Atomistic study of grain-boundary segregation and grain-boundary diffusion in Al-Mg alloys

被引：121

作者：

Koju, R. K. ^{[1
]}

Mishin, Y. ^{[1
]}

机构：

[1] George Mason Univ, Dept Phys & Astron, MSN 3F3, Fairfax, VA 22030 USA

来源：

ACTA MATERIALIA | 2020年 / 201卷

基金：

美国国家科学基金会;

关键词：

Atomistic modeling; Al-Mg alloys; Grain boundary segregation; Grain boundary diffusion; INTERATOMIC POTENTIALS APPROPRIATE; POINT-DEFECTS; SOLUTE DRAG; SIMULATION; STRENGTH;

D O I：

10.1016/j.actamat.2020.10.029

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Mg grain boundary (GB) segregation and GB diffusion can impact the processing and properties of Al-Mg alloys. Yet, Mg GB diffusion in Al has not been measured experimentally or predicted by simulations. We apply atomistic computer simulations to predict the amount and the free energy of Mg GB segregation, and the impact of segregation on GB diffusion of both alloy components. At low temperatures, Mg atoms segregated to a tilt GB form clusters with highly anisotropic shapes. Mg diffuses in Al GBs slower than Al itself, and both components diffuse slowly in comparison with Al GB self-diffusion. Thus, Mg segregation significantly reduces the rate of mass transport along GBs in Al-Mg alloys. The reduced atomic mobility can be responsible for the improved stability of the microstructure at elevated temperatures. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

引用

页码：596 / 603

页数：8

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