Materials Science Research – serie

The Proceedings of the International Materials Symposium on Ceramic Microstructures '86: Role of Interfaces presents a comprehensive coverage of the past decade's advances in ceramic science and technology related to microstructures. The term microstructure is used in the broad sense and is synonymous with char~cter. Character is defined as a complete detailed description of chemical and physical characteristics of a material. This symposium is the third in a series, held every ten years, on ceramic microstructures. The first symposium, in 1966, had as a subtitle "Their Analysis, Significance and Production" and emphasized the need and importance of characterization in order to fully understand the chemical and physical properties of materials. The second Symposium, in 1976, placed emphasis on the exploration of characters most suited and needed for "Energy-Related Applications." By the time of that conference, the sequence of processing--characterization--properties was fully accepted. It was recognized that characterization was the basis of materials science; the objective of processing was to produce a desired character that was considered necessary to realize a given property or behavior. To further emphasize the importance of character, the symposium dealt primarily with the property/character coupling.

The proceedings of the Twenty-First University Conference on Ceramic Science held at The Pennsylvania State University, University Park, PA on July 17, 18 and 19, 1985 are compiled in this volume "Tailoring Multiphase and Composite Ceramics". This Conference emphasized the' discussion and analysis of the properties of multiphase ceramic materials in which the microstructure is deliberately tailored for specific applications or properties. Inter­ nationally recognized authorities presented keynote and invited lectures on topics dealing with processing and fabrication of multiphase and com­ posite electroceramics, fiber reinforced composites and high temperature multiphase ceramics. Results of recent research were presented in oral and poster sessions by leading researchers from several countries. This collection of papers represents the state of the art in our understand­ ing of the processing-structure-property interrelationships for these materials which possess unique and useful electrical, magnetic, optical, mechanical and thermal properties as a result of their multiphase nature. We are grateful for the financial support of the National Science Foundation, the Office of Naval Research, the Air Force Office of Scien­ tific Research, and the Defense Advanced Research Projects Agency for this conference. We gratefully acknowledge Prof. Robert Davis' leader­ ship role in steering and expanding this university conference series on ceramic science. We thank Ron Avillion and Linda Rose for their expert assistance in planning and coordinating the meeting. Thanks are due to Ms. Marian Reed, Ms. Judy Bell and Ms.

The Sixth International Conference on Sintering and Related Phenomena took place at the University of Notre Dame, Notre Dame, Indiana June 6-8, 1983. This conference was also the twentieth Conference on Ceramic Sciences organized yearly by a "confederation" of four institutions: North Carolina University at Raleigh, N.C., the University of California at Berkeley, CA, Alfred University at Alfred, NY and the University of Notre Dame, Notre Dame, IN. The papers presented at the last Notre Dame conference collect­ ed in this volume, reflect the progress in our understanding of the process of sintering achieved in the past four years. It seems that the analysis of the two particle models is finally extended to the analysis of the models of compacts. In these investigations strong emphasis is put on pore-grain boundar­ ies interaction which appear to be central to this problem. It is to be hoped that in the near future an adequate model of the compact will be developed which may serve as a useful basis of powder tech­ nology. Also, the effects of atmosphere on the sintering of ceramics after a long period of neglect, seem to attract the attention of more workers in the field.

This volume "Deformation of Ceramic Materials II" constitutes the proceedings of an international symposium held at The Pennsyl­ vania State University, University Park, PA on July 20, 21, and 22, 1983. It includes studies of semiconductors and minerals which are closely related to ceramic materials. The initial conference on this topic was held in 1974 at Penn State and the proceedings were published in the volume entitled "Deformation of Ceramic Materials." This conference emphasized the deformation behavior of crystals and po1ycrysta11ine and polyphase ceramics with internationally recognized authorities as keynote lecturers on the major subtopics. Several papers dealing with cavity nucleation and creep crack growth represent a major new research thrust in ceramics since the first conference. This collection of papers represents the state-of-the art of our understanding of the plastic deformation behavior of ceramics and the crystals of which they are composed. We are grateful for the suggestions of our International Advisory Committee .in recommending experts in their respective countries to participate. We are particularly grateful that the organizers of the previous Dislocation-Point Defect Interaction Workshops agreed to participate in the Penn State Symposium as an alternative at the suggestion of Prof. A. H. Heuer. We acknowledge the financial support of the National Science Foundation for this conference.

