. A

two-dimensional model for solidification and secondary phase precipitation in directionally solidified

superalloys is presented by [2000Boe], with application to Al-Cr-Ni as a ternary model system.

[1960Kor] established that the electric resistivity for Al-10 mass% Cr-Ni alloys increases from

0.85·10-4 m at 3 mass% Al to 1.5·10-4 m at 8.5 mass% Al. [1972Sch] studied the polarization relations

to quantitatively isolate the ' phase by electrochemical treatment from Al-Cr-Ni alloys with more than 70

at.% Al. The isolated particles were examined by X-ray and electron microscopy. The lattice parameters did

not change with changing the form or size of the particles. Dependence of the magnetic susceptibility on the

temperature in the interval 0-1000°C of the alloy Cr6.5Ni46.1Al47.4 (at.%) was established by [1999Zya]. No

long-range ordering is observed in the Ni3Al-CrNi3 phase in the temperature range 893-1073°C

[1961Ham]. In high-Al-content alloys, the precipitation rate is extremely high and cannot be suppressed

by ice-brine quenching; the creep strength and yield strength of CrNi3-Ni3Al alloys at 750°C increased five

or six fold as a result of precipitation [1961Ham]. Atom probe field-ion microscopy (APFIM) data were

used by [1984Hil] to differentiate the spinodal decomposition mode in a Ni-14Al (at.%) alloy and a

nucleation, growth and coarsening mechanism for the two-phase microstructure of a Ni-20Cr-14Al (at.%)

alloy in the quenched state at 620°C [1984Hil]. High temperature X-ray diffraction was used by [1971Cli]

(25 to 1000°C) and [1976Low] (25 to 1200°C) to study the temperature variation in the unit cell dimensions

for the , , , and ' phases in a series of Cr-Ni-Al alloys ranging from 6 to 30 at.% Al and 10 to 22 at.%

Cr [1976Low], and for ,NiAl in a directionally solidified eutectic alloy containing 34 vol% Cr rods of 2

m diameter in the NiAl matrix [1971Cli]. Unit cell dimensions were found to follow an empirical thermal

expansion equation a(T) = a (250°C)(1+R)(1+T/293)1.5 where the expansion constant R was given as

13.4 10-4 for Cr, 19.2 10-4 for / ' and R = 19.9 10-4 for NiAl [1976Low]. [1996Sch] and [1997Sch]

presented results of atomic scale investigation of ordering and precipitation of the ' phase in a model

Al-Cr-Ni alloy, composition of which was 15Cr80Ni5Al (at.%) or 14.7Cr80.1Ni5.2Al (at.%), respectively,

aged at 600°C. Both three-dimensional (3D) atom probe (AP) and TEM techniques were used. It was shown

in both publications that small ' particles, 2 nm in diameter, form already after 1 h. Even for such very

small sizes, particles are well ordered. Their composition is close to the equilibrium composition of the '

phase and does not evolve as ageing proceeds. The time evolution of the particle size and of the composition

of the matrix suggests that a growth mechanism is involved before 4 h, followed by a coarsening regime.

The alloys on the base of the ' phase were also studied by [1997Kre], [1997Sai] and [2001Ter]. [1997Kre]

established the presence of the hypostoichiometric ' Ni3Al phase in chill- cast Ni20Cr13Al alloy using XRD

and TEM. The spheroid particles of ' change their shape to cubical at the very beginning of annealing at

800°C. This change is accompanied by a decrease in volume fraction of ' and at the same time by an

increase in hardness. Such annealing also leads to the precipitation of Cr-rich phase, starting at grain

boundaries. The Monte-Carlo method was applied by [1997Sai] to the simulation of temporal evolutions of

atomic arrangement in Ni-base ternary alloy Cr3.0Ni73.5Al23.5 (at.%). The ordering of the fcc phase to

L12 structure is controlled by randomly selecting a single atom with one of its neighboring atoms. [2001Ter]

proposed a method of the site preference determination of substitutional elements in intermetallic

compounds through the measurements of thermal conductivities. The authors note that the laser-flash

method for thermal conductivity measurement is very convenient for intermetallic compounds, since the

preparation of a coin shaped specimen for the laser-flash measurement is very easy to achieve even for

brittle materials. It is demonstrated in Ni3Al-2Cr (at.%) alloy that the ridge direction in thermal conductivity

contours in the ternary ' phase agrees with that of the solubility lobe of the ' phase in ternary

phase diagrams.

[1999Tia, 1999Zak] and [2002Fis] investigated phase based alloys. In particular, [1999Tia] and [2002Fis]

studied the precipitation of ( Cr) in B2-ordered ,NiAl using TEM method [1999Tia] and atom probe field

ion microscopy [2002Fis]. According to [1999Tia], by aging at temperatures around 1073 K after solution

annealing at 1290°C, fine spherical particles of Cr appear in the NiAl matrix between the ( Cr), which

rapidly precipitate during quenching. Atom location by channeling enhanced microanalysis technique has

been used to determine the site occupancy of Cr in NiAl. [2002Fis] studied the alloys (at.%): Cr2Ni48Al48,

Cr2Ni49Al49 and Cr2Ni48Al50, annealed at 550°C for 100 h, and precipitates of ( Cr) were detected in the

first two alloys ranging from few nanometers in size. As to Cr2Ni48Al50 samples, different precipitates

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Al–Cr–Ni

containing 77 at.% Cr and 23 at.% Al are observed in it. [1999Zak] established temperature coefficients of

linear and volume expansion of the Cr0.14NiAl1.03 alloy at temperature ranges of 25 to 760°C and 760 to

1000°C using high-temperature XRD studies. [1999Zya] investigated the electronic structure of the

Cr6.5Ni46.1Al47.4 (at.%) alloy. Mechanism of hot corrosion of the Al-Cr-Ni alloys were investigated by

[1993Gle] and [1996Lon]. Development of oxidation-resistant high-temperature intermetallics and

corrosion-resistant coatings was carried out by [1992Gra] and [1993Nic]. In particular, it was established

that an increase in the Cr content of two-phase NiAl-Cr alloys reduces the oxidation resistance [1992Gra].

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MSIT®

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Al–Cr–Ni

[1984Och2] Ochiai, S., Mishima, Y., Suzuki, T., “Lattice Parameter Data of Ni ( ), Ni3Al( ') and

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SSSR, 30(4), 334-336 (1986) (Experimental, 3)





[1987Nes1] Nesbitt, J.A., Heckel, R.F., “Interdiffusion in Ni-Rich, Ni-Cr-Al Alloys at 1100°C and

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[1987Nes2] Nesbitt, J.A., Heckel, R.F., “Interdiffusion in Ni-Rich, Ni-Cr-Al Alloys at 1100°C and

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Thermodyn., 44)

[1988Li] Li, X.Z., Kuo, K.H., “Decagonal Quasicrystals with Different Peridicities along the Tenfold

Axis in Rapidly Solidified Al-Ni Alloys”, Phil. Mag. Lett., 58(3), 167-171 (1988)


[1988Ten] van Tendeloo, G., van Landgut, J., Amelinckx, S., Ranganathan, S., “Quasi-Crystals and

their Crystalline Homologues in the Al60Mn11Ni14 Ternary Alloys”, J. Microscopy, 149, 1

(1988) (Exeperimental, Crys. Structure, 12)

384


MSIT®

Al–Cr–Ni

[1989Ell] Ellner, M., Braun, J., Predel, B., “X-Ray Diffraction Investigation of Al-Cr Phases of the

W-Family” (in German), Z. Metallkd., 80, 374-383 (1989) (Experimental, Crys. Structure,

38)

[1989Hon] Hong, Y.M., Nakayama, H., Mischma, Y., Suzuki, T., “The -Solvus Surface in Ni-Al-X

(X=Cr, Mo and W) Ternary Systems”, ISIJ International, 29(1), 78-84 (1989)


[1989Zho] Zhou, W.L., Li, X.Z., Kuo K.H., “A New Hexagonal Metastable Phase Coexisting with the

Decagonal Quasicrystal in Al-Cr-Ni and Al-Mn-Ni Alloys”, Scr. Metall., 23, 1571-1574


[1990Col] Colin-Urtado, P., Thesis, Institut National Polytechnique de Grenoble (1990)

[1990Dav] David, D., Thesis, Institut National Polytechnique de Grenoble (1990)

[1990Kek] Kek, S., Rzyman, C., Sommer, F., An. Fis. B, 86, 31-38 (1990) (as quoted by [2001Dup]),

[1991Fie] Field, R.D., Lahrman, D.F., Darolia, R., ”The Effect of Alloying on Slip Systems in [001]

Oriented NiAl Single Crystals”, Acta Metall. Mater., 39, 2961-2969 (1991) (Crys.




Inst. Met. Mater., 29(9), 960-966 (1991) (Mechan. Prop., Experimental, 15)

[1991Miu] Miura, S., Hayashi, T., Takekawa, M., Mishima, Y., Suzuki, T., “The Compression Creep

Behavior of Ni3Al-X Single Crystals”, Mater. Res. Soc. Symp. Proc.: High-Temp. Ordered

Intermetallic Alloys IV, 213, 623-628 (1991) (Experimental, Phys. Prop., 9)

[1991Rog] Rogl, P., “Aluminum-Chromium-Nickel”, MSIT Ternary Evaluation Program, in MSIT



Assessment, 62)

[1992Gor] Goretsky, G.P., “Study of Alloys of Binary Eutectics + and + in the Ni-Cr-Al

Systems” (in Russian), Metally, (5), 199-202 (1992) (Equi. Diagram, Experimental)

[1992Gra] Grabke, H.J., Brumm, M., Steinhorst, M., “Development of Oxidation Resistant High

Temperature Intermetallics”, Mater. Sci. Technol., 8, 339-344 (1992) (Equi. Diagram,

Experimental, Thermodyn., 21)

[1992Hil] Hilpert, K., Miller, M., “Study of the Vaporization of Ni-Cr-Al and Fe-Cr-Al Base Alloys

by Knudsen Effusion Mass Spectrometry”, Z. Metallkd., 83(10), 739-743 (1992)



B2 7R Martensitic Transformation in a Ni-37.0 at.% Al Alloy”, Mater. Trans. JIM, 33(3),



Crystalline and Quasicrystalline Phases”, Met. Trans. A., 23A, 2437-2445 (1992) (Crys.


[1993Cot1] Cotton, J.D., Noebe, R.D., Kaufman, M.J., “NiAl-Rich Portion of the NiAl-Cr

Pseudobinary Eutectic System”, J. Phase Equilib., 14(5), 579-582 (1993) (Equi. Diagram,

Experimental, 16)

[1993Cot2] Cotton, J.D., Kaufman, M.J., Noebe, R.D., “The Effects of Chromium on NiAl Intermetallic

Alloys: Part I. Microstructure and Mechanical Properties”, Intermetallics, 1, 3-20 (1993)

(Crys. Structure, Experimental, Equi. Diagram, Mechan. Prop., 59)

[1993Gle] Gleeson, B., Cheung, W.H., Young, D.J., “Cyclic Oxidation Behaviour of Two-Phase

Ni-Cr-Al Alloys at 1100°C”, Corros. Sci., 35(5-8), 923-929 (1993) (Equi. Diagram,

Experimental, Kinetics, 13)

[1993Kha] Khadkikar, P.S., Locci, I.E., Vedula, K., Michal, G.M., “Transformation to Ni5Al3 in a 63.0

at.% Ni-Al Alloy”, Metall. Trans. A, 24A, 83-94 (1993) (Equi. Diagram, Crys. Structure,

Experimental, 28)

385


MSIT®

Al–Cr–Ni

[1993Nic] Nicholls, J.R., Lawson, K.J., Al Yasiri, L.H., Hancock, P., “Vapour Phase Alloy Design of

Corrosion-Resistant Overlay Coatings”, Corros. Sci., 35(5-8), 1209-1223 (1993) (Equi.

Diagram, Experimental, Kinetics, 29)

[1994ICD] ICDD Powder Diffraction File. International Centre for Diffraction Data, Newtown Square,

PA (1994) (Crys. Structure, Experimental)

[1994Jia] Jia, C.C., Ishida, K., Nishizawa, T., “Partition Of Alloying Elements Between (A1), `

(L12) and (B2) Phases In Ni-Al Base Systems”, Metall. Mater. Trans. A, 25, 473-485


[1994Mur] Murthy, A.S., Goo, E., “Triclinic Ni2Al Phase in 63.1 Atomic Procent NiAl”, Met. Mater.

A, 25A(1), 57-61 (1994) (Crys. Structure, Experimental, 10)

[1994Yeu] Yeung, C.W., Hopfe, W.D., Morral, J.E., Romig Jr., A.D., in “Experimental Methods of

Phase Diagram Determination, Warrendale”, Morral, J.E., Sciffmann, R.S., Merchant,

S.M., (Eds.), Warrendale, PA: The Minerals, Metals and Materials Society, 39-44 (1994)

(Crys. Structure, Experimental, Equi. Diagram, 5)


System”, J. Alloys Compd., 220, 225-230 (1995) (Crys. Structure, Experimental, 17)

[1996Eng] Engstroem, A., Agren, J., “Assessment of Diffusional Mobilities in Face-centred Cubic

Ni-Cr-Al Alloys”, Z. Metallkd., 87(2), 92-97 (1996) (Calculation, Diffusion, 12)

[1996Lon] Longa-Nava, Y., Zhang, Y.S., Takemoto, M., Rapp, R.A., “Hot Corrosion of

Nickel-Chromium and Nickel-Chromium-Aluminum Thermal-Spray Coatings by Sodium

Sulfate-Sodium Metavanadate Salt”, Corros. Sci., 52(9), 680-689 (1996) (Experimental,

33)


Ni1+xAl1-x”, Acta Crystallogr., Sect. A: Found. Crystallogr., A52, C319 (1996) (Crys.


[1996Ros] Rosell-Laclau, E., Durand-Charre, M., Audier, M., “Liquid-Solid Equilibria in the

Aluminium-Rich Corner of the Al-Cr-Ni System”, J. Alloys Compd., 233, 246-263 (1996)


[1996Sch] Schmuck, C., Danoix, F., Caron, P., Hauet, A., Blavette, D., “Atomic Scale Investigation of

Ordering and Precipitation Processes in a Model Ni-Cr-Al Alloy”, Appl. Surf. Sci., 94/95,


[1996Vik] Viklund, P., Haeussermann, U., Lidin, S., “NiAl3: a Structure Type of its Own?”, Acta

Cryst., Sect. A: Found Crystallogr., A52, C-321 (1996) (Crys. Structure, Experimental, 0)

[1996Wu] Wu, R., Report to Investment Casting Cooperative Arrangement, Madison, WI: University

of Wisconsin (1996)


Liquid Aluminium”, Z. Metallkd., 88(6), 446-451 (1997) (Thermodyn., Experimental, 15)

[1997Eng] Engstroem, A., Morral, J.E., Agren, J., “Computer Simulations of Ni-Cr-Al Multiphase

Diffusion Couples”, Acta Mater., 45(3), 1189-1199 (1997) (Calculation, Equi. Diagram, 28)

[1997Kai] Kainuma, R., Ikenoya, H., Onuma, I., Ishida, K., “Pseodo-Interface Formation and

Diffusion Behaviour in the B2 Phase Region of NiAl-Base Diffusion Couples”, Def. Diffus.

Forum, 143-147, 425-430 (1997) (Crys. Structure, Equi. Diagram, Experimental, Phys.

Prop., 10)

[1997Kre] Kreici, J., Svoboda, M., Buchal, A., Svejcar, J., “Structure of Ni20Cr13Al Alloy with and

without Carbon Addition annelaed at 800°C”, Mater. Sci. Eng. A, A232, 191-199 (1997)


[1997Li] Li, X.Z., Hiraga, K., Yamamoto, A., “Icosahedral Cluster in the Structure of an Al-Cr-Ni

k-Phase”, Philos. Mag. A, 76(3), 657-666 (1997) (Assessment, Crys. Structure, 13)


Alloys”, Acta Mater., 45, 2155-2166 (1997) (Experimental, Crys. Structure, 48)

386


MSIT®

Al–Cr–Ni

[1997Pot] Potapov, P.L., Song, S.Y., Udovenko, V.A., Prokoshkin, S.D., “X-ray Study of Phase



[1997Sai] Saito, Y., “The Monte Carlo Simulation of the Ordering Kinetics of fcc to L12 Structure in

Ni-Al-X Ternary Alloys”, Mater. Sci. Eng. A, A223, 10-16 (1997) (Calculation, Equi.

Diagram, Experimental, Kinetics, 8)

[1997Sat] Sato, A., Yamamoto, A., Li, X.Z., Haibach, T., Steurer, W., “A New Hexagonal kappa

Phase of Al-Cr-Ni”, Acta Crystallogr., Sect. C: Cryst. Struct. Commun., C53(11),


[1997Sch] Schmuck, C., Caron, P., Hauet, A., Blavette, D., “Ordering and Precipitation of gama` Phase

in Low Supersaturated Ni-Cr-Al Model Alloy: an Atomic Scale Investigation”, Philos.

Mag. A, 76(3), 527-542 (1997) (Crys. Structure, Equi. Diagram, Experimental, Phys. Prop.,

Thermodyn., 22)

[1998Mat] Matan, N., Winand, H.M.A., Carter, P., Karunaratne, M., Bogdanoff, P.D., Reed, R.C., “A

Coupled Thermodynamic/Kinetic Model for Diffusional Processes in Superalloys”, Acta

Mater., 46(13), 4587-4600 (1998) (Calculation, Kinetics, Thermodyn., 42)



[1998Qia] Qiao, Q.M.S., “Interdiffusion Microstructure in + / + ' Diffusion Couples", Thesis,

University of Connecticut (1998) (Experimental, Equi. Diagram)


Vibrational Entropy Difference between Ordered and Disordered Ni3Al”, Phys. Rev. B,




558-561 (1998), translated from Neorg. Mater., 34(6), 684-687 (1998) (Crys. Structure,

Experimental, 12)

[1999Che] Chen, H., Morral, J.E., “Variation of the Effective Diffusivity in Two-Phase Regions”, Acta

Mater., 47(4), 1175-1180 (1999) (Calculation, Equi. Diagram, Experimental, 15)

[1999Hua] Huang, W., Chang, Y.A., “Thermodynamic Properties of the Ni-Al-Cr System”,

Intermetallics, 7, 863-874 (1999) (Equi. Diagram, Thermodyn., Calculation, 39)

[1999Kau] Kaufman, L., Dinsdale, A.T., “Summary of the Proceedings of the CALPHAD XXVII

Meeting, 17-22 May 1998, Beijing, China, Calphad, 23(3-4), 265-303 (1999) (Assessment,

Calculation, Equi. Diagram, Thermodyn., 125)

[1999Sun] Sung, P.K., Poirier, D.R., “Liquid-Solid Partition Rations in Nickel-Base Alloys”, Metall.

