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

被引:116
作者
Koju, R. K. [1 ]
Mishin, Y. [1 ]
机构
[1] George Mason Univ, Dept Phys & Astron, MSN 3F3, Fairfax, VA 22030 USA
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
收藏
页码:596 / 603
页数:8
相关论文
共 46 条
[1]  
[Anonymous], 1995, Fundamentals of Grain and Interface Boundary Diffusion
[2]   Electrochemical characteristics of intermetallic phases in aluminum alloys - An experimental survey and discussion [J].
Birbilis, N ;
Buchheit, RG .
JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 2005, 152 (04) :B140-B151
[3]   Coupling grain boundary motion to shear deformation [J].
Cahn, John W. ;
Mishin, Yuri ;
Suzuki, Akira .
ACTA MATERIALIA, 2006, 54 (19) :4953-4975
[4]   IMPURITY-DRAG EFFECT IN GRAIN BOUNDARY MOTION [J].
CAHN, JW .
ACTA METALLURGICA, 1962, 10 (SEP) :789-&
[5]   Grain boundary diffusion of Al in Mg [J].
Das, Sazol Kumar ;
Brodusch, Nicolas ;
Gauvin, Raynald ;
Jung, In-Ho .
SCRIPTA MATERIALIA, 2014, 80 :41-44
[6]   Grain boundary segregation and intermetallic precipitation in coarsening resistant nanocrystalline aluminum alloys [J].
Devaraj, A. ;
Wang, W. ;
Vemuri, R. ;
Kovarik, L. ;
Jiang, X. ;
Bowden, M. ;
Trelewicz, J. R. ;
Mathaudhu, S. ;
Rohatgi, A. .
ACTA MATERIALIA, 2019, 165 (698-708) :698-708
[7]   Diffusion and segregation of silver in copper Σ5(310) grain boundary [J].
Divinski, Sergiy V. ;
Edelhoff, Henning ;
Prokofjev, Sergei .
PHYSICAL REVIEW B, 2012, 85 (14)
[8]   Phases, phase equilibria, and phase rules in low-dimensional systems [J].
Frolov, T. ;
Mishin, Y. .
JOURNAL OF CHEMICAL PHYSICS, 2015, 143 (04)
[9]   Effect of Interface Phase Transformations on Diffusion and Segregation in High-Angle Grain Boundaries [J].
Frolov, T. ;
Divinski, S. V. ;
Asta, M. ;
Mishin, Y. .
PHYSICAL REVIEW LETTERS, 2013, 110 (25)
[10]   MASS-TRANSPORT DURING ELECTROMIGRATION IN ALUMINUM-MAGNESIUM THIN-FILMS [J].
GANGULEE, A ;
DHEURLE, FM .
THIN SOLID FILMS, 1975, 25 (02) :317-325