The characterization of materials and phenomena has historically been the principal limitation to the development in each area of science. Once what we are observing is well defined, a theoretical analysis rapidly follows. Modern theories of chemical bonding did not evolve until the methods of analytical chemistry had progressed to a point where the bulk stoichiometry of chemical compounds was firmly established. The great progress made during this century in understanding chemistry has followed directly from the development of an analytical chemistry based on the Dalton assumption of multiple proportions. It has only become apparent in recent years that the extension of our understanding of materials hinges on their non-stoichiometric nature. The world of non-Daltonian chemistry is very poorly understood at present because of our lack of ability to precisely characterize it. The emergence of materials science has only just occurred with our recognition of effects, which have been thought previously to be minor variations from ideality, as the principal phenomena controlling properties. The next step in the historical evolution of materials science must be the development of tools to characterize the often subtle phenomena which determine properties of materials. The various discussions of instrumental techniques presented in this book are excellent summaries for the state-of-the-art of materials characterization at this rather critical stage of materials science. The application of the tools described here, and those yet to be developed, holds the key to the development of this infant into a mature science.

In this volume there is set forth the text of the Pro­ ceedings of the Third International Conference on Sintering and Related Phenomena, which conference was held at the University of Notre Dame on June 5-7, 1972. This conference was the seventh in the series of University Conferences on Ceramic Science organized yearly by a happy "confederation" of four institutions; North Carolina State University, Raleigh, North Carolina; the University of California, Berkeley, California; Alfred University, Alfred, New York; and the University of Notre Dame, Notre Dame, Indiana. The 1972 Conference at Notre Dame was devoted to prob­ lems of sintering and allied phenomena. Previous gatherings at Notre Dame took place in 1954 and 1965. The proceedings of the first Notre Dame Conference were not published by reason of the conviction that a free forum similar in spirit to the Gordon Conferences should prevail. However, discus­ sions of the second Conference were preserved for posterity in a rather substantial volume (894 pp) published by Gordon and Breach in 1967. As the spirit of free exchange of ideas was not diminished by threat of publication of the revela­ tions of the second Notre Dame Conference, we deemed it just that the 1972 Proceedings be made public. Thus the present volume is a report upon progress realized in our science during the past six years.

This book represents the proceedings of the second inter­ disciplinary conference on materials characterization held from July 30 through August 3, 1984 at the New York State College of Ceramics at Alfred University. The conference was the 20th in the University Series on Ceramic Science, instituted in 1964 by Alfred University, the University of California at Berkeley, North Carolina State University and Notre Dame University. Volume I of the proceedings of the first conference using this interdisciplinary approach to materials characterization was published as "Advances in Materials Characterization", edited by D. R. Rossington, R. A. Condrate and R. L. Snyder, and was listed as volume 15 of the Materials Science Research series of Plenum Press (New York, 1983). The purpose of bringing together scientists from a wide range of disciplines to present and discuss the latest developments in their fields is to promote cross fertilization. The first conference of this type and its resulting volume of proceedings stimulated a significant dialogue between disciplines concerning the characterization of materials, therefore indicating a need for a continuing series of such conferences. Characterization lies at the core of materials science.

The proceedings of the 4th International Conference on Sin­ tering and Related Phenomena, contained in this volume, have been broadened in scope to include the phenomena of sintering and coa­ lescence of catalytic materials dispersed upon refractory oxides. For it has long been recognized within the circles of chemists and chemical engineers working in the field of catalysis that one of the chief causes of the decline in heterogeneous catalytic activity and/or selectivity is, indeed sintering, or perhaps using a better term, coalescence of the supported catalytic metal and compounds thereof. Essentially catalytic deactivation by sintering is now weIl recognized as Ostwald ripening; which of course is a phenome­ non familiar to scientists grappling with the problem of sintering of powder compacts. The 4th Conference at Notre Dame marks the first occasion at which scientists and engineers of each discipline were assembled in the same room to exchange views on these phenome­ na of mutual concern. In the wake of the Conference at Notre Dame, all parties acknowledged the synergistic benefit which issued from this exchange, both at the formal and informal level. All were persuaded that signal benefits will be realized by a continuation of this collab­ oration in the form of future sintering conferences in which both powder metallurgists and catalytic scientists and engineers would participate.