Mater. Trans. A, 30A, 2173 (1999) (Crys. Structure, Experimental, 41)

[1999Tia] Tian, W.H., Han, C.S., Nemoto, M., “Precipitation of -Cr in B2-ordered NiAl”,

Intermetallics, 7, 59-67 (1999) (Equi. Diagram, Experimental, *, 23)

[1999Zak] Zakharov, R.G., Zyazev, V.L., Petrova, S.A., Vatolin, N.A., “High-Temperature X-ray

Diffraction Studies of Nikel-Chromium Aluminides”, Dokl. Phys., 44(11), 760-762 (1999)


[1999Zya] Zyazev, V.L., Dovgopol, S.P., Medvedeva, N.I., Bulanov, V.Ya, “Crystal Structure,

Magnetic Susceptibility, and Electron Structure of Nickel Chromium Aluminide”, Phys.

Met. Metallogr. (Engl. Transl.), 88(3), 256-260 (1999) (Crys. Structure, Equi. Diagram,

Experimental, 8)

[2000Boe] Boettger, B., Grafe, U., Ma, D., Fries, S.G., “Simulation of Microsegregation and

Microstructural Evolution in Directionally Solidified Superalloys”, Mater. Sci. Technol.,

16, 1425-1428 (2000) (Calculation, Phys. Prop., 15)




387


MSIT®

Al–Cr–Ni

[2000Sal] Saltykov, P.A., Witusiewicz, V.T., Arpshofen, I., Seifert, H.-J., Aldinger, F.,

“Thermodynamics of Liquid and Undercooled Liquid Al-Cr-Ni Alloys”, Proc. Disc. Meet.

Thermodyn. Alloys, 64 (2000) (Thermodyn., 0)




Rapidly Solidified Cr-40 at.% Al Alloy”, Phil. Mag. Let., 80(11), 703-710 (2000) (Crys.


[2000Uch] Uchida, M., Matsui, Y., “A New Stacking Motif: Complex Alloy Structures Interpreted as

Modulated Structures”, Acta Crystallogr., Sect. B: Struct. Crystallogr. Crys. Chem., 56,


[2001Com] Compton, D.N., Cornish, L.A., Witcomb, M.J., “The Effect of Microstructure on Hardness

Measurements in the Aluminium-Rich Corner of the Al-Ni-Cr System”, J. Alloys Compd.,

317-318, 372-378 (2001) (Equi. Diagram, Experimental, Mechan. Prop., 29)

[2001Dup] Dupin, N., Ansara, I., Sundman, B., “Thermodynamic Re-Assessment of the Ternary

System Al-Cr-Ni”, Calphad, 25(2), 279-298 (2001) (Assessment, Equi. Diagram,

Thermodyn., #, *, 44)

[2001Ter] Terada, Y., Ohkubo, K., Mohri, T., Suzuki, T., “Site Preference Determination in

Intermetallic Compounds by Thermal Conductivity Measurement”, J. Mater. Res., 16(8),

2314-2320 (2001) (Calculation, Crys. Structure, Experimental, Thermal Conduct., 63)

[2002Bro] Brozh, P., Svoboda, M., Burzhik, J., Kroupa, A., Havrankova, J., “Theoretical and

Experimental Study of the Influence of Cr on the + ’ Phase Field Boundary in the

Ni-Al-Cr System”, Mat. Sci. Eng.A, A325, 59-65 (2002) (Equi. Diagram, Thermodyn.,

Calculation, 15)

[2002Cam] Campbell, C.E., Boettinger, W.J., Kattner, U.R., “Development of a Diffusion Mobility

Database for Ni-Base Superalloys”, Acta Mater., 50, 775-792 (2002) (Assessment,

Calculation, Equi. Diagram, Experimental, Phys. Prop., Thermodyn., 75)

[2002Fis] Fischer, R., Frommeyer, G., Schneider, A., “Chromium Precipitation in B2-ordered NiAl-2

at.% Cr Alloys Investigated by Atom Probe Field Ion Microscopy”, Mat. Sci. Eng. A, A327,


[2002Guo] Guo, J.T., Du, X.H., Zhou, L.Z., Zhou, B.D., Qi, Y.H., Li, G.S., “Superplasticity in NiAl

and NiAl-Based Alloys”, J. Mater. Res., 17(9), 2346-2356 (2002) (Experimental, Mechan.

Prop., 17)


(Aluminium-Chromium)”, MSIT Binary Evaluation Program, in MSIT Workplace,

Effenberg, G. (Ed.), MSI, Materials Science International Services GmbH, Stuttgart; to be

published, (2003) (Crys. Structure, Equi. Diagram, Review, 50)



International Services GmbH, Stuttgart; to be published, (2003) (Crys. Structure, Equi.


388


MSIT®

Al–Cr–Ni


Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice

Parameters

[pm]

Comments/References

(Al)

660.452

CrxNiyAl1-x-y

cF4

Fm3m

Cu

a = 404.88 pure Al, T = 24°C [V-C]

x = 0, y = 0 to 0.004 [2003Sal]

y = 0, x = 0 to 0.00375 [2003Cor]

, (Cr)

1863

, Cr1-x-yNiyAlx

cI2

Im3m

W

a = 288.4 pure Cr, T = 27°C [V-C]

x = 0, y = 0 to 0.31 [Mas2]

y = 0, x = 0 to 0.46 [1980Sch]

, (Ni)< 1455 CryNi1-x-yAlx

cF4Fm3mCu

a = 352.40a = 353.4a = 353.8a = 354.5a = 355.1a = 356.0a = 355.8a = 356.5

pure Ni, T = 25°C [1984Och2, Mas2]x = 0, y = 0.1 [1952Tay2]x = 0, y = 0.15 [1952Tay2]x = 0, y = 0.2 [1952Tay2]x = 0, y = 0.25 [1952Tay2]x = 0, y = 0.25 [1984Och2]x = 0, y = 0.3 [1984Och2]x = 0, y = 0.35 [1984Och2]

a = 352.8a = 353.8a = 355.1a = 355.8a = 356.3a = 353.2a = 353.7a = 354.1a = 354.8 a = 355.4a = 355.9a = 356.5

Slowly cooled alloys, x = 0.025 or 0.05, y = 0 to 0.3 [1952Tay2]:x = 0.025, y = 0x = 0.025, y = 0.12x = 0.025, y = 0.22x = 0.025, y = 0.27x = 0.025, y = 0.32x = 0.05, y = 0x = 0.05, y = 0.05x = 0.05, y = 0.1x = 0.05, y = 0.15x = 0.05, y = 0.2x = 0.05, y = 0.25x = 0.05, y = 0.3

[1985Ofo]:x = 0 to 0.16, y = 0 to 0.48, T = 1150°C [1982Tu]:x = 0 to 0.14, y = 0 to 0.43, T = 1025°C[1952Tay2]:x = 0 to 0.4, y = 0 to 0.4, T = 850°C x = 0 to 0.38, y = 0 to 0.37, T = 750°C

a = 356.4Quenched from 1200°C [1961Pry]:x = 0.17, y = 0.111

a = 354.6a = 355.3a = 353.5a = 362.3

Quenched from T = 1000°C:x = 0, y = 0.2 [1955Kor1]x = 0.1, y = 0.2 [1955Kor1]x = 0, y = 0.111 [1961Pry]x = 0.14, y = 0.111 [1961Pry]

Sublattice of ,(Ni), order-disorder transformation at~500°C

- x = 0.05, y = 0.4 [1952Tay1], adapted from [1991Rog]

389


MSIT®

Al–Cr–Ni

, Cr2Al13

791

,

(Cr,Ni,Al)2(Al,Cr,Ni)13

mC104

C2/m

V7 Al45

Monoclinic

C2/m

(?)

Triclinic

P3m

(?)

a = 2519.6

b = 757.4

c = 1094.9

= 128.7°

a = 2525.6

b = 758.2

c = 1095.5

= 128.68°

a = 1100

b = 2470

c = 1320

= 113.85°

a = 1100

b = 1905

c = 1320

= 79.2°

= 113.85°

= 78.3°

Room temperature, 13.5 at.% Cr [1975Ohn,

1995Aud, 2003Cor]


From 0 to ~2.5 at.% Ni, as-cast [2001Com]

In the alloys (at.%) Cr4Ni4Al92 and

Cr10Ni3Al87 quenched from liquidus

temperature [1996Ros]

In the alloy (at.%) Cr4Ni4Al92 quenched

from liquidus temperature, two polytypes,

resulting in a periodic (111) twinning of

[1996Ros]

, Cr2Al11

941

,


oC584

Cmcm

a = 1240

b = 3460

c = 2020

a = 1260

b = 3460

c = 2000

16.9 to 19.2 at.% Cr [1995Aud, 2000Mah,

2003Cor]


Quenched from 920°C, 16.9 to 19.2 at.% Cr

[1995Aud, 2000Mah, 2003Cor]

“ CrAl4” [1992Wen]


, CrAl4

1031

, Cr1-xAlx

,


hP574

P63/mmc

MnAl4 a = 1998

c = 2467

a = 2010

c = 2480

x = 0.78 to 0.80 [2003Cor]

x = 0.788 to 0.794, T = 800°C [1995Aud]

x = 0.791 ± 0.003 [1995Aud, 2000Mah,

2003Cor]

x = 0.777 ± 0.001, quenched from 1000°C

[2000Mah, 2003Cor]

From 0 to ~4 at.% Ni, as-cast [2001Com]

i, CrAl4 (or CrAl5) icosahedral - In spinning alloys Al-Cr at 8 to 13 at.% Cr;

or in transformed amorphous of 20 at.% Cr,

metastable [1998Mur]

1, Cr4Al9 (h)

1, Cr1-xAlx~1170 to ~1060

1,


cI52

I43m

Cu4Al9

a = 912.3

x 0.65 to 0.70 [Mas2]

x = 0.71 at Al-rich limit, quenched from

920°C [1995Aud]


From 0 to 3.5 at.% Ni; 3.5 at.% Ni at 60

at.% Al, annealed at 1025°C [1982Tu]

2, Cr4Al9 (r)

Cr1-xAlx 1060

hR52

R3m

Cr4Al9 a = 1291

c = 1567.7

x = 0.650 to 0.69 [Mas2]

[1968Lin, Mas2]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice

Parameters

[pm]

Comments/References

390


MSIT®

Al–Cr–Ni

3, Cr4Al9 (r)

Cr1-xAlx 700

- - x 0.67 to 0.69 [Mas2]

1, Cr5Al8(h)

1, Cr1-xAlx~1350 to ~1100

1,


cI52

I43m

Cu5Zn8

a = 904.7 to

910.4

x = 0.58 to 0.65 quenched from liquid

[1989Ell]

From 0 to ~3.3 at.% Ni; 3.3 at.% Ni at ~60

at.% Al, as-cast [2001Com]

2, Cr5Al8(r)

1100(?)

2, Cr1-xAlx

hR26

R3m

a = 1271.9

c = 793.6

a = 1276.5 to

1271.5

c = 795.4 to

782.8

a = 1272.8

c = 794.2

[1994ICD], No. 29-15

x = 0.58 to 0.65 [1989Ell]

[1977Bra]

, Cr2Al

<910

tI6

I4/mmm

MoSi2

a = 300.45

c = 864.77

a = 300.5(1)

c = 864.9(1)

~65.5 to 71.4 at.% Cr [1998Mur]

[1937Bra, 1998Mur]

[1989Ell]

X

400

Cr5Al3 or Cr3Al

superlattice

- Possibly metastable [1998Mur]

~75 to ~80 at.% Cr [1981Bro, 1981Ten]

- - In quenched alloys Cr-Al at 60 to 100 at.%

Cr, like metastable Ti in Ti alloys

[2000Sha1, 2000Sha2]

, NiAl3<856

, (Ni,Cr)Al3

oP16

Pnma

NiAl3

oP16

Pnma

CFe3

Modulated

a = 661.15

b = 736.64

c = 481.18

a = 661.3 ± 0.1

b = 736.7 ± 0.1

c = 481.1 ± 0.1

a = 659.8

b = 735.1

c = 480.2

a = 660

b = 740

c = 480

[L-B]

[1996Vik]

[1997Bou, V-C]

In the alloys (at.%) Cr9Ni9Al82 and

Cr4Ni4Al92, as-cast [1996Ros]

, Ni2Al3 <1138 a = 403.63

c = 490.65

a = 402.8

c = 489.1

36.8 to 40.5 at.% Ni [Mas2]

[L-B]

[1997Bou, V-C]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice

Parameters

[pm]

Comments/References

391


MSIT®

Al–Cr–Ni

,

(Ni,Cr,Al)2(Al,Cr,Ni)3

a = 404.5

c = 489.5

a = 406

c = 492

a = 408

c = 494

a = 409

c = 496

a = 410

c = 493

From 0 to ~17 at.% Cr, as-cast [2001Com]

From 0 to 3 at.% Cr; 3 at.% Cr at 36 at.%

Ni, annealed at 1025°C [1982Tu]

In the alloy Cr0.14NiAl1.03 [1999Zak]:

T = 25°C

T = 400°C

T = 850°C

T = 1000°C

In the alloy Cr6.5Ni46.1Al47.4, T = 1000°C

[1999Zak]

Ni3Al4< 702

cI112

Ia3d

Ni3Ga4

a = 1140.8(1) [1989Ell, V-C]

, NiAl

< 1676

,


cP2

Pm3m

CsCl

a = 287.04

a = 287.26

a = 286.0

a = 287.0

a = 288.72(2)

a = 287.98(2)

a = 289.0

a = 289.7

a = 290.4

a = 291.2

a = 291.9

a = 293.2

a = 290.2

a = 290.9

42 to 69.2 at.% Ni [Mas2]

57.7 at.% Ni [L-B]

46.6 at.% Ni [L-B]

[1987Kha]

63 at.% Ni [1993Kha]

50 at.% Ni [1996Pau]

54 at.% Ni [1996Pau]

[1971Cli]:

T = 0°C

T = 200°C

T = 400°C

T = 600°C

T = 800°C

T = 1000°C

33 at.% Cr, T = 600°C [1971Cli]

33 at.% Cr, T = 800°C [1971Cli]

0 to ~8 at.% Cr; ~8 at.% Cr at ~50 at.% Ni,

annealed at 1290°C [1999Tia]

0 to ~12 at.% Cr; ~12 at.% Cr at ~57 at.%

Ni, T = 1200°C [1984Car]

~8 at.% Cr at ~62 at.% Ni, T = 1127°C

[1989Hon]

8 at.% Cr at 58 at.% Ni, annealed at

1025°C [1982Tu]

0 to < 2 at.% Cr at 48 to 50 at.% Ni,

annealed at 550°C [2002Fis]

Ni5Al3< 723

oC16

Cmmm

Pt5Ga3

a = 753

b = 661

c = 376

63 to 68 at.% Ni [1993Kha, Mas2]

at 63 at.% Ni [1993Kha]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice

Parameters

[pm]

Comments/References

392


MSIT®

Al–Cr–Ni

’, Ni3Al <1372

’,


cP4

Pm3m

Cu3Au

a = 356.6

a = 357.0

a = 356.77

a = 356.32

a = 357.92

a = 356.3

a = 356.5

a = 357.0

a = 357.0

a = 356.1

73 to 76 at.% Ni [Mas2]

[1952Tay2]

[1984Och2, 1959Gua]

[1986Hua]

disordered [1998Rav]

ordered [1998Rav]

From 0 to 5 at.%Cr; 5 at.%Cr at 72 at.%Ni,

1300°C [1994Jia, 2001Dup]

From 0 to 7.5 at.%Cr; 7.5 at.%Cr at 70 at.%

Ni, 1200°C [1984Car, 1998Qia, 2001Dup]


Ni, 1127°C [1989Hon]


Ni, annealed at T = 1025°C [1982Tu]

2.5 at.% Cr [1952Tay2]

5 at.% Cr [1952Tay2]

7 at.% Cr [1959Gua, 1984Och2, 1985Mis]

8 at.% Cr [1952Tay2]

10 at.% Cr [1963Arb]

Ni2Al9 mP22

P21/c

Ni2Al9

a = 868.5(6)

b = 623.2(4)

c = 618.5(4)

= 96.50(5)°

Metastable

[1988Li, 1997Poh]

NixAl1-x0.60 < x < 0.68

tP4

P4/mmm

AuCu

m**

a = 383.0

c = 320.5

a = 379.5

c = 325.6

a = 379.5

c = 325.6

a = 379.5

c = 325.6

a = 379.9 to

380.4

c = 322.6 to

323.3

a = 371.7 to

376.8

c = 335.3 to

339.9

a = 378.00

c = 328.00

a = 418

b = 271

c = 1448

= 90°

= 93.4°

= 90°


[1993Kha]

62.5 at.% Ni [1991Kim]

63.5 at.% Ni [1991Kim]

66.0 at.% Ni [1991Kim]

64 at.% Ni [1997Pot]

65 at.% Ni [1997Pot]

[1998Sim]

[1992Mur]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice

Parameters

[pm]

Comments/References

393


MSIT®

Al–Cr–Ni

Ni2Al hP3

P3m1

CdI2

a*126

P1

a = 407

b = 499

a = 1252

b = 802

c = 1526

= 90°

= 109.7°

= 90°

Metastable

[1993Kha]

[1994Mur]

D1 - Metastable [1988Li]

D4 - Metastable [1988Li]

CrNi2 oP6

Immm

MoPt2 (?)

a = 252.4

b = 757.1

c = 356.8

60 to 76.5 at.% Ni [Mas2]

[P]

*Cr15Ni10Al75 940

- - [1982Tu], adapted from [1984Mer1,

1984Mer2]

* 1

* 1'

* 1, CrxNiyAlz

Monoclinic,

P21 or P21/m

Orthorhombic

polytype,

Pn21a

a = 1340

b = 1255

c = 1255

= 100°

a = 1255

b = 1255

c = 2640

Called “ ”

15.7 to 17.9 at % Cr, 5.6 to 9.7 at.% Ni,

73.3 to 78.5 at.% Al [1996Ros]

Cr17.9Ni5.6Al76.5, quenched from liquid,

[1996Ros]

Cr17.9Ni5.6Al76.5, quenched from liquid,

results in a periodic twinning of 1[1996Ros]

Cr16Ni8Al76, annealed at 840°C (5 h)

[1990Col]; Cr17.0Ni9.7Al73.3, annealed at

800°C (6 d) [1996Ros]

Cr17.0Ni9.7Al73.3 Cr15.7Ni5.8Al78.5, as cast

[1996Ros]

* 2

* 2'

* 2, CrxNiyAlz

Orthorhombic

Immm (?)

