Download or read book Indentation Creep in Crystals at Low Homologous Temperatures written by Walter Wyrick Walker and published by . This book was released on 1968 with total page 672 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Creep of Crystals written by Jean-Paul Poirier and published by Cambridge University Press. This book was released on 1985-02-28 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook describes the physics of the plastic deformation of solids at high temperatures. It is directed at geologists or geophysicists interested in the high-temperature behaviour of crystals who wish to become acquainted with the methods of materials science in so far as they are useful to earth scientists. It explains the most important models and recent experimental results without losing the reader in the primary literature of materials science. In turn the book deals with the essential solid-state physics; thermodynamics and hydrostatics of creep; creep models and their applications in the geological sciences; diffusion creep; superplastic deformation and deformation enhanced by phase transformations. Five concluding chapters give experimental results for metals, ceramics and minerals. There are extensive bibliographies to aid further study.
Download or read book Indentation Fracture and Mechanical Properties of Ceramic Fuels and Glasses written by Commission of the European Communities and published by CRC Press. This book was released on 1979 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Nanoindentation Size Effects of Creep written by Han Li and published by . This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "The Nanoindentation Size Effects of Creep" by Han, Li, 李晗, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled: The Nanoindentation Size Effects of Creep Submitted by LI, Han for the degree of Master of Philosophy at The University of Hong Kong in December, 2004 Nanoindentation provides convenient and localized measurements of the mechanical properties of materials, and is an especially useful technique for the study of thin films and materials of small volumes. Previous investigations showed that the submicron contacts with the rigid indenting punch could yield creep at an enormous speed at low homologous temperatures, where the same material in bulk condition would normally not exhibit any creep. The influence of this time dependent deformation on the calculation of material properties has been investigated, and compensation methods have been proposed, but the fundamental mechanisms leading to such a high creep rate remain unknown. It would also be interesting to establish if creep behavior and its mechanisms change as the indent size diminishes towards incipient plasticity, and if so, how. The aim of this study is therefore to investigate the characteristics and mechanisms of the nanoindentation creep in different materials over a wide range of indent sizes (from several nm to above one micron). A depth-sensing, constant load creep test was used to measure the stress exponent, chosen to quantify indentation creep behavior, at different indentation sizes on both Ni Al (111) single crystal, polycrystalline Al, amorphous fused quartz and nanocrystalline Ni-at25%Al alloy films with a spectrum of grain sizes. bExperimental results demonstrated that the stress exponents in all materials increased significantly as the indent size increased, exhibiting an intense size effect. The near unity stress exponent of Al in the smallest indent suggests that the creep mechanism is likely to be diffusional flow, and a simple pipe-diffusion model is proposed as a theoretical explanation. For the amorphous fused quartz, the size effect on the stress exponent can be explained by a reduction of the localized shear volume as the indent size decreases. For the nanocrystalline thin films with different average grain sizes, the stress exponent was also found to increase with grain size at the same nominal peak load. This is ascribed to the operation of increasing dislocation activities near grain boundaries at larger grain sizes. A preliminary study of the initial contact behavior of a nanocrystalline film during nanoindentation is also presented. It is well known that single crystals with low defect densities can support stresses near the theoretical limit without yielding, and incipient plasticity is usually manifested in the indentation curve as a sudden displacement burst, associated with dislocation nucleation and multiplication. The initial contact deformation of nanocrystalline materials appears to be more complicated and less well documented. Through nanometer scale indentation tests on a nanocrystalline Ni-25at.%Al alloy thin film, three representative deformation modes were observed by immediate pre and post-indentation atomic force microscopy. One exhibited near elastic deformation, with elastic modulus equal to the upper limit for all loads and even close to the bulk value. In the other two modes, the deformation was elastoplastic from the very beginning. Strain burst was rarely observed. 473 words (main body) DOI: 10.5353/th_b3069638 Subje
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1990 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Crystal Indentation Hardness written by Ronald W. Armstrong and published by MDPI. This book was released on 2018-07-05 with total page 335 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a printed edition of the Special Issue "Crystal Indentation Hardness" that was published in Crystals
Download or read book Science of Hard Materials written by R. Viswanadham and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 990 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains the proceedings of the first International Conference on the Science of Hard Materials held in Moran, Wyoming, Aug. 23-28, 1981. The objective of the conference was to review and advance the state of knowledge of the basic physical and chemical properties of hard materials and show how these properties influence performance in a variety of applications. To this end, the 49 con tributed papers and the four keynote papers by Prof. Fischmeister and Drs. Hintermann, Exner and Almond, present an excellent overview of the state of the art in the "science" of hard materials. The contents of these proceedings also reflect the fact that hard metal technology is now well matured and several aspects of the behavior of these materials are well understood and firmly established. Structure-property relationships in this class of materials are currently well known. Pitfalls in some of the traditional test methods have been recognized and new test methods are being developed which discriminate between intrinsic material properties and flaw content and distribution. Application of fracture mechanics, al though a late corner to the hard materials area (as compared to other structural materials), is rapidly gaining acceptance and new fracture toughness test methods are being developed. Application of modern analysis and analytical techniques to these materials has begun and entirely new and unexpected information has been obtained. For a variety of reasons, "hard metals" have dominated the research and development scene of "hard materials".
