THE

SANTA FE SYMPOSIUM

ON JEWELRY

MANUFACTURING

TECHNOLOGY

20 1 1

Edited ByEddie Bell

Proceedings of the Twenty-FifthSanta Fe Symposium in

Albuquerque, New Mexico

Contents

quality Excellence in the Direct casting of rp resins:

Reality or fiction? 1

Dr. Marco Actis Grande

In recent years the jewelry industry has shown an increasing interest in rapidprototyping techniques as an answer to several design challenges. Even thoughrapid prototyping can produce models for direct casting, at the moment this

opportunity is not fully exploited. One reason for this has certainly to be the

lack of information about materials and their correct handling and processing,causing confusion and uncertainty when using them. Understanding of their

characteristics is critical and represents the starting point for the achievement of

a high-quality casting.

In order to match resin requirements, many studies have been carried out in the

past, reconsidering and adapting process parameters, developing new techniquesand new materials to fit resin needs, and looking for practical tricks. However,

great attention should also be paid to critical phases both in resin partsproduction (slicing and orienting of the pattern, accuracy, UV curing) and in the

cycle (particularly to oxygen supply during burnout and residual evacuation).In addition to the aforementioned process parameters, several other "external

factors" could also play a role in the response of resins, such as aging, packaging,cleaning, handling, etc., and their influence should be taken into account when

considering results from direct casting of RP resins.

Resins can differ substantially from one to another. Tine market offers a wide

range of materials from wax-like resins to fully polymeric ones. It is therefore

essential to take into account that the final results are highly dependent on the

chemical and physical characteristics of the material adopted. The aim of this

work is to analyze rapid prototyping resins from a scientific approach, to derive

information on the thermal and physical behavior of materials, and then to

transfer that knowledge into practical applications, looking for a correlation

between the material characteristics and proper processing.

Dr. Actis Grande is assistant professor at Politecnico di Torino, Italy (Alessandria

Campus) and holds a M.Sc. in materials engineering and a Ph.D. in metallurgicalengineering from the same college. He is a recipient of both the Santa Fe Symposium*Research Award and the Collaborative Research Award. This is his third year presentingat the Symposium.

CAD/CAM Follies 37

Steven Adler

While CAD technologies can provide jewelers significant flexibility to create

their works, often the results are beyond the ability of traditional investment

casting. As new CAD designers (who aspire to become modelmakers and

fabricators-turned-computer geeks) confront the constraints of investment

casting, opportunities abound for folly and the inevitable failure in

manufacturing. In this 3D presentation, the author will present a collection of

CAD jewelry designs received over the years as examples of both what to do and,more importantly, what not to do when using CAD software. At the expense of

their peers, attendees can expect to be both amused and educated in designing for

manufacturability.

Mr, Adler is the founder and president of A3DM, a leading supplier of productengineering and technical consulting services in support of jewelry manufacturingapplications. He has more than 30 years of experience in product developmentand is a featured writer on jewelry manufacturing technology for several trade

organizations. A3DM has affiliations with the Rapid Prototype Association of the

Society ofManufacturing Engineers, the Global Alliance ofRapid Prototype Association,and is a member of the ASTM International F42 Committee on Additive ManufacturingTechnologies. Mr. Adler is the recipient of both the Santa Fe Symposium® Collaborative

Research and Industry Leader Awards. This paper, presented in 2010, was his third

presentation at the Symposium.

The Quest for the Perfect RP Burnout S3

Alan S. (Andy) Andrews

It is safe to state that Rapid Prototyping (RP) is here to stay. This paper examines

the problems encountered in direct casting of those RP resins produced byphotosensitive resins that consistently contribute to defects in the cast products.The alloys used in this study have melting ranges that do not exceed 1200°C

(2192°F). We will examine the thermal and physical properties of both the RP

material and investment utilized. In the summary we will suggest cost-effec¬

tive procedures and equipment that will assist individual casting installations

to customize procedures and burnout programs for their particular castingrequirements.

Mr. Andrews is currently the production manager at Best-Cast in River Edge, New

Jersey. He attended Manhattan University. He has given numerous presentationspertaining to manufacturing in the jewelry industry. This is his first presentation at the

Symposium.

