Co-segregation of Mg and Zn atoms at the planar η1-precipitate/Al matrix interface in an aged Al-Zn-Mg alloy

SCRIPTA MATERIALIA

卷:185

Article

Cheng, Bingqing¹  Zhao, Xiaojun²  Zhang, Yong¹  Chen, Houwen²  Polmear, Ian¹  Nie, Jian-Feng¹ 

[1] Monash Univ, Dept Mat Sci & Engn, Clayton, Vic 3800, Australia

[2] Chongqing Univ, Coll Mat Sci & Engn, Chongqing 400044, Peoples R China

关键词: Aluminium alloys;    Interface segregation;    Energy-Dispersive X-ray Spectroscopy;    High-angle annular dark field;    Deep neural network based calculation and simulation;   

DOI  :  10.1016/j.scriptamat.2020.04.004

来源: Elsevier

【 摘 要 】

Using aberration-corrected scanning transmission electron microscopy, the interface between Thprecipitates and Al matrix in the aged Al-2.1Zn-1.7Mg (at.%) alloy has been investigated. Atomic-resolution X-ray dispersive spectroscopy mapping reveals the occurrence of co-segregation of Mg and Zn atoms in the {002}(alpha) habit plane of the eta(1)(MgZn2) precipitates. Site-specific Mg atoms segregate outside the concave of an outermost zig-zag Zn-rich layer of the eta(1) habit plane. Zn segregation surround the segregated Mg atomic columns was also observed. Hybrid molecular dynamics (MD) and Monte Carlo (MC) atomistic simulations with the accuracy of density functional theory indicate the site-specific segregation is energetically favourable. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

【 授权许可】

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