Download or read book Transformation Toughening Of Ceramics written by David J. Green and published by CRC Press. This book was released on 2018-02-06 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this book is to provide a coherent and up-to-date discussion of the scientific work concerning the transformation toughening of ceramics. We hope the book is useful to scientists, engineers and students who are new to these materials. It is intended both as a source of learning and information to those who are new to these materials. It is intended both as a source of learning behaviour and microstructural relationships in transformation-toughened ceramics. While it has been our aim to present a book that is current as possible at the time of publication, the subject is still expanding in many areas; so our hope is that the reader will also gain an insight into the direction of future advances.

Download or read book Transformation Toughening of Composite Ceramics written by and published by . This book was released on 1990 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt: Research is underway into the application of martensitic transformations in ceramics to toughen a variety of ceramic-ceramic composites, i.e., to reduce their brittleness. The toughening agents of interest and their volume changes are dicalcium silicate (Ca2SiO4, 12%), nickel sulfide (NiS, 4%), lanthanide sesquioxides (Ln2O3, 8%) and lutentium borate (LuBO3, 8%). Ceramic processing routes have been developed to fabricate different types of toughened composites, viz., either by using a dispersed second phase microstructure or as a fine grained, single phase material. Specifically, Ca2SiO4 has been dispersed in CaZrO3 and the mechanical properties measured by bend tests. The critical importance of matrix toughness and grain size, as well as role of intergranular microcracking has been established. Dense pellets of fine grained, pure beta- Ca2SiO4 have been sintered and their transformability by grinding established. Their microstructures were examined by TEM and preliminary micromechanical studies made on it, and on Gd2O3, by indentation and SEM techniques. NiS inclusions in glass were examined by TEM and EDS and a sol gel processing route to precipitate NiS in glass has been identified. Composites of Dy2O3 in SiC and powders of LuBO3 in B2O3 have been fabricated.

Download or read book Tailoring Multiphase and Composite Ceramics written by Richard E. Tressler and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 783 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Martensitic Transformation written by Zenji Nishiyama and published by Elsevier. This book was released on 2012-12-02 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt: Martensitic Transformation examines martensitic transformation based on the known crystallographical data. Topics covered range from the crystallography of martensite to the transformation temperature and rate of martensite formation. The conditions for martensite formation and stabilization of austenite are also discussed, along with the crystallographic theory of martensitic transformations. Comprised of six chapters, this book begins with an introduction to martensite and martensitic transformation, with emphasis on the basic properties of martensite in steels such as carbon steels. The next two chapters deal with the crystallography of martensite and discuss the martensitic transformation behavior of the second-order transition; lattice imperfections in martensite; and close-packed layer structures of martensites produced from ? phase in noble-metal-base alloys. Thermodynamical problems and kinetics are also analysed, together with conditions for the nucleation of martensite and problems concerning stabilization of austenite. The last chapter discusses the theory of the mechanism underlying martensitic transformation. This monograph will be of interest to metallurgists and materials scientists.

Download or read book Transformation Toughening Of Ceramics written by David J. Green and published by CRC Press. This book was released on 2018-02-06 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this book is to provide a coherent and up-to-date discussion of the scientific work concerning the transformation toughening of ceramics. We hope the book is useful to scientists, engineers and students who are new to these materials. It is intended both as a source of learning and information to those who are new to these materials. It is intended both as a source of learning behaviour and microstructural relationships in transformation-toughened ceramics. While it has been our aim to present a book that is current as possible at the time of publication, the subject is still expanding in many areas; so our hope is that the reader will also gain an insight into the direction of future advances.

Download or read book Microstructurally Developed Toughening Mechanisms in Ceramics Transformation Toughening in the A1 Sub 2 O Sub 3 ZrO Sub 2 Composite System written by F. F. Lange and published by . This book was released on 1979 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: Three A1203/ZrO2 composites series, containing 0, 2, and 7.5 mole % Y203, respectively, were fabricated. For the A1203/ZrO2(+2M/oY203) series, tetragonal ZrO2 was retained from one end-member to the other. Significant increases in fracture toughness and strength were observed for materials in this system. Strengths decreased with increasing temperature. These results are consistent with previous theoretical predictions. (Author).

Download or read book Mechanics of Transformation Toughening and Related Topics written by J.H. Andreasen and published by Elsevier. This book was released on 1996-05-01 with total page 541 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the benefit of stress-induced tetragonal to monoclinic phase transformation of confined tetragonal zirconia particles was first recognized in 1975, the phenomenon has been widely studied and exploited in the development of a new class of materials known as transformation toughened ceramics (TTC). In all materials belonging to this class, the microstructure is so controlled that the tetragonal to monoclinic transformation is induced as a result of a high applied stress field rather than as a result of cooling the material below the martensitic start temperature. The significance of microstructure to the enhancement of thermomechanical properties of TTC is now well understood, as are the mechanisms that contribute beneficially to their fracture toughness. The micromechanics of these mechanisms have been extensively studied and are therefore presented here in a cogent manner. The authors also review dislocation formalism for the modelling of cracks and Eshelby's technique. In compiling this monograph the authors present the most up-to-date and complete review of the field and include several topics which have only recently been fully investigated.