DYNAMIC RECRYSTALUIZATION AND THE HOT WORKING OF

PRECIOUS METAL ALLOYS 83

Paolo Battaini

Although the process of metal hot working is lost in the mists of time, a

satisfactory understanding of it was finally achieved within the last 40 years.The easy workability of metals and alloys at high temperature is due to the

quick change in microstructure, of which dynamic recrystallization is one of the

main aspects. Because it is so easy to cold work precious metals, it is difficult

to find information about their hot working. However, the difference in results

between cold working followed by annealing and hot working is interesting anduseful to know in order to improve product quality. The present work will givea general and simplified description of the microstructural phenomena occurringduring hot working, such as dynamic recovery and dynamic recrystallization.Furthermore, the advantages of the hot working of some precious metals alloyswill be shown by means of practical examples including microstructural

observations.

Mr. Battaini holds a degree in nuclear engineering, is a consulting engineer with 8853

S.p.A., and is a professor of Precious Metal Working Technologies at Milano Bicocca

University, Italy. He is a recipient of the Santa Fe Symposium® Ambassador Award. This

is his sixth year presenting at the Symposium.

WHERE TO DIRECT DEVELOPMENT MONEY? SOME EXAMPLES OF

SUCCESSFUL AND NOT-SO-SUCCESSFUL PROJECTS 1 07

Prof. Dr. Wolfgang Boehm

Precious metal thin wires are used in electronic and catalyst products. Combiningthis know-how with textile production techniques is resulting in necklaces with

high pliability and novel surface structure. Coloration of the wires extends the

design possibilities. A surface decoration method with plate-like gold powdersmakes new designs possible. Sintering or hot pressing ceramic materials shows

the potential of other basic materials in addition to precious metals.

Not only can projects with innovative materials support the jewelry industry, but

engineering adapted to the specific needs of the jewelry industry can improve

productivity. An example is an electronic ring measuring gauge, which transfers

the ring size to the different international units used for rings. Also, manual

marking of rings can be supported by a device that positions the marking tool,

thus producing uniform marks in the middle of the band.

Dr. Boehm is the director of the Jewelry Technology Institute at the University of

Pforzheim in Germany. He holds a Ph.D. in material science and has more than 30 years

ofexperience in the precious metals industry. The Jeivelry Technology Institute supportsthe jewelry industry with innovations and failure analysis. This is his first presentationat the Symposium.

A gift Fit for a Pope, isoo years after its First

Creation 123

Frank CooperThe Staffordshire Hoard was first discovered in the UK in July 2009 by a metal

detectorist. The Hoard comprises in excess of 1,600 individual items. Most are

gold, some are silver, many are decorated with precious stones; almost all are

warlike in nature. The only items that are clearly non-martial are two crosses.

The largest may have been an altar or processional cross and other than the

loss of the settings used to decorate it, it is intact. However, it has been folded,

possibly to make it fit into a smaller space prior to burial. It is this particularcross that is the subject of this paper, which describes the extraordinary journeyof this anciently crafted symbol of seventh century religious piety to becoming a

twenty-first century gift fit for a Pope. Utilizing the full range of technologies andskills available at the Jewellery Industry Innovation Centre and the multitude of

skilled trades found within the square mile of Birmingham's Jewellery Quarter,the paper explores the complexities and collaborations involved in turning this

unique, ancient, hand-crafted artifact into a truly remarkable example of the

modern goldsmiths' art.

Mr. Cooper is the technical manager of the Jewellery Industry Innovation Centre,

Birmingham City University, School of Jewellery. He has written and presented many

published technical papers and articles in the UK and Europe, specializing in the areas ofCAD and prototypingfor jewelry and silversmithing. This is his first presentation at the

Symposium.

Basic Metallurgy of the Precious Metals: Part 1 145

Dr. Christopher W. Corti

This presentation introduces the basic metallurgy of jewelry metals (gold, silver,

platinum and palladium) to individuals involved in the design and manufacture

of jewelry. It gives an understanding of how properties of jewelry metals and

alloys can be manipulated by alloying additions and mechanical and thermal

treatments. The variation of properties with alloy composition is shown in the

context of the influence of alloying additions and the microstructure. The basis

for this is explained in simple, mechanistic terms. The effect of working and heat

treatment on mechanical properties and the recovery of ductility by annealingare also explained in terms of changes to the microstructure—how these can be

influenced is also shown. The influence of minor alloying additions and

impurities on structure and properties is discussed in terms of grain size

control and embrittlement. The importance of phase diagrams as "road maps" to

predicting microstructure and properties is explained, and how they can limit

important properties such as workability is discussed.

