Technical progress has for a very long time been directly dependent on progress in metallurgy, which is itself connected with improvements in the technology of alloys. Metals are most frequently used in the form of alloys for several reasons: the quantity of pure metal in its native state in the earth's crust is very limited; pure metals must be extracted from ores which are themselves impure. Finally, the methods of treatment used lead more easily to alloys than to pure metals. The most typical case is that of iron, where a pure ore may be found, but which is the starting point for cast iron or steel, alloys of iron and carbon. In addition, the properties of alloys are in general superior to those of pure metals and modem metallurgy consists of controlling these properties so as to make them conform to the requirements of the design office. Whilst the engineer was formerly compelled to adapt his designs and constructions to the materials available, such as wood, stone, bronze, iron, cast iron and ordinary steels, he can now expect, due to metallurgical research, the creation of special alloys meeting specific requirements. These requirements must of course be reasonable, but VIII INTRODUCTION must be sufficiently imperative for them to become the motive for progress.

Grain boundaries are important structural components of polycrystalline materials used in the vast majority of technical applications. Because grain boundaries form a continuous network throughout such materials, their properties may limit their practical use. One of the serious phenomena which evoke these limitations is the grain boundary segregation of impurities. It results in the loss of grain boundary cohesion and consequently, in brittle fracture of the materials. The current book deals with fundamentals of grain boundary segregation in metallic materials and its relationship to the grain boundary structure, classification and other materials properties.

The results of a NATO Advanced Study Institute (ASI) entitled "Coordination Chemistry Environments in Iron-Containing Proteins and Enzymes - Including Smaller Molecules and Model Systems" are summarized in this book. The ASI was held in the Province of Alberta, Canada, from August 23 to September 4, 1981. The first half of the conference was held on the campus of the University of Alberta, Edmonton, and the second half at the Overlander Lodge, Hinton. Two other conferences had the greatest impact upon the planning for this ASI. One was a NATO ASI held in Tomar, Portugal in September of 1979, entitled "Metal Ions in Biology." Among the organizers for that conference were Allen Hill and Antonio Xavier; we are happy to acknowledge their beneficial influence on our subsequent conference. The other most influential conference was one organized by Ralph Wilkins and Dennis Darnell entitled "Methods for Determining Metal Ion Environments in Proteins" which was held in Las Cruces, New Mexico, U.S.A., January 10-12, 1979. The Las Cruces conference invited lectures were published as Volume 2 of "Advances in Inorganic Biochemistry," G. Eichhorn and L. Marzilli, editors.

The European Collaborative Programme on Materials for Gas Turbines known as COST-50 was initiated in 1971 and has been supported since then by the Commission of European Communities. The achievements made during the first phase of COST-50 were reviewed at the Conference held in Liege, September 25-27, 1978 and published by Applied Science Publishers Ltd. Nine European Countries : Austria, Belgium, the Federal Republic of Germany, France, Italy, The Netherlands, Sweden, Switzerland, the United Kingdom, and the Joint Research Center of the Community, agreed to continue their participation in COST-50 and the results of the second phase were presented at the Conference held in Liege, October 4-6, 1982 under the following headings : - Corrosion and Coatings - Fatigue, Creep and Structural Stability - Processing The technical sessions consisted of invited papers reviewing recent progress in the development of high temperature alloys with particular emphasis on the results of the European Collaborative Programme. Furthermore, some areas were reviewed by eminent speakers from the United States of America, due to their expertise in their respective fields. In this context and as a tradition introduced in 1978, the keynote lecture "Superalloys technology : today and tomorrow" was del ivered by Dr. F. L. Versnyder. The Conference was completed with a significant Poster Session comprising about fifty contributions from Europe and elsewhere. This book comprises a total of fifty four contributions representing almost all of the papers delivered at the technical sessions and a large part of the presentations made at the Poster Session.

