Download or read book Ultrasonic Studies of Dislocation Dynamics and of the Deformation of Solids written by Akira Hikata and published by . This book was released on 1967 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: The report consists of two parts, (1) plastic deformation of gallium single crystals, (2) amplitude dependence of ultrasonic attenuation in lead single crystals. In the case of gallium, it is found that the dislocations do not contribute to the attenuation of ultrasonic waves of 10 Mc/sec or higher frequencies, despite the fact that the gallium crystals undergo plastic deformation with well defined dislocation glide. This phenomenon is quite in contrast to that observed in other metal single crystals such as aluminum, and is tentatively attributed to the large frictional resistance against the high velocity motion of dislocations. In the case of lead, large amplitude-dependent attenuation is observed at low temperatures. At 4.2K, a maximum in attenuation as a function of ultrasonic amplitude is found. From this attenuation maximum, it is possible to reduce the values of the electron contribution to the damping constant and of the interaction force between point defects and dislocations. (Author).
Download or read book Dislocation Dynamics During Plastic Deformation written by Ulrich Messerschmidt and published by Springer Science & Business Media. This book was released on 2010-04-19 with total page 509 pages. Available in PDF, EPUB and Kindle. Book excerpt: Along with numerous illustrative examples, this text provides an overview of the dynamic behavior of dislocations and its relation to plastic deformation. It introduces the general properties of dislocations and treats the dislocation dynamics in some detail.
Download or read book Dislocation Dynamics and Plasticity written by Taira Suzuki and published by Springer Science & Business Media. This book was released on 2013-03-07 with total page 237 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the 1950s the direct observation of dislocations became possible, stimulat ing the interest of many research workers in the dynamics of dislocations. This led to major contributions to the understanding of the plasticity of various crys talline materials. During this time the study of metals and alloys of fcc and hcp structures developed remarkably. In particular, the discovery of the so-called in ertial effect caused by the electron and phonon frictional forces greatly influenced the quantitative understanding of the strength of these metallic materials. Statis tical studies of dislocations moving through random arrays of point obstacles played an important role in the above advances. These topics are described in Chaps. 2-4. Metals and alloys with bcc structure have large Peierls forces compared to those with fcc structure. The reasons for the delay in studying substances with bcc structure were mostly difficulties connected with the purification techniques and with microscopic studies of the dislocation core. In the 1970s, these difficulties were largely overcome by developments in experimental techniques and computer physics. Studies of dislocations in ionic and covalent bonding materials with large Peierls forces provided infonnation about the core structures of dislocations and their electronic interactions with charged particles. These are the main subjects in Chaps. 5-7.
Download or read book Dislocation Dynamics written by Alan R. Rosenfield and published by . This book was released on 1968 with total page 806 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dislocations in Solids written by and published by Elsevier. This book was released on 2007-05-16 with total page 681 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dislocations are lines of irregularity in the structure of a solid analogous to the bumps in a badly laid carpet. Like these bumps they can be easily moved, and they provide the most important mechanism by which the solid can be deformed. They also have a strong influence on crystal growth and on the electronic properties of semiconductors.·Influence of dislocations on piezoelectric behavior·New mechanisms for hardening in twinned crystals·Bringing theories of martensite transformation into agreement·Atomic scale motion of dislocations in electron microscopy·Dislocation patterns deduced from X-ray diffraction·Role of dislocations in friction·Dislocation motion in quasicrystals
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1985 with total page 1346 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dislocation Dynamics and Mechanical Properties of Crystals written by Edward Nadgornyi and published by Elsevier Science & Technology. This book was released on 1988 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dislocations in Solids written by Frank R.N. Nabarro and published by Elsevier. This book was released on 2002-12-05 with total page 687 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dislocations are lines of irregularity in the structure of a solid analogous to the bumps in a badly laid carpet. Like these bumps, they can be easily moved, and they provide the most important mechanism by which the solid can be deformed. They also have a strong influence on crystal growth and on the electronic properties of semiconductors.
