Keramisk teknologi og glasteknologi

The last 30 years have seen a steady development in the range of ceramic materials with potential for high temperature engineering applications: in the 60s, self-bonded silicon carbide and reaction-bonded silicon nitride; in the 70s, improved aluminas, sintered silicon carbide and silicon nitrides (including sialons); in the 80s, various toughened Zr0 materials, ceramic matrix composites reinforced with silicon 2 carbide continuous fibres or whiskers. Design methodologies were evolved in the 70s, incorporating the principles of fracture mechanics and the statistical variation and time dependence of strength. These have been used successfully to predict the engineering behaviour of ceramics in the lower range of temperature. In spite of the above, and the underlying thermodynamic arguments for operations at higher temperatures, there has been a disappointing uptake of these materials in industry for high temperature usc. Most of the successful applications are for low to moderate temperatures such as seals and bearings, and metal cutting and shaping. The reasons have been very well documented and include: ¿ Poor predictability and reliability at high temperature. ¿ High costs relative to competing materials. ¿ Variable reproducibility of manufacturing processes. ¿ Lack of sufficiently sensitive non-destructive techniques. With this as background, a Europhysics Industrial Workshop sponsored by the European Physical Society (EPS) was organised by the Netherlands Energy Research Foundation (ECN) and the Institute for Advanced Materials of the Joint Research Centre (JRC) of the EC, at Petten, North Holland, in April 1990 to consider the status of thermomechanical applications of engineering ceramics.

Corrosion behaviour is one of the most poorly understood characteristics of ceramics. A balanced mixture of scientists from material science, metallurgy, physics, chemistry and mineralogy sum up the state of the art of measurement and modelling and reveal future research directions. The book reviews the theory of corrosion of ceramics, including the diffusion of gases and the predictions of thermodynamics; it discusses critically the kinetic models and representation tools for layer growths and material destruction. Corrosion of nitrides, carbides and oxides by simple and complex gases (O2, H2O, SO2, halides) and melts (ionic and metallic) reveal current measurement and modelling methods, advanced experimental techniques, such as laser diagnostics, TV holography, Raman spectroscopy and NDE surface methods. Frontier areas (e.g. the modelling of porous materials corrosion and protection) are revealed. For scientists and engineers in materials science, dealing with ceramics and their application. A valuable source for research students, solid state physicists and physical chemists.

This book is an introductory work on the broad topics included in Materials Science. It encompasses a number of different materials classes and properties with a focus on the structure-property relationships between them. Each class of materials will include and discuss recycling techniques and other green methods of production. Materials Chemistry: For Scientists and Engineers is ideal for all newcomers to the fi eld as well as for those seeking a knowledge of solid state chemistry.

This three volume set presents papers from the first collaborative global metallurgy conference focused exclusively on extractive topics, including business and economic issues. Contributions examine new developments in foundational extractive metallurgy topics and techniques, and present the latest research and insights on emerging technologies and issues that are shaping the global extractive metallurgy industry. The book is organized around the following main themes: hydrometallurgy, pyrometallurgy, sulfide flotation, and extractive metallurgy markets and economics.

Materials Science and Fuel Technologies of Uranium and Plutonium Mixed Oxide offers a deep understanding of MOX properties for nuclear fuels that will be useful for performance evaluation. It also reviews fuel property simulation technology and an irradiation behavior model required for performance evaluation.

Wisdom is the principal thing; therefore get wisdom; and with all thy getting, get understanding. Proverbs 4:7 In the early chapters of the book of Proverbs there is a strong emphasis on three words: knowledge, understanding, and wisdom. Perhaps we can apply these words to our philosophy behind the technology of Predictive Process Control. Knowledge is the accumulation of information provided by education as we begin to store the data in our brains that should prepare us for the challenges of the manufacturing environment. It applies to every level and every opportunity of education, formal and informal. This is simply to Know, without any requirement except a good memory, and is the basis for the following two thoughts. Understanding is the assimilation of knowledge, or the thinking process, as we begin to arrange and rearrange the data we Know for quick recall as it may be needed. This also applies to every level and opportunity of education. It is Know-Why based upon what we Know, and it requires some scepticism of oversimplified answers and a hunger for mental consistency. Wisdom is the application of both knowledge and understanding in real life enterprises. As we apply both our knowledge and understanding in those situations, all three are further enhanced by each progressive experience. This is that wonderful Know-How - to apply our education based upon Know-why, which was based upon Knowledge - which provides the confidence we need to advance in all phases of performance.