The thermochemistry of alloys has interested generations of scientists and the subject was treated in classical textbooks long ago, e.g. by Hume-Rothery, by Wagner, and by Kubaschewski and Alcock. Nevertheless, the appearance of new materials and the desire to improve traditional materials and metallurgical processes has kept up demand for more information on the thermodynamics of these systems. The advent of computing power has created new opportunities to tie various aspects and properties together, such as phase diagrams and thermodynamic functions, that are in principle thermodynamically inter related but were too cumbersome to work out before. The computer has also been a powerful tool in buUding and testing models that help to explain the underlying causes of non-ideal behavior. At the same time, these calculations have pinpointed areas, where additional and more accurate data are needed. In the laboratory, new methods, improved materials, and sophistica ted instrumentation have gradually changed the way in which experiments are done. Within the time span of perhaps thirty years, the development went from jotting down individual readings of data points to strip chart recording to automatic digital data acquisition. Scholars and students active in the field of "Thermochemistry of Alloys" convened for a NATO Advanced Study Institute at Kiel in August 1987 to discuss these developments. This book collects most of the lectures and seminar papers given at the Institute."

This publication documents Proceedings of the Symposium on Metal lurgy and Technology of Refractory Metal Alloys, held in Washington, D.C. at the Washington Hilton Hotel on April 25-26, 1968, under sponsorship of the Refractory Metals Committee, Institute of Metals Division, of the Metallurgical Society of AIME, and the National Aeronautics and Space Administration. The Symposium presented critical reviews of selected topics in refractory metal alloys, thereby contributing to an in-depth understanding of the state-of-the-art, and establishing a base line for further research, development, and application. This Symposium is fifth in a series of conferences on refractory metals, sponsored by the Metallurgical Society of AlME. Publications issuing from the conferences are valuable technical and historical source books, tracing the evolution of refractory metals from early laboratory alloying studies to their present status as useful engineering materials. Refractory metals are arbitrarily defined by melting point. A 0 melting temperature of over 3500 F was selected as the minimum for this Symposium, thus excluding chromium and vanadium, which logically could be treated with other refractory metals in Groups VA and VIA of the periodic table. The Refractory Metals Committee is planning reviews of chromium and vanadium in subsequent conferences.

Powder metallurgy literature in the English language includes a large number of books and several thousand articles in various journals. The rate of growth of this literature increases from year to year. It covers well the whole field of powder metallurg- materials, processes and products - with two exceptions: friction and antifriction branches of powder metallurgy. This lack of information has nothing to do with scientific or technical considerations, and definitely has nothing to do with lack of initiative in the development of these materials. The industry concerned with the production of friction and antifriction materials is continually developing new products and techniques and produc tion is steadily growing. However, most companies working on these materials regard their experiences and new advancements as "proprietary" and, for competitive reasons, are not interested in publishing in the technical literature except for very perfunctory and usually highly commercial papers. Very little work on fric tion and antifriction materials is going on in independent labora tories and university laboratories, although fundamental studies in this field offer very interesting aspects.

Advances in industrial technologies and improved performance of constructional materials are interdependent and have become of increasing concern in recent years. This Conference aimed to - provoke discussion of the limits towards which high temperature alloys properties can, ultimately, be developed, identify the resulting R&D requirements and design developments. Following a key-note paper concerning the relation of current capabilities to requirements for gas turbines the conference was structured into 3 sessions which examined: * the theoretical?ldpracticallimits for HT Alloys, * the potential for development in alloys and processing, * engineering considerations. Finally, feeling perhaps the approaching "wind of change"??1s Conference on remaining alloy potential was wound up with a paper entit1ed "The potential?ld problems ofEngineering Ceramics". The different sessions each included a number of invited papers followed by a series of posters and were concluded by a presentation of a "synthesis" by a sess10n rapporteur and general discussion. This structure is retained in the proceedings, including the discussion points in those cases where?le authors have provided written answers to questions raised.

