Entropy-induced transition on grain-boundary migration in multi-principal element alloys

SCRIPTA MATERIALIA

卷:194

Article

Tan, Fusheng¹  Li, Jia¹  Feng, Hui¹  Fang, Qihong¹  Jiang, Chao¹  Liu, Yong²  Liaw, Peter K.³ 

[1] Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Peoples R China

[2] Cent South Univ, State Key Lab Powder Met, Changsha 410083, Peoples R China

[3] Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA

关键词: Grain boundary;    Multi-principal element alloy;    Grain boundary migration;   

DOI  :  10.1016/j.scriptamat.2020.113668

来源: Elsevier

【 摘 要 】

In-depth understanding of grain boundaries (GBs) in multi-principal element alloys (MPEAs) is considered significant for designing MPEAs by GB engineering. This work explores the nanoscale GB structure and migration mechanism in MPEAs using atomic simulations. The GB-roughening transformation is observed as the mixing entropy increases, and the effect of entropy is confirmed by thermodynamic analysis. The entropy-induced transition of GB migration is proved: 1) the concentrated shuffling mechanism controls the migration of ordered GBs in low-entropy systems, leading to the obviously stepwise migration; 2) the dispersed shuffling mechanism dominates the migration of disordered GBs in high-entropy systems, resulting in the continuous migration manner. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

【 授权许可】

Free