This volume constitutes the Proceedings of the Sixth University Conference on Ceramic Science which was held at North Carolina State University in Raleigh, December 7-9, 1970. Previous host institutions and resultant publications in this ongoing series have been: 1. North Carolina State University, November 16-18, 1964. W. W. K:r>iegeZ and H. PaZmour III~ Eds. ~ The RoZe of Grain Boundaries and Surfaaes in Ceramias. 631 pp.~ Mater'iaZs Saienae Researah~ Vol-. 3~ PZenwn P1'eSs~ New York~ 1966 . * 2. University of Notre Dame, June 21-23, 1965. G. C. Kuazynski~ N. A. Hooten and C. F. Gibbon~ Eds.~ Sintering and ReZated Phenomena~ 894 pp. Gordon and Breaah Saienae PubZishers~ Ina.~ New York~ 1967. 3. University of California at Berkeley, June 13-16, 1966. R. M. FuZrath and J. A. Pask~ Eds.~ Ceramia ~arostruatures- Their AnaZysis~ Signifiaanae and Produatidn. 1008 pp. John WiZey & Sons~ Ina.~ New York~ 1968. 4. State University of New York, College of Ceramics at Alfred University, June 18-23, 1967. T. J. Gray and V. D. Freahette~ Eds.~ Kinetias of Reaations in Ionia SoZids. 571 pp. MateriaZs Saienae Researah~ VoZ. 4~ PZenwn Press~ New York~ 1969. 5.University of Florida, Novem1:>er 10-14, 1969. L. L. Henah and D. B. Dove~ Eds.~ Physias of EZeatronia Ceramias. M. Dekker~ Ina. (In Press).

Awarenes s of the great significance of surface consti- tution in understanding the behavior and perforITlance of ITlaterials has been growing in proportion to the ITleans which have becoITle available for surface study. Recent years have seen iITlportant advances in analytical tools and ITlethods; their applications to date will certainly suggest ITlany other fruitful lines of investigation. The Conference "Surfaces and Interfaces of Glass and CeraITlics" held at the New York State College of CeraITlics at Alfred University under the sponsorship of the U. S. ArITly Research Office, DurhaITl, and the National Aeronautics and Space AdITlinistration, in August 1973, was tenth in the Uni- versity Series in CeraITlic Science, held in rotation aITlong North Carolina State University, the University of California at Berkeley, the University of Notre DaITle and Alfred Uni- versity. The chapters are arranged in order of their particular eITlphasis beginning with those principally concerned with analytical ITlethods.Chapters dealing with friction and wear follow, highly topical in the present-day concern with effi- cient use of energy in finishing processes, on the one hand, and the avoidance of preITlature failure by frictional daITlage to ITloving parts on the other. Surface reactions are then considered, including the iITlportant questions of physiological interactions with ceraITlic candidates for prosthetic applica- tions. Material-ITlaterial interfaces and transition zones are discussed through exaITlples which include grain bound- aries in ceraITlics as well as interfaces aITlong various solid, liquid and gaseous phases.

The Conference on Emerging Priorities in Ceramic Engineer­ ing and Science, held at Alfred University, November 4-6, 1974, was arranged to provide a basis for reassessment of professional goals, procedures and outlook. American priorities among comfort, safety, national prestige, security, convenience and environmental quality are significantly different from those of a dozen years ago. Economic factors have shifted, as exempli­ fied by scarcities in energy, mate rials and world food supplies. At the same time, demands for safer products, healthier work­ ing conditions and fairer rules of behavior are making them­ selves felt. Governmental, corporate and consumer interests are all involved and they are intricately inte rrelated. Higher education, for its part, must not only respond wisely to changing student attitude, itself a part of the national scene, but must gain perspective toward the present and toward changes of yet unknown nature which can be expected in the future. Persistent and pointed questions from engineers, managers, and students were an indication to us of wide-spread concern to understand the new pattern of priorities that is presently emerging. In response to this need, Conference papers were invited from distinguished engineers, scientists, and other specialists; their willingness to contribute from their expertise and their thinking is very much appreciated by the editors. The first four chapters of the volume deal with the larger scene and with the viewpoints of those concerned with it in behalf of government, corporations and the professions.

The Eleventh University Conference on Ceramic Science held at Case Western Reserve University fran June 3 - 5, 1974 was devoted to the subject of M:l.ss Transport Phenanena in Ceramics. '!his book follows closely the fonn of the oonference. While the active participation at the meeting was not reoorded, it is clear that many of the contributors have benefited fran the ranarks, suggestions, and criticisms of the participants. Fur- thennore, the session chainnen -- Delbert Day (Univ. of Missouri), WU. IaCourse {AlfrErl Univ.) , W. Richard ott (Rutgers Univ.) , A.L. FriErlberg (Univ. of Illinois), v. Stubican (Penn. State Univ.), and R. Loehman (Univ. of Florida) -- successfully kept the meeting to a reasonable schedule, but also stimulated the lively discussion. The book divides naturally into four sections, focusing on correlation and ooup1ing effects in diffusion in ionic materials, understanding of fast ion transport, diffusion and electrical con- ductivity in crystalline and glassy oxides and applications of diffusion to oxidation and other processes of current interest. The editors have benefited fran the cheerful help and assis- tance of many people. !-1rs.Karyn P1etka typed the entire manu- script with unusual accuracy and tolerance. Mr. MakmJd E1Lei1, Ajit Sane, Leslie M:l.jor and Ms. Jenny Sang provided the subject index. The authors have been cooperative and understanding and we ack.now1Erlge our enjoyment in working with them.

