AP3170Materials Testing Techniques

Dr. C. H. ShekG6720; Tel: 2788 7798

apchshek@cityu.edu.hk

Characterization is an essential aspect of materials research and of quality control in materials production.

“Characterization describes those features of the composition and structure (including defects) of a material that are significant for a particular preparation, study of properties, or use, and suffice for reproduction of the materials.” as

defined by National Research Council.

Aim

To develop an elementary understanding of some basic techniques on the analysis and testing of materials.

 

Objectives

1) Understand the principles and functions of some commonly used materials testing methods and equipment.

2) Interpret simple experimental results obtained from the testing techniques covered in the course.

3) Do simple calculations with the data from experiments.

Teaching Pattern:

•Duration of course: 1 semester

•Lecture/tutorial/ mix: 2 hrs lecture + 0.5 hr tutorial.

The course consists of lectures and tutorials. There is one hour of tutorial for every 4 hours of lecture. In the tutorial classes, students are encouraged to discuss on the taught topics and are given chance to clarify on questions concerning the lecture and the notes.

Assessment Pattern:

Examination duration: 2 hrs

Percentage of coursework, examination, etc: 30% by coursework; 70% by exam

Coursework consists of assignments, tutorial presentations and quizzes.

In order to pass the course (i.e. grade D or above), students have to achieve a minimum of 30% in both coursework and examination.

Schedule for TutorialsSchedule for Tutorials

;

Wk4 Wk6 Wk8 Wk10 Wk12 Wk13

26/9 10/10 24/10 7/11 21/11 28/11

Reference Books:

P. E. J. Flewitt and R. K. Wild; Microstructural Characterization of Metals and Alloys; The Institute of Metals (1986).D. A. Skoog; Principles of Instrumental Analysis; Holt-Saunders (1985).R. F. Speyer; Thermal Analysis of Materials; Marcel Dekker (1994).J. R. Fried; Polymer Science and Technology; Prentice Hall (1995).Annual Book of ASTM Standards, e.g. Section 3 “Metals Tests Methods and Analytical Procedures” and Section 8 “Plastics”; British Standards; Japan Industrial Standard, etc.R. J. Young and P.A. Lovell, Introduction to Polymers, 2nd Ed. Chapmen & Hall, p.222-227 (1991).J.D. Ingle, S.R. Crouch, Spectrochemical Analysis, Pentice Hall, (1988).P.E. Mix, Introduction to nondectructive testing, John Wiley & Sons, (1987).http://www.ndt-ed.org/index_flash.htm for NDT

Introduction

• To answer “What is the … of the material?”

• Always “many-to-one” relationships between techniques and problems

• Results from different techniques usually must be combined to draw conclusions

• Play important roles in various aspects

To answer the “what” questions?Properties Techniques

Compositions Energy Dispersive Analysis of x-ray, Atomic absorption spectroscopy, x-ray photoelectron spectroscopy …

Crystal structure x-ray diffraction, neutron diffraction, electron diffraction, …

Mechanical properties

Tensile test, hardness test, fatigue test, …

Thermal properties Differential scanning calorimeter, dilatometer, thermogravimeter, …

Magnetic properties AC susceptometer, Vibrating sample magnetometer, Faraday’s balance, …

Bonding situations or molecular structure

Secondary ion mass spectroscopy, Infra-red absorption spectroscopy, Raman spectroscopy, …

The role of testing

• At R&D stage, material properties must be comprehensively characterized

• Detailed specifications must be presented to potential customers

• The acceptance of delivered goods involving checking against specifications with standard tests

• At production stage, quality of materials must be closely monitored

• On reception of complaints, analysis of substandard materials for future improvement. (The recent case of malachite green!)

• Settlement of disputes calls for carrying out of accepted tests

Basic points to note about materials testing

• Technique of testing

• Physical and mechanical principles involved in the testing apparatus and procedure

• Theory of measurement (e.g. source of errors)

• Variability of materials

• Interpretation of results

Level of accuracy

• For obtaining fundamental physical quantities, may call for resources only affordable by big countries(e.g. gravitation constant = 6.67259(85) 10-11 m3kg-1s-2; uncertainty = ± 128 ppm;electron mass = 9.1093897(54) 10-31 kg; uncertainty = ± 0.59ppm)

• For R&D works, the best available tests are used• For quality control purpose, usually a “go-no go”

test is suffice

Further classifications

• Full size test• Test on models• Specimens extracted

from components• Specimens from raw

materials

• Destructive tests• Non-destructive tests

Optical microscopy

SEM, TEM(including EDS, WDS)

Microscopy(morphology & microstructures)

Tensile test

hardness test

Impact test, etc.

Mechanical Testing

Chemical analysis using IR

X-ray diffraction (XRD)

Crystallography and Diffraction(Crystal Structure)

Thermogravimetry

Dynamic Mechanical Analysis

Differential Scanning Calorimetry

Thermal Analysis(Properties vs Temperature)

Dye penetrant

Ultrasonic testing

Eddy current

Radiographic methods

Magnetic-particle inspection

Non-destructive Testing(Crack or defect detection)

AP3170Syllabus

What you are expected to know after the lectures

• what type of technique to use when you face a problem

• some basic concepts about the techniques, e.g. their principles, accuracy, limitations,...

• be able to do some simple calculations based on the experimental data and to interpret the results

Assessments

• Tests on week 7 and week 13

• Exam. usually split into two sections, A & B

• section A questions on basic concepts, usually very short answers are expected

• section B call for more in-depth understanding in certain techniques, therefore, you can choose from a range of questions

Summary

• The amount of information in this module is huge, so prepare to work hard

• To know “What?”, “Why?” but not “How?”

• You may have hand-on experience when you do your laboratory work or final year project

• Learn these techniques in conjunction with the other course in your program.