Download or read book Dislocation Evolution in Fe 10 Cr written by J. Bentley and published by . This book was released on 1987 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: The dislocation microstructure found in the binary ferritic alloy, Fe-10% Cr, has been characterized for damage levels ranging from 0.3 to 100 dpa. The specimens were irradiated at 850 K with a "triple beam" of He+, D+, and 4 MeV Fe++ ions. Transmission electron microscopy revealed that dislocation loops were dominant in the dislocation microstructure from 0.3 to 3 dpa. At 0.3 dpa the loops were round to slightly rectilinear in shape, whereas at higher doses the majority of the loops had a convoluted shape that indicated preferential growth in the 110 directions. Analyses showed that all of the loops at low doses and the convoluted loops at 3 dpa were near-edge interstitial loops with b = a100. At 3 dpa, round interstitial loops with b = a/2111 were also observed. Network segments with b = a/2111 were found at the intersection of a100 loops with a/2111 loops. At damage levels greater than 10 dpa, the structure consisted of a coarse distribution of network segments along with a few loops with b = a/2111. At 30 and 100 dpa a relatively low dislocation density,

Download or read book Dislocation Mechanism Based Crystal Plasticity written by Zhuo Zhuang and published by Academic Press. This book was released on 2019-04-12 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dislocation Based Crystal Plasticity: Theory and Computation at Micron and Submicron Scale provides a comprehensive introduction to the continuum and discreteness dislocation mechanism-based theories and computational methods of crystal plasticity at the micron and submicron scale. Sections cover the fundamental concept of conventional crystal plasticity theory at the macro-scale without size effect, strain gradient crystal plasticity theory based on Taylar law dislocation, mechanism at the mesoscale, phase-field theory of crystal plasticity, computation at the submicron scale, including single crystal plasticity theory, and the discrete-continuous model of crystal plasticity with three-dimensional discrete dislocation dynamics coupling finite element method (DDD-FEM). Three kinds of plastic deformation mechanisms for submicron pillars are systematically presented. Further sections discuss dislocation nucleation and starvation at high strain rate and temperature effect for dislocation annihilation mechanism. - Covers dislocation mechanism-based crystal plasticity theory and computation at the micron and submicron scale - Presents crystal plasticity theory without size effect - Deals with the 3D discrete-continuous (3D DCM) theoretic and computational model of crystal plasticity with 3D discrete dislocation dynamics (3D DDD) coupling finite element method (FEM) - Includes discrete dislocation mechanism-based theory and computation at the submicron scale with single arm source, coating micropillar, lower cyclic loading pillars, and dislocation starvation at the submicron scale

Download or read book Mechanics of Dislocation Fields written by Claude Fressengeas and published by John Wiley & Sons. This book was released on 2017-09-25 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: Accompanying the present trend of engineering systems aimed at size reduction and design at microscopic/nanoscopic length scales, Mechanics of Dislocation Fields describes the self-organization of dislocation ensembles at small length scales and its consequences on the overall mechanical behavior of crystalline bodies. The account of the fundamental interactions between the dislocations and other microscopic crystal defects is based on the use of smooth field quantities and powerful tools from the mathematical theory of partial differential equations. The resulting theory is able to describe the emergence of dislocation microstructures and their evolution along complex loading paths. Scale transitions are performed between the properties of the dislocation ensembles and the mechanical behavior of the body. Several variants of this overall scheme are examined which focus on dislocation cores, electromechanical interactions of dislocations with electric charges in dielectric materials, the intermittency and scale-invariance of dislocation activity, grain-to-grain interactions in polycrystals, size effects on mechanical behavior and path dependence of strain hardening.

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 Finite element simulation of dislocation based plasticity and diffusion in multiphase materials at high temperature written by Albiez, Jürgen and published by KIT Scientific Publishing. This book was released on 2019-05-22 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: A single-crystal plasticity model as well as a gradient crystal plasticity model are used to describe the creep behavior of directionally solidi?ed NiAl based eutectic alloys. To consider the transition from theoretical to bulk strength, a hardening model was introduced to describe the strength of the reinforcing phases. Moreover, to account for microstructural changes due to material ?ux, a coupled diffusional-mechanical simulation model was introduced.

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 Dislocation Mechanics of Metal Plasticity and Fracturing written by Ronald W. Armstrong and published by MDPI. This book was released on 2020-11-03 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: The modern understanding of metal plasticity and fracturing began about 100 years ago, with pioneering work; first, on crack-induced fracturing by Griffith and, second, with the invention of dislocation-enhanced crystal plasticity by Taylor, Orowan and Polanyi. The modern counterparts are fracture mechanics, as invented by Irwin, and dislocation mechanics, as initiated in pioneering work by Cottrell. No less important was the breakthrough development of optical characterization of sectioned polycrystalline metal microstructures started by Sorby in the late 19th century and leading eventually to modern optical, x-ray and electron microscopy methods for assessments of crystal fracture surfaces, via fractography, and particularly of x-ray and electron microscopy techniques applied to quantitative characterizations of internal dislocation behaviors. A major current effort is to match computational simulations of metal deformation/fracturing behaviors with experimental measurements made over extended ranges of microstructures and over varying external conditions of stress-state, temperature and loading rate. The relation of such simulations to the development of constitutive equations for a hoped-for predictive description of material deformation/fracturing behaviors is an active topic of research. The present collection of articles provides a broad sampling of research accomplishments on the two subjects.