Triclinic

superstructure

a = 1255

b = 1255

c = 3075

a = 1255

b = 2510

c = 1775

= = 110.4°

= 90°

Called “ ” [1996Ros]

11.7 to 12.8 at.% Cr, 8.5 to 10.4 at.% Ni,

76.8 to 79 at.% Al

Cr12.5Ni8.5Al79.0, quenched from liquid

[1996Ros]

Cr12.5Ni8.5Al79.0, quenched from liquid or

from liquidus during DTA experiment

[1996Ros]

Cr12.4N9.5Al78.1 and Cr11.7Ni9.3Al79, as cast

Cr12.8Ni10.4Al76.8, in the alloy Cr2Ni23Al75annealed at T = 830°C (7 d) [1996Ros]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice

Parameters

[pm]

Comments/References

394


MSIT®

Al–Cr–Ni


* 3 (h) Rhombohedral

R3 or R3

or

hexagonal system

a = 2870

= 36°

a = 1770

c = 8040

Called “ 1”


[1996Ros]

4 (h) Hexagonal,

P63 a = 1770

c = 1240

Called “ 2”


[1996Ros]

* 5 (...) Hexagonal

P63 a = 3070

c = 1240

a = 1767.4

c = 1251.6

Called “ 3”

~Cr18.7Ni1.7Al79.6, quenched from liquidus

during DTA experiment [1996Ros]

~Cr18Ni6Al76, called “ ”, single crystal

separated from slowly cooled Cr10Ni10Al80alloy [1997Li, 1997Sat]; in conventionally

solidified alloy Cr15Ni5Al80

* 6,”H-(CrNiAl)” Hexagonal a = 1240

c = 1240

Metastable phase in the rapidly solidified

alloy Cr0.5Ni0.5Al6 together with

icosahedral and decagonal quasicrystals

[1989Zho]

*i Metastable [1989Zho]

*d Metastable [1989Zho], analogous to the

Al-Mn-Ni phase [1988Ten]


Al Cr Ni

L + > 1445 e1 - - - -

L + + 1350 U1 L 23.6

23.4

20.4

28.4

4.5

2.9

4.2

2.4

71.9

73.7

75.4

69.2

L + + 1300 ± 20 E1 L 17.4

3.1

30.2

12.9

32.5

79.9

14.5

36.2

50.1

16.9

55.2

50.9

L + + ? U2 L ?

~34.0

~51.0

~41.0

?

~63.0

~9.0

~52.0

?

~3.0

~40.0

~7.0

L + + ? U3 L ?

~40.0

~37.0

61.9

?

~5.0

~3.0

36.3

?

~55.0

~60.0

~1.8

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice

Parameters

[pm]

Comments/References

395


MSIT®

Al–Cr–Ni

Table 3: Integral Excess Gibbs Energies, Enthropies of Formation of Al-Cr-Ni Alloys and Activity

Coefficients of Aluminium at 1045 and 1180 K [1966Mal, 1968Mal]

Table 4: Activity Data of Cr, Ni and Al for a Temperature 1423 K (the Reference States are fcc-Ni, bcc-Cr

and Liquid Aluminium) [1983Ofo, 1985Ofo]

+ + 996 U4 11.7

30.5

21.2

0.2

28.1

9.6

10.8

96.3

60.2

59.8

68.0

3.5

L + (Al) + 634 E2 - - - -

xAl fGex [J·mol-1] fS

ex [J·(K·mol)-1] lg Al

1045 K 1180 K 1045 K 1180 K

0

0.01

0.05

0.07

0.11

0.13

0.15

0.21

–670

–1755

–5560

–7400

–10630

–12120

–13600

–17870

–590

–1630

–5400

–7060

–10250

–11790

–13260

–17530

–0.84

–1.26

–2.51

–2.51

–2.51

–5.53

–4.72

–4.39

–3.75

–3.68

–3.69

–4.65

–3.86

–3.69

–3.37

–3.29

–3.23

Alloy compositions (at.%) Activities ai

Cr Ni Al Cr Ni Al

8.4

19.39

19.9

20.3

20.6

37.3

38.1

38.7

39.7

59.7

63.5

20.51

59.7

58.8

37.2

19.9

39.5

41.9

15.9

20.4

28.1

60.1

20.4

20.9

42.2

42.8

22.4

19.4

44.4

19.9

0.441

0.18

0.644

0.511

0.569

0.629

0.566

0.603

0.3

0.644

0.343

<0.0001

0.067

0.392

0.036

0.021

0.142

0.219

<0.001

0.067

0.0003

0.34

0.003

0.0006

0.014

0.231

0.0004

0.0008

0.29

0.003


Al Cr Ni

396


MSIT®

Al–Cr–Ni

Table 5: Partial Pressures of Cr, Ni and Al over the Alloy Ti-1.85Ta-3.9W-2.05Mo-14.9Cr-70.3Ni-4.5Al

(mass%) and Temperature Range of the Measurements T [1992Hil]

*) 1463 K is the solvus temperature

Table 6: Chemical Activities ai and Excess Chemical Potentials iEof the Components in the Alloy

Ti-1.85Ta-3.9W-2.05Mo-14.9Cr-70.3Ni-4.5Al (mass%) at 1500 K [1992Hil]. Reference states like in Table 4.

Gaseous species i T [K] ln(pi /Pa) = A·104/T+B Pi [Pa] at 1500 K

A B

Cr 1393-1463

1463-1562

3.941 ± 0.096

4.264 ± 0.092

22.56 ± 0.71

24.77 ± 0.58 2.6 ·10-2 ± 19 %

Ni 1393-1463*)

1463-1562

4.821 ± 0.215

5.219 ± 0.080

26.0 ± 1.47

28.73 ± 0.43 2.4 · 10-3 ± 21 %

Al 1443-1463

1463-1562

3.810 ± 0.879

5.322 ± 0.621

13.10 ± 6.05

22.88 ± 3.79

3.5 · 10-6 ± 49 %

Alloy component i ai (at 1500 K) iE (at 1500 K) [kJ·mol-1]

Cr 0.46 ± 0.09 12.9 ± 2.6

Ni 0.45 ± 0.11 5.2 ± 2.9

Al (2.6 ± 1.3)·10–6 13.1 ± 8

397


MSIT®

Al–Cr–Ni

Fig

. 1:

A

l-C

r-N

i. A

par

tial

rea

ctio

n s

chem

e

Al-

Ni

Cr-

Ni

Al-

Cr

Al-

Cr-

Ni

lα

+ γ

1345

e 3

l +

γγ´

1372

p1

L +

γ´

β +

γ1350

U1

l +

α

ζ1352

p2

Lα

+ β

> 1

445

e 1(m

ax)

lπ

+ (

Al)

644

e 4

l +

βδ

1138

p3

lβ

+ γ´

1369

e 2

β +

γα

+ γ

´996

U4

L +

αβ

+ ζ

?U2

Lα

+ β

+γ

1300

E1

Lθ

+ (

Al)

+ π

634

E2

l +

θ

(A

l)

661.5

p4

L +

βδ

+ ζ

?U3

β +

γ +

γ´ L

+ β

+ γ

α +

β +

γ

L +

β +

ζα

+ β

+ ζ

β +

δ +

ζ L

+ δ

+ ζ

α +

γ´ +

γα

+ β

+ γ´

L +

(A

l) +

θ

θ +

(A

l) +

π

L+

θ+π

398


MSIT®

Al–Cr–Ni

20

40

60

80

20 40 60 80

20

40

60

80

Cr Ni


Axes: at.%

p2

ζU3

βU2

e1

α

1600

1500

e3

1350γ

U1

e2

p1

γ'

1600

1500

14501400

E1

1700

1450

1400

1425

145013

501445

Fig. 2: Al-Cr-Ni.

Liquidus surface

projection at

Al < 65 at.%,

temperature in °C

50

50

Cr 10.00Ni 45.00Al 45.00

Cr 0.00Ni 55.00Al 45.00

Cr 0.00Ni 45.00Al 55.00 Data / Grid: at.%

Axes: at.%

1630

1600

1620

1610

15901580

1570

Fig. 3: Al-Cr-Ni.

β-phase liquidus

surface in the vicinity

of Ni0.5Al0.5

composition after

[1993Cot1],

temperature in °C

399


MSIT®

Al–Cr–Ni

20

40

60

80

20 40 60 80

20

40

60

80

Cr Ni


Axes: at.%

14271377

1327

1427

1527

152716

27

1727

1427

10

20

30

40

60 70 80 90

10

20

30

40

Cr 50.00Ni 50.00Al 0.00

Ni


Axes: at.%

γ

γ'β+γ

β

L

γ+γ´

L+γ

L+β

β+γ´

Fig. 4: Al-Cr-Ni.

Calculated partial

liquidus surface

projection

[2001Dup]

(existence of ’

phase is not

considered),

temperature in °C

Fig. 5: Al-Cr-Ni.

Calculated partial

isothermal section at

1300°C [2001Dup]

400


MSIT®

Al–Cr–Ni

10

20

30

40

60 70 80 90

10

20

30

40

Cr 50.00Ni 50.00Al 0.00

Ni


Axes: at.%

γ

γ'β+γ

β

γ+γ´

20

40

60

80

20 40 60 80

20

40

60

80

Cr Ni


Axes: at.%

α

ζ

α+β+γ

γ

γ'

β

β+γ+γ'

α+ζ+β

Fig. 6: Al-Cr-Ni.

Calculated partial


1200°C [2001Dup]

Fig. 7a: Al-Cr-Ni.

Partial isothermal

section at 1150°C

after [1985Ofo,

1991Rog]

401


MSIT®

Al–Cr–Ni

20

40

60

80

20 40 60 80

20

40

60

80

Cr Ni


Axes: at.%

α

ζ

α+β+γ

γ

γ'

β

β+γ+γ'

α+ζ+β

10

20

30

40

60 70 80 90

10

20

30

40

Cr 50.00Ni 50.00Al 0.00

Ni


Axes: at.%

α+γ

β+γ

γ

γ+γ'

α+β

γ'α+β+γ

β+γ'

β

Fig. 7b: Al-Cr-Ni.

Partial isothermal

section at 1150°C:

solid lines are

calculated by

[2001Dup]; dashed

lines are experimental

data [1985Ofo]

Fig. 8: Al-Cr-Ni.

Calculated partial


1127°C [2001Dup]

402


MSIT®

Al–Cr–Ni

10

20

30

40

60 70 80 90

10

20

30

40

Cr 50.00Ni 50.00Al 0.00

Ni


Axes: at.%

α+γ

γ

γ'β+γ

β

α+β+γ

γ+γ´

20

40

60

80

20 40 60 80

20

40

60

80

Cr Ni


Axes: at.%

αγ

γ'

β

δ

α+β+ζ

α+β

ζ

α+β+γ

Fig. 9: Al-Cr-Ni.

Calculated partial


1100°C [2001Dup]

Fig. 10a:Al-Cr-Ni.

Partial isothermal

section at 1025°C

[1982Tu, 1984Mer]

403


MSIT®

Al–Cr–Ni

20

40

60

80

20 40 60 80

20

40

60

80

Cr Ni


Axes: at.%

αγ

γ'

β

δ

α+β

ζ

10

20

30

40

60 70 80 90

10

20

30

40

Cr 50.00Ni 50.00Al 0.00

Ni


Axes: at.%

α+γ γ

γ+γ'

γ'α+β+γ'

β+γ'

β

α+β+γ

α+β

Fig. 10b:Al-Cr-Ni.

Partial isothermal

section at 1025°C

calculated by

[2001Dup]

Fig. 11: Al-Cr-Ni.

Calculated partial


1000°C [2001Dup]

404


MSIT®

Al–Cr–Ni

10

20

30

40

60 70 80 90

10

20

30

40

Cr 50.00Ni 50.00Al 0.00

Ni


Axes: at.%

α+γγ

γ+γ'α+γ+γ'

α+γ'

γ'

α+β+γ'

β

β+γ'

10

20

30

40

60 70 80 90

10

20

30

40

Cr 50.00Ni 50.00Al 0.00

Ni


Axes: at.%

α+γ

α+γ+γ'

γ

γ+γ'

α+γ'

γ'

α+β+γ'

β+γ'

β

α+β

Fig. 12: Al-Cr-Ni.

Calculated partial


900°C [2001Dup]

Fig. 13a:Al-Cr-Ni.

Partial isothermal

section at 850°C after

[1952Tay2, 1991Rog]

405


MSIT®

Al–Cr–Ni

20

40

60

80

20 40 60 80

20

40

60

80

Cr Ni


Axes: at.%

α+γ γ

γ+γ'α+γ+γ'α+γ'

γ'α+β+γ'

β

β+γ'

10

20

30

40

60 70 80 90

10

20

30

40

Cr 50.00Ni 50.00Al 0.00

Ni


Axes: at.%

α+γ

α+γ+γ'

γ

γ+γ'

α+γ'

γ'

α+β+γ´

β+γ'

β

Fig. 13b:Al-Cr-Ni.

Partial isothermal

section at 850°C:

solid lines are

calculated by

[2001Dup]; dashed


data [1952Tay2]

Fig. 14: Al-Cr-Ni.

Calculated partial


800°C [2001Dup]

406


MSIT®

Al–Cr–Ni

10

20

30

40

60 70 80 90

10

20

30

40

Cr 50.00Ni 50.00Al 0.00

Ni


Axes: at.%

α+γ

α+γ+γ'

γ

γ+γ'

α+γ' γ'

α+β+γ' β+γ'

β

20

40

60

80

20 40 60 80

20

40

60

80

Cr Ni


Axes: at.%

α+γ

α+γ+γ'

γ

γ+γ'

α+γ'

γ'α+β+γ'

β+γ'

β

Fig. 15a:Al-Cr-Ni.

Partial isothermal

section at 750°C after

[1952Tay2, 1991Rog]

Fig. 15b:Al-Cr-Ni.

Partial isothermal

section at 750°C:

solid lines are

calculated by

[2001Dup]; dashed


data [1952Tay2]

407


MSIT®

Al–Cr–Ni

50

50

Cr 10.00Ni 45.00Al 45.00

Cr 0.00Ni 55.00Al 45.00


Axes: at.%

α+β β

50

50

Cr 10.00Ni 45.00Al 45.00

Cr 0.00Ni 55.00Al 45.00


Axes: at.%

1625

16001575

1550

1525

1500

Fig. 16: Al-Cr-Ni.

Solvus isotherm of β-

phase at about 600°C

in the vicinity of

Ni0.5Al0.5

composition after

[1993Cot1]

Fig. 17: Al-Cr-Ni.

β-Phase solidus

surface in the vicinity

of Ni0.5Al0.5

composition after

[1993Cot1],

temperature in °C

408


MSIT®

Al–Cr–Ni

20 40

1000

1250

1500

1750

Cr Cr 0.00Ni 50.00Al 50.00Al, at.%

Tem

pera

ture

, °C

βα

α+β

L+β

L

L+α

1651°C

1863°C

1445

L+α+β

20 10

750

1000

1250

1500

Cr 25.00Ni 75.00Al 0.00

Cr 0.00Ni 75.00Al 25.00Cr, at.%

Tem

pera

ture

, °C γ

γ´

γ+γ´

L

Fig. 18: Al-Cr-Ni.

Polythermal section

Cr - 50Ni50Al

[2001Dup]

Fig. 19a:Al-Cr-Ni.

Polythermal section

Ni3Cr - Ni3Al, after

[1952Tay2, 1984Mer]

409


MSIT®

Al–Cr–Ni

20 10

750

1000

1250

1500

Cr 25.00Ni 75.00Al 0.00

Cr 0.00Ni 75.00Al 25.00Cr, at.%

Tem

pera

ture

, °C γ

γ´

γ+γ´

L

Fig. 19b:Al-Cr-Ni.

Calculated

polythermal section

Ni3Cr - Ni3Al

[2001Dup]

50

800

900

1000

1100

1200

1300

1400

Cr 53.00Ni 47.00Al 0.00

Cr 40.00Ni 45.00Al 15.00Cr, at.%

Tem

pera

ture

, °C

α+γ´

α+γ+γ´

α+β+γ+γ´

1000α+γ

α+β+γ

L+α+β+γ

LL+α

L+α+γ

Fig. 20: Al-Cr-Ni.

Polythermal section

53Cr47Ni

-40Cr45Ni15Al

[1991Gor]

410


MSIT®

Al–Cr–Ni

800

900

1000

1100

1200

1300

1400

Cr 39.00Ni 43.00Al 18.00

Cr 34.00Ni 33.00Al 33.00Cr, at.%

Tem

pera

ture

, °C

1300

α+βα+

γ+γ́

α+γ́ α+β+γ´

α+β+γ+γ´

α+β+γ

LL+α

L+α+β

L+α+β+γ

1000

Fig. 21: Al-Cr-Ni.

Polythermal section

39Cr43Ni18Al

-34Cr33Ni33Al

[1992Gor]

411


MSIT®

Al–Cr–Si

Aluminium – Chromium – Silicon

Rainer Schmid-Fetzer

Literature Data

Two ternary phases have been seen in a superficial study of the liquidus surface of the Al-corner

[1943Mon]. The shape of the liquidus surface was found to be quite different in a more extensive study

[1951Pra1] in which primary crystals from slowly cooled alloys were extracted from sectioned samples and

studied by chemical and X-ray analysis. In addition, annealing experiments of chill-cast alloys at 550°C for

21 days and some at 559 to 580°C were performed and the microstructures of these and the slowly cooled

samples were studied [1951Pra1]. In a follow-up paper [1951Pra2] results are discussed in view of alloying

theory. The basic shape of the liquidus surface and the resulting equilibria [1951Pra1] agree qualitatively

with a very detailed study of the Al-corner in the range 0 to 5 mass% Cr and 0 to 14 mass% Si by DTA,

metallography on air-cooled and slowly-cooled (DTA) samples and X-ray analysis [1965Ess].

The crystal structures of the two assumed ternary phases, and , were determined by [1953Rob1] and

[1953Rob2] who used the samples of [1951Pra1]. Single crystals of with almost stoichiometric

Cr4Al13Si4 composition were used for a detailed X-ray structure analysis (reported space group Td2 - F3m)

and a powder photograph was used for determination of the cubic unit cell dimension [1953Rob1]. A

probable range of homogeneity of was also noted [1951Pra1]. The second “ternary” phase, , turned out

to be a solid solution of Al in CrSi2 as determined by X-ray analysis of single crystals and powders

[1953Rob2]. This was confirmed in a detailed X-ray investigation of the solid state equilibria of pressed

samples, annealed at 1300°C [1961Bru]. Homogeneous CrSi2-xAlx ( ) samples up to 25 at.% Al were

obtained [1961Bru], while a -crystal, precipitated from an Al-rich liquid, contained only 14.3 at.% Al in

replacement of Si [1953Rob2] and [1951Pra1]. The lattice parameters given for at x = 0.43 (a = 449.6,

c = 637.7 pm) [1953Rob2] essentially agree with the data of [1961Bru] (Table 1). The possibility of

(spinodal) decomposition of the phase at room temperature is mentioned by [1961Bru] since measured

lattice parameters form two groups, separated by about 2 to 5 pm. [1961Bru] also detected extensive solid

solubility of Al in the Cr5Si3 and the Cr3Si phase.

A solubility of Si in Cr2Al ( ) was detected by X-ray investigation in cast samples, annealed at 700°C for

60 to 80 h [1964Ram]. A sample of composition Cr67Al30Si3 was still homogeneous ( ), but Cr67Al27Si6contained and Cr3Si ( ). The alloy Cr67Al17Si16 consisted of mostly and some Cr5Si3 ( ) and Cr5Al8( 2). The solubility of Al in Cr5Si3 ( ) was also mentioned by [1964Ram], but not quantitatively given as

was done at 1300°C by [1961Bru]. The influence of Si on the primary crystallization of CrAl7 was

investigated by thermal analysis and metallography [1960Zol] and the data of [1951Pra1] were essentially

confirmed. Chemical analysis of extracted primary CrAl7 crystals gave a negligible solubility of Si in CrAl7which was confirmed by microhardness and X-ray measurements [1960Zol]. A diffusion couple study

Al-Cr/Al-Si at 550°C for 7 days was briefly described and a reaction product in the contact zone, probably

CrSi, was found in proximity to non-reacted CrAl7 [1935Bos].

