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INTRODUCTION

POLYCRYSTALLINE fcc materials usually deform in a variety of slip, twinning, and shear banding modes and exhibit marked plastic anisotropy at the grain level. This causes the evolution of the preferred grain orientation distribution (crystallographic texture) that affects in turn the distribution of heterogeneous stresses within materials. Accordingly, an accurate understanding and control of micromechanical behavior is a prerequisite for the development and successful application of the materials that have a texture evolution closely linked to their featured deformation mechanism and

N. JIA, Lecturer, Z.H. NIE, Doctoral Student, and X. ZHAO, Professor, are with the Key Laboratory for Anisotropy and Texture of Materials (MOE), Northeastern University, Shenyang 110004, P.R. China. Y. REN, Facility Scientist, is with the X-Ray Science Division, Argonne National Laboratory, Argonne, IL 60439. R. LIN PENG, Associate Professor, is with the Department of Mechanical Engineering, Linko¨ping University, S-58183 Linko¨ping, Sweden. Contact e-mail: [email protected] Y.D. WANG, Professor, formerly with the Key Laboratory of Anisotropy and Texture of Materials (MOE), Northeastern University, is with the School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 10081, P.R. China. This article is based on a presentation given in the symposium ‘‘Neutron and X-Ray Studies of Advanced Materials,’’ which occurred February 15–19, 2009, during the TMS Annual Meeting in San Francisco, CA, under the auspices of TMS, TMS Structural Materials Division, TMS/ASM Mechanical Behavior of Materials Committee, TMS Advanced Characterization, Testing, and Simulation Committee, and TMS Titanium Committee. Article published online December 2, 2009 1246—VOLUME 41A, MAY 2010

microstructure.[1–3] The stacking fault energy (SFE) plays an important role in fcc metals in determining the prevailing mechanism of plastic deformation and the resultant textures.[4,5] For example, for brass and other metals with low SFEs during cold rolling, a tendency toward mechanical twinning aside from slip occurs at large plastic deformations and they develop the f011gh211i (brass) texture, whereas copper and other high-SFE metals still exhibit dislocation slip and develop the f112gh111i (copper) texture. In the past decade, much attention has been paid to accurately modeling the anisotropic micromechanical behavior and quantitatively predicting the deformation textures using various numerical and analytical models.[6–8] Among those, the self-consistent (SC)[9] approach proves to be effective in describing the mechanical anisotropy and the preferred orientation in metals, because based on the deformation mechanism involving dislocation slip and mechanical twinning, the model can account well for the elastic and plastic interactions among the grain families (in each specified grain family, the constituent single crystals have similar orientations) using different boundary conditions applicable at small and moderate plastic strains.