Electron beam irradiation induced metastable phase in a Mg-9.8 wt%Sn alloy  

作　　者：Chaoqiang Liu Houwen Chen Min Song Jian-Feng Nie 

机构地区：[1]State Key Laboratory of Powder Metallurgy,Central South University,Changsha,410083,China [2]College of Materials Science and Engineering,Chongqing University,Chongqing,400044,China [3]Electron Microscopy Center,Chongqing University,Chongqing,400044,China [4]