The critical evaluation made by [1991Sch] covers literature published until the year 1989. The present

evaluation updates this work and considers all data available.

Binary Systems

The binary systems Cr-Si, Al-Si and Al-Cr are accepted from [2003Leb], [2003Luk], [2003Cor],

respectively. The crystal structures of the Al-Cr phases in the region from 58 to 70 at.% Al have been

reinvestigated by [1989Ell], who did not confirm the existence of Cr3Al as claimed from TEM analyses

[1981Bro]. The Al-Cr phase diagram is essentially based on [1998Mur], and Cr-Si on [2000Du].

412


MSIT®

Al–Cr–Si

Solid Phases

The solid phases observed in this system are given in Table 1. The solubility limit of Si in is estimated

[1964Ram]. The lattice parameters of , and are from [1961Bru]. They are averaged at the solubility

limits from data of the homogeneous region with special emphasis on the c/a ratio in the case of .


A partial reaction scheme for Al-rich liquids involving the solidification of phases in the

Al-Si-CrSi2( )-Cr2Al11( ) subsystem was taken from [1965Ess] and adapted to the accepted binaries

(Fig. 1). It also agrees with the data of [1951Pra1]. The peritectic formation of at 710°C (P) was only

measured by [1965Ess] while [1961Bru] speculated about a possible congruent melting point at about

600°C which cannot be accepted.

Liquidus Surface

The liquidus surface of the Al-corner corresponding to Fig. 1 is given in Fig. 2 [1965Ess]. The solid

(Al)-phase participating in the three phase equilibria is marked by a line with one arrow. The liquidus

surface of becomes very narrow at higher Si content. It intersects the liquidus surface of Si between the

points U3 and E, which cannot be seen from Fig. 2, but easily from the reaction scheme in Fig. 1.

Isothermal Sections

The isothermal section at 1300°C in Fig. 3 is based upon [1961Bru]; however, the equilibria with the liquid

phase are estimated from the binaries. An isothermal section at 500°C was constructed in Fig. 4 based upon

the scattered data of [1951Pra1, 1965Ess] and [1964Ram] and the assumption of similar solubilities of ,

, and at 1300°C. The ternary compound plays a dominant role in the Al-Si- -CrAl4 subsystem,

despite its rather low incongruent melting temperature. It probably exhibits a range of homogeneity

[1951Pra1].


Vertical sections at 5 mass% Cr and 4 mass% Si in the Al-corner are also reported by [1965Ess]. A typical

error in the slope of intersecting liquidus lines in that (Al+4%Si)-Cr section was pointed out by [1988Zak].

The effect of Cr additions (0.25, 0.5 and 0.8 mass%) on the microstructure of cast, near-eutectic Al-Si alloys

was examined by [1930Ota].

Thermodynamics

The enthalpy of the liquid phase at 1677°C was shown in a ternary plot of iso-enthalpy lines, calculated by

an extrapolation scheme from the binary systems [2001Sud].

Miscellaneous

The structure and thermal stability of rapidly solidified alloys Cr14Al86-xSix with x up to 24 was studied by

XRD and DTA. Below 24 at.% Si the amorphization was not complete at quenching rates of 1.5 106 K s-1.

Crystallization temperatures are around 320°C [1986Dun].

The crystal structure of the phase , Cr4Al13Si4 was studied in relation to “stuffed pyrochlore” [1983Nym].

413


MSIT®

Al–Cr–Si

References

[1930Ota] Otani, B., “Silumin and its Structure” (in Japanese), Kinzoku no Kenkyu, 7, 666-686 (1930)

(Experimental, 8)

[1935Bos] Bosshard, M., ”Diffusion Research as a Means for the Simple Micrographic Detection of

Compound Formation Between Alloy Constituents in Ternary and Polynary Systems” (in

German), Aluminium, 17, 477-481 (1935) (Experimental, 1)


Diagram”, J. Inst. Met., 60, 319-337 (1937) (Crys. Structure, Experimental, Equi. Diagram,

8)

[1941Kna] Knappwost, A., Nowotny, H., “Magnetic Investigation of Aluminium - Chromium - Copper

System” (in German), Z. Metallkd., 33, 153-157 (1941) (Equi. Diagram, Experimental, #, *,

27)

[1943Mon] Mondolfo, L.F., “Metallography of Aluminium Alloys”, Wiley, & Sons, Inc., New York,

74pp. (1943) (Equi. Diagram, Experimental, #, 0)

[1951Pra1] Pratt, J.N., Raynor, G.V., “The Intermetallic Compounds in the Alloys of Aluminium and

Silicon with Chromium, Manganese, Iron, Cobalt and Nickel”, J. Inst. Met., 79, 211-232


[1951Pra2] Pratt, J.N., Raynor, G.V., “Intermetallic Compounds in Ternary Aluminium-Rich Alloys

Containing Transition Metals”, Proc. Roy. Soc. London, 205(Al), 103-118 (1951) (Equi.


[1953Rob1] Robinson, K., “The Structure of (AlCrSi)-Cr4Si4Al13”, Acta Crystallogr., 6, 854-859


[1953Rob2] Robinson, K., “The Structure of (AlCrSi)”, Acta Crystallogr., 6, 667 (1953) (Crys.


[1960Coo] Cooper, M.J., “The Structure of the Intermetallic Phase (Cr-Al)”, Acta Crystallogr., 13,


[1960Zol] Zoller, H., “The Influence of Zn, Mg, Si, Cu, Fe, Mn and Ti on the Primary Crystallisation

of Al7Cr” (in German), Schweiz. Arch. Angew. Wiss. u. Techn., 26, 437-448 and 478-491


[1961Bru] Brukl, C., Nowotny, H., Benesovsky, F., “Investigations in the Ternary Systems V-Al-Si,

Nb-Al-Si, Cr-Al-Si, Mo-Al-Si, or Cr(Mo)-Al-Si” (in German), Monatsh. Chem., 92,

967-980 (1961) (Crys. Structure, Equi. Diagram, Experimental, #, *, 20)




[1964Ram] Raman, A., Schubert, K., “The Occurrence of Zn2Cu- and Cr2Al-Type Intermetallic


23)

[1965Ess] Esslinger, P., Quartrehomme, F., Bleidorn, H., “Constitution of Al-Rich Al-Cr-Si Alloys”

(in German), Z. Metallkd., 56, 735-739 (1965) (Equi. Diagram, Experimental, #, *, 11)

[1968Lin] Lindahl, T., Pilotti, A., Westman, S., “Rhombohedrally Distorted Gamma Phases in the




(Equi. Diagram, Crys. Structure, Experimental) quoted by [1998Mur]



[1977Vis] Visser J.W., “On The Structure of Chromium-Aluminum (Cr5Al8) 26r A Correction”, Acta

Crystallogr., Sect. B, 33B(1), 316 (1977) (Experimental, Crys. Structure)

[1981Bro] den Broeder, F.J.A., van Tendeloo, G., Amelinckx, S., Hornstra, J., de Ridder, R., van

Landuyt, J., van Daal, H.J., “Microstructure of Cr100-xAlx Alloys (10 at% < x < 33 at%)

414


MSIT®

Al–Cr–Si


New Phase”, Phys. Status Solidi, A, 67, 233-248 (1981) (Equi. Diagram, Experimental, 2)


Daal, H.J., “Microstructure of Cr100-xAlx Alloys (10 at% < x < 33 at%) Studied by Means


Phys. Status Solidi A, 67, 217-232 (1981) (Equi. Diagram, Experimental, 10)

[1983Nym] Nymon, H., “A Relation Between the Structures of Ce24Co11, Ru7B3, and Pyrochlore”,

J. Solid State Chem., 49, 263-263 (1983) (Crys. Structure, Theory, 10)

[1986Dun] Dunlap, R.A., Dini, K., “Amorphization of Rapidly Quenched Quasicrystalline

Al-Transition Metal Alloys by the Addition of Si”, J. Mater. Res., 1(3), 415-419 (1986)


[1988Zak] Zakharov, A.M., “Typical Errors Encountered on State Diagrams of Ternary Metallic

Systems”, Izv. Vyss. Uchebn. Zaved., Tsvetn. Metall., 5, 76-87 (1988) (Equi. Diagram,

Review, 33)

[1989Ell] Ellner, M., Braun, J., Predel, B., “X-ray Investigations on the Cr-Al Phases Belonging to the

W Family” (in German), Z. Metallkde., 80(5), 374-383 (1989) (Equi. Diagram, Crys.


[1990Ram] Ramon, J.J., Shechtman, D., Dirnfeld, S.F., “Synthesis of Al-Cr Intermetallic Crystals”,

Scr. Metall. Mater, 24, 1087 (1990) (Experimental, Crys. Structure)

[1991Sch] Schmid-Fetzer, R., “Aluminium - Chromium - Silicon”, MSIT Ternary Evaluation Program,



Assessment, 12)


Crystalline and Quasicrystalline Phases”, Met. Trans. A, 23A, 2437-2445 (1992) (Crys.


[1993Sut] Sutliff, J.A., Bewlay, B.P., Lipsitt, H.A., “High Temperature Phase Equilibria in Cr-Cr3Si

Two Phase Alloys”, J. Phase Equilib., 14, 583-587 (1993) (Crys. Structure, Equi. Diagram,

Experimental, 12)


Solidi A, 141, 31-41 (1994) (Crys. Structure, Experimental, 19)


System”, J. Alloys Compd, 220, 225-230 (1995) (Crys. Structure, Experimental, *, 17)



Experimental, 17)

[1998Li] Li, X.Z., Sui, H.X., Kuo, K.H., Sugiyama, K., Hiraga, K., “On the Structure of the Al4Cr

Phase and its Relation to the Al-Cr-Ni Phase”, J. Alloys Compd., 264, L9-L12 (1998)




[2000Du] Du, Y., Schuster, C., “Experimental Reinvestigations of the CrSi-Si Partial System and

Update of the Thermodynamic Description of the Entire Cr-Si system”, J. Phase Equilib.,

21, 281-286 (2000) (Calculation, Equi. Diagram, Experimental, Thermodyn., *, #, 35)







Rapidly Solidified Cr-40 at.% Al Alloy”, Philos. Mag. Let., 80(11), 703-710 (2000) (Crys.


415


MSIT®

Al–Cr–Si

[2001Oka] Okamoto, H., “Cr-Si (Chromium-Silicon)”, J. Phase Equilib., 22, 593 (2001) (Crys.

Structure, Equi. Diagram, Review, *, #, 4)

[2001Sud] Sudavtsova, V.S., Kudin, V.G., “About Thermodynamic Properties of the Alloys of the

Si-Al-Me(VIb) Ternary Systems” (in Russian), Metally, (1), 29-31 (2001) (Experimental,

Thermodyn., 8)

[2001Tan] Tanaka, K., Nawata, K., Inui, H., Yamaguchi, M., Koiwa, M., “Refinement of

Crystallograpic Parameters in Transition Metal Disilicides with the C11b, C40 and C54

Structures”, Intermetallics, 9, 603-607 (2001) (Experimental, Crys. Structure, 12)


(Aluminum-Chromium)”, MSIT Binary Evaluation Program, in MSIT Workplace,


published, 2003 (Equi. Diagram, Assessment, Crys. Structure, 51)

[2003Luk] Lukas, H.L., “Al-Si (Aluminum-Silicon)”, MSIT Binary Evaluation Program, in MSIT


Stuttgart, to be published, 2003 (Equi. Diagram, Assessment, Crys. Structure, 29)

[2003Leb] Lebrun, N., “Cr-Si” (Chromium-Silicon)”, MSIT Binary Evaluation Program, in MSIT


Stuttgart, to be published, 2003 (Equi. Diagram, Assessment, Crys. Structure, 31)


Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

(Al)

<660.452

cF4

Fm3m

Cu

a = 404.96 at 25°C [Mas]

0 to 0.37 at.% Cr

in equilibria; to 3 at.% Cr after spinning;

to 5 at.% Cr by gun technique

[1998Mur]

(Al) (I) hP2

P63/mmc

Mg

a = 269.3

c = 439.8

at 25°C, 20.5 GPa

[Mas2]

(Cr)

< 1907

cI2

Im3m

W

a = 288.47

a = 288.47 ± 5

a = 288.09 ± 2

at 25°C [Mas2]

0 - 13 at.% Si [2001Oka]

at 4.5 ± 0.2 at.% Si [1993Sut] at 1200°C

at 6.7 ± 0.2 at.% Si [1993Sut] at 1400°C

(Cr) (I) tI2

I4/mmm

'Cr

a = 288.2

c = 288.7

at 25°C, high pressure phase

[Mas2]

(Si)

< 1414

cF8

Fd3m

C (diamond)

a = 543.06 at 25°C [Mas2]

100 at.% Si [2001Oka]

(Si) (III) hP4

P63/mmc

La

a = 380

c = 628

at 25°C, 16 GPa 1 bar [Mas2]

(Si) (II) cI16

Ia3

Si

a = 663.6 at 25°C, 16 GPa [Mas2]

416


MSIT®

Al–Cr–Si

(Si) (I) tI4

I41/amd

Sn

a = 468.6

c = 258.5

at 25°C, 9.5 GPa [Mas2]

, Cr2Al13 (CrAl7)

<790

mC104

C2/m

V7Al45

a = 2519.6

b = 757.4

c = 1094.9

= 128.7


[1960Coo, 1975Ohn, 1995Aud]

, Cr2Al11 (CrAl5)

940-790

Orthorhombic

oC584

Cmcm

a = 1240

b = 3460

c = 2020

a = 1252.1

b = 3470.5

c = 2022.3

a = 1260

b = 3460

c = 2000


16.9 to 19.2 at.% Cr;

[1995Aud, 2000Mah]

single crystal

“ CrAl4” [1997Li, 1998Li]

“ CrAl4” [1992Wen]

CrAl4< 1030

hP574

P63/mmc

MnAl4

a = 1998

c = 2467

a = 2010

c = 2480


20.9 ± 0.3 at.% Cr

[1995Aud, 2000Mah]

[1990Ram]

20.6 to 21.2 at.% Cr [1995Aud];

22.3 ± 0.1 at.% Cr


Cr4Al9 (h2)

1170-1060

[2003Cor]

Cr4Al9 (h1)

1060

cI52

I43m

Cu4Al9


[1941Kna, Mas2];


[1995Aud]

Cr4Al9 (r)

< 700 (?)

hR52

R3m

Cr4Al9

a = 1291

c = 1567.7

32.8 to 35 at.% Cr

[1968Lin, Mas2]

1, Cr5Al8 (h)

1100 (?)

I52

I43m

Cu5Zn8


[1989Ell]

2, Cr5Al8 (r)

1100 (?)

hR78-1.50

R3m

Cr5Al8

a = 1271.9

c = 793.6

a = 1272.8

c = 794.2

a = 1281.3

c = 795.1

[1977Vis, Mas2]

[1977Bra]

[1989Ell]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

417


MSIT®

Al–Cr–Si

, Cr2Al1-xSix

Cr2Al

< 910

Cr2Al0.91Si0.09

tI6

I4/mmm

MoSi2

a = 300.45

c = 864.77

a = 300.5 to 302.8

c = 864.9 to 875.5

a = 300

c = 864

a = 300

c = 861

0 x 0.12 at 700°C [1964Ram]

at x = 0, binary Al-Cr

~65.5 to ~71.4 at.% Cr

[1937Bra, 1963Koe, 1998Mur]

[1989Ell]

at x = 0 [1964Ram]

x = 0.09 [1964Ram]

X(Al-Cr)

400

Cr5Al3 or

Cr3Al super lattice

~75 to ~80 at.% Cr [1981Bro, 1981Ten];


“ 'CrAl4” Pmcm in as-cast alloy 15 at.% Cr, lattice

parameters are the same as for ” 'CrAl4”

metastable [1994Sel]





(Al-Cr) - - in quenched Al-Cr alloy of 60-100 at.%

Cr, like metastable Ti [2000Sha1,

2000Sha2]

, Cr3Si1-xAlx

(Cr3Si)

< 1780

Cr3Si0.5Al0.5

cP8

Pm3n

Cr3Si

a = 455.60 ± 0.04

a = 456.27 ± 0.04

a = 456.46 ± 0.02

a = 456.67 ± 0.02

a = 456.65 ± 0.03

a = 454.7

a = 456.3

0 x 0.5 [1961Bru]

at x = 0, binary Cr-Si [V-C2]

20.8 - 25.3 at.% Si [2001Oka]

at 22.5 ± 0.4 at.% Si, at 1200°C,

[1993Sut]

at 21.5 ± 0.4 at.% Si, at 1400°C,

[1993Sut]

at 20.8 ± 0.4 at.% Si, at 1600°C,

[1993Sut]

as solidified [1993Sut]

at x = 0 [1961Bru]

at x = 0.5 [1961Bru]

Cr5Si3 (h)

1666-1488

37.5 - 37.7 at.% Si [2001Oka]

, Cr5(Si1-xAlx)3 (r)

Cr5Si3(r)

< 1488

Cr5Si2.4Al0.6

tI32

I4mcm

W5Si3

a = 917.0

c = 463.6

a = 914

c = 463

a = 915.7

c = 464.2

x = 0 to 0.2 [1961Bru]

at x = 0, binary Cr-Si [V-C2]

37.5 at.% Si [2001Oka]

at x = 0 [1961Bru]

at x = 0.2 [1961Bru]

, CrSi

< 1424

cF8

P213

FeSi

a = 462.2 ± 0.1 [V-C2]

50 at.% Si [2001Oka]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

418


MSIT®

Al–Cr–Si

, Cr(Si1-xAlx)2

CrSi2< 1438 ± 2

CrSi1.25Al0.75

hP9

P6422

CrSi2

a = 442.83 ± 0.01

c = 636.80 ± 0.09

a = 442.0

c = 635.4

a = 453.2

c = 639

x = 0 to 0.75 [1961Bru],

microhardness 8530 MPa [1965Ess]

at x = 0, binary Cr-Si

66.3 - 68 at.% Si [2000Du]

[2001Oka]

[2001Tan]

at x = 0 [1961Bru]

at x = 0.375 [1961Bru]

* , Cr4Al13Si4< 710

cF84

F43m

Cr4Al13Si4

a = 1091.7 ± 0.1 [1953Rob1], probably with a range of

homogeneity [1951Pra1],

microhardness 5710 MPa [1965Ess]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

Fig. 1: Al-Cr-Si. Partial reaction scheme

Al-Cr Cr-SiAl-Cr-Si Al-Si

l (Si) + β1328 e

1

L + η + β

l + η θ790 p

1

l (Al) + (Si)

577 e2

L + η + β τ710 P

η + β + τ

L + η + τ

L + η θ + τ680 U1

η + θ + τ L + θ + τl + θ (Al)

661.5 p2

L + θ (Al) + τ625 U2

(Al) + θ + τL + (Al) + τ

L + β τ + (Si)590 U3

L + τ + (Si) τ + β + (Si)

L (Al) + τ + (Si)575 E

(Al) + τ + (Si)

L + τ + β

419


MSIT®

Al–Cr–Si

10

90

10

Cr 15.00Al 85.00Si 0.00

Al

Cr 0.00Al 85.00Si 15.00 Data / Grid: at.%

Axes: at.%

640

620

600

580E

e2

580

600

680720

880860840820

800780760720

p1 p2

U2

τ

640P

920900880860840

820800

(β)

θ

U3

(Al)

(Si)

U1

η

20

40

60

80

20 40 60 80

20

40

60

80

Cr Al


Axes: at.%

L

L+β

L+(Si)

β+(Si)β

γ

δ

εε+δ

(Cr)+ε ζ1+ε+(Cr)

ζ1+δ+ε

ζ1+β+δ

δ+βδ+β+γ

L+β+ζ

1

L+ζ1

ζ1

(Cr)

(Si)

Fig. 2: Al-Cr-Si.