Download or read book Transformation Toughening of Ceramics written by and published by . This book was released on 1995 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes the results from a 3-year research program aimed at developing a basic understanding of the microstructural design, fabrication, and properties of multilayered zirconia-based composites with high toughness and oxidation resistance. Most of the effort focused on multilayered composites of Ce-ZrO2 and Al2O3 which have strongly bonded interfaces. The design of the layered composite microstructure was based on micromechanics analysis: the layers modify the shape and extent of a crack tip transformation zone, leading to toughnesses over 20 MPa.m1/2. Optimum layer thicknesses were determined and related to effects of autocatalytic transformation and crack tip advance mechanisms. Crack resistance curves were measured at various temperatures: the very high toughnesses (> 10 MPa.m1/2) were limited to temperature range of approx. 100 deg C above the Ms temperature for the martensitic transformation. A preliminary study of multilayered composites containing weakly bonded layers (which achieve toughening by debonding) indicated that rare earth phosphates (LaPO4 and CePO4) are potentially suitable layers for Y- and Ce-stabilized zirconia composites. jg.

Download or read book Bioceramics and Biocomposites written by Iulian Antoniac and published by John Wiley & Sons. This book was released on 2019-04-04 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides comprehensive coverage of the research into and clinical uses of bioceramics and biocomposites Developments related to bioceramics and biocomposites appear to be one the most dynamic areas in the field of biomaterials, with multiple applications in tissue engineering and medical devices. This book covers the basic science and engineering of bioceramics and biocomposites for applications in dentistry and orthopedics, as well as the state-of-the-art aspects of biofabrication techniques, tissue engineering, remodeling, and regeneration of bone tissue. It also provides insight into the use of bionanomaterials to create new functionalities when interfaced with biological molecules or structures. Featuring contributions from leading experts in the field, Bioceramics and Biocomposites: From Research to Use in Clinical Practice offers complete coverage of everything from extending the concept of hemopoietic and stromal niches, to the evolution of bioceramic-based scaffolds. It looks at perspectives on and trends in bioceramics in endodontics, and discusses the influence of newer biomaterials use on the structuring of the clinician’s attitude in dental practice or in orthopedic surgery. The book also covers such topics as biofabrication techniques for bioceramics and biocomposites; glass ceramics: calcium phosphate coatings; brain drug delivery bone substitutes; and much more. Presents the biggest trends in bioceramics and biocomposites relating to medical devices and tissue engineering products Systematically presents new information about bioceramics and biocomposites, developing diagnostics and improving treatments and their influence on the clinicians' approaches Describes how to use these biomaterials to create new functionalities when interfaced with biological molecules or structures Offers a range of applications in clinical practice, including bone tissue engineering, remodeling, and regeneration Delineates essential requirements for resorbable bioceramics Discusses clinical results obtained in dental and orthopedic applications Bioceramics and Biocomposites: From Research to Use in Clinical Practice is an excellent resource for biomaterials scientists and engineers, bioengineers, materials scientists, and engineers. It will also benefit mechanical engineers and biochemists who work with biomaterials scientists.

Download or read book Silicon Carbide Ceramics 1 written by S. Somiya and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: Discovered by Edward G. Acheson about 1890, silicon carbide is one of the oldest materials and also a new material. It occurs naturally in meteorites, but in very small amounts and is not in a useable state as an industrial material. For industrial require ments, large amounts of silicon carbide must be synthesized by solid state reactions at high temperatures. Silicon carbide has been used for grinding and as an abrasive material since its discovery. During World War II, silicon carbide was used as a heating element; however, it was difficult to obtain high density sintered silicon carbide bodies. In 1974, S. Prochazka reported that the addition of small amounts of boron compounds and carbide were effective in the sintering process to obtain high density. It was then possible to produce high density sintered bodies by pressureless sintering methods in ordinary atmosphere. Since this development, silicon carbide has received great attention as one of the high temperature structural ceramic materials. Since the 1970s, many research papers have appeared which report studies of silicon carbide and silicon nitride for structural ceramics.

Download or read book Designing with Structural Ceramics written by R.W. Davidge and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Advances in Ceramic Matrix Composites VIII written by J. P. Singh and published by John Wiley & Sons. This book was released on 2012-04-11 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ceramic composites are leading candidate materials for high-temperature structural applications. This new book updates readers on the latest in state-of-the-art ceramic composite processing and fabrication methods, process modeling, processing-microstructure-property relationships, mechanical behavior, and characterization. Many of the most important aspects necessary for the understanding and further development of ceramic composites is covered in this volume. It will be of great interest to the technical community involved in advanced ceramic composite processing, characterization, component development, and manufacturing. Proceedings of the symposium held at the 104th Annual Meeting of The American Ceramic Society, April 28-May1, 2002 in Missouri; Ceramic Transactions, Volume 139.

Download or read book Advanced Structural Ceramics written by Bikramjit Basu and published by John Wiley & Sons. This book was released on 2011-09-26 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the area of advanced ceramic composites broadly, providing important introductory chapters to fundamentals, processing, and applications of advanced ceramic composites. Within each section, specific topics covered highlight the state of the art research within one of the above sections. The organization of the book is designed to provide easy understanding by students as well as professionals interested in advanced ceramic composites. The various sections discuss fundamentals of nature and characteristics of ceramics, processing of ceramics, processing and properties of toughened ceramics, high temperature ceramics, nanoceramics and nanoceramic composites, and bioceramics and biocomposites.

Download or read book The Shearing Contribution in Transformation Toughening of Brittle Materials written by P. Sofronis and published by . This book was released on 1985 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: A simple constitutive law is proposed for the description of a ceramic composite which undergoes stress induced martensitic transformation. This law is used in finite element calculations to investigate the shear effect on the transformation zone near a crack tip. A formula describing the stress intensity factor change due to the shear contribution of the transformation is given. Significant loss of toughness is observed in the case of a stationary crack and is attributed entirely to the shear component of the transformation is given. Significant loss of toughness is observed in the case of a stationary crack and is attributed entirely to the shear component of the transformation. As the crack grows, the wake of the transformed material left behind the crack constitutes a source of toughening. This toughening is due to both dilatancy and shear in the phase change and rises to a maximum level just after a propagation comparable with the zone height. Finally, it is shown that the shear component can be important when prediction of the fracture toughness of the transformation toughened ceramics are made.

Download or read book Tribology of Ceramics and Composites written by Bikramjit Basu and published by John Wiley & Sons. This book was released on 2011-10-07 with total page 550 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book helps students and practicing scientists alike understand that a comprehensive knowledge about the friction and wear properties of advanced materials is essential to further design and development of new materials. With important introductory chapters on the fundamentals, processing, and applications of tribology, the book then examines in detail the nature and properties of materials, the friction and wear of structural ceramics, bioceramics, biocomposites, and nanoceramics, as well as lightweight composites and the friction and wear of ceramics in a cryogenic environment.

Download or read book Theory of Ceramic Zirconia Composites Toughening Strengthening and Synergism written by B. Budiansky and published by . This book was released on 1990 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: A review is given of recent theoretical results concerning toughening and strengthening in brittle ceramics reinforced with dilatantly transforming zirconia particles. Small-scale analysis of 'long' dominant cracks provides resistance curves that exhibit peak fracture toughnesses for finite amounts of crack growth. Similar results for the tensile fracture strengths of 'short' cracks have implications for transformation strengthening. The interaction due to the presence of both transforming particles and ductile metal particles can result in synergistic reinforcing effects over a parametric range of material properties. Keywords: Ceramic materials, Zirconium alloys, Particle reinforcements, Mechanical properties, Crystal structure, Transformation toughening, Transformation strengthening, Synergism. (JG).

Download or read book Toughening Mechanisms in Quasi Brittle Materials written by S.P. Shah and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 590 pages. Available in PDF, EPUB and Kindle. Book excerpt: A variety of ceramic materials has been recently shown to exhibit nonlinear stress strain behavior. These materials include transformation-toughened zirconia which undergoes a stress-induced crystallographic transformation in the vicinity of a propagating crack, microcracking ceramics, and ceramic-fiber reinforced ceramic matrices. Since many of these materials are under consideration for structural applications, understanding fracture in these quasi-brittle materials is essential. Portland cement concrete is a relatively brittle material. As a result mechanical behavior of concrete, conventionally reinforced concrete, prestressed concrete and fiber reinforced concrete is critically influenced by crack propagation. Crack propagation in concrete is characterized by a fracture process zone, microcracking, and aggregate bridging. Such phenomena give concrete toughening mechanisms, and as a result, the macroscopic response of concrete can be characterized as that of a quasi-brittle material. To design super high performance cement composites, it is essential to understand the complex fracture processes in concrete. A wide range of concern in design involves fracture in rock masses and rock structures. For example, prediction of the extension or initiation of fracture is important in: 1) the design of caverns (such as underground nuclear waste isolation) subjected to earthquake shaking or explosions, 2) the production of geothermal and petroleum energy, and 3) predicting and monitoring earthquakes. Depending upon the grain size and mineralogical composition, rock may also exhibit characteristics of quasi-brittle materials.