Download or read book Fundamentals of Creep in Metals and Alloys written by Michael E. Kassner and published by Elsevier. This book was released on 2004-04-06 with total page 289 pages. Available in PDF, EPUB and Kindle. Book excerpt: * Numerous line drawings with consistent format and units allow easy comparison of the behavior of a very wide range of materials * Transmission electron micrographs provide a direct insight in the basic microstructure of metals deforming at high temperatures * Extensive literature review of over 1000 references provide an excellent reference document, and a very balanced discussion Understanding the strength of materials at a range of temperatures is critically important to a huge number of researchers and practitioners from a wide range of fields and industry sectors including metallurgists, industrial designers, aerospace R&D personnel, and structural engineers. The most up-to date and comprehensive book in the field, Fundamentals of Creep in Metals and Alloys discusses the fundamentals of time-dependent plasticity or creep plasticity in metals, alloys and metallic compounds. This is the first book of its kind that provides broad coverage of a range of materials not just a sub-group such as metallic compounds, superalloys or crystals. As such it presents the most balanced view of creep for all materials scientists. The theory of all of these phenomena are extensively reviewed and analysed in view of an extensive bibliography that includes the most recent publications in the field. All sections of the book have undergone extensive peer review and therefore the reader can be sure they have access to the most up-to-date research, fully interrogated, from the world’s leading investigators. · Numerous line drawings with consistent format and units allow easy comparison of the behavior of a very wide range of materials· Transmission electron micrographs provide a direct insight in the basic microstructure of metals deforming at high temperatures· Extensive literature review of over 1000 references provide an excellent reference document, and a very balanced discussion
Download or read book Creep Behaviour of Crystalline Solids written by B. Wilshire and published by Ashgate Publishing. This book was released on 1985 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mechanics of Creep Brittle Materials 2 written by A.C.F. Cocks and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 379 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mechanics of Creep Brittle Materials-l was published in 1989 as the proceedings of a Colloquium held in Leicester in the summer of 1988. The Colloquium examined the creep response of a wide range of materials, including metals, engineering ceramics and ice, with the aim of determining similarities in the response of these materials and the way in which their behaviour is modelled. The proceedings were structured so as nature of the Colloquium, with papers to reflect the interdisciplinary grouped together largely on the basis of the phenomena being examined, rather than by class of material. Mechanics of Creep Brittle Materials-2 was held in Leicester in Septem ber 1991 to discuss advances made in our understanding of the response of creep brittle materials since the first Colloquium. The scope of the Colloquium was extended to include mineral salts, concrete and com posite systems. These proceedings are once more structured so that the reader can readily compare the response of different material systems and evaluate the suitability of the range of models presented to the materials he is interested in. In fact a number of papers directly compare the of a range of different materials with the aim of identifying behaviour general strategies for the testing and modelling of creeping materials.
Download or read book Low Temperature Creep Deformation of Crystals Particularly Phenomena at Liquid Helium Temperatures written by Anthony Arko and published by . This book was released on 1965 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Creep behavior of cadmium and mercury were investigated in the liquid helium temperature range with emphasis on the possible mechanisms of creep. Creep was found to be temperature dependent at all temperatures of investigation down to 1.75 K, and impurities in the metals had no noticeable effects. Activation energies were determined in the range 1.75-30 K and activation volume measurements were carried out. Creep behavior in the liquid temperature range was found to differ little from the usual low temperature creep at higher temperatures. At liquid helium temperatures, however, creep did not follow low temperature theories, but correction could be made by Alefeld's new rate equation for processes at low temperatures. Quantum tunneling effects on creep were found to be unimportant at temperatures above 0.04 K. (Author).
Download or read book Ceramic Hardness written by I.J. McColm and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 331 pages. Available in PDF, EPUB and Kindle. Book excerpt: As the utilization of ceramic materials is developing at a great pace, so too is the science of ceramics improving the understanding we have about these high-technology materials. New and improved ways of examining and investigating monolithic ceramics and ceramic composites are also being developed and reported at a great pace in a wide-ranging area of the scientific and technical literature. This book has been written with the aim of increas ing the awareness of the general materials worker of developments in modern ceramics and of bringing to a focus how much the study of their hardness can contribute to our understanding of them and lead to technical data that can be of considerable use in this fast-growing field. The readership will consist of materials scientists, metallurgists, and engineers moving into the new worlds of advanced ceramics and ceramic-containing composites. Detailed works on hardness are to be found in the metallurgical area, where much of the theory and early applications were developed. This book does not overly stress this early development of theory and practice, but concentrates wherever possible on the ceramics and glasses. Thus Chapter 1 introduces the general subject area to those whose interest may have been blunted in the past by the emphasis on one area of materials. Subjects raised in the first chapter are developed more fully in later chapters.