Partial liquidus

surface of the

Al-corner with

primary crystallization

fields of (Al), (Si), τ, β, η and θ.The solidus of (Al) is

marked by a single

arrow

Fig. 3: Al-Cr-Si.


1300°C

420


MSIT®

Al–Cr–Si

20

40

60

80

20 40 60 80

20

40

60

80

Cr Al


Axes: at.%

(Al)+(Si)+τ

τ+(Si)+β

β+(Si)β

γ

δ+β+γδ+β

δ

εε+δ

(Cr)+εξ+ε+(Cr)

ζ2+ε+ξ

ξ

ζ2+δ+ε

ζ2+β+δ

ζ2 Cr4Al9(r) CrAl4 θ

τ

(Cr)

(Al)

(Si)Fig. 4: Al-Cr-Si.


500°C

421


MSIT®

Al–Cr–Zr

Aluminium – Chromium – Zirconium

Leonid Guzei, updated by Viktor Kuznetsov

Literature Data

In this system experimental information on phase equilibria comprises isothermal sections at several

temperatures: 800°C [1970Mar], 620 and 450°C [1972Kad], 400°C [1967Zar] and series of isopleths in the

Zr-rich region at fixed composition ratios of Al:Cr = 4:1, 1:1, 1:4 and at fixed content of 3 mass% Cr

[1968Gru]. [1970Mar] studied phase equilibria at 800°C on 114 alloys, prepared by melting pure elements

(above 99.9% purity) under argon in an arc furnace. The specimens were annealed at 800°C for 1000 h

followed by quenching in cold water and examined by X-ray and metallographic analysis. The phase

compositions of solid alloys in the Al corner at 400°C were established by [1967Zar] where arc melted

ingots were annealed for 1000 h at 400°C and quenched in toluene. Using optical microscopy and electrical

resistivity measurements, [1972Kad] investigated the solubility of Cr and Zr in Al at 450 and 620°C. Alloys

were homogenized for 48 h at 500°C and after hot-working heated for 280 h at 620°C with an additional

annealing for 100 h at 620°C after cold-working to ensure that equilibrium was reached. The Zr corner of

the system was investigated by [1968Gru]. However, the results are in contradiction to [1970Mar] and are

not shown here. The thermodynamic calculations made by [1977Cha] are not accepted in this evaluation as

they do not take into account the well confirmed existence of the continuous solid solution between ZrCr2

and ZrAl2 at high temperatures. A short review of the system is given by [1990Kum].

[1989Sok1], [1989Sok2] and [1992Dob] observed an increase of solubility of Cr and Zr in Al in metastable

state which is achieved by cooling the alloys rapidly at rates of 106 to 107K s-1. The authors also

investigated the corrosion behavior and the kinetics of decay of these solid solutions. [1991Des] examined

the ZrAl3 based L12 phase in the mechanically alloyed samples. [1993Tai] studied microstructure and some

mechanical properties of samples obtained by powder extrusion. The present evaluation updates the review

made by [1991Guz].

Binary Systems

The ternary description presented here is consistent with the edge boundary systems Al-Cr as published by

[2003Cor] and Cr-Zr by [2002Per]. For the Al-Zr edge the description by [2003Sch] is accepted.

Solid Phases

No stable ternary phases have been found. The phase with L12 structure, found by [1991Des] in

mechanically alloyed two-phase sample with an over-all composition of Al-12.5Cr-25Zr (at.%) is most

probably metastable, although the authors do not exclude that it is stable at low temperatures.

In the as cast state a continuous series of solid solutions exists between ZrCr2 and ZrAl2. At 800°C solid

solutions based on ZrCr2( 2) and ZrAl2 ( 1) are formed with limited concentrations of Al and Cr, up to 7.5

and 54 at.%, respectively [1970Mar]. The known solid phases are listed in Table 1.

Liquidus Surface

No experimental investigations seem to exist. Figure 1 shows a partial liquidus projections extrapolated

thermodynamically from binary data using a Muggianu formalism [1986Sau]. Three transition reactions

(U-type) are shown with liquid phase composition very close to the Al-Cr side.

Isothermal Sections

Figure 2 displays the isothermal section at 800°C after [1970Mar] with minor corrections to meet the

boundary system, in particular to account for the homogeneity range of the binary intermetallic compound

ZrCr2. Furthermore, [1970Mar] plotted an , CrAl3, phase which, by more recent assessment [1986Sau],

422


MSIT®

Al–Cr–Zr

has been proved to exist only at temperatures higher than 1060°C, as the high-temperature modification of

the compound Al9Cr4.

Figure 3 shows the Al corner at 620°C [1972Kad]. Cr and Zr solubility in (Al) decrease with decreasing

temperature from 0.187 at.% Cr and 0.049 at.% Zr at 620°C to 0.057 at.% Cr and 0.016 at.% Zr at 450°C.

The agreement between the experimental phase boundaries by [1972Kad] and the calculated ones by

[1986Sau] in the Al-rich corner of the 620°C and 450°C isothermal sections is very good and the

calculations proved to be insensitive to any ternary interaction parameter in the fcc-(Al) phase [1986Sau].


Two polythermal sections, (1) at constant mass ratio Zr:Cr = 5:7 and (2) at ZrAl3 - CrAl7 have been

constructed by [1989Sok1]. They are in general agreement with the solid state equilibria presented in Figs.

2 and 3. However, both sections do not reflect the present knowledge on the edge binary systems, in

particular with respect to the temperature at which the CrAl7 phase forms; also temperature scale is not

shown by [1989Sok1] for the Zr:Cr = 5:7 section. Therefore, these sections are not presented in this

evaluation.


[1989Sok1, 1989Sok2] studied the corrosion behavior of supersaturated Al based solid solutions.

[1991Des] investigated mechanical properties of the probably metastable L12 phase which turned out to be

slightly more ductile than the equilibrium ZrAl3 phase. [1993Tai] reports the microstructure, mechanical

properties and thermal stability of the Al-1.6Cr-1.6Zr (at.%) alloy prepared by hot-extrusion of rapidly

solidified powder.

Magnetic susceptibilities have been recorded by [1984Sup] for the MgZr2 type solution ZrCr2-xAlxrevealing Pauli-paramagnetism for all compositions x.

Miscellaneous

Figure 4 shows the metastable solubility of Cr and Zr in (Al) after solidification at different cooling rates,

compared with equilibrium data by [1972Kad] at 620°C (curve 1). Curves 2 and 3 by [1977Ela] relate to

material cooled at 10 K s-1 and 100 K s-1 rates, respectively. Additions of Zr to an Al-Cr alloy increased the

maximum solid solubility of Cr from 5 to 8 mass% in alloys produced by the atomization splat quenching

method [1987Kim]. Rapidly solidified alloys (106-107 K s-1) showed a maximum solid solubility of 6.5

at.% Cr and 0.55 at.% Zr, respectively [1989Sok1]. Figure 5 presents the limits of metastable solubility at

cooling rates of 103 to 106 K s-1 [1992Dob].

References

[1937Bra] Bradley, A.J., Lu, S.S., ”An X-Ray Study of the Chromium-Aluminium Equilibrium

Diagram”, J. Inst. Met., 60, 319-337 (1937) (Experimental, Crys. Structure, Equi. Diagram,

8)

[1941Kna] Knappwost, A., Nowotny, H., ”Magnetic Investigations in the Ternary Al-Cr-Cu System”,

Z. Metallkd., 33, 153-157 (1941)

[1960Coo] Cooper, M.J., ”The Structure of the Intermetallic Phase (Cr-Al)”, Acta Crystallogr., 13,





[1964Ram] Raman, A., Schubert, K., “The Occurrence of Zr2Cu and Cr2Al Type Intermetallic


23)

[1967Zar] Zarechnyuk, O.S., Malinkovich, A.N., Lalayan, E.A., Markiv, V.Ya., “X-Ray Investigation

of Aluminium-Rich Alloys of the Ternary Al-Cu-Cr, Al-Cu-Zr, Al-Cr-Zr Systems and the

423


MSIT®

Al–Cr–Zr

Quaternary Al-Cu-Cr-Zr System”, Russ. Metall., (6), 105-107 (1967), translated from Izv.

Akad. Nauk SSSR, Met., (6), 201-204 (1967) (Equi. Diagram, Experimental, 2)

[1968Gru] Gruzdeva, N.M., Tregubov, I.A., “The Zr Corner of the Zr-Al-Cr Phase Diagram and the

Alloy Properties” (in Russian), Fiz-Khimiya Splavov Tsirkoniya, Publ. Nauka, Moscow,

23-30 (1968) (Equi. Diagram, Experimental, Phys. Prop., 2)

[1968Lin] Lindahl, T., Pilotti, A., Westman, S., ”Rhombohedrally Distorted Gamma Phases in the



[1970Mar] Markiv, V.Ya., Burnashova, V.V., “Study on the Zr-Cr-Al and Zr-Cu-Al Systems” (in

Russian), Poroshk. Metall., 12, 53-58 (1970) (Equi. Diagram, Experimental, #, *, 14)

[1972Kad] Kadaner. E.S., Kuz'mina, V.I., “Phase Equilibria in the Al-Cr-Zr System” (in Russian) in

“Metallovedenie Tsvetnych Metallov i Splavov”, Drits, M.E. (Ed.), Nauka, Moscow, 41-44


[1973Pet] Pet'kov, V.V., Prima, S.B., Tretjachenko, L.A., Kocherszinskij, Yu.A., “New Data on Laves

Phases in the Zr-Cr System” (in Russian), Metallofizika, 46, 80-84 (1973) (Crys. Structure,



(Equi. Diagram, Crys. Structure, Experimental) as quoted by [1998Mur]



[1977Cha] Chart, T.G., “The Calculation of Multicomponent Alloy Phase Diagrams at the National

Physical Laboratory”, NBS Special Publ., 2, No. 496, 1186-1199 (1977, Publ. 1978) (Equi.

Diagram, Thermodyn., Theory, 26)

[1977Ela] Elagin, V.I., Fedorov, V.M., “The Al-Cr-Zr System: A Basis for Precipitation Hardened

Aluminium Alloys”, Russ. Metall., (5), 193-198 (1977), translated from Izv. Akad.Nauk

SSSR, Met., (5), 239-245 (1977), (Experimental, 14)

[1977Vis] Visser J.W., ”On the Structure of Chromium-Aluminum (Cr5Al8) 26r A Correction”, Acta

Crystallogr., Sect. B, 33B(1), 316 (1977)

[1981Bro] den Broeder, F.J.A., Tendeloo, G. van, Amelinckx, S., Hornstra, J., de Ridder, R., van

Landgut, J., van Daal, H.J., “Microstructure of Cr100-xAlx Alloys (10 at.% x 33 at.%)

Studied by Means of Electron Microscopy and Diffraction, II. Discovery of a New Phase”,

Phys. Status Solidi, 67, 233-248 (1981) (Equi. Diagram, Crys. Structure, Experimental, 9)




Phys. Stat. Sol. A, 67, 217-232 (1981) (Equi. Diagram, Experimental, 10)

[1984Sup] Suprunenko, P.A., Markiv, V.Ya., Tsvetkova, T.M., “Magnetic and X-Ray Diffraction

Study of Laves Phases in the Ternary Systems (Ti, Zr, Hf)-Cr-Al”, Russ. Metall., (1),

207-210 (1984), translated from Izv. Akad. Nauk SSSR, Met., (1), 207-210 (1984) (Crys.


[1986Ari] Arias, D., Abriata, J.P., ”The Cr-Zr (Chromium-Zirconium) System”, Bull. Alloy Phase

Diagram, 7(3), 237-244, (1986) (Equi. Diagram, Review, #, 32)

[1986Sau] Saunders, N., Rivlin, V.G., “Thermodynamic Characterization of Al-Cr, Al-Zr and

Al-Cr-Zr Systems”, Mater. Sci. Technol., 2, 521-527 (1986) (Equi. Diagram, Review, 48)

[1987Kim] Kim, J.R., Kim, T.H., “The Effect of Additional Element Zr on Solid Solubility of Cr and

Mechanical Properties of Rapidly Solidified Al-Cr Alloys” (in Korean), J. Korean Inst.

Met., 25, 506-513 (1987) (Crys. Structure, Experimental, Mechan. Prop., 14)

[1987Vec] Vecchio, K.S., Williams, D., ”Convergent Beam Electron Diffraction Study of Al3Zr in

Al-Zr and Al-Li-Zr Alloys”, Acta Metall., 35(12), 2959-2970 (1987) (Experimental)

[1989Ell] Ellner, M., Braun, J., Predel, B., “X-Ray Study on Cr-Al Phases of the W-Family” (in

German), Z. Metallkd., 80, 374-383 (1989) (Equi. Diagram, Crys. Structure, Experimental,

38)

424


MSIT®

Al–Cr–Zr

[1989Sok1] Sokolovskaya, E.M., Badalova, L.M., Podd’yakova, E.I., Kazakova, E.F., Loboda, T.P.,

Gribanov, A.V., “Phase Composition and Properties of Rapidly Cooled Aluminium Alloys

with Zirconium and Chromium”, Russ. Metall., (1), 168-172 (1989), translated from Izv.

Akad. Nauk SSSR, Met., (1), 164-168 (1989) (Equi. Diagram, Electrochem. Prop.,

Experimental, 6)

[1989Sok2] Sokolovskaya, E.M., Badalova, L.M., Podd’yakova, E.I., Kazakova, E.F., Loboda, T.P.,

“Formation, Stability and Properties of Metastable Phases in the Al-Zr-Cr System” (in

Russian), Dokl. Akad. Nauk SSSR, 306, 396-398 (1989) (Electrochem. Prop., Kinetics,

Experimental, 3)


Cr, Mn, Fe, Co, Ni, Cu, Zn)”, Int. Mater. Rev., 35, 293-327 (1990) (Crys. Structure, Equi.


[1990Ram] Ramon, J.J., Shechtman, D., Dirnfeld, S.F., ”Synthesis of Al-Cr Intermetallic Crystals”, Scr.

Metall. Mater, 24, 1087 (1990) (Experimental, Crys. Structure)

[1991Des] Desch, P.B., Schwarz, R.B., Nash, P., “Formation of Metastable L12 Phases in Al3Zr and

Al-12.5% X-25% Zr (X = Li, Cr, Fe, Ni, Cu)”, J. Less-Common Met., 168, 69-80 (1991)


[1991Guz] Guzei L., ”Al-Cr-Zr (Aluminium - Chromium - Zirconium ),” MSIT Ternary Evaluation




[1992Dob] Dobatkin, V.I., Beloserkovets, V.V., Golder, Yu.G., “The Metastable Equilibria During

Crystallization of Alloys of Ternary Systems” (in Russian), Metally, (5), 169-177 (1992)

(Equi. Diagram, Kinetics, Experimental, Review, *, #, 8)

[1992Ma] Ma, Y., Romming, C., Lebech, B., Gjonnes, J., Tafto, J., ”Structure Refinement of Al3Zr

Using Single Crystal X-Ray Diffraction, Powder Neutron Diffraction and CBED”, Acta

Crystallogr., B48, 11-16 (1992) (Experimental, Crys. Structure, 11)


Crystalline and Quasicrystalline Phases”, Met. Trans. A, 23A, 2437-2445 (1992) (Crys.


[1993Tai] Tai, H., Furushiro, N., Mae, T., Fujitani, W., Hori, S., “Microstructures and Hardness of

Al-1.6%Cr-1.6%Zr Alloy Prepared by Hot-Extrusion of Rapidly Solidified Powder”, Met.

Abstr. Light Metals and Alloys, 26, 62 (1993) (Phys. Prop., 0)


Solidi A, 141, 31-41 (1994) (Crys. Structure, Experimental, 19)

[1995Aud] Audier, M., Durand-Charre, M., Laclau, E., Klein, H., “Phase Equilibria in the Al–Cr

System”, J. Alloys Compd., 220, 225-230 (1995) (Crys. Structure, Experimental, *, 17)

[1995Sou] Soubeyroux, J.L., Bououdina, M., Fruchart, D., Pontonnier, L., ”Phase Stability and

Neutron Diffraction Studies of Laves Phases Zr(Cr1-xMx)2 with M = Mn, Fe, Co, Ni, Cu and

0 < x < 0.2 and their Hydrides”, J. Alloys Compd., 219, 48-54, (1995) (Crys. Structure,

Experimental, 20)

[1997Kur] Kuranaka, S., Gamo, T., Morita, Y., “Powder X-ray Diffraction under a High Pressure

Hydrogen Atmosphere for Zr-Cr Based Laves Phase Alloys”, J. Alloys Compd., 253-254,

268-271, (1997) (Crys. Structure, Experimental, 13)



Experimental, 17)

[1998Li] Li, X.Z., Sui, H.X, Kuo, K.H., Sugiyama, K., Hiraga, K., “On the Structure of the Al4Cr

Phase and its Relation to the Al–Cr–Ni Phase”, J. Alloys Compd., 364, L9-L12 (1998)


[1998Mur] Murray, J.L., “The Al–Cr (Aluminium–Chromium) System”, J. Phase Equilib., 19(4),


425


MSIT®

Al–Cr–Zr

[2000Mah] Mahdouk, K., Gachon, J.-C., “Thermodynamic Investigation of the Aluminium–Chromium



[2000Sha1] Shao, G., Tsakiropoulos, P., “On the Phase Formation in Cr-Al and Ti-Al-Cr Alloys",



Rapidly Solidified Cr-40 at.% Al Alloy”, Philos. Mag. Let., 80(11), 703-710 (2000) (Crys.