Download or read book Crystal Plasticity Finite Element Methods written by Franz Roters and published by John Wiley & Sons. This book was released on 2011-08-04 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by the leading experts in computational materials science, this handy reference concisely reviews the most important aspects of plasticity modeling: constitutive laws, phase transformations, texture methods, continuum approaches and damage mechanisms. As a result, it provides the knowledge needed to avoid failures in critical systems udner mechanical load. With its various application examples to micro- and macrostructure mechanics, this is an invaluable resource for mechanical engineers as well as for researchers wanting to improve on this method and extend its outreach.

Download or read book High Performance Computing Systems and Technologies in Scientific Research Automation of Control and Production written by Vladimir Jordan and published by Springer Nature. This book was released on 2021-01-15 with total page 241 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes selected revised and extended papers from the 10th International Conference on High-Performance Computing Systems and Technologies in Scientific Research, Automation of Control and Production, HPCST 2020, Barnaul, Russia, in May 2020. Due to the COVID-19 pancemic the conference was partly held in virtual mode. The 14 full papers presented in this volume were thoroughly reviewed and selected form 51 submissions. The papers are organized in topical sections on hardware for high-performance computing and its applications; information technologies and computer simulation of physical phenomena.

Download or read book High Temperature Deformation and Fracture of Materials written by Jun-Shan Zhang and published by Elsevier. This book was released on 2010-09-01 with total page 383 pages. Available in PDF, EPUB and Kindle. Book excerpt: The energy, petrochemical, aerospace and other industries all require materials able to withstand high temperatures. High temperature strength is defined as the resistance of a material to high temperature deformation and fracture. This important book provides a valuable reference to the main theories of high temperature deformation and fracture and the ways they can be used to predict failure and service life. - Analyses creep behaviour of materials, the evolution of dislocation substructures during creep, dislocation motion at elevated temperatures and importantly, recovery-creep theories of pure metals - Examines high temperature fracture, including nucleation of creep cavity, diffusional growth and constrained growth of creep cavities - A valuable reference to the main theories of high temperature deformation and fracture and the ways they can be used to predict failure and service life

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1985 with total page 728 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Investigation of Plastic Behavior by Discrete Dislocation Dynamics for Single Crystal Pillar at Submicron Scale written by Yinan Cui and published by Springer. This book was released on 2016-10-26 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis transports you to a wonderful and fascinating small-scale world and tells you the origin of several new phenomena. The investigative tool is the improved discrete dislocation-based multi-scale approaches, bridging the continuum modeling and atomistic simulation. Mechanism-based theoretical models are put forward to conveniently predict the mechanical responses and defect evolution. The findings presented in this thesis yield valuable new guidelines for microdevice design, reliability analysis and defect tuning.

Download or read book Continuum Scale Simulation of Engineering Materials written by Dierk Raabe and published by John Wiley & Sons. This book was released on 2004-08-06 with total page 904 pages. Available in PDF, EPUB and Kindle. Book excerpt: Die Simulation von Materialien gehört zu den interessantesten neuen Forschungsgebieten der Ingenieurwissenschaften. Dieser Band spricht alle wichtigen Aspekte des Themas an, von den mathematischen Grundlagen der Simulation über Anwendungen beim Design von Mikrostrukturen bis zur computergestützten Werkstoffauswahl und -entwicklung. Doktoranden und Praktiker aus Materialwissenschaft und Technik lernen, aus den existierenden Simulationsmethoden den für ihr Problem am besten geeigneten Ansatz auszuwählen.

Download or read book Effects of Radiation on Materials written by N. H. Packan and published by ASTM International. This book was released on 1990 with total page 679 pages. Available in PDF, EPUB and Kindle. Book excerpt: Annotation Effects of Radiation on Materials: Fourteenth International Symposium was presented at Andover, MA, June 1988. The symposium was sponsored by ASTM Committee E-10 on Nuclear Technology and Applications. The papers from the first three days of the symposium appear in the two volumes of this publication. Volume I encompasses radiation damage- induced microstructures; point defect, solute, and gas atom effects; atomic-level measurement techniques; and applications of theory. Volume II includes mechanical behavior, all papers dealing with pressure-vessel steels, breeder reactor components, dosimetry, and nuclear fuels. The fourth day of the symposium was devoted to the single topic of reduced-activation materials (see TK9204). The two volumes are separately sold at $127 and $128 respectively; each is independently indexed. Annotation copyrighted by Book News, Inc., Portland, OR.

Download or read book Structural Alloys for Power Plants written by A. Shirzadi and published by Elsevier. This book was released on 2014-07-30 with total page 519 pages. Available in PDF, EPUB and Kindle. Book excerpt: Current fleets of conventional and nuclear power plants face increasing hostile environmental conditions due to increasingly high temperature operation for improved capacity and efficiency, and the need for long term service. Additional challenges are presented by the requirement to cycle plants to meet peak-load operation. This book presents a comprehensive review of structural materials in conventional and nuclear energy applications. Opening chapters address operational challenges and structural alloy requirements in different types of power plants. The following sections review power plant structural alloys and methods to mitigate critical materials degradation in power plants.

Download or read book Advances on Hot Extrusion and Simulation of Light Alloys written by A. Erman Tekkaya and published by Trans Tech Publications Ltd. This book was released on 2009-12-03 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume is indexed by Thomson Reuters CPCI-S (WoS). This special collection comprises 36 peer-reviewed papers giving an insight into the latest advances in extrusion technology and its simulation. The papers cover a wide range of topics and are grouped into the categories of: benchmark, microstructure, seam welds and composite extrusion, material flow and constitutive equations, dies and tools and process control and optimization. However, many other topics, such as new materials (magnesium and its composites) and new composite profiles, are covered.

Download or read book Effects of Radiation on Materials written by H. R. Brager and published by ASTM International. This book was released on 1982 with total page 786 pages. Available in PDF, EPUB and Kindle. Book excerpt: