Superplasticity And Grain Boundaries In Ultrafine Grained Materials

Superplasticity is a state in which solid crystalline materials, such as some fine-grained metals, are deformed well beyond their usual breaking point. The phenomenon is of importance in processes such as superplastic forming which allows the manufacture of complex, high-quality components in such areas as aerospace and biomedical engineering. Superplasticity and grain boundaries in ultrafine-grained materials discusses a number of problems associated with grain boundaries in metallic polycrystalline materials. The role of grain boundaries in processes such as grain boundary diffusion, relaxation and grain growth is investigated. The authors explore the formation and evolution of the microstructure, texture and ensembles of grain boundaries in materials produced by severe plastic deformation. Written by two leading experts in the field, Superplasticity and grain boundaries in ultrafine-grained materials significantly advances our understanding of this important phenomenon and will be an important reference work for metallurgists and those involved in superplastic forming processes. Discusses significant problems associated with grain boundaries in polycrystals incorporating structural superplasticity and grain boundary sliding Assesses the role of grain boundaries in processes such as grain boundary diffusion, relaxation and grain growth Explores the formation and evolution of the microstructure, texture and ensembles of grain boundaries in materials produced by severe plastic deformation

The book deals with a number of problems associated with the description and experimental verification of the individual boundaries and ensembles of the grain boundaries in polycrystals. The role of these boundaries in processes such as grain boundary diffusion, relaxation and grain growth is investigated. It is attempted to construct a general model of superplasticity based on the experimentally determined relationships relating to the bands of co-operative grain boundary sliding. Special attention is given to the problems of formation and evolution of the microstructure, the texture and ensembles of the grain boundaries in materials produced by severe plastic deformation methods.

The book discusses a number of problems associated with grain boundaries in polycrystals and other topics of interest to metallurgists and researchers concerned with the problems of nanomaterials. and nanotechnology.

Superplasticity and Grain Boundaries in Ultrafine-Grained Materials, Second Edition, provides cutting-edge modeling solutions surrounding the role of grain boundaries in processes such as grain boundary diffusion, relaxation and grain growth. In addition, the book's authors explore the formation and evolution of the microstructure, texture and ensembles of grain boundaries in materials produced by severe plastic deformation. This updated edition, written by leading experts in the field, has been revised to include new chapters on the basics of nanostructure processing, the influence of deformation mechanisms on grain refinement, processing techniques for ultrafine-grained and nanostructured materials, and much more. Provides practical applications and methods for the proper implementation of models, allowing for more effective complex metal forming processes Features new chapters on the microstructure, mechanical behavior and functional properties of HCP metals, processing ultrafine-grained and nanostructured materials, and more Covers experimental assessment and computational modeling techniques for adiabatic heating and saturation of grain refinement during SPD of metals and alloys

Proceedings of a symposium sponsored by the Shaping and Forming Committee of the Materials Processing and Manufacturing Division (MPMD) and the Mechanical Behavior Committee (Jt. SMD/ASM-MSCTS) of the Structural Materials Division (SMD) of TMS (The Minerals, Metals & Materials Society) and held during the 2002 TMS Annual Meeting in Seattle, Washington February 17-21,2002.

Superplasticity is generally associated with fine grains, grain boundary sliding, and high tensile ductility at elevated temperature. This paper reviews some of the recent important findings in fine-grained superplasticity, including the areas of superplastic ceramics and bf-high-strain-rate superplasticity (HSRS). Deformation mechanism maps are shown to be powerful tools for predicting the conditions where HSRS can be expected. Ultrafine grained materials, processed economically, remain an important objective in achieving HSRS. Threshold stresses, observed in fine-grained superplastic materials, are shown to be functions of temperature and grain size but their origin, however, remains obscure. Quasi-superplastic materials, with a strain-rate-sensitivity exponent of m = 0.33, are shown to have high elongations, and have considerable promise for netshape isothermal forming of sheet and bulk components.

Collection of Selected, Peer Reviewed Papers from the 12th International Conference on Superplasticity in Advanced Materials (ICSAM 2015), September 7-11, 2015, Tokyo, Japan. The 99 papers are grouped as follows: Chapter 1: Keynote Lecture Chapter 2: Mechanism of Superplasticity Chapter 3: Superplastic Materials Chapter 4: Microstructure Refinement Chapter 5: Industrial Application