Metals and alloys rely for their application at high temperature on the formation and retention of oxide scales, which act as a barrier between the metallic substrate and the reactive species in the environment such as 0, S, N, C, Cl, etc. This protection concept requires that the oxide grows slowly, develops a dense, uniform layer, is well adherent, has sufficient ductility to accom modate plastic deformation of the substrate and is resistant to thermal cycling. For many years it has been known that small concentrations of certain "active elements" such as Y and the rare earths, as well as carbon and sulphur, can exercise a significant influence upon the oxidation corrosion behaviour of high temperature metals and alloys. An increasing number of experimental studies on this topic have been published recently. However no generally accepted understanding with regard to the detailed mechanisms and the way in which alloy composition and structure, temperature and environmental conditions, etc., are interacting has yet been achieved, although many - often controversial - theories and ideas have been presented. It therefore seemed to be an appropriate time to bring together a group of experts to review and evaluate the current state-of-the-art and to discuss various aspects of this important topic."

The 4th International Symposium on the Science and Technology of Sintering was held on 4-6 November 1987 in Tokyo. Among the many technical sessions was one entitled 'Session for Sintering-Case Study'. Over 200 participants heard these invited talks. Although some papers were over 20 years old, it is necessary to understand the authors' way of thinking. Since the end of the Second World War, many excellent papers related to sintering have appeared in many different academic journals. Some of these papers are still of value, and are still being read by today's students. The questions we have to ask are: Why does the scholar think this way? Why did the scholar perform his experiments? What is the mechanism of sintering? What is the liquid phase of sintering? What is the behavior of sintering additives? What is the history and development of sintering theory? This book includes these sort of historical papers and also new original papers on sintering, all of which are very important to our understanding of the subject. Several papers have been added for this English edition, which is thus more comprehensive than its Japanese counterpart. These papers were spread out in many different sources and the benefits of collecting them together in book form is obvious.

R. J. MOREAU, Professor MADYLAM, Inst. Nat. Poly technique de Grenoble, France The material on which the foundryman 1S focus1ng his attent10n 1S a molten metal, ferrous or not, coming from the melt1ng equipment, Wh1Ch is to be del1vered into a mould where it w1ll solidify. The foundryman 1S the last person 1n th1S process who still has the poss1b1l1 ty of acting to control the quality of the casting. Indeed, most of the respons1bil1ty 1n th1S quality bus1ness is vested 1n him. Bes1des, as anyone involved 1n metals processing, he 1S engaged 1n the ongoing effort to achieve the highest eff1c1ency and the best working condit10ns. To deal w1th th1S metal he needs to know f1rst its physical properties (temperature, composit1on, 1mpur1ties ...) and the way they influence 1tS behav10ur (llqU1dus, solidus, structure *. . ). He also needs to know how this complex flu1d flows (head losses in gating parts, flow rates, levels in moulds ...) and 1S modif1ed by its enV1ronment (heat fluxes, temperature var1at10ns, solidification ...). Responding to th1S need requires an important and regularly updated knowledge as well as preC1se measurements and advanced control processes. One may therefore appreciate why the topic "MEASUREMENT AND CONTROL IN LIQUID METAL PROCESSING" was chosen by the CIATF for the 1986 workshop.

The 13th Rare Earth Research Conference was held October 16- 19, 1977 in Wilson Lodge at Oglebay Park near Wheeling, West Vir g1n1a. From the small conference held originally at Lake Arrow head, California in 1960 the meetings have grown steadily in size and stature until they are now recognized as the premier conference devoted exclusively to the science and technology of rare earth systems. In keeping with the spirit which has prevailed since the Lake Arrowhead days a number of improvements were instituted on the oc casion of the 13th Conference. For the first time poster sessions were introduced, and they proved to be a splendid success. This was a year of another first - a review system for manuscripts. Dr. McCarthy, who undertood the arduous task of Program Chairman, and Dr. Rhyne, who along with Dr. McCarthy edited the conference proceedings, were mainly responsible for suggesting and implement ing these innovations. The layout at Wilson Lodge was nearly ideal for the conference in that poster and oral sessions were in very close proximity, facilitating the efforts of the attendees to make the most of the conference.