[2002Per] Perrot, P., “Cr-Zr (Chromium-Zirconium)”, MSIT Binary Evaluation Program, in MSIT



Assessment, 14)


(Aluminum-Chromium)”, MSIT Binary Evaluation Program, in MSIT Workplace,


published, 2003 (Crys. Structure, Equi. Diagram, Review, 51)

[2003Sch] Schuster, J.C., “Al-Zr (Aluminium-Zirconium)”, MSIT Binary Evaluation Program, in


GmbH, Stuttgart; submitted for publication (2003) (Crys. Structure, Equi. Diagram,

Assessment, 151)


Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

(Al)

< 660.452

cF4

Fm3m

Cu

a = 404.96 at 25°C [Mas2]

0.37 at.% Cr at 661.5°C

0.07 at.% Zr at 660.8°C

(Cr)

< 1863

cI2

Im3m

W

a = 288.48 at 25°C [Mas2]

46 at.% Al at 1350°C

0.6 at.% Zr at 1592°C

( Zr)(h)

1855-863

cI2

Im3m

W

a = 356.90 at 25°C [V-C2]

8 at.% Cr at 1332°C

26 at.% Al at 1350°C

( Zr)(r)

< 863

hP2

P63/mmc

Mg

a = 323.2

c = 514.7

at 915°C [V-C2]

8.3 at.% Al at 910°C

0.5 at.% Cr at 836°C

Cr2Al13 (CrAl7)

< 790

mC104

C2/m

V7Al45

a = 2519.6

b = 757.4

c = 1094.9

= 128.7


[1960Coo, 1975Ohn, 1995And]

426


MSIT®

Al–Cr–Zr

Cr2Al11 (CrAl5)

940-790

Orthorhombic

oC584

Cmcm

a = 1240

b = 3460

c = 2020

a = 1252.1

b = 3470.5

c = 2022.3

a = 1260

b = 3460

c = 2000


16.9 to 19.2 at.% Cr;

[1995Aud, 2000Mah]

single crystal

“ CrAl4”

[1997Li, 1998Li]

“ CrAl4” [1992Wen]

CrAl4< 1030

hP574

P63/mmc

MnAl4

a = 1998

c = 2467

a = 2010

c = 2480

at room temperature, 20.9 ± 0.3 at.% Cr

[1995Aud, 2000Mah]; [1990Ram]

20.6 to 21.2 at.% Cr [1995Aud];

22.3 ± 0.1 at.% Cr


1, Cr4Al9 (h2)

1170-1060

[2003Cor]

2, Cr4Al9 (h1)

<~ 1060

cI52

I43m

Cu4Al9


[1941Kna, Mas2];


[1995Aud]

3, Cr4Al9 (r)

< 700 (?)

hR52

R3m

Cr4Al9

a = 1291

c = 1567.7

32.8 to 35 at.% Cr

[1968Lin, Mas2]

1, Cr5Al8 (h)

1100 (?)

I52

I43m

Cu5Zn8


[1989Ell]

2, Cr5Al8 (r)

1100 (?)

hR78-1.50

R3m

Cr5Al8

a = 1271.9

c = 793.6

a = 1272.8

c = 794.2

a = 1281.3

c = 795.1

[1977Vis, Mas2]

[1977Bra]

[1989Ell]

Cr2Al

< 910

tI6

I4/mmm

MoSi2

a = 300.45

c = 864.77

a = 300.5 to 302.8

c = 864.9 to 875.5

~65.5 to ~71.4 at.% Cr

[1937Bra, 1963Koe, 1998Mur]

[1989Ell]

X(Al-Cr)

400

Cr5Al3 or

Cr3Al super lattice

~75 to ~80 at.% Cr [1981Bro, 1981Ten];


“ ’CrAl4” Pmcm in as-cast alloy 15 at.% Cr, lattice

parameters are the same as for ” ’CrAl4”

metastable [1994Sel]




Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

427


MSIT®

Al–Cr–Zr


(Al-Cr) in quenched Al-Cr alloys of 60-100 at.%

Cr, like metastable Ti [2000Sha1,

2000Sha2]

ZrAl3 (m) cP4

Pm3m

Cu3Au

a = 408 [1987Vec] at 16.5 at.% Zr

ZrAl3< 1580

tI16

I4/mmm

ZrAl3

a = 399.93 ± 0.05

c = 1728.3 ± 0.02

[1992Mur, 2003Sch]

1, Zr(CrxAl1-x)2

ZrAl2<1660

hP12

P63/mmc

MgZn2

a = 519

c = 848

a = 528.24

c = 874.82

0 x 0.8 [1970Mar]

at 33 at.% Cr; 80 h at 700°C [1964Ram]

[V-C]

Zr2Al3<1590

oF40

Fdd2

Zr2Al3

a = 960.1 ± 0.2

b = 1390.6 ± 0.2

c = 557.4 ± 0.2

[2003Sch]

ZrAl

< 1275±25

oC8

Cmcm

CrB

a = 335.9 ± 0.1

b = 1088.7 ± 0.3

c = 427.4 ± 0.1

[2003Sch]

Zr5Al4(h)

1550-~1000

hP18

P63/mcm

Ti5Ga4

a = 844.8

c = 580.5

[2003Sch]

Zr4Al3<~1030

hP7

P6/mmm

Zr4Al3

a = 543.3 ± 0.2

c = 539.0 ± 0.2

[12003Sch]

Zr3Al2<1480

tP20

P42/mnm

Zr4Al3

a = 763.0(1)

c = 699.8(1)

[2003Sch]

Zr5Al3(h)

<1400

tI32

I4/mcm

W5Si3

a = 1104.4

c = 539.1

[2003Sch]

Zr5Al3(r?) hP16

P63/mcm

Mn5Si3

a = 817.4

c = 569.8

[2003Sch]

Zr2Al

<1350

hP6

P63/mmc

Ni2In

a = 489.39 ± 0.05

c = 592.83 ± 0.05

[2003Sch]

Zr3Al

<1019

cP4

Pm3m

Cu3Au

a = 437.2 ± 0.3 [2003Sch]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

428


MSIT®

Al–Cr–Zr

Zr(Al,Cr)3

metastable

cP4

Pm3m

AuCu3

a = 438.0

a = 465.2

in Al-Zr binary (metastable) [V-C2]

[1991Des], two-phase sample, no

composition of phase is given

ZrCr2

1677-1625

hP12

P63/mmc

MgZn2

a = 510.2

c = 828.9

a = 511.1

c = 834.1

C14 structure [1995Sou]

at 20°C [1997Kur]

at 300°C [1997Kur]

ZrCr2

1625-1546

hP24

P63/mmc

MgNi2

a = 510.0

c = 1661

C36 structure [1986Ari]

2, Zr(Cr1-xAlx)2

ZrCr2

< 1560

cF24

Fd3m

MgCu2 a = 721.8

a = 719.4

a = 720.4

0 x 0.1, 64 to 69 at.% Cr

[1970Mar], [1973Pet]

at 64 at.% Cr [1973Pet]

at 69 at.% Cr

C15 structure [1995Sau]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

Zr 10.00Cr 0.00Al 90.00

Zr 0.00Cr 10.00Al 90.00


Axes: at.%

1000

1100

1200

1250

Cr2Al11

CrAl4

p, 790

900

p, 940

950

CrAl7

p, 664 p, 661.5(Al)

ZrAl3

Fig. 1: Al-Cr-Zr.

Partial liquidus

projection

extrapolated from

binary data

429


MSIT®

Al–Cr–Zr

20

40

60

80

20 40 60 80

20

40

60

80

Zr Cr


Axes: at.%

L+ZrAl3+Cr2Al11

L

ZrAl3

Zr2Al3

Zr4Al3

Zr3Al2

Zr3Al

(αZr)

λ1

λ2

ζ2+λ1+Cr2Al

Cr2Al11

CrAl4

ε2

ζ2

Cr2Al

(αZr)+λ2+λ1

(αZr)+λ1+Zr3Al(Cr)

Zr2Al

ZrAl

ZrAl2

Fig. 2: Al-Cr-Zr.


800°C

Zr 1.00Cr 0.00Al 99.00

Zr 0.00Cr 1.00Al 99.00


Axes: at.%

(Al)

(Al)+ZrAl3

(Al)+ZrAl3+CrAl7

(Al)+CrAl7

Fig. 3: Al-Cr-Zr.


the Al-corner at

620°C

430


MSIT®

Al–Cr–Zr

Zr 2.00Cr 0.00Al 98.00

Zr 0.00Cr 2.00Al 98.00


Axes: at.%

1

2

3

1: equilibrium solubility at 640°C 1972Kad;2: metastable solubility at 20°C

3: metastable solubility at 20°C (cooling rate 10 K/s);

(cooling rate 100 K/s)

Fig. 4: Al-Cr-Zr.

Anomalous

solubility curves of

Cr and Zr in (Al)

10

10

90

Zr 14.00Cr 0.00Al 86.00

Zr 0.00Cr 14.00Al 86.00

Al Data / Grid: mass%

Axes: mass%

1

2

3

1: at cooling rate 1000 K/s;2: at cooling 106 K/s;3: at cooling rate 108 K/s.

Fig. 5: Al-Cr-Zr.

Limits of Cr and Zr

solubility in (Al) for

metastable alloys

431


MSIT®

Al–Cu–Dy

Aluminium – Copper – Dysprosium

Paola Riani, Laura Arrighi, Pierre Perrot

Literature Data

After the assessment previously carried out by [1991Ran] all the data have been reviewed by Riani et al.

[2003Ria], considering also the more recent literature data. [1989Kuz] studied the isothermal section at

500°C of the Al-Cu-Dy system by X-ray diffraction on 109 samples prepared from 99.5% Dy and purer Cu

and Al. The samples were then annealed at 500°C for 600 h and the solubility of the third component was

determined in some of the binary compounds. All other works on this system are devoted to ternary

compounds. The following compounds were found: DyCuAl [1968Dwi, 1973Oes], DyCuAl3 [1988Kuz],

DyCu4Al [1978Tak], DyCu4Al8 [1979Fel], DyCu6Al6 [1980Fel, 1981Fel], Dy2Cu7Al10 [1982Pre],

DyCu0.9Al2.1 [1992Kuz] and Dy3Cu2.6Al8.4 [2000Ste]. The alloys were prepared from 99.5 to 99.9% pure

Dy [1968Dwi, 1973Oes, 1978Tak, 1979Fel, 1980Fel, 1981Fel, 1982Pre] and Cu and Al of higher purity,

either by arc melting or in an induction furnace under inert protective atmosphere.

A high pressure modification of the compound DyCuAl and its structure are reported by [1987Tsv1] and

[1987Tsv2]. Samples made from 99.9% pure metals were either rapidly quenched from a melt at a constant

pressure of 7.7 GPa or annealed at 1450 to 1500°C. After vacuum annealing at 700°C for 6 h, this high

pressure modification was reported to decompose into the initial phases obtained at atmospheric pressure.

Binary Systems

In this ternary evaluation the edge binary system Al-Dy is accepted as reported by [2003Gry] and the Al-

Cu system as reported by [2003Gro] with changes being applied in the crystal structure data. The Cu-Dy is

used as published by [1988Sub, 1994Sub].

Solid Phases

[1989Kuz] confirmed the existence of the earlier reported ternary compounds 1,DyCu4Al8,

2,Dy2Cu7Al10, 3,Dy(Cu1-xAlx)5, 5,DyCuAl3 and 6,DyCuAl, and found two new ternary compounds,

4,Dy5Cu6Al9 and 7,Dy4Cu4Al11. The DyCu6Al6 compound reported by [1980Fel] identified to be the

1,DyCu4Al8 compound. Both, 1,DyCu4Al8 and DyCu6Al6 have the same structure (ThMn12 type) and

possibly belong to the same solid solution range, although the investigators did not mention this point. Two

of the ternary phases, 2 and 3, are reported to have a homogeneity range with constant Dy content:

2,Dy2(Cu1-xAlx)17 and 3,Dy(Cu1-xAlx)5. For 3 [1989Kuz] gives a homogeneity range with a maximum

Cu content at DyCu3.8Al1.2 which does not cover the composition DyCu4Al, for which [1978Tak] reported

the same crystal structure as was allocated to 3 by [1989Kuz]. [2000Ste] gave a slightly different

composition and structure for the 5,DyCuAl3 compound (BaAl4-type) previously proposed by [1988Kuz],

i.e. 5,Dy3Cu2.6Al8.4 and a La3Al11 type structure. The structure of the 4,Dy5Cu6Al9 compound is not

given. For the 4,DyCu0.9Al2.1 phase [1992Kuz] observed the hR36 structure of the PuNi3-type or NbBe3

type and assumed that it is identical with the Dy5Cu6Al9 compound identified in the earlier work

[1989Kuz]. It is isostructural with HoCuAl2 with some Al atoms substituting Cu. The 8,Dy6Cu16Al7 phase

has been identified as pertaining to the cubic Th6Mn23-type structure by [1990Ste]. Crystallographic data

for the ternary and binary phases are given in Table 1.

Isothermal Sections

The isothermal section at 500°C, studied by [1989Kuz], is used as base for Fig. 1. The Al rich part of the

[1989Kuz] diagram was later supported by the observations of [1997Sok] at 400°C, by the tie lines of Al-

1, DyAl3- 1 and DyAl3- 5. However, we brought some modifications to the original diagram to make it

consistent with the accepted binary diagrams: on the Al-Cu edge, the phase, unstable at 500°C is omitted;

on the Al-Dy edge [1989Kuz] indicated a compound Dy3Al, which is not a stable phase of the binary system

432


MSIT®

Al–Cu–Dy

but more probably stabilized by impurities, therefore it is omitted in Fig. 1. On the other hand, the Dy2Cu9

compound, whose stability is doubtful, was not observed by [1989Kuz]. The copper rich part of the diagram

has also been slightly modified for the sake of thermodynamic consistency. Seven ternary phases have been

identified and included. Three of them 4,Dy5Cu6Al9, 5,DyCuAl3 and 7,Dy4Cu4Al11 have been described

as point compounds. For the remaining phases, the following solubility ranges are accepted: 1,Dy(CuxAl1-

x)12 (0.33 < x < 0.37), 2,Dy2(CuxAl1-x)17 (0.394 x 0.588), 3,Dy(CuxAl1-x)5 (0.46 x 0.8) and

6,DyCu2-xAlx (0.95 x 1). The point phase given by [1989Kuz] as corresponding to the composition

5,DyCuAl3 was subsequently [2000Ste] described as 5,Dy3Cu2.6Al8.4 with the La3Al11 type structure.

The composition of the 5,DyCuAl3 phase is rather close to that of the 7,Dy4Cu4Al11 (or 7,DyCuAl2.75)

and the crystal structure of 7, is unknown. However, we did not consider these two phases as belonging to

the same solid solution because the general trend in the Al-Cu-Dy system is the mutual exchange of Al and

Cu atoms on a same crystallographic site. The 8,Dy6Cu16Al7 phase described by [1990Ste] was not

observed when [1989Kuz] examined the equilibria at 500°C. Its position is shown in the Fig. 1, but no

reliable equilibrium lines can be drawn between 8 and the surrounding phases.


Much of the research effort done in the recent years on Rare Earth-Al-Cu compounds has been focused on

their magnetic behavior. Basic information is mainly obtained from magnetization curves at various

temperatures. The paramagnetic Curie temperature of the compound 6,DyCuAl compound, once

determined as 35 K by [1973Oes] was later estimated to be lower, at 25.9 K by [1998Jav] or 28 K by

[2001Hav].

[1979Fel] studied the magnetism and hyperfine interactions of 151Eu, 155Gd, 161Dy, 166Er and 170Yb in

RCu4Al8 and reported a Neel temperature of 19 K for the 1,DyCu4Al8 compound. [1981Fel] reported

3.9 K for 1,DyCu6Al6. [1998Jav] studied the magnetic properties of the RCuAl (R = Y, Ce to Sm, Gd to

Tm and Lu) intermetallic compounds measuring susceptibility, magnetization and specific heat and

observed a magnetic ordering at low temperatures in most of these materials: PrCuAl and NdCuAl showed

an antiferromagnetic behavior while in the heavy rare-earth compounds (R=Gd-Er) a ferromagnetic

coupling was found. Moreover [1999And] studied the magnetic anisotropy and the spontaneous

magnetostriction of DyCuAl by means of X-ray diffraction.

The interaction of H2 with RCuAl (R = Dy, Ho, Er) was studied by [1996Mit].

References

[1931Pre] Preston, G.D., “An X-ray Investigation of Some Copper-Aluminium Alloys”, Philos. Mag.,


[1968Dwi] Dwight, A.E., Müller, M.H. Conner Jr, R.A., Downey, J.W., Knott, H., “Ternary

Compounds with the Fe2P-Type Structure”, Trans. Met. Soc. AIME, 242, 2075-2080 (1968)


[1973Oes] Oesterreicher, H., “Structural and Magnetic Studies on Rare Earth Compounds RNiAl and

RCuAl”, J. Less-Common Met., 30, 225-236 (1973) (Crys. Structure, Experimental, 21)

[1978Tak] Takeshita, T., Malik, S.K., Wallace, W.E., “Crystal Structure of RCu4Ag and RCu4Al (R =

Rare Earth) Intermetallic Compounds”, J. Solid State Chem., 23, 225-229 (1978) (Crys.


[1979Fel] Felner, I., Nowik, I., “Magnetism and Hyperfine Interactions of 57Fe, 151Eu, 155Gd, 161Dy,166Er and 170Yb in RM4Al8 Compounds (R=Rare Earth or Y, M=Cr, Mn, Fe, Cu)”, J. Phys.

Chem. Solids, 40, 1035-1044 (1979) (Crys. Structure, Experimental, 8)

[1980Fel] Felner, I., “Crystal Structure of Ternary Rare Earth - 3d Transition Metal Compounds of the

RT6Al6 Type”, J. Less-Common Met., 72, 241-249 (1980) (Crys. Structure, Experimental,

10)

[1981Fel] Felner, I., Seh, M., Rakavy, M., Nowik, I., “Magnetic Order and Hyperfine Interactions in

RFe6Al6 (R = Rare Earth)”, J. Phys. Chem. Solids, 42, 369-377 (1981) (Crys. Structure,

Experimental, 6)

433


MSIT®

Al–Cu–Dy

[1982Pre] Prevarskiy, A.P., Kuz'ma, Yu.B., “New Compounds with Th2Sn17 Type Structure in REM-

Al-Cu Systems”, Russ. Metall., 6, 155-156 (1982) (Crys. Structure, Experimental, 5)

[1987Tsv1] Tsvyashchenko, A.V., Fomicheva, L.N., “High-Pressure Synthesis and Structural Studies of

Rare Earth (R) Compounds RCuAl”, J. Less-Common Met., 134, L13-L15 (1987) (Crys.


[1987Tsv2] Tsvyashchenko, A.V., Fomicheva, L.N., “New Polymorphic Modifications of the

Compounds RTAl (R = Rare Earth, T = Cu, Ni)”, Inorg. Mater., 23, 1024-1027 (1987),

translated from Izv. Akad. Nauk SSSR, Neorg. Mater., 23, 1148-1152 (1987) (Crys.


[1988Gsc] Gschneidner Jr, K.A., Calderwood, F.W., “The Al-Dy (Aluminum-Dysprosium) System”,

Bull. Alloy Phase Diagrams, 9, 673-675 (1988) (Equi. Diagram, Review, #, 29)

[1988Kuz] Kuz'ma, Yu.B., Stel'makhovich, B.M., “New RCuAl3 Compounds (R = Tb, Dy, Ho, Er, Tm,

Yb) and Their Crystal Structure" (in Russian), Dokl. Akad. Nauk Ukr. SSR, Ser. B: Geol.