Dr. Corti holds a Ph.D. in metallurgy from the University of Surrey (UK) and is the

managing director of COReGOLD Technology Consultancy. He has more than 30 years

of experience in the precious metals industry. He worked for the World Gold Council

from 1994 to 2004 and served as a consultant there until 2009. Dr. Corti edited Gold

Technology, Gold Bulletin, and the series of World Gold Council Handbooks/Manuals.He is currently a consultant for the Worshipful Company of Goldsmiths in London

and edits the Goldsmith's Company Technical Bulletin. A recipient of the Santa Fe

Symposium® Research Award, Technology Award and Ambassador Award, this is Dr.

Corti's sixteenth year presenting at the Symposium.

Combining Art and Science to Optimize the Investment

Casting Process 183

Samuel A. Davis, P.E.

In past presentations at the Santa Fe Symposium®, various authors have shown

that computational fluid dynamics (CFD) and finite element analysis (FEA)may be used to model mold filling and temperature distributions duringthe investment casting process. The power of mathematically modeling any

chemical/metallurgical process is having the ability to predict the outcome of

the product when variables and parameters are changed. A natural extension of

this concept is to combine the mathematical modeling of the investment casting

process with the design of the model made using three-dimensional CAD

(computer aided design) software. By combining art and science in this manner,

it may be possible to optimize the investment casting process by minimizingmanufacturing costs, defects, and scrap.

Mr. Davis is the president of UDesign Jewelry, LLC, a company he recently started to

manufacture jewelry. While employed at Cookson Precious Metals he developed processesto manufacture Argentium® Silver sheet, wire, casting grain and granules. He also led a

committee that implemented numerous ergonomic improvements at Cookson. He holds a

B.S. degree in chemical engineering and a M.S. degree in metallurgical engineering. This

is his third year presenting at the Symposium.

Platinum alloys in the 21st century: A Comparative

study 201

Teresa FryeIn the mid-1990s several jewelry industry publications asserted the need for

platinum alloy improvements. Authors noted that existing alloy compositionswere too soft, too difficult to cast without porosity, and too time consuming to

polish. Since then, only a limited amount of alloy development has taken place,and there is wide agreement among jewelry manufacturers and retailers that these

previously identified problems still largely exist today.

This research is intended to explore the casting quality of mainstream North

American platinum alloys, together with a new alloy that attempts to address

the shortcomings found in these alloys. Metallurgical results will be reported for

95Pt5Ru, 95Pt5Co, 90PtlOIr, and a mimber of 950 Pt alloys containing elements

that substantially increase hardness. Characteristics to be assessed include sources

and patterns of internal porosity, surface hardness, and the metallurgical effects

of thermal post-processing of castings.

Ms. Frye has more than 25 years ofexperience working in the investment casting industry.She spent her early years in sales and marketingfor Precision Castparts Corp., serving the

broad international customer base for aerospace castings in Europe and Japan. In 1994,

she co-founded TechForm Advanced Casting Technology. TechForm specializes in castingplatinum, palladium, cobalt-chrome and stainless steel for the jewelry industry. She is

the two-time recipient of both the Santa Fe Symposium9 Ambassador and Collaborative

Research Awards. This is her third year presenting at the Symposium.

Trust but Verify: A Survey of Refining Returns 231

Brett Gober

All users of precious metals must depend on the services of a refiner. We trust

them with highly valuable material, but often this trust is blind. There are many

ways for a dishonest or inept refiner to abuse this trust. No matter how much we

may trust our banker, we don't just send them a bag of cash, tell them to count it

and let us know how much they deposited into our account. That's just what wedo with our scrap metals, though. Now, more than ever, it is important to ensure

that your refiner is honest and conscientious. We probably trust our chosen

refiner or we would not be using them, but there is always some degree of doubt.