It has been shown both experimentally {2} and theoretically {2,3} that surface skimming SH waves propagating along symmetry axes of the texture have velocities that differ in proportion to the magnitude of any stress that lies along one of the symmetry axes. Specifically, the stress is directly proportional to the relative velocity difference through the equation -,--V ik=---V. -=ki) ( I) cr. = 2G (-V ~ ik where cr. is the stress in the direction i, G is the shear modulus and Vik is the ~elocity of an SH wave propagating in the i direction and polarized in the k direction. This rather simple relationship is particularly useful because the constant of proportionality involves only the well known shear modulus and the velocity term can be measured directly by observing the transit time shift when a transmitter-receiver pair of SH wave transducers are rotated through 90 degrees on the surface of the part. Experimentally, Equation (I) was tested on the web of railroad rails which had been loaded by a 200,000 pound mechanical testing machine {I}. The method of exciting and detecting the necessary surface skimming SH waves used electromagnetic acoustic transducers (EMATs) that operated through a magnetostrictive mechanism at high magnetic fields {4}. Wave velocities parallel and perpendicular to the axis of the rail on the web differed by the amount predicted by Equation (I) to an absolute accuracy of 30 percent in the worst case.

This volume is the proceedings of the 3rd European Symposium on Engineering Ceramics, held in London, 28-29 November 1989, under the auspices of IBC Technical Services Ltd. The Symposium sessions were chaired by Eric Briscoe, who also introduced the Symposium with the very appropriate review 'Ceramics in Europe'. The term 'engineering ceramics' is commonly taken to mean a group of special high-strength and heat-resistant ceramic materials developed almost exclusively for the advanced internal combustion engine of the next century. It is not always fully appreciated that high grade fine microstructure ceramics both of the oxide and of the non-oxide classes, whether they be termed engineering, fine, special, advanced, structural or technical, have been supporting a large number of diverse and profitable industries over many decades. Indeed, in some respects these materials can be regarded as natural developments from the long­ established refractories field, and the distinction between an engineering ceramic and a refractory can become blurred, as the contribution in this volume on 'Nitride Bonded Carbide Engineered Ceramics' shows. It is of significance that in Japan, for example, much development work in the engineering ceramics field was initiated by the refractories industries, seeking to diversify possibly but doing so on the basis oflong experience in the refractories area. The main objective of this Symposium was to help engineers and designers to assess the present state of the field of engineering ceramics.

This volume is one in a series which attempts to bring together comprehensive articles on recent advances in ceramics. The volume is dedicated to Professor Shigeyuki Somiya on the occasion of his retirement from the Tokyo Institute of Technology; and it is a most fitting tribute. Professor Somiya has been one of the earliest and most persistent and versatile champions of research in ceramic materials in Japan. He has served this cause extraordinarily well by mixing two strategies. First, by making bridges to the entire international community of ceramic researchers in the US and Europe. Thereby, he kept a window for all of Japanese ceramic science on world class research in the field. It was largely through his efforts that the series of US-Japan International Cooperation Sessions in Ceram­ ics were started. I was honored to be US chairman of the first such in 1969. At Penn State we are delighted to claim Professor Somiya as an honorary alumnus. The high regard in which he is held is shown by the many of his colleagues from the University who have chosen to come over for this conference. He was also recognized with a Penn State MRL Bridge-Building award in 1988 to reflect his pioneering in establishing the two-way exchange with Japan.

This meeting, ZIRCONIA 'SS - Advances in Zirconia Science and Technology, was held within the framework of the 7tb SIMCER - International Symposium on Ceramics (Bologna, December 14-17, 1988) organized by the Italian Ceramic Center of Bologna, with the sponsorship of ENEA and Agip and the endorsement of the American Ceramic Society, and under the auspices of the European Ceramic Society. In the year 1988, the University of Bologna celebrated its 900th Anniversary. ZIRCONIA '88 was one of the celebration events which brought together academics and researchers from allover the world. Under the chairmanship of Prof. C. Palmonari, Director of the Italian Ceramic Center of the University of Bologna, the Organizing Committee consisting of J. Castaing (C.N.R.S. Meudon, France), S. Meriani (University of Trieste, Italy), V. Prodi (Un-iversity of Bologna, Italy) and J. Routbort (U.S. Dept. of Energy, Washington, USA) conducted a conference program of 47 contributions presented to the 220 enrolled Zirconia participants, out of the 775 enlisted within the main SIMCER framework. The aim of ZIRCONIA '88 was to follow the stream of the well known International Conferences on the Science and Technology of zj rconia held in Cleveland, Ohio (1980), Stuttgart, Federal Republic of Germany (1983) and Tokyo, Japan (1986). SIMCER's goal was to bring together not only scientists and engineers directly involved with "advanced" ceramics but also a larger audience connected to the nearby Italian Ceramic District of Sassuolo.