Khim. Biol. Nauki, (11), 40-43 (1988) (Crys. Structure, Experimental, 4)

[1988Sub] Subramanian, P.R., Laughlin, D.E., “The Cu-Dy (Copper-Dysprosium) System”, Bull.


[1989Kuz] Kuz'ma, Yu.B., Milyan, V.V., “Phase Equilibria in the System Dy-Cu-Al at 500°C”, Russ.

Metall., (1), 216-218 (1989), translated from Izv. Akad. Nauk SSSR Metally, (1), 211-213

(1989) (Crys. Structure, Equi. Diagram, Experimental, *, #, 8)

[1989Mee] Meetsma, A., De Boer, J.L., Van Smaalen, S., “Refinement of the Crystal Structure of

Tetragonal Al2Cu”, J. Solid State Chem., 83(2), 370-72 (1989) (Crys. Structure,

Experimental, 17)

[1990Ste] Stel’makhovych, B.M., Kuz’ma, Yu.B., “ New Compounds Ln6(Cu,Al)23 and their Crystal

Structure”, Dopov. Akad. Nauk. URSR, 6, 60 (1990) (Crys. Structure, 4)

[1991Ran] Ran, Q., “Aluminium - Copper - Dysprosium”, MSIT Ternary Evaluation Program, in MSIT



Assessment, 13)

[1992Kuz] Kuz’ma, Yu.B., Stel’makhovych, B.M., Babizhetsky, V.S., “New Compounds with PuNi3-

Type Structure in REM-Cu-Al Systems”, Russ. Metall., (1), 196-199 (1992), translated

from Izv. Ross. Akad. Nauk Metally, (2), 227-230 (1992) (Experimental, Crys. Structure, 7)

[1994Mur] Murray, J.L., “Al-Cu (Aluminum-Copper)”, Phase Diagrams of Binary Copper Alloys,

Subramanian, P.R., Chakrabarti, D.T., Laughlin, D.E. (Eds.), ASM International, Materials

Park, OH, pp. 18-42 (1994) (Equi. Diagram, Review, 226)

[1994Sub] Subramanian, P.R., Laughlin, D.E., “Cu-Dy (Copper-Dysprosium)”, in Monograph Series

on Alloy Phase Diagrams - Phase Diagrams of Binary Copper Alloys, Subramanian, P.R.,

Chakrabati, D.T., Laughlin, D.E. (Eds.), ASM International, Materials Park, OH, 10, 154-

157 (1994) (Equi. Diagram, Review, 23)

[1996Goe] Gödecke, T., Sommer, F., “Solidification Behaviour of the Al2Cu Phase”, Z. Metallkd.,

87(7), 581-586 (1996) (Equi. Diagram, Crys. Structure, 8)

[1996Mit] Mitrokhin, S.V., Shlychkov, A.P., Verbetskii, V.N., “Interaction of Hydrogen with RCuAl

Compounds of Dysprodium, Holmium and Erbium”, Vest. Moskov. Univ. Ser. 2 Khim.,

37(3), 294-297 (1996) (Experimental)

[1997Sok] Sokolovskaya, E.M., Kazakova, E.F., Loboda, T.P., “Formation and Interaction of Phases

in Multicomponent Metallic Systems of Aluminium Containing d and f Transition Metals”

(in Russian), Izv. Vyssh. Uchebn., Zaved., Tsvetn. Metall., (2), 45-51 (1997) (Equi. Diagram,


[1998Jav] Javorský, P., Havela, L., Sechovský, V., Michor, H., Jurek, K., “Magnetic Behaviour of

RCuAl Compounds”, J. Alloys Compd., 264, 38-42 (1998) (Experimental, Magn. Prop.,


434


MSIT®

Al–Cu–Dy


the Cu-Al Binary System”, J. Alloys Compd., 264, 201-208 (1998) (Equi. Diagram, Crys.

Structure, 25)

[1999And] Andreev, A.V., Javorsky, P.A., Lindbaum, A., “Magnetic Anisotropy and Spontaneous

Magnetostriction of RCuAl (R = Gd, Dy, Ho)”, J. Alloys Compd., 290, 10-16 (1999)

(Experimental, Magn. Prop., Crys. Structure, 15)

[2000Sac] Saccone, A., Cardinale, A.M., Delfino, S., Ferro, R., “Gd-Al and Dy-Al Systems: Phase

Equilibria in the 0 to 66.7 at.% Al Composition Range”, Z. Metallkd., 91(1), 17-23 (2000)

(Experimental, Equi. Diagram, Crys. Structure, #, 12)

[2000Ste] Stel’makhovych, B.M., Gumeniuk, R.V., Kuz’ma, Yu.B., “Compounds Dy3Ag2.3Al8.7,

Ho3Ag2.1Al8.9, Dy3Cu2.6Al8.4 and Ho3Cu2.4Al8.6 as New Representatives of the La3Al11-

type Structure”, J. Alloys Compd., 307, 218-222, (2000) (Experimental, Crys. Structure, 11)

[2001Hav] Havela, L., Divis, M., Sechovsky, V., Andreev, A.V., Honda, F., Oomi, G., Meresse, Y.,

Heathman, S., “U Ternaries with ZrNiAl Structure – Lattice Properties”, J. Alloys Compd.,

322, 7-13 (2001) (Crys. Structure, Magn. Prop., 18)




[2003Gro] Groebner, J., “Al-Cu (Aluminium - Copper)”, MSIT Binary Evaluation Program, in MSIT



[2003Gry] Grytsiv, A., “Al-Dy (Aluminium - Dysprosium)”, MSIT Binary Evaluation Program, in


GmbH, Stuttgart; Document ID 20.20073.1.20 (2003) (Equi. Diagram, Assessment, #, 8)

[2003Ria] Riani, P., Arrighi, L., Marazza, R., Mazzone, D., Zanicchi, G., Ferro, R., “Ternary Rare

Earth Aluminium Systems with Copper: a Review and a Contribution to their Assessment”,

submitted for publication J. Phase Equilib., submitted for publication (2003) (Review,

Assessment, 267)


Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

(Al)

<660

cF4

Fm3m

Cu

a = 404.96 pure Al at 25°C [Mas2]

Cu solubility 2.48 at.% [Mas2]

Negligible solid solubility of Dy

[1988Gsc]

(Cu)

< 1084.62

Cu1-xAlx

cF4

Fm3m

Cu

a = 361.46

a = 361.52

a = 365.36

pure Cu at 25°C [Mas2],

0 to 19.7 at.% Al [Mas2]

negligible solid solubility of Dy

[1994Sub]

[2003Gro], x = 0, quenched from 600°C

[2003Gro], x = 0.152, quenched from

600°C

( Dy)

1412-1381

cI2

Im3m

W

a = 398.0 [Mas2]

dissolves up to ~12 at.% Cu at 800°C

[1994Sub]

dissolves up to ~3 at.% Al at 1300°C

[1988Gsc]

435


MSIT®

Al–Cu–Dy

( Dy)

< 1381

hP2

P63/mmc

Mg

a = 359.15

c = 565.01

[Mas2]

dissolves up to 1 at.% Al at 1300°C

[1988Gsc]

, Cu3Al(h)

1049-559

cI2

Im3m

W

a = 294.6

a = 295.64

~70 to 82 at.% Cu [1994Mur], [1998Liu]

at 580°C

at 672°C in two-phase (Cu)+ alloy

2, Cu100-xAlx< 363

t**

TiAl3Long period

super-lattice

a = 366.8

c = 368.0

22 x 23.5 [1994Mur]

76.5 to 78.0 at.% Cu

at 76.4 at.% Cu (subcell only)

0, Cu100-xAlx Cu∼2Al

1037-800

cI52

I43m

Cu5Zn8

31.5 x 40.2 [Mas2],

32.0 x 38.0 [1998Liu]

1, Cu9Al4< 890

cP52

P43m

Cu9Al4 a = 870.23

62 to 68 at.% Cu [Mas2, 1998Liu]

From single crystal [V-C2] at 68 at.% Cu

, Cu100-xAlx< 686

hR*

R3m

38.1 x 40.7 [1994Mur]

59.3 to 61.9 at.% Cu

at x = 38.9 [V-C2]

1, Cu100-xAlx958-848

Cubic? 40.6 x 37.9

59.4 to 62.1 at.% Cu [Mas2, 1994Mur]

2, Cu2-xAl

850-560

hP6

P63/mmc

Ni2In

a = 414.6

c = 506.3

0.78 x 0.45

55 to 61 at.% Cu [Mas, 1994Mur, V-C2],

NiAs type in [Mas2, 1994Mur]

1, Cu47.8Al35.5 (h)

590-530

oF88 - 4.7

Fmm2

Cu47.8Al35.5

a = 812

b = 1419.85

c = 999.28

55 to 57 at.% Cu [Mas2, 1994Mur]


2, Cu11.5Al9(r)

< 570

oI24 - 3.5

Imm2

Cu11.5Al9

a = 409.72

b = 713.13

c = 997.93

55.2 to 56.3 at.% Cu

[V-C, Mas2, 2003Gro]


1, CuAl(h)

624-560

o*32 a = 408.7

b = 1200

c = 863.5

49.8 to 52.4 at.% Cu

[V-C, Mas2, 1994Mur]


2, CuAl(r)

< 560

mC20

C2/m

CuAl

a = 1206.6

b = 410.5

c = 691.3

= 55.04°

49.8 to 52.3 at.% Cu [V-C2]

, CuAl2< 591

tI12

I4/mcm

CuAl2 a = 606.7

c = 487.7

32.05 to 32.6 at.% Cu at 549°C

32.4 to 32.8 at.% Cu at 250°C [1996Goe]


Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

436


MSIT®

Al–Cu–Dy

DyCu1-xAlx

DyCu

< 955

cP2

Pm3m

CsCl

a = 357

a = 344 to 346

0 x 0.6

x = 0.6 [1989Kuz]

[1994Sub]

DyCu2

< 890

oI12

Imma

CeCu2

a = 430

b = 680

c = 729

[1994Sub]

Al solubility ~3 at.% [1989Kuz]

Dy2Cu7

~905 - ~855

? [1994Sub]

Dy2Cu9

< 970

t** a = 499.9

c = 1394

[1994Sub]. The existence of this phase

was questioned by [1994Sub] and can

not be confirmed by ternary data

, DyCu5

965 - 930

hP6

P6/mmm

CaCu5

a = 502

c = 408

Lattice parameters interpolated from the

systematics of crystal data of RE-Cu

alloys [1994Sub]

Dy(AlxCu1-x)5

< 930

DyCu5

cF24

F43m

AuBe5 a = 702.5

0 x 0.012 from figure in [1989Kuz]

[1994Sub]

DyCu7

~860 - ~775

hP8

TbCu7

Closely related to

hP6 - CaCu5

a = 493.2

c = 415.6

[1994Sub]

DyAl31090-1005

hR60

R3m

HoAl3

a = 607.0

c = 3594

[1988Gsc]

DyAl3< 1005

hP16

P63/mmc

TiNi3

a = 609.1

c = 953.3

[1988Gsc]

DyCuxAl2-x

DyAl2< 1500

cF24

Fd3m

MgCu2

a = 778

a = 783.6

0 x 0.32

at x = 0.32 [1989Kuz]

at x = 0 [1988Gsc], [2000Sac]

DyAl

< 1100

oP16

Pbcm

ErAl

a = 582.2

b = 1137 to 1134

c = 560 to 559

[1988Gsc], [2000Sac]

Dy3Al2< 1025

tP20

P42/mnm

Zr3Al2

a = 817 to 820

c = 754 to 755

[1988Gsc], [2000Sac]

Dy2Al

< 990

oP12

Pnma

Co2Si

a = 654 to 653

b = 508

c = 940 to 938

[1988Gsc] [2000Sac]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

437


MSIT®

Al–Cu–Dy

1, Dy(CuxAl1-x)12

DyCu4Al8

DyCu6Al6

tI26

I4/mmm

ThMn12

a = 872.5

c = 513.7

a = 869.0

c = 506.2

a = 866.2

c = 504.2

0.33 x 0.50 at 800°C [1980Fel]

0.33 x 0.37 at 500°C (x range

estimated from figure in [1989Kuz])

at x = 0.33, as cast sample [1979Fel]

at x = 0.33, 500°C [1989Kuz]

at x = 0.5, 800°C [1980Fel]

2, Dy2(CuxAl1-x)17 hR57

R3m

Th2Zn17

a = 881.2

c =1284.4

a = 871.6

c =1273.5

0.394 x 0.588 [1989Kuz]

at x = 0.394 [1989Kuz]

at x = 0.588 [1982Pre]

3, Dy(CuxAl1-x)5 hP6

P6/mmm

CaCu5

a = 506.4

c = 415.2

a = 520

c = 408

0.46 x 0.8 [1989Kuz]

at x = 0.8 [1978Tak]

at x = 0.46 [1989Kuz]

4, DyCu0.9Al2.1 hR36

R3m

PuNi3

a = 545.7

c = 2531.7

[1992Kuz]

Previously reported as Dy5Cu6Al9[1989Kuz]

5, DyCuAl3 oI10

Immm

HoCuAl3

oI12

Immm

La3Al11

a = 420.5

b = 414.3

c = 981.3

a = 421.25

b = 1243.2

c = 982.67

[1988Kuz, 1997Sok]

Melting point higher than 1550°C

[1989Kuz]

[2000Ste] for 5-Dy3Cu2.6Al8.4

This cell possibly is a superstructure of

that described above (3b)

6, DyCu2-xAlx hP9

P62m

ZrNiAl

a = 701.5

c = 402.4

a = 702.29

c = 402.49

0.95 x 1 (from figure in [1989Kuz])

[1999And, 2001Hav] at 25°C

[1968Dwi] (hP9 type Fe2P)

7, Dy4Cu4Al11 [1989Kuz]

8, Dy6Cu16Al7 cF116

Fm3m

Th6Mn23

a = 1227.5 [1990Ste]

not observed by [1989Kuz] in the

investigation of the isothermal section

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

438


MSIT®

Al–Cu–Dy

20

40

60

80

20 40 60 80

20

40

60

80

Dy Cu


Axes: at.%

θ,CuAl2

η2,CuAl

α,DyAl3

DyAl2

DyAl

Dy3Al2

Dy2Al

ζ2

δγ1τ6

τ8

τ3

τ2

τ1

τ5

τ7

τ4

DyCu DyCu 2α,DyCu5

(Dy)(Cu)

(Al)Fig. 1: Al-Cu-Dy.


500°C

439


MSIT®

Al–Cu–Er

Aluminium – Copper – Erbium

Paola Riani, Laura Arrighi, Pierre Perrot

Literature Data

A critical review of the literature data up to 1989 has been made by [1991Ran] and later literature considered

in a general review of the crystallochemical and phase equilibria of the R-Cu-Al systems (R =

rare-earth) by [2003Ria]. Different compounds have been identified and their crystal structures determined:

(1) ErCuAl by [1968Dwi, 1973Oes, 1989Kuz], with a high pressure modification reported by [1987Tsv1,

1987Tsv2], (2) ErCuAl3 by [1988Kuz, 1989Kuz], (3) ErCu4Al by [1978Tak], (4) Er2Cu7Al10 by [1982Pre,

1989Kuz], (5) ErCu4Al8 by [1976Bus, 1979Fel, 1989Kuz], (6) ErCu6Al6 by [1980Fel, 1981Fel] and (7)

ErCu0.9Al2.1 reported by [1992Kuz].

The alloys generally were prepared from 99.5% to 99.9 mass% Er and higher purity Cu and Al. They were

melted either by arc melting or under argon protection in induction furnaces using MgO crucibles; followed

by homogenization heat treatments. [1989Kuz] studied the phase equilibria at 600°C by X-ray powder

analysis on 107 samples and reported trends in the lattice parameters for a number of solid solutions.

[1974Oes] studied the homogeneity ranges of Er(Cu1–xAlx)2 and Er(CuxAl1–x)2 and determined the limits

of solubility by the appearance of X-ray diffraction lines characterizing a new phase. The results reveal that

copper in ErCu2 can be replaced by up to about 1.5 mole% aluminium and that in ErAl2 up to about 15

mole% aluminium can be replaced by copper.

Binary Systems

The reported ternary experimental data are limited and can be summarized in the isothermal section at

600°C, which is consistent in its binary boundaries with (a) the Al-Er phase diagram by [1988Gsc], the

Al-Cu phase diagram by [2003Gro] and Er-Cu as reported by [1994Sub]. Amendments have been made to

the reported crystal structure data based on [2003Ria].

Solid Phases

According to [1980Fel] the ThMn12 type structure is observed for RCu4Al8 and RCu6Al6, where R = rare

earth from Gd to Lu and Y. From the literature it is not always explicit whether the two compositions 1:4:8

and 1:6:6 correspond to two different phases or whether they are the limits of a solid solution range.

[1989Kuz] found 1,ErCu4Al8 to be stoichiometric and did not confirm the existence of 1,ErCu6Al6.

However, on the basis of [1980Fel], we considered the 1,Er(CuxAl1-x)12 as non stoichiometric with 0.33

x 0.5. Obviously its range changes with the temperature, as [1980Fel] and [1989Kuz] observed it at

different compositions at different temperatures, see Table 1. The existence of a homogeneity range for the

compounds R(CuxAl1-x)12, where R is a rare earth, was recently suspected by the same team for R = Y

[2003Kra] and confirmed for R = Sc [2003Kan].

The crystal structure of the RCu4Al phases (R = La to Sm and Gd to Tm) has been studied by [1978Tak];

this composition is included by [1989Kuz] in the homogeneity range of the phase 3,Er(CuxAl1-x)5 with

0.46 x 0.82.

Subsequently [1992Kuz] determined the crystal structure of the 4,ErCu0.9Al2.1 phase as pertaining to the

PuNi3 type (hR36).

Crystallographic data for all solid phases are given in Table 1.

Isothermal Sections

Figure 1, an isothermal section at 600°C is based on the work of [1989Kuz], corrected at the Al-Cu

boundary to be in agreement with the accepted binary diagram. At the Cu-Er edge of the ternary isothermal

section, however, the two compounds Er2Cu7 and Er2Cu9 are omitted, although they are reported in the

accepted binary, as they were not observed at this temperature in the ternary alloys by [1989Kuz]. These

440


MSIT®

Al–Cu–Er

two compounds, designated Er2Cu7 and Er2Cu9 by [1994Sub] have been designated as ErCux and ErCuy by

[1970Bus], who assumes that ErCux forms peritecticaly at 940°C, that ErCuy melts congruently at 1010°C.

By lack of data in the Cu-Er system these assumptions are based on the melting behavior of other similar

rare earth-copper compounds.

Inside the ternary system there are four ternary solid solutions: (1) 1,Er(CuxAl1-x)12 (ThMn12 type), which

is shown as a stoichimetric phase at this temperature according to [1989Kuz], (2) 2, Er2(CuxAl1-x)17 with

Th2Zn17 type structure and a solution range of 0.41 x 0.56, (3), 3, Er(CuxAl1-x)5 in a range of

0.46 x 0.82 and with a CaCu5 type structure and (4) the 6, ErCuAl with a small solubility range and

ZrNiAl type structure.

