Platelet precipitate in an age-hardening Mg-Zn-Gd alloy

被引：28

作者：

Koizumi, T. ^{[1
]}

Egami, M. ^{[1
,2
]}

Yamashita, K. ^{[1
]}

Abe, E. ^{[1
,2
]}

机构：

[1] Univ Tokyo, Dept Mat Sci & Engn, Tokyo 1138656, Japan

[2] Natl Inst Mat Sci, Res Ctr Struct Mat, Tsukuba, Ibaraki 3050047, Japan

来源：

JOURNAL OF ALLOYS AND COMPOUNDS | 2018年 / 752卷

关键词：

Magnesium alloys; Fine precipitations; Atomic structure; Electron microscopy; First principles calculations; STACKING ORDERED STRUCTURE; PERIOD SUPERLATTICE PHASE; MECHANICAL-PROPERTIES; ELECTRON-MICROSCOPY; MG97ZN1YB2; ALLOYS; Y-ALLOY; 14H; STRENGTH; CRYSTAL; 18R;

D O I：

10.1016/j.jallcom.2018.04.136

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The structure of a unique platelet precipitate with a three close-packed layer thickness, which occurred in a Mg-1 at.%Zn-2at.%Gd alloy aged at low temperatures (<similar to 500 K), has been determined based on scanning transmission electron microscopy and first principles calculations. The platelet precipitate is constructed by well-defined Gd networks that cause significant atomic displacements in the adjacent close-packed layer, in which the atomic sites are preferentially occupied by Zn atoms. Local Zn concentrations at the reconstructed-layer have been successfully tuned according to a similar manner of Vegard's law by reference to the local Gd-Gd interatomic distance along the c-axis. Therefore, the present platelet precipitate is found to be not a simple ordered hexagonal-close-packed Mg-Gd as previously reported, but a reconstructed ternary Mg-Zn-Gd structure. (C) 2018 Elsevier B.V. All rights reserved.

引用

页码：407 / 411

页数：5

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