This volume contains the proceedings of the 2nd European Symposium on Engineering Ceramics held in London, 23-24 November 1987. The meeting was attended by almost 200 scientists and engineers, primarily drawn from industry, and the Sessions were chaired by Mr Eric Briscoe, past President of the Institute of Ceramics. Very effective symposium organisation was provided by IBC Technical Services Ltd. The engineering ceramics are a class of materials which has over some 50 years found well-established applications based on the materials' chemical stability and wear resistance. The last 20 years have seen intensified efforts to extend applications for these materials into areas traditionally occupied by metals, but in which the typical metallic weaknesses of wear, and of high temperature creep and oxidation, are now creating significant problems. These efforts have, however, in many cases been undermined on the one hand by the inherent ceramic weaknesses of brittleness and flaw sensitivity, and on the other by an inadequate understanding, and control, of the basic ceramic fabrication processes required for the low-cost mass production of relatively complex components. The positive results of the efforts of the last 20 years have been the development of a large new group of ceramic materials believed to possess intrinsic mechanical property advantages, of which the transformation toughened zirconias, and the ceramic matrix composites are good examples, together with improved powder production methods and powder shaping processes.

'!he present survey is the result of a ccrnprehensive study of patents and patent applications suhnitted in France, the Federal Republic of Gennany, the United Kingdan and Europe (Munich), p..!blished since 1976 and canprising !lOre than 750 publications, classified in accordance with the INl'ERNATICNAL PATENT CLASSIFI~TION, classes C 01 B; sub-classes 21, 33, 35; C 01 G, sub­ class 25; C 04 B, sub-class 35. '!he Ill3.jor part of the patents was granted to applicants fran the United Kingdan, the Federal Republic of Gennany, France, the United States of America and .Japan. Alt:hcA1gh the I.P.C. of basic refractories and ceramics produced therefran is !lOSt useful in assessing validity and in supporting "prior art" searches, it does not satisfy the requirements of scientists and technicians Who work in this field and Who are also interested in the oanposition of such Ill3.terials and the methods for producing them. As regards Part III, relating to finished products, it was decided to follow a classification based on specific parts of Ill3.chines and installations Where ceramics are !lOSt CClTITOnly applied. It should be observed that ceramic Ill3.chine parts and other ceramic canp:Jsitions are widely spread over the I.P.C. system, canprising !lOre than 10,000 docurrents published since 1975.

Corrosion behaviour is one of the most poorly understood characteristics of ceramics. A balanced mixture of scientists from material science, metallurgy, physics, chemistry and mineralogy sum up the state of the art of measurement and modelling and reveal future research directions. The book reviews the theory of corrosion of ceramics, including the diffusion of gases and the predictions of thermodynamics; it discusses critically the kinetic models and representation tools for layer growths and material destruction. Corrosion of nitrides, carbides and oxides by simple and complex gases (O2, H2O, SO2, halides) and melts (ionic and metallic) reveal current measurement and modelling methods, advanced experimental techniques, such as laser diagnostics, TV holography, Raman spectroscopy and NDE surface methods. Frontier areas (e.g. the modelling of porous materials corrosion and protection) are revealed. For scientists and engineers in materials science, dealing with ceramics and their application. A valuable source for research students, solid state physicists and physical chemists.

Recent developments in advanced ceramics are critically evaluated in respect to their thermal shock and thermal fatigue behavior from an interdisciplinary viewpoint by leading experts. The book covers the aspects of material development, mechanical and fracture mechanical models and experimental testing methods. Special emphasis is given to the influence of a rising crack resistance on the thermal shock behavior, novel irradiation testing methods for a quantitative characterization of the thermal shock and fatigue loading as well as detailed fracture mechanical models for single and multiple crack propagation. This book summarizes developments of the last decade concerning the thermal shock and thermal fatigue behavior of advanced ceramics. The scientific articles of the book were carefully arranged in order to achieve a textbook-like form which will be of great value to researchers and students. (ABSTRACT) This book summarizes developments of the last decade concerning the thermal shock and thermal fatigue behavior of advanced ceramics. The book covers the aspects of material development, mechanical and fracture mechanical models and testing methods. The scientific articles were carefully arranged in order to achieve a textbook-like form which will be of great value to researchers and students.

Ceramic Catalysts: Materials, Strategies and Applications focuses on synthesis techniques and applications of ceramic materials in heterogenous catalysis. In order to enable an affordable, sustainable, low-carbon economy, research activities have been intensified in this area over recent years. The rapid accumulation of results has been evaluated and summarized by recognized experts working in their respective fields in the form of separate and complementary chapters. The first part of the book is dedicated to synthesis and catalytic applications of different categories of ceramics that include both porous ceramics and ceramic composites. Catalytic applications of ceramics mainly involving waste-water treatment, combustion reactions, and fine chemical synthesis are also discussed. Use of ceramics as catalyst supports is also given importance in the book. The book is intended to act as a valuable reference resource for both researchers and postgraduate students with key emphasis on the following areas of research: Recent techniques for the synthesis of different ceramics; specific characteristics of each type of ceramics for catalytic applications; different types of catalyzed reactions based on inherent chemical characteristics and sustainable technologies based on ceramic catalysts. The book will be an essential reference resource for industrial and academic researchers, materials scientists, chemists, and environmental scientists.