As ironmakers are well aware, it was only a few decades ago that the blast furnace was viewed as a strange 'black box'. Recently, however, various in-furnace phenomena have become the subject of serious scientific study, largely as the result of the 'dissection' of dead furnaces, together with the development of advanced monitoring and control techniques. In this way, a new frontier has been opened within the venerable domain of metallurgy. In the light of these new developments, the Committee on Reaction within Blast Furnaces was set up in March 1977 by the Joint Society ofIron and Steel Basic Research - a cooperative research organization of the Iron and Steel Institute of Japan (ISIJ), the Japan Institute of Metals (JIM) and the Japan Society for the Promotion of Science (JSPS). Consisting of twenty-six members and advisors drawn from the fields of academia and industry, this committee collected, discussed, and evaluated numerous papers during its five year commission. Particular attention was paid to the interpretation of findings drawn from the autopsy of dead furnaces, in the context of the live furnace state, and the correlation of data regarding cohesive zone configuration, level, and furnace performance. The results of this intense research activity are presented here in the hope that they will serve not only as a source of enrichment to the professional knowledge of researchers and operators, but also as textual material for graduate students in the field of metallurgy."

This volume contains the edited version of lectures and selected research contributions presented at the NATO ADVANCED STUDY INSTITUTE on MECHANICAL BEHA VI OUR OF MATERIALS AT HIGH TEMPERATURE, held in Sesimbra, Portugal, 12th-22nd September 1995, and organized by 1ST-Lisbon Institute of Technology, PortugaL The Institute was attended by 88 participants, including 15 lecturers from 17 countries including five CP countries. The lecturers were leading scientists and technologists from universities, research institutions and industry. The students were mainly young PhD students and junior academic or research staff with postgraduate qualifications (MSc or PhD). Fourteen students were from the five CP countries. The students presented research papers or posters during the Institute reporting the current progress of their research projects. A total of thirty three lectures, ten research papers and fifty posters were presented. This book does not contain the poster presentations and seven research papers were selected for publication. All the sessions were very active and quite extensive discussions on scientific aspects took place during the Institute. The Advanced Study Institute provided a forum for interaction among scientists and engineers from different areas of research, and young researchers.

This book is the proceedings of a Symposium entitled "The Physics of Solid-Solution Strengthening in Alloys" which was held at McCormick Place, Chicago, on October 2, 1973, in association with a joint meeting of the American Society for Metals (ASM) and The Metallurgical Society (TMS) of the American Institute of Mining, Metallurgical, and Petroleum Engineers (AIME). The symposium, which was initiated and organized by the editors of this volume, was sponsored by the Committee on Alloy Phases, Institute of Metals Division, TMS, AIME, and the Flow and Fracture Section of the Materials Science Division, ASM. The discipline of Alloy Design has been very active in recent years, during which considerable stress has been placed on the roles of crystallography and microstructure in the rationalization and prediction of properties. Underestimated as a component of alloy design, however, has been the importance of physical property studies, even though physical property measurements have tradi tionally been employed to augment direct or x-ray observations in the determination of phase equilibrium (and, indeed, metastable equilibrium) boundaries."

Liquid metal MHO is within the scope of two series of international conferences. One is the International Congress on "MHD Power Generation," held every four years, which includes technical and economical aspects as well as scientific questions. The other if the Beer-Sheva Seminar on "MHO Flows and Turbulence," held every three years in Israel. In addition to these well established meetings, an IUTAM Symposium was previously organized in Cambridge (UK) in 1982 on "Metallurgical Applications of MHD" by the late Arthur Shercliff. It was focussed on a very specific subject developing radiply from the middle of the 1970's. The magnetic field was generally AC, including frequencies high enough for the skin-depth to be much smaller than the typical length scale of the liquide pool. And the development of new technologies, or the improvement of existing ones, was the main justification of most of the researches presented and discussed. Only two participants from Eastern countries attended this Symposium. By the middle of the 1980's we felt that on this very same topic ideas had reached much more maturity than in 1982. We also realized that a line of research on MHD flows related to fusion reactors (tokamaks) was developing significantly, with particular emphasis on flows at large interaction parameter.