Boron Oxide plays a key role in numerous glasses of high technological importance, yet its role in glass structure is far from clear. Indeed, in recent years there have been serious chal­ lenges to previous structure concepts for both crystalline and glassy borates. These challenges were sufficient to warrant a re­ examination of the structure of borate glasses using the most pow­ erful tools currently available. To provide a suitable forum for this undertaking, a four-day conference on "Boron in Glass and Glass Ceramics" was convened at Alfred University, June 3-8, 1977 to review the best scientific thinking on structure and to debate conflicting views and discuss properties and applications of borate glasses. This conference was also the first in a New University series on Glass Science to be rotated among Alfred University, The Pensyl vania State University, Rensselaer Polytechnic Institute, and the University of Missouri-Rolla. The present volume represents the proceedings of the first conference in this series. The volume begins with a review of the remarkable contribution of Jan Krogh-Moe to the understanding of the structure of Borate glasses. This review, authored by Professor N. J. Kreidl, concludes by dedicating the proceedings of this conference as a Krogh-Moe Fest­ schrift. The volume continues with a historical review by D. L. Griscom, originally prepared for circulation to the contributors prior to the conference. An Epilogue to the opening chapter brings the survey up-to-date in light of the conference papers.

This volume constitutes the Proceedings of the November 7-9, 1977 Conference on PROCESSING OF CRYSTALLINE CERAMICS, held at North Carolina State University in Raleigh. It was the Fourteenth in a series of "University Conferences on Ceramic Science" initiated in 1964 and still coordinated by a founding group of four ceramic­ related institutions, of which North Carolina State University is a charter member, along with the University of California at Berkeley, Notre Dame University, and the New York State College of Ceramics at Alfred University. In addition, two other ceramic-oriented schools, the University of Florida and Case-Western Reserve University, have also hosted Conferences in the series. These research-oriented conferences, each uniquely concerned with a timely ceramic theme, have been well attended by audiences which typically were both inter­ national and interdisciplinary in character; their published Proceedings have been well received and are frequently cited. This three day conference was concerned with (a) scientific aspects of all process steps which must be combined and controlled effectively and sequentially in producing crystalline ceramics (both oxides and nonoxides), and (b) utilization of these principles in developing processes for several classes of advanced ceramics critical to present and future technology.

The 17th University Conference on Ceramics, which also was the 7th LBL/MMRD International Materials Symposium, was held on the campus of the University of California at Berkeley from July 28 to August 1, 1980. It was devoted to the subject of surfaces and interfaces in ceramic and ceramic-metal systems. The program was timely and of great interest, as indicated by the large number of contributed papers, which included contributions from ten foreign countries. These proceedings are divided into the following categories dealing with the chemistry and physics of interfaces: calculations of interface/surface states, characterization of surfaces and inter­ faces, thermodynamics of interfaces, influence of surface and inter­ faces on selected ceramic processes, grain boundary structures, effects of grain boundaries on deformation and fracture, interfacial phenomena, formation of interfaces, development of adhesion, and reactions at interfaces. A number of papers deal specifically with the Si-Si02 interface, which probably has received more attention than any other because of its importance in the electronics industry. This coverage fulfills the principal objective of the symposium which was to explore and assess the current fundamental understand­ ing of interfaces and surfaces. A parallel objective of the symposium was fulfilled by a group of papers dealing with the correlation of interfacial characteris­ tics with mechanical behavior. This group includes papers dealing with the adherence of dissimilar materials at interfaces.

This volume constitutes the Proceedings of the November 8-10, 1982 Conference on EMERGENT PROCESS METHODS FOR HIGH TECHNOLOGY CERAMICS, held at North Carolina State University in Raleigh. It was the nineteenth in a series of "University Conferences on Ceramic Sci­ ence" initiated in 1964 by four institutions of which North Carolina State University is a charter member, along with the University of California at Berkeley, Notre Dame University, and the New York State College of Ceramics at Alfred University. More recently, ceramic­ oriented faculty in departments at the Pennsylvania State University and Case-Western Reserve University have joined the four initial institutions as permanent members of the consortium. These research­ oriented conferences, each uniquely concerned with a timely ceramic theme, have been well attended by audiences which typically were both international and interdisciplinary in character; their published Proceedings have been well received and are frequently cited. This three day conference addressed the fundamental scientific background as well as the technological state-of-the-art of several novel methods which are beginning to influence present and future directions for non-traditional ceramic processing, thus affecting many of the advanced ceramic materials needed for a wide variety of research and industrial applications. The number, the importance and the application of new ceramic processing techniques have expanded considerably during the last ten years.