Refiners appeal to this doubt with their advertisements and sales calls exclaiming,"Highest Returns!", "Accurate Assays!", "Honest Results!" Clearly, refiners want

us to think their peers are less than trustworthy—or at least incompetent.

This paper will discuss some of the problems of homogenizing and dividingsamples for comparative analysis, establish a provable method for evenlydividing a large amount of precious metal grindings, and compare the results

from various refiners sent identical samples. The purpose of this paper is

not to identify "good" or "bad" refiners; therefore, the results are presentedanonymously.

Mr. Gober is the owner of Freedom Design & Contracting in Hannibal, Missouri. He

has a long history in the jewelry industry spanning sales, bench work and productionmanagement. This is his first presentation at the Symposium.

Enamel and Epoxy Resins—A Look at Their Usage in

Jewelry manufacturing 257

Richard Greinke

Enamel has been used for several thousands of years as a decorative coating and

accent to metals. This paper will include a brief explanation of several enamelingtechniques and when they originated. It will also include examples of jewelryusing those techniques. The main focus of this paper will be on the current usageof epoxy resins, which has replaced enamel for many companies in the

emblematic and recognition industry. It will include an explanation of the

materials used, finishing, safety, and some tips for working with epoxy resins.

Mr. Greinke is currently plant manager at Award Concepts, Inc. He has worked in the

emblematic/recognition segment of the jewelry industryfor 37 years. He is a recipient ofboth the Santa Fe Symposium® Industry Leader Award and the Ambassador Award. This

is his third year presenting at the Symposium.

Characterization of Jewelry Solders and Their

applications in the Manufacturing Process 287

Stewart Grice

What makes a good solder? Is it flow or how it wets, hardness or ductility,strength or melt gap that is the most important quality, or is it a combination of

all of these properties? There are many examples of jewelers who claim solder A

is excellent but solder B is not so good, while others claim exactly the opposite.Why is this and who is correct? Can we quantify the physical and mechanical

properties of solders to predict which will be good and which will not? Can

we predict from this information which solders are best suited to specificapplications, or is it like the above statement and purely a subjective assessment

with a "if it works for you, use it" philosophy?

This paper will discuss the principles behind metal joining, measure propertiesof solders and joints in various applications, and determine if guidelines can be

identified to predict which solders work best in specific applications.

Mr. Grice is the mill products director at Hoover & Strong, Inc. He has a B.Sc. in

materials science and a M.Phil, in metallurgy & materials. He is a recipient of the Santa

Fe Symposium9 Ambassador Award and a three-time recipient of both the Collaborative

Research and Research Awards. This is his ninth year presenting at the Symposium.

Passion and Spirituality in Jewelry Design 321

Chuck Hunner

Jewelry design is informed by spirituality and passion. They are two sides of

the same coin known as inspiration. One inspiration is an outward passion for

survival. Other inspirations are more internal and concerned with inner spiritual

meaning. This paper gives examples of these fields of inspiration and draws the

conclusion that jewelry design gives substance and form to feeling. This is not

a scientific paper. It is about perspective and motivation. It's about breathing life

into a process that can be dry and mundane. It's about bringing juiciness and

fertility into an everyday activity.

Mr. Hunner has a B.U.S. degree from the University of New Mexico and has been an

independent jewelry artist since 1972. He is a recipient of the Santa Fe Symposium®Outstanding Technical Presentation Award and the Ambassador Award. This is his third

presentation at the Symposium.

Thin-Film Anti-Tarnish method for Silver—Further

Study of Wearing and Nanoscale Properties 329

Nora Isomaki

Atomic layer deposition (ALD) was introduced at the 2010 Santa Fe Symposium®as a new method to protect silver against tarnishing. With ALD a thin film can

be applied, which is a durable and invisible coating on silver to prevent tarnish.

Traditionally, ALD has mainly been used in the semiconductor and displayindustries, but its ability to produce pinhole-free and highly conformable thin-film

coatings even on complex-shaped objects is highly applicable to silver jewelry.

This paper presents the results of the anti-tarnishing tests from 2010 and further

studies of ALD thin films on silver. Wear resistance and nanoscale properties are

investigated. Experiences of silver manufacturers using ALD as a protective layeron silver are reported.