Download or read book Internal Friction and Ultrasonic Attenuation in Solids written by C. C. Smith and published by Elsevier. This book was released on 2017-08-31 with total page 431 pages. Available in PDF, EPUB and Kindle. Book excerpt: Internal Friction and Ultrasonic Attenuation in Solids contains the proceedings of the Third European Conference on Internal Friction and Ultrasonic Attenuation in Solids, held at the University of Manchester in England on July 18-20, 1980. The papers explore the principles of internal friction and ultrasonic attenuation in solids such as pure metals and their alloys, ceramics, glasses, and polymers. Structural features such as point defects, dislocations, interfaces, and second phases in solids are discussed, together with the processes by which these features contribute to energy dissipation. Topics covered range from point defect interactions to the establishment of high damping capacity materials for absorption of noise and vibration. This book is comprised of 65 chapters and begins with a brief review of the internal friction peaks observed in face-centered cubic, body-centered cubic, and hexagonal metals due to dislocation relaxation processes. Subsequent chapters focus on the internal friction of cold-worked single crystals of high-purity copper; evidence of Peierls Nabarro stress from microdeformation and attenuation experiments; effects of cyclic deformation and irradiation at low temperature on the internal friction of pure aluminum; and internal friction of high-purity magnesium after plastic deformation. The peaking effect in copper and silver is also analyzed, along with Zener relaxation and dislocation damping. The final chapter is devoted to anelastic behavior of ice at low temperature due to quenched point defects. This monograph will be a valuable resource for metallurgists, physicists, and mechanical engineers.
Download or read book Fundamental Aspects of Dislocation Interactions written by G. Kostorz and published by Elsevier. This book was released on 2013-09-03 with total page 471 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fundamental Aspects of Dislocation Interactions: Low-Energy Dislocation Structures III covers the papers presented at a European Research Conference on Plasticity of Materials-Fundamental Aspects of Dislocation Interactions: Low-Energy Dislocation Structures III, held on August 30-September 4, 1992 in Ascona, Switzerland. The book focuses on the processes, technologies, reactions, transformations, and approaches involved in dislocation interactions. The selection first offers information on work softening and Hall-Petch hardening in extruded mechanically alloyed alloys and dynamic origin of dislocation structures in deformed solids. Discussions focus on stress-strain behavior in relation to composition, structure, and annealing; comparison of stress-strain curves with work softening theory; sweeping and trapping mechanism; and model of dipolar wall structure formation. The text then ponders on plastic instabilities and their relation to fracture and dislocation and kink dynamics in f.c.c. metals studied by mechanical spectroscopy. The book takes a look at misfit dislocation generation mechanisms in heterostructures and evolution of dislocation structure on the interfaces associated with diffusionless phase transitions. Discussions focus on dislocation representation of a wall of elastic domains; equation of equilibrium of an elastic domain; transformation of dislocations; and theoretical and experimental background. The selection is a valuable reference for readers interested in dislocation interactions.
Download or read book High Velocity Deformation of Solids written by K. Kawata and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Review of the Air Force Materials Research and Development Program written by and published by . This book was released on 1966 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: Technical reports published by the Air Force Materials Laboratory during the period 1 July 1964 - 30 June 1965 are abstracted herein. Reports on research conducted by the Air Force Materials Laboratory personnel as well as that conducted on contract are included.
Download or read book Dislocations Mesoscale Simulations and Plastic Flow written by L. Kubin and published by Oxford University Press (UK). This book was released on 2013-04-18 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the past twenty years, new experimental approaches, improved models and progress in simulation techniques brought new insights into long-standing issues concerning dislocation-based plasticity in crystalline materials. Dislocation dynamics simulations are becoming accessible to a wide range of users. This book presents to students and researchers in materials science and mechanical engineering a comprehensive coverage of the physical body of knowledge on whichthey are based. This includes classical studies, which are too often ignored, recent experimental and theoretical advances, as well as a discussion of selected applications on various topics.
Download or read book Evolution Interaction and Intrinsic Properties of Dislocations in Intermetallics written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The generation, motion, and interaction of dislocations play key roles during the plastic deformation process of crystalline solids. 3D Dislocation Dynamics has been employed as a mesoscale simulation algorithm to investigate the collective and cooperative behavior of dislocations. Most current research on 3D Dislocation Dynamics is based on the solutions available in the framework of classical isotropic elasticity. However, due to some degree of elastic anisotropy in almost all crystalline solids, it is very necessary to extend 3D Dislocation Dynamics into anisotropic elasticity. In this study, first, the details of efficient and accurate incorporation of the fully anisotropic elasticity into 3D discrete Dislocation Dynamics by numerically evaluating the derivatives of Green's functions are described. Then the intrinsic properties of perfect dislocations, including their stability, their core properties and disassociation characteristics, in newly discovered rare earth-based intermetallics and in conventional intermetallics are investigated, within the framework of fully anisotropic elasticity supplemented with the atomistic information obtained from the ab initio calculations. Moreover, the evolution and interaction of dislocations in these intermetallics as well as the role of solute segregation are presented by utilizing fully anisotropic 3D dislocation dynamics. The results from this work clearly indicate the role and the importance of elastic anisotropy on the evolution of dislocation microstructures, the overall ductility and the hardening behavior in these systems.