Three stoichiometric compounds have been found. (I) Er5Cu6Al9 (PuNi3 type) for which [1992Kuz]

suggested that it assimilates with ErCu0.9Al2.1( 4) (PuNi3 type) in samples annealed at 600°C, (II) the

5,ErCuAl3 being of HoCuAl3 type structure and (II) the 7,Er2Cu3Al5 whose structure is unknown. At

600°C ErCu2 dissolves up to ~1 at.% aluminium, ErCu dissolves up to ~20 at.% aluminium and ErAl2 up

to about 13 at.% copper. The 8,Er6Cu16Al7 (Th6Mn23 type) identified by [1990Ste] has not been observed

at 600°C by [1989Kuz]. Its position in the phase diagram is shown in Fig. 1, but it is not possible to draw

reliable equilibrium lines between 8 and its surrounding phases.


[1979Fel] studied the magnetism and hyperfine interactions of 151Eu, 155Gd, 161Dy, 166Er and 170Yb in

RCu4Al8 and [1995Cac] reported neutron spectroscopy studies of crystal-field interaction in RT4Al8compounds (R = Tb, Ho, Er; T = Mn, Fe, Cu).

[1973Oes] measured the Curie temperature of the ErCuAl compound as 17 K. [1996Jav] found that ErCuAl

orders ferromagnetically below Tc= 6.8 K with the magnetic moments parallel to the c-axis, a behavior

which [1998Jav] confirmed later by measuring susceptibility, magnetization and specific heat.

[1996Mit] studied the interaction of H2 with RCuAl (R = Dy, Ho, Er).

For the ErCu4Al8 compound, a type 1 antiferromagnetic structure is observed by neutron powder diffraction

in [1997Bai].

References



[1968Dwi] Dwight, A.E., Mueller, M.H., Conner, R.A., JR., Downey, J.W., Knott, H., “Ternary

Compounds with the Fe2P-Type Structure”, Trans. Met. Soc. AIME, 242, 2075-2080 (1968)


[1970Bus] Buschow, K.H.J., “The Erbium-Copper System”, Philips J. Res., 25, 227-230 (1970) (Equi.

Diagram)

[1973Oes] Oesterreicher, H., “Structural and Magnetic Studies on Rare Earth Compounds RNiAl and

RCuAl”, J. Less-Common Met., 30, 225-236 (1973) (Crys. Structure, Magn. Prop.,

Experimental, 21)

[1974Oes] Oesterreicher, H., “Constitution of Aluminum Base Rare Earth Alloys RT2-RAl2 (R = Pr,

Gd, Er; T = Mn, Fe, Co, Ni, Cu)”, Inorg. Chem., 13, 2807-2811 (1974) (Equi. Diagram,


[1976Bus] Buschow, K.H.J., van Vucht, J.H.N., van Den Hoogenhof, W.W., “Note on the Crystal

Structure of the Ternary Rare Earth - 3d Transition Metal Compounds of the Type RT4Al8”,

J. Less-Common Met., 50, 145-150 (1976) (Crys. Structure, Experimental, 2)

[1978Tak] Takeshita, T., Malik, S.K., Wallace, W.E., “Crystal Structure of RCu4Ag and RCu4Al (R =

Rare Earth) Intermetallic Compounds”, J. Solid State Chem., 23, 225-229 (1978) (Crys.


[1979Fel] Felner, I., Nowik, I., “Magnetism and Hyperfine Interactions of 57Fe, 151Eu, 155Gd, 161Dy,166Er and 170Yb in RM4Al8 Compounds (R=Rare Earth or Y, M=Cr, Mn, Fe, Cu)”, J. Phys.

Chem. Solids, 40, 1035-1044 (1979) (Crys. Structure, Magn. Prop., Experimental, 8)

441


MSIT®

Al–Cu–Er

[1980Fel] Felner, I., “Crystal Structure of Ternary Rare Earth - 3d Transition Metal Compounds of the

RT6Al6 Type”, J. Less-Common Met., 72, 241-249 (1980) (Crys. Structure, Experimental,

10)

[1981Fel] Felner, I., Seh, M., Rakavy, M., Nowik, I., “Magnetic Order and Hyperfine Interactions in

RFe6Al6 (R = Rare Earth)”, J. Phys. Chem. Solids, 42, 369-377 (1981) (Crys. Structure,


[1982Pre] Prevarsky, A.P., and Kuz'ma, Yu.B., “New Compounds with Th2Sn17 Type Structure in

REM-Al-Cu Systems”, Russ. Metall., 6, 155-156 (1982) (Crys. Structure, Experimental, 5)

[1985Mur] Murray, J.L., “The Aluminum-Copper System”, Int. Met. Rev., 30(5), 211-233 (1985)

(Equi. Diagram, Crys. Structure, Review, 230)

[1987Tsv1] Tsvyashchenko, A.V., Fomicheva, L.N., “High Pressure Synthesis and Structural Studies of

Rare Earth (R) Compounds RCuAl”, J. Less-Common Met., 134, L13-L15 (1987) (Crys.


[1987Tsv2] Tsvyashchenko, A.V., Fomicheva, L.N., “New Polymorphic Modifications of the

Compounds RTAl (R = r.e.m., T = Cu, Ni)”, Inorg. Mater., 23, 1024-1027 (1987), translated

from Izv. Akad. Nauk SSSR, Neorg. Mater., 23, 1148-1152 (1987) (Crys. Structure,

Experimental, 15

[1988Gsc] Gschneidner Jr, K.A., Calderwood, F.W., “The Al-Er (Aluminum-Erbium) System”, Bull.


[1988Kuz] Kuz'ma, Yu.B., Stel'makhovich, B.M., “New RCuAl3 Compounds (R = Tb, Dy, Ho, Er, Tm,

Yb) and Their Crystal Structure” (in Russian), Dokl. Akad. Nauk Ukr. SSR, B: Geol. Khim.

Biol., (11), 40-43 (1988) (Crys. Structure, Experimental, 4)

[1988Sub] Subramanian, P.R., Laughlin, D.E., “The Cu-Er (Copper-Erbium) System”, Bull. Alloy

Phase Diagrams, 9, 337-342 (1988) (Equi. Diagram, Review, 17)

[1989Kuz] Kuz'ma, Yu.B., Pan'kiv, T.V., “X-Ray Structural Study of the Er-Cu-Al System”, Russ.

Metall., (3), 208-210 (1989), translated from Izv. Akad. Nauk SSSR Met., (3), 218-219

(1989) (Equi. Diagram, Crys. Structure, Experimental, 5)

[1989Mee] Meetsma, A., De Boer, J.L., van Smaalen, S., “Refinement of the Crystal Structure of

Tetragonal Al2Cu”, J. Solid State Chem., 83(2), 370-372 (1989) (Crys. Structure,

Experimental, 17)

[1990Ste] Stel’makhovych, B.M., Kuz’ma, Y.B., “New Compounds La6(CuAl)23 and their Crystal

Structure”, Dopov. Akad. Nauk. URSR, (6), 63-65 (1990) (Crys. Structure, Experimental, 4)

[1991Ell] Ellner, M., Kolatschek, K., Predel, B., “On the Partial Atomic Volume and the Partial Molar

Enthalpy of Aluminium in Some Phases with Cu and Cu3Au Structures”, J. Less-Common


[1991Ran] Ran, Q., “Aluminium-Copper-Erbium”, MSIT Ternary Evaluation Program, in MSIT


Stuttgart; Document ID: 10.12785.1.20, (1991) (Crys. Structure, Equi. Diagram.,

Assessment, 13)

[1992Kuz] Kuz’ma, Y.B., Stel’makhovych, B.M., Babizhetsky, V.S., “New Compounds with

PuNi3-Type Structure in REM-Cu-Al Systems”, Russ. Metall., 1, 196-199 (1992),

translated from Izv. Ross. Akad. Nauk Metally, (2), 227-230, 1992 (Experimental, Crys.

Structure, 7)

[1994Mur] Murray, J.L., “Al-Cu (Aluminum-Copper)” in “Phase Diagrams of Binary Copper Alloys”,

Subramanian, P.R., Chakrabarti, D.T., Laughlin, D.E. (Eds.), ASM Intl., Materials Park,

OH, 18-42 1994 (Equi. Diagram, Review, 226)

[1994Sub] Subramanian, P.R., Laughlin, D.E., “Cu-Dy (Copper-Dysprosium)” in “Monograph Series

on Alloy Phase Diagrams - Phase Diagrams of Binary Copper Alloys”, Subramanian, P.R.,

Chakrabarti, D.T., Laughlin, D.E. (Eds.), ASM Intl., Vol. 10, 154-157 (1994) (Equi.


442


MSIT®

Al–Cu–Er

[1995Cac] Caciuffo, R., Amoretti, G., Buschow, K.H.J., Moze, O., Murani, A.P., Paci B., “Neutron

Spectroscopy Studies of the Crystal-Field Interaction in RET4Al8 Compounds (RE = Tb,

Ho or Er; T = Mn, Fe, or Cu)”, J. Phys.: Condens. Matter, 7, 7981-7989 (1995)


[1996Goe] Gödecke, T., Sommer, F., “Solidification Behaviour of the Al2Cu Phase”, Z. Metallkd.,

87(7), 581-586 (1996) (Equi. Diagram, Crys. Structure, 8)

[1996Jav] Javorský, P., Burlet, P., Ressouche, E., Sechovský, V., Michor, H., Lapertot, G., “Magnetic

Structure Study of ErCuAl and ErNiAl”, Physica B, 225, 230-236 (1996) (Magn. Prop.,

Experimental, 16)

[1996Mit] Mitrokhin, S.V., Shlychkov, A.P., Verbetskii, V.N., “Interaction of Hydrogen with RCuAl

Compounds of Dysprodium, Holmium and Erbium”, Vest. Moskov. Univ. Ser. 2 Khim.,

37(3), 294-297 (1996) (Experimental)

[1997Bai] Baio, G., Moze, O., Amoretti, G., Sonntag, R., Stüßer, N., Bschow, K.H.J., “Neutron

Diffraction Study of RMn4Al8 (R=Nd, Dy, Ho, Er), ErCr4Al8 and ErCu4Al8”, Z. Phys. B,

102, 449-459 (1997) (Crys. Structure, Experimental, Magn. Prop., 20)

[1998Jav] Javorský, P., Havela, L., Sechovský, V., Michor, H., Jurek, K., “Magnetic Behaviour of

RCuAl Compounds”, J. Alloys Compd., 264, 38-42 (1998) (Experimental, Magn. Prop.,



the Cu-Al Binary System”, J. Alloys Compd., 264(1-2), 201-208 (1998) (Equi. Diagram,



System”, Abstr. VIII Int. Conf. ”Crystal Chemistry of Intermetallic Compounds”,




Stuttgart, to be published, (2003) (Equi. Diagram, Review, Assessment, 68)

[2003Kan] Kang, Y.M., Chen, N.X., “Site Preference and Vibrationnal Properties of ScCuxAl12–x”, J.

Alloys Compd., 349, 41-48 (2003) (Crys. Structure, Experimental, Thermodyn., 29)

[2003Kra] Krachan, T., Stel’makhovych, B., Kuz’ma, Yu., “The Y-Cu-Al System”, J. Alloys Compd.,

349, 134-139 (2003) (Equi. Diagram, Crys. Structure, #, 25)

[2003Ria] Riani, P., Arrighi, L., Marazza, R., Mazzone, D., Zanicchi, G., Ferro, R., “Ternary Rare

Earth Aluminum Systems with Copper: a Review and a Contribution to Their Assessment”

submitted to J. Phase Equilib. (Review, 267)


Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

(Al)

<660.45

cF4

Fm3m

Cu

a = 404.96 at 25°C [Mas2]

Cu solubility 2.48 at.% [Mas2]

no appreciable solubility of Er [1988Gsc]

(Cu)

< 1084.62

Cu1-xAlx

cF4

Fm3m

Cu

a = 361.46

a = 361.52

a = 365.36

at 25°C [Mas2],

0 to 19.7 at.% Al [Mas2]

no appreciable solubility of Er [1994Sub]

[1991Ell], x = 0, quenched from 600°C

[1991Ell], x = 0.152, quenched from

600°C

443


MSIT®

Al–Cu–Er

(Er)

<1529

hP2

P63/mmc

Mg

a = 355.92

c = 558.50

pure Er at 25°C [1994Sub]

solubility: < 1 at.% Al, [1988Gsc]

<0.5 at.% Cu [1994Sub]

, Cu3Al(h)

1049-559

cI2

Im3m

W

a = 294.6

a = 295.64

~70 to 82 at.% Cu [1985Mur],

[1998Liu] at 580°C

at 672°C in two-phase (Cu)+ alloy

2, Cu100-xAlx< 363

t**

TiAl3long period

super-lattice

a = 366.8

c = 368.0

22 x 23.5 [1985Mur]

76.5 to 78.0 at.% Cu

at 76.4 at.% Cu

(subcell only)

0, Cu100-xAlxCu∼2Al

1037-800

cI52

I43m

Cu5Zn8

31.5 x 37 [Mas2],

32 x 38 [1998Liu]

1, Cu9Al4< 890

cP52

P43m

Cu9Al4

a = 870.23

62 to 68 at.% Cu [Mas2, 1998Liu];

from single crystal [V-C2] at 68 at.% Cu

, Cu100-xAlx< 686

hR*

R3m

a = 1226

c = 1511

38.1 x 40.7 [1985Mur]

59.3 to 61.9 at.% Cu

at x = 38.9 [V-C2]

1, Cu100-xAlx958-848

cubic? 37.9 x 40.6

59.4 to 62.1 at.% Cu [Mas2, 1985Mur]

2, Cu2-xAl

850-560

hP6-x

P63/mmc

Ni2In

a = 414.6

c = 506.3

0.47 x 0.78

55 to 61 at.% Cu [Mas, 1985Mur, V-C2],

NiAs in [Mas2, 1994Mur]

1, Cu47.8Al35.5(h)

590-530

oF88 - 4.7

Fmm2

Cu47.8Al35.5

a = 812

b = 1419.85

c = 999.28

55.2 to 57 at.% Cu [Mas2, 2003Gro]


2, Cu11.5Al9(r)

< 570

oI24 - 3.5

Imm2

Cu11.5Al9

a = 409.72

b = 703.13

c = 997.93

55.2 to 56.3 at.% Cu [Mas2, 1985Mur]


1, CuAl(h)

624-560

o*32 a = 408.7

b = 1200

c = 863.5

49.8 to 52.4 at.% Cu

[V-C2, Mas2, 1985Mur]


2, CuAl(r)

< 560

mC20

C2/m

CuAl

a = 1206.6

b = 410.5

c = 691.3

= 55.04°

49.8 to 52.3 at.% Cu [V-C2]

, CuAl2< 591

tI12

I4/mcm

CuAl2 a = 606.7

c = 487.7

32.05 to 32.6 at.% Cu at 549°C

31.9 to 33 at.% Cu at 250°C [1996Goe]


Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

444


MSIT®

Al–Cu–Er

ErCu1-xAlxErCu

< 1065

cP2

Pm3m

CsCl

a = 343.1

a = 341.0

a = 347

at x = 0 [1994Sub]

0 x 0.4 at 600°C [1989Kuz]

at x = 0

at x = 0.4

Er(Cu1-xAlx)2

ErCu2

< 935

oI12

Imma

CeCu2

a = 427.4

b = 673.3

c = 726.6

0 x 0.015 (1 at.% Al) [1974Oes]

at x = 0, [1988Sub] [1994Sub]

Er2Cu7

< 940

? [1994Sub]

Er2Cu9

< 1010

? [1994Sub]

ErCu5

<1005

cF24

F43m

AuBe5

a = 700.3 [1994Sub]

at 600°C dissolves up to ~2 at.% Al

according to the figure in [1989Kuz]

ErAl3< 1070

cP4

Pm3m

AuCu3

a = 421.4 [1988Gsc]

ErAl2< 1455

ErCuxAl2-x

cF24

Fd3m

Cu2Mg a = 779.3

a = 773.7

0 x 0.38 (~19 at.% ErCu2) at 600°C

[1989Kuz]

at x = 0 [1988Gsc, 1989Kuz]

at x = 0.38 [1989Kuz]

ErAl

< 1140

oP16

Pbcm

ErAl

a = 580.1

b = 1127

c = 557.0

[1988Gsc]

Er3Al2< 1060

tP20

P42/mnm

Gd3Al2

a = 812.3

c = 748.4

[1988Gsc]

Er2Al

< 1040

oP12

Pnma

Co2Si

a = 651.6

b = 501.5

c = 927.9

[1988Gsc]

* 1, Er(CuxAl1-x)12

ErCu4Al8

ErCu6Al6

tI26

I4/mmm

ThMn12 a = 866.3

c = 510.5

a = 869.1

c = 511.9

a = 863.0

c = 502.9

0.33 x 0.5 (x range tentatively

assigned)

x = 0.33 at 600°C [1989Kuz]

at x = 0.33, as-cast sample [1979Fel]

at x = 0.5 at 800°C [1980Fel]

* 2, Er2(CuxAl1-x)17 hR57

R3m

Th2Zn17

a = 880.4

c = 1285.1

a = 871.0

c = 1274.6

0.41 x 0.56 at 600°C [1989Kuz]

at x = 0.41 [1982Pre]

at x = 0.56 [1989Kuz]

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

445


MSIT®

Al–Cu–Er

* 3, Er(CuxAl1-x)5

ErCu4Cu

hP6

P6/mmm

CaCu5

a = 502.9

c = 413.9

a = 503.9

c = 413.9

a = 524.1

c = 407.1

0.46 x 0.82 at 600°C [1989Kuz]

at x = 0.82 [1989Kuz]

at x = 0.8 [1978Tak]

at x = 0.46 [1989Kuz]

* 4, ErCu0.9Al2.1 hR36

R3m

PuNi3

a = 542.1

c = 2529.9

[1992Kuz]

Previously reported as Er5Cu6Al9[1989Kuz]

* 5, ErCuAl3 oI10

Immm

HoCuAl3

a = 418.4

b = 411.2

c = 977.3

[1988Kuz]

* 6, ErCuAl

ErCu1+xAl1-x

hP9

P62m

ZrNiAl

a = 697.40

c = 400.19

x = 0 [1968Dwi]

-0.02 x 0.1 at 600°C [1989Kuz]

* 7, Er2Cu3Al5 [1989Kuz]

* 8, Er6Cu16Al7 cF116

Fm3m

Th6Mn23

a = 1224.0 [1990Ste]. Not observed by [1989Kun] in

the investigation of the isothermal section

at 600°C

Phase/

Temperature Range

[°C]

Pearson Symbol/

Space Group/

Prototype

Lattice Parameters

[pm]

Comments/References

20

40

60

80

20 40 60 80

20

40

60

80

Er Cu


Axes: at.%

β

γ1

δ

ErAl3

ErAl2

ErAl

Er3Al2

Er2Al

(Er)

ErCu ErCu2 ErCu5

τ5

τ4τ2

τ3

τ6

(Cu)

τ7

τ8

L

τ1

η1ε2

(Al)Fig. 1: Al-Cu-Er.


600°C

light metal systems. part 1: selected systems from ag-al-cu to al-cu-er

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