Ms. Isomaki is a project manager for Beneq Oy in Finland, a company specializing in

coating technologies for glass, solar and thin-film markets that are used in applicationssuch as optics, barriers and passivation layers, and energy generation. She holds a M.Sc.

in material technologyfrom Tampere University of Technology. This is her second year

presenting at the Symposium.

platinum Solders: Proper Use and Application in

Jewelry Making 345

Jurgen J. Maerz

There are several different kinds of platinum solders in use today. Some contain

up to 95% platinum, others contain no platinum at all. Each vendor tries to have

their own mix, but in principle platinum solders are all pretty much the same

except for some minor content variations. They are divided into traditional

solders and plumb solders. In this paper I will explain the different types of

solders, discuss the proper solder for the application, be it sizing, fabrication or

assembly. Safety and eye protection will be covered as well as solders used in the

U.S. and abroad. Detailed information on when to solder, when to weld, solderingpicks, soldering techniques, torch use, fuels, and flames will be shared. The use of

video clips makes the presentation lively, interesting and educational.

Mr. Maerz is technical consultant and supportfor Platinum Guild International, USA.

His love for teaching and more than 45 years of experience in the jewelry industry have

led him to teach all over the world. He is the recipient of the Santa Fe Symposium®Ambassador Award. This is his eleventh year presenting at the Symposium.

Characterization of 14-Karat Gold Alloys 357

Daniele MaggianData about the characterization of 18-karat gold alloys were presented by Progoldat the 2010 Santa Fe Symposium®. In this paper we are going to discuss the

chemical and physical properties of 14-karat red-, yellow- and white-gold alloys.

As with 18-karat gold alloys, knowing the alloy's properties enables us to choose

the most suitable composition for each particular production process. Color is

fundamental to the selection of a gold alloy but how to get the desired color

and favorable working properties is a question. In this paper we analyze howsmall additions of some elements may improve some important characteristics

in the production cycle. The goal is to correlate the features of each alloy with its

chemical composition so you can choose the optimum 14K gold alloy for each use.

Tine methods and tests used to collect data are not presented here as they are the

same used with the 18K gold alloys reported in the 2010 proceedings.

Mr. Maggian is the R&D manager at Progold S.p.A. in Italy. He holds a five-year degreein materials engineering. Progold is a four-time recipient of the Santa Fe Symposium'1'Research Award. This is Mr. Maggian'sfourth presentation at the Symposium.

New metals and Alloys of Interest in the Jewelry

Industry 395

Ajit Menon

Find gold; silver, platinum and palladium continue to demand high prices in the

market. Many jewelry manufacturers in the United States and other countries

are now looking into alternative, cheaper metals to manufacture jewelry. Most

of these metals are non-traditional and unregulated metals and formulations.

Examples of these non-traditional metals include various types of steels, such as

tungsten and cobalt-based steels, titanium alloys, palladium and platinum 585

and 420 alloys, non-sterling colored silver alloys, colored brass alloys, and low

karat (IK to 6K) yellow-, pink- and white-gold alloys.

This paper will discuss the pros and cons of casting, fabrication, ways to improvechemical/tarnish resistance properties, hallmarking issues, etc. for these alloys.The paper will also discuss and compare various mechanical properties such as

hardness, tensile strengths, microstructure and the costs involved to make jewelryfrom the above metals.

Mr. Menon has more than 20 years of experience working with precious metals and is

director of technology at United Precious Metals Refining, Inc. He holds a bachelor's

degree in metallurgical engineering and a master's degree in material science and

business administration. He is a recipient of the Santa Fe Symposium® Ambassador

Award, the Research Award, and the Industry Leader Award. This is his seventh year

presenting at the Symposium.

Modern Manufacture of Seamless, Wrought Wedding

Bands—an Engineering Approach 411

Paul W. Nordt III

The craft of making finger rings is perhaps as old as any human art form.

Although the fundamentals of molding precious metals (copper, silver and gold)'nto rings has, perhaps, changed very little over the centuries, the sophistication)f these technologies has increased dramatically. This paper will examine how

nodern engineering and metallurgy have been applied to manufacture the

highest quality wrought, seamless rings both economically and responsively to

current market requirements.

Key aspects of this application include 1) vacuum melting and hot working(extrusion) to achieve fully wrought, fine-grain microstructure, 2) near-net-shapeprocesses to maximize precious metal yield, 3) customer accessible CAD

integrated with on-the-fly CNC code generation for precision machining, 4)application of "LEAN" principles for one-piece flow, 5) maximized

inventory turnover and loss control, and 6) quality systems in accordance with

ISO 9001:2008.

Mr. Nordt holds a B.S. degree in metallurgical engineeringfrom Lehigh University. Heis the chairman and CEO of John C. Nordt Co., Inc. and has served as chairman of the

Jewelers Board of Trade. Mr. Nordt has pioneered the application of hot extrusion to the

fabrication ofprecious metal alloys. This is his first presentation at the Symposium.

Knowledge Exchange Programs and Collaborative

projects—Do these Initiatives really work and are

They worth Pursuing? How Can the Jewelry Industry

Benefit From Them? 443

Gay Penfold

Increasingly, "knowledge" and "innovation" appear to be recognized as

significant driving forces of economic growth, social development, and jobcreation. "Knowledge exchange" and "innovation" have become buzz words

that are often the subject of both public and economic policy. As a result of this,a myriad of programs and other initiatives have been created and designedby some governments to assist and persuade industry and commerce to move

towards a knowledge-based production. Additionally, in much of the current

innovation literature there is an underlying assumption that there is a potentialfor increased collaboration between industry and universities, with an

assumption that universities are an important source for accessing external ideas.

This paper will report on and examine an illustrative selection of different

government and research-funded initiatives and partnership projects undertaken

by the UK-based Jewellery Industry Innovation Centre QIIC) with a wide rangeof jewelry small and medium-sized enterprises (SME). It will include examplesof the successful, the less than successful, and the ones that exceeded all

expectations, and will report on the Centre's experiences in the development,delivery and participation in these initiatives. It will also consider the value of

this interchange of knowledge and its impacts and results, both commercially and

through "softer" outcomes.

Ms. Penfold is the manager of the Jewellery Industry Innovation Centre at BirminghamCity University, UK. She holds a B.A. in metalwork and jewelry from Sheffield Hallam

University and a M.A. from the Royal College of Art, London. This is her fourth year

presenting at the Symposium.

Mokume Any Other Way? 461

Chris Ploof and Dr. Joseph Tunick Strauss

Mokume gane is a material- and labor-intensive process. Materials are

diffusion bonded and then worked to consolidate and shape the billet. Once

shaped, considerable additional working, with its attendant loss of material, is

required to produce the desired pattern. Only then can the material be made into

individual jewelry items. In addition, the traditional mokume gane methods limit

the type of materials that can be bonded together as the extensive downstream

processing can destroy the billet by failure of the bonds between materials with

disparate properties.

The paper will describe methods to make net- and near-net-shape mokume gane

jewelry items or blanks on a per-piece basis. This alternative method will alleviate

many of the disadvantages of bulk mokume gane processing through creative use

of solids and powders. These methods will also provide for new patterns specificto this method and the materials used, as well as the potential to create new

combinations of metals.

This paper is essentially two studies and will thus contain two discrete sections.

Section I will cover the science and engineering of diffusion bonding and the

development of hot pressing methods used to make samples. Section II will cover

the conversion of these samples into jewelry items and compare testing,properties, and aesthetics with materials and items made by conventional

mokume gane methods.

Mr. Ploof is owner and principal artist of Chris Ploof Studio, a manufacturer ofhigh-quality wedding rings and other jewelry specially created using laminated materials.

He is also founder of Chris Ploof Tools, a company involved in the production ofhigh-quality specialty jewelry tools. His background includes studies ranging fromlarge-scale casting and glasswork to lapidary, blacksmithing and machining. He is a

recipient of the Santa Fe Symposium'1' Industry Leader Award. This is his third year

presenting at the Symposium.

Dr. Strauss is president ofHJE Company, Inc. He holds a Ph.D. in materials engineeringfrom Rensselaer Polytechnic Institute. He has authored more than 40 published works

and writes an annual column for International Journal of Powder Metallurgy. He is a

recipient of the Santa Fe Symposium Ambassador and Applied Engineering Awards. This

is his tenth year presenting at the Symposium.

Age Hardenable 14-karat white golds 489

Greg RaykhtsaumThis paper concludes the discussion on age hardenable gold jewelry alloys. In our

presentation at the 2009 Santa Fe Symposium®, we reviewed hardenable colored

karat golds, discussed hardening mechanisms in Au-Ag-Cu-Zn alloys and their

compositional limits, color variation and mechanical properties. The benefits of

using hardenable colored gold alloys, including the possibility of manufacturinglightweight jewelry, are equally applied to white golds as well. The metallurgy of

white-gold alloys, however, is different because, in addition to Au, Ag, Cu and

Zn, these alloys contain a significant amount of such whitening elements as Ni

and/or Pd. The subject of Ni-containing white golds can be found in literature,

whereas there is practically no data on Pd-containing white golds even thoughthey show much easier processing, better workability and resistance to corrosion.

We discuss 14K Pd-white hardenable gold alloys' color and mechanical propertiesin terms of Pd-Cu and Ag-Cu ratios.

Mr. Raykhtsaum is the chief metallurgist at Sigmund Cohn Corp. in New York. He

holds a M.S. degree in physicsfrom Polytechnic Institute, St. Petersburg, Russia. He has

co-authored eleven patents and a number of articles. He is a recipient of both the Santa

Fe Symposium® Research Award and the Ambassador Award. This is his twelfth year

presenting at the Symposium.

buy By weight: think Volume 499

Dr. John C. WrightPrecious metals fineness, alloy composition and bullion cost are expressed byweight and this powerfully affects manufactured cost. Jewelers and silver and

goldsmiths order stock materials and components by volume. Jewelry designerstake an aesthetic volumetric view; they use shape, dimensions, color and texture

but rarely complex design formulae.

Five 'jewelry' case studies show where weight percent is not the onlyconsideration. Starting with precious metal clays, the volumetric argument

develops to explain some surprising results. Platinum is a highly desirable

jewelry material, yet as little as 5% addition can vary the color slightly and changeproduction properties significantly. Does an alloy of equal weights of platinumand palladium act like standard platinum, like palladium, or does it have a

character of its own? Electroforming gold produces hollow shapes that appear to

be weighty solid gold. One percent titanium in otherwise pure gold changes the

production process characteristics and end properties of an item to a surprisingextent. It is interesting to speculate how the technology of these processes could

further influence jewelry design and production.

Dr. Wright holds a B.S. in metallurgy and a Ph.D. in gas turbine technology fromthe University of London. He is a Fellow of the City & Guilds of London Institute;

of the Institute of Materials, Minerals and Mining; of the Gemological Association ofGreat Britain; and of the Institution of Engineering and Technology. He is a materials

consultant and expert zuitness with Wilson-Wright Associates in England. He has worked

as a consultant with Johnson Matthey, Platinum Guild International, World Gold

Council, and several assay offices and jewelry and equipment manufacturers. Dr. Wrightis a recipient of the Santa Fe Symposium9 Ambassador, Applied Engineering and LifetimeAchievement Awards. This is his twelfth presentation at the Symposium.

X-Ray Computed Tomography: A powerful Tool for

NON-DESTRUCTIVE MATERIALS ANALYSIS SIS

Dr.-Ing. Andreas Zielonka

The classic application of industrial X-ray 3D Computed Tomography (CT) is the

inspection and three-dimensional measurement of different materials. However,

high-resolution X-ray technology now available opens up a variety of new

applications in different fields of engineering, material and natural sciences. The

computed tomography system at the FEM is the ideal system for 3D analysis(computed radiography) as well as for high precision 3D metrologyapplications. Due to its 300kV microfocus X-ray tube, the system can be used

for scans of strongly absorbing samples as well as for high magnificationapplications. For the first time a 300kV microfocus X-ray tube achieves a detail

detectability of up to lum. With different computer tools the geometry of objectsand the amount and local distributions of defects can be analyzed. The paper

gives an introduction into this technique and shows its application for the

non-destructive analysis of materials and components, e.g., cast objects.

Dr. Zielonka is the director of the Research Institute for Precious Metals and Metal

Chemistry (FEM) in Germany. He holds a Ph.D. in electrochemistry and electroplating.He is a recipient of the Santa Fe Symposium® Ambassador Aivard. This is his fifth year

presenting at the Symposium.