Download or read book Ultrasonic Methods in Solid State Physics written by Rohn Truell and published by Academic Press. This book was released on 2013-10-22 with total page 479 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ultrasonic Methods in Solid State Physics is devoted to studies of energy loss and velocity of ultrasonic waves which have a bearing on present-day problems in solid-state physics. The discussion is particularly concerned with the type of investigation that can be carried out in the megacycle range of frequencies from a few megacycles to kilomegacycles; it deals almost entirely with short-duration pulse methods rather than with standing-wave methods. The book opens with a chapter on a classical treatment of wave propagation in solids. This is followed by separate chapters on methods and techniques of ultrasonic pulse echo measurements, and the physics of ultrasonically measurable properties of solids. It is hoped that this book will provide the reader with the special background necessary to read critically the many research papers and special articles concerned with the use of ultrasonic methods in solid state physics. The book is intended to help the person beginning work in this field. At the same time, it will also be useful to those actively involved in such work. An attempt has been made to provide a fairly general and unified treatment suitable for graduate students and others without extensive experience.
Download or read book Dislocations in Solids written by and published by Elsevier. This book was released on 2004-08-05 with total page 603 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first volume to appear under the joint editorship of J.P. Hirth and F.R.N. Nabarro. While Volume 11 concentrated on the single topic of dislocations and work hardening, the present volume spreads over the whole range of the study of dislocations from the application by Kléman and his colleagues of homotopy theory to classifying the line and point defects of mesomorphic phases to Chaudhri's account of the experimental observations of dislocations formed around indentations.Chapter 64, by Cai, Bulatove, Chang, Li and Yip, discusses the influence of the structure of the core of a dislocation on its mobility. The power of modern computation allows this topic to be treated from the first principles of electron theory, and with empirical potentials for more complicated problems. Advances in electron microscopy allow these theoretical predictions to be tested.In Chapter 65, Xu analyzes the emission of dislocations from the tip of a crack and its influence on the brittle to ductile transition. Again, the treatment is predominantly theoretical, but it is consistently related to the very practical example of alpha iron.In a dazzling interplay of experiment and abstract mathematics, Kléman, Lavrentovich and Nastishin analyze the line and point structural defects of the many mesomorphic phases which have become known in recent years.Chapter 67, by Coupeau, Girard and Rabier, is essentially experimental. It shows how the various modern techniques of scanning probe microscopy can be used to study dislocations and their interaction with the free surface.Chapter 68, by Mitchell and Heuer, considers the complex dislocations that can form in ceramic crystals on the basis of observations by transmission electron microscopy and presents mechanistic models for the motion of the dislocations in various temperature regimes.While the underlying aim of the study of dislocations in energetic crystals by Armstrong and Elban in Chapter 69 is to understand the role of dislocations in the process of detonation, it has the wider interest of studying dislocations in molecular crystals which are ``elastically soft, plastically hard, and brittle''.Chaudhri in Chapter 70 discusses the role of dislocations in indentation processes, largely on the basis of the elastic analysis by E.H. Yoffe. The special case of nanoindentations is treated only briefly.
Download or read book DISLOCATIONS AND MECHANICAL BEHAVIOUR OF MATERIALS written by M. N. SHETTY and published by PHI Learning Pvt. Ltd.. This book was released on 2013-01-31 with total page 991 pages. Available in PDF, EPUB and Kindle. Book excerpt: Primarily intended for the senior undergraduate and postgraduate students of Metallurgical and Materials Engineering/Mechanical Engineering, the book begins with the description of elementary mechanical testing method and then moves on to the theory of elasticity, the micromechanics of high strain rate deformation phenomenon and quantitative methods of materials selection. Dislocation and their applications is the strength of this book. The topics such as creep, fatigue and fracture are comprehensively covered. The final chapter presents the principles of materials selection. The book contains numerous solved and unsolved examples to reinforce the understanding of the subject.