Thermoelectric and related transport properties of metals have been a source of information and, also, exasperation to physicists for over a century. Perhaps the principal reasons for interest in these phenomena are their sensitivity to composition, structure and external fields and, until fairly recently, the distressing fact that often even gross experimental features such as the sign of the thermopower eluded theoretical understanding. During the past two decades many of the previously perplexing aspects of thermoelectricity have yielded to more sophisticated theoretical treat ment. As a result of this effort and concomitant experimental work using advanced measurement techniques, there is now good reason to believe that thermoelectric phenomena can shed much light on the interactions between electrons and phonons, impurities, and other defects. The last few years have witnessed new and fascinating developments that promise to stimulate new activity in this field. In contrast to the more conventional transport properties, second-and high-order contributions in electron scattering theory appear to play a profound role in thermoelectricity-the controversy surrounding ordinary and "phony" phonon drag is far from resolved; the startlingly large effect of magnetic fields on the thermopower of metals appears to be linked intimately to scattering anisotropy; quantum oscillations of thermopower are orders of magnitude larger than corresponding oscillations of the magnetoresistance; a new approach to thermoelectric studies allows extension of thermopower measurements into the millikelvin region of temperature; finally, the advent of superconducting detection devices permits the precise measurement of extremely small voltages, an essential requirement in this field."

About 35 years ago, thermal fatigue was identified as an important phenomenon which limited the lifetime of high temperature plant. In the intervening years many investigations have been carried out, primarily to give guidance on likely endurance (especially in the presence of time dependent deformation) but latterly, with the introduction of sophisticated testing machines, to provide knowledge of the underlying mechanisms of failure. A previous edited book (Fatigue at High Temperature, Elsevier Applied Science Publishers, 1983) summarised the state-of-the-art of high temperature fatigue testing and examined the factors influencing life, such as stress state, environment and microstructural effects. It also considered, in some detail, cyclic crack growth as a more rigorous approach to life limitation. The aim of the present volume (which in style and format follows exactly the same lines as its predecessor) is once again to pursue the desire to translate detailed laboratory knowledge into engineering design and assessment. There is, for example, a need to consider the limitations of the laboratory specimen and its relationship with engineering features. Many design procedures still rely on a simple endurance approach based on failure of a smooth specimen, and this is taken to indicate crack initiation in the component. In this volume, therefore, crack propagation is covered only incidentally, emphasis being placed instead on basic cyclic stress strain properties, non-isothermal behaviour, metallography, failure criteria and the need for agreed testing procedures."

The history of gold begins in antiquity. Bits of gold were found in Spanish caves that were used by Paleolithic people around 40,000 B.C. Gold is the "child of Zeus," wrote the Greek poet Pindar. The Romans called the yellow metal aurum ("shining dawn"). Gold is the first element and first metal mentioned in the Bible, where it appears in more than 400 references. This book provides the most thorough and up-to-date information available on the extraction of gold from its ores, starting with the miner alogy of gold ores and ending with details of refining. Each chapter con cludes with a list of references including full publication information for all works cited. Sources preceded by an asterisk (*) are especially recom mended for more in-depth study. Nine appendices, helpful to both students and operators, complement the text. I have made every attempt to keep abreast of recent technical literature on the extraction of gold. Original publications through the spring of 1989 have been reviewed and cited where appropriate. This book is intended as a reference for operators, managers, and designers of gold mills and for professional prospectors. It is also designed as a textbook for extractive metallurgy courses. I am indebted to the Library of Engineering Societies in New York, which was the main source of the references in the book. The assistance of my son, Panos, in typing the manuscript is gratefully acknowledged."

