The Inhomogeneity Of Plastic Deformation

Grain size is recognized as a key microstructural factor affecting mechanical and, to some extent, physical properties of metals and metallic materials. For this reason, all the means designed to control and modify the grain size are considered a proper way to design and tailor metallic materials with desired properties. In this sense, microstructure refinement through severe plastic deformation (SPD) techniques can be considered a key method for this purpose. A typical SPD process is currently defined as any method of metal forming under extensive hydrostatic pressure intended to impose a very high strain on a bulk solid without involving any significant change in the overall dimensions and having the ability to produce exceptional grain refinement. What makes SPD processing techniques so popular and attractive is the possibility of using them to enhance the strength behavior of conventional metallic materials by a factor of up to eight for pure metals such as copper and by some 30-50% for alloys. Despite the impressive property improvement achievable with SPD techniques, their uptake by industry has been rather sluggish. This book intends to give a panorama of the typical SPD techniques intended to optimize the mechanical and physical properties of metals through a significant grain size reduction process. Modeling for this purpose is also presented.

High-technology industries using plastic deformation demand soundly-based economical decisions in manufacturing design and product testing, and the unified constitutive laws of plastic deformation give researchers aguideline to use in making these decisions. This book provides extensive guidance in low cost manufacturing without the loss of product quality. Each highly detailed chapter of Unified Constitutive Laws of Plastic Deformation focuses on a distinct set of defining equations. Topics covered include anisotropic and viscoplastic flow, and the overall kinetics and thermodynamics of deformation. This important book deals with a prime topic in materials science and engineering, and will be of great use toboth researchers and graduate students. Describes the theory and applications of the constitutive law of plastic deformation for materials testing Examines the constitutive law of plastic deformation as it applies to process and product design Includes a program on disk for the determination and development of the constitutive law of plastic deformation Considers economical design and testing methods

Present developments in materials science, mechanics and engineering, as well as the demands of modern technology, result in a new and growing interest in plasticity and in bordering domains of the mechanical behavior of materials. This growing interest is attested to by the success of both The International Journal of Plasticity, which after its inception rapidly became the leading journal for plasticity research, and the series ofInternational Symposia on Plasticity and Its Current Applications, which is now the premier international forum for plasticity research dissemination. The First International Symposium on Plasticity and Its Current Applications was conceived and organized by Professor Akhtar S. Khan, and was held at the University of Oklahoma (Norman, Oklahoma, USA) from July 30 to August 3, 1984. It was attended by over one hundred scientists from fifteen countries. "Plasticity '89: the Second International Symposium on Plasticity and Its Current Applications" was held at Mie University (Tsu, Japan) from July 31 to August 4, 1989; this symposium was co-chaired by Professors Khan and Tokuda. The main emphasis of this meeting was on dynamic plasticity and micromechanics, although it included other aspects of plasticity as well. It was attended by over two hundred researchers from twenty-three nations.

Ductility and Formability of Metals: A Metallurgical Engineering Perspective uses metallurgical, mechanical and physical principles and concepts to explain ductility while emphasizing the influence of material microstructure on damage mechanisms. Focusing on steel, aluminum, copper, titanium and magnesium alloys, the book examines the strain hardening behaviors of these metals and alloys, the influence of strain rate and temperature, and ductile fracture mechanics. Hot plastic deformation is covered with special consideration given to its interplay with recrystallization phenomena. Other phenomena such as Dynamic Strain Ageing (DSA) and Adiabatic Shear Banding (ASB) are discussed, and metal working applications such as forging, extrusion and machining are included throughout. Methods for control of ductile cracks in metal parts resulting from rolling, forging, extrusion, drawing, and sheet metal forming are also outlined. Provides an overview on the plastic deformation behavior and ductile fracture of steel, aluminum, copper, titanium and magnesium alloys Illustrates the influence of microstructure on yield behavior, strain hardening of metals, and the influence of strain rate and temperature Covers the role of the strain hardening coefficient (n), strain rate index (m), Dynamic Strain Ageing (DSA), and Adiabatic Shear Banding (ASB) Metalworking applications are provided throughout, including forging, rolling, extrusion, wire drawing, sheet metal forming and machining

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

Strength of Metals and Alloys, Volume 1 covers the proceedings of the Seventh International Conference on the Strength of Metals and Alloys. The book presents papers that discuss the properties of various metals and alloys. The text contains 133 studies, which are grouped into six sections. The first section covers the work hardening consolidation, while the second section discusses anisotropy and texture. The third section tackles the solute hardening and alloy theory, and the fourth section covers precipitation hardening. The fifth section discusses martensitic and phase transformations, and the sixth section deals with creep resistance. The book will be of great interest to researchers and professionals whose work requires knowledge about the properties of metals and alloys.

In 1979 the first InternationalSymposium on Low CycleFatigue and Elasto-Plastic Behaviour of Materials was held in Stuttgart, FRG. Since then research in low cycle fatigue has proceeded rapidly. The vital interest of engineers and researchers in communicating the rapid advances in the ongoing research in low cycle fatigue has encouraged me to initiate again the Second International Conference which was held in Munich, FRG, 7-11 September 1987. Failure in low cycle fatigue represents a serious problem in the design and opera tion of highly stressed structures. Under complex loading and environmental cir cumstances, especially for high temperature services, reliable life prediction can not be expected without detailed consideration of the failure mechanism and with out extensive use of mechanistic approaches. The purpose of this conference was to provide a forum to discuss the advances in recent research in the field of low cycle fatigue. The conference was intended to help to further bridge the gap between those who are involved in basic research, and the engineers who have to perform the design of highly stressed structural components.