Download or read book Plastic Deformation of Ceramics written by R.C. Bradt and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 661 pages. Available in PDF, EPUB and Kindle. Book excerpt: This proceedings volume, "Plastic Deformation of Ceramics," constitutes the papers of an international symposium held at Snowbird, Utah from August 7-12, 1994. It was attended by nearly 100 scientists and engineers from more than a dozen countries representing academia, national laboratories, and industry. Two previous conferences on this topic were held at The Pennsylvania State University in 1974 and 1983. Therefore, the last major international conference focusing on the deformation of ceramic materials was held more than a decade ago. Since the early 1980s, ceramic materials have progressed through an evolutionary period of development and advancement. They are now under consideration for applications in engineering structures. The contents of the previous conferences indicate that considerable effort was directed towards a basic understanding of deformation processes in covalently bonded or simple oxide ceramics. However, now, more than a decade later, the focus has completely shifted. In particular, the drive for more efficient heat engines has resulted in the development of silicon-based ceramics and composite ceramics. The discovery of high-temperature cupric oxide-based superconductors has created a plethora of interesting perovskite-Iike structured ceramics. Additionally, nanophase ceramics, ceramic thin films, and various forms of toughened ceramics have potential applications and, hence, their deformation has been investigated. Finally, new and exciting areas of research have attracted interest since 1983, including fatigue, nanoindentation techniques, and superplasticity.
Download or read book Indentation Hardness and Indentation Creep in Solids at Temperatures Below 0 5 T written by John Edward Morgan and published by . This book was released on 1976 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Metals Abstracts written by and published by . This book was released on 1998 with total page 1076 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mechanics of Creep Brittle Materials 1 written by A.C.F. Cocks and published by Springer. This book was released on 1989-05-31 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: Failure of components which operate in the creep range can result either from the growth of a dominant crack or through the accumulation of 'damage' in the material. Conventional and nuclear power generating plant are generally designed on the basis of continuum failure, with assessment routes providing an indication of the effects of flaws on component performance. Another example where an understanding of creep failure is important is in the design of offshore structures which operate in arctic waters. These structures can be subjected to quite considerable forces by wind-driven ice sheets, which are limited by failure of the ice sheet. Design codes are currently being developed which identify the different mechanisms of failure, ranging from continuum crushing to radial cracking and buckling of the ice sheet. Our final example concerns engineering ceramics, which are currently being considered for use in a wide range of high-temperature applications. A major problem preventing an early adoption of these materials is their brittle response at high stresses, although they can behave in a ductile manner at lower stresses. In each of the above situations an understanding of the processes of fast fracture, creep crack growth and continuum failure is required, and in particular an understanding of the material and structural features that influence the transition from brittle to ductile behaviour. The translation of this information to component design is most advanced for metallic components.
Download or read book Tribology Issues and Opportunities in MEMS written by Bharat Bhushan and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 652 pages. Available in PDF, EPUB and Kindle. Book excerpt: Micro Electro Mechanical Systems (MEMS) is already about a billion dollars a year industry and is growing rapidly. So far major emphasis has been placed on the fabrication processes for various devices. There are serious issues related to tribology, mechanics, surfacechemistry and materials science in the operationand manufacturingof many MEMS devices and these issues are preventing an even faster commercialization. Very little is understood about tribology and mechanical properties on micro- to nanoscales of the materials used in the construction of MEMS devices. The MEMS community needs to be exposed to the state-of-the-artoftribology and vice versa. Fundamental understanding of friction/stiction, wear and the role of surface contamination and environmental debris in micro devices is required. There are significantadhesion, friction and wear issues in manufacturing and actual use, facing the MEMS industry. Very little is understood about the tribology of bulk silicon and polysilicon films used in the construction ofthese microdevices. These issues are based on surface phenomenaand cannotbe scaled down linearly and these become increasingly important with the small size of the devices. Continuum theory breaks down in the analyses, e. g. in fluid flow of micro-scale devices. Mechanical properties ofpolysilicon and other films are not well characterized. Roughness optimization can help in tribological improvements. Monolayers of lubricants and other materials need to be developed for ultra-low friction and near zero wear. Hard coatings and ion implantation techniques hold promise.