Surface engineering is an increasingly important field and consequently those involved need to be aware of the vast range of technologies available to modify surfaces. This text provides an up-to-date, authoritative exposition of the major condensed phase methods used for producing metallurgical and ceramic coatings. Each method is discussed thoroughly by an expert in that field. In each chapter the principle of the method, its range of applications and technical aspects involved are described. The book not only informs the reader about established technologies familiar only to specialists, but also details activity on the frontier of coating technology providing an insight into those potential technologies not yet fully developed but which should emerge in the near future.

textbook. Basic description is attempted, and the bibliography has been specifically chosen to guide the reader toward a fuller treatment of his special ised interests. No fully satisfactory term has yet emerged to describe the processing of minerals, which is also called "ore dressing," "mineral dressing," "mineral engineering" and, in the University of London degree course "mineral technology." The dressing of ores was an excellent description of the older processes which aimed to break down rock to appropriate sizes, grade it, and separate the heavy fraction from the light one in each grade or size by gravity methods. The work done in the mill today goes far beyond these simple operations, and requires some knowledge of physical chemistry, particularly the branches which deal with the physics and chemistry of surfaces and of the interphase between solid particle and the surrounding liquid. At the same time, the engineer must not become so absorbed in the study of fundamental and applied technology as a physico-chemical science that he overlooks the mechanical, economic, and humanistic aspects oli his work. He is an engineer, a chemist, a physicist, and an administrator and, as such, should have a sound scientifj. c and cultural education. Technically, his work is to extract the valuable minerals from the ore sent to his mill; economically, it is to balance all the financial costs and returns in such a way as to ensure the maximum profit from the operation."

The principal reasons which induced the authors to write this book and the features of the book are set forth in the preface to the Russian edition. That section of the science of metals which in Russian is called "metallovedenie" or the "physical chemistry of metals" is generally referred to in scientific and technical literature published in the English language by the term "physical metallurgy." These concepts are much broader than the term" metallography," used in the scientific and technical literature of various countries, and applied solely to research on the interrelationships of the structure and proper ties of metals and alloys. Each science must have its own subject and its own method of research. Certainly, all specialists will agree that metals and alloys, including their solid solutions, mechanical mix tures, and metallic compounds, form the subject of "physical metallurgy" or "physical chemis try of metals." The aim of this science. is to produce a theory and to elucidate the experimental relationships which ought finally to make it possible to calculate quantitatively alloys Of given properties for any working conditions and parameters."

This beryllium treatise was made possible by the expertise and hard work of members of the Joint US-UK Working Group on Beryllium (JOWOG 22), which was set up in the 1960s to allow a controlled exchange of technical information on the science and application of beryllium between the two countries. The leading roles in JOWOG 22 of Dr. Lee Roberts of the Lawrence Livermore Laboratory and Dr. Geoffrey Ellis ofthe Atomic Weapons Research Establishment (A WRE) at Aldermaston are particularly noteworthy. Excerpts from so me of the material in this book were presented at an international conference "Beryllium 77" in London in October 1977. The conference, which was superbly organized by Dr. John Martin and his co workers at A WRE, was sponsored by the Metals Society and the Institu tion of Metallurgists, and was particularly instructive in revealing the unexpectedly strong position of the USSR in some aspects of beryllium physical metallurgy and ductility improvement. Advance publicity for this book was also provided by presentations at the AlME 1977 annual meeting in Atlanta, Georgia. The presentations were co-sponsored by the Metal lurgy and Non-Ferrous Metals Committees at the request of committee members John E. Smugeresky and Gilbert J. London. D. Webster G. J. London vii Contents 1 * Introduction .... . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . .

Here is the first book to discuss the current understanding of silver metallization and its potential as a future interconnect material for integrated circuit technology. With the lowest resistivity of all metals, silver is an attractive interconnect material for higher current densities and faster switching speeds in integrated circuits. Over the past ten years, extensive research has been conducted to address the issues that have prevented silver from being used as an interconnect metal. The authors provide details on a wide range of experimental, characterization, and analysis techniques. The book is written for students, scientists, engineers, and technologists in the fields of integrated circuits and microelectronics research and development.