A phase field model of grain boundary migration and grain rotation under elasto-plastic anisotropies

INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES

卷:178

Article

Mikula, Jakub^1,2  Joshi, Shailendra P.³  Tay, Tong-Earn²  Ahluwalia, Rajeev¹  Quek, Siu Sin¹ 

[1] ASTAR, Inst High Performance Comp, Singapore 138632, Singapore

[2] Natl Univ Singapore, Dept Mech Engn, Singapore 117576, Singapore

[3] Univ Houston, Dept Mech Engn, Houston, TX 77204 USA

关键词: Grain boundaries;    Anisotropic material;    Phase field model;   

DOI  :  10.1016/j.ijsolstr.2019.06.014

来源: Elsevier

【 摘 要 】

We propose a phase field framework to model both grain rotation and grain boundary migration in a mechanically loaded elasto-plastic solid. We develop this framework on the grounds of the phase field model of grain boundaries proposed by (Kobayashi et al., Physica D 140 (2000)) by coupling the grain orientation phase field theta with the strain energy of an elasto-plastic solid. The lattice plasticity is described by the phenomenological quadratic Hill yield potential. This coupling permits both grain rotation and grain boundary migration to evolve simultaneously with the bulk lattice plasticity minimizing the total energy of the system. Hence, the presented phase field framework allows the study of a rich set of phenomena that emerge from the interplay between grain boundary mediated and dislocation mediated plasticity under the effects of elastic and plastic anisotropy. We demonstrate the model in two case studies: A) bicrystalline nanopillar and B) multigrain nanocrystalline system. In case A, we study the behaviour of stress driven (curvature free) grain boundaries and evaluate the limits for the grain boundary velocity. In case B, additional grain boundary curvature effects come into play and we analyse the constitutive response for different strain rate regimes. (C) 2019 Elsevier Ltd. All rights reserved.

【 授权许可】

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