Atomistic modeling study of a strain-free stress driven grain boundary migration mechanism

SCRIPTA MATERIALIA

卷:134

Article

Wan, Liang^1,2  Ishii, Akio¹  Du, Jun-Ping^1,3  Han, Wei-Zhong²  Mei, Qingsong⁴  Ogata, Shigenobu^1,3 

[1] Osaka Univ, Dept Mech Sci & Bioengn, Osaka 5608531, Japan

[2] Xi An Jiao Tong Univ, State Key Lab Mech Behav Mat, Ctr Adv Mat Performance Nanoscale, Xian 710049, Peoples R China

[3] Kyoto Univ, Ctr Elements Strategy Initiat Struct Mat, Kyoto 6068501, Japan

[4] Wuhan Univ, Sch Power & Mech Engn, Wuhan 430072, Peoples R China

关键词: Grain boundary migration;    Density functional theory (DFT);    Coincidence lattice;    Grain boundary structure;    Atomic shuffling motion;   

DOI  :  10.1016/j.scriptamat.2017.02.041

来源: Elsevier

【 摘 要 】

A recent experiment (Scripta Mater., 65:990, 2011) shows that the Sigma 7 {032]/{032} grain boundary in Al can migrate under external stress but produces no strain. Here, based on a bi-crystallographic analysis, an atomic shuffling path was identified as the feasible mechanism for this grain boundary migration. By a density functional theory calculation, it reveals that the enthalpy barrier of this atomic shuffling path increases by external shear stress applied with shear of the grain boundary along the tilt axis < 111 >, which is in good agreement with experimentally measured shear-direction-dependence of activation enthalpy for this grain boundary migration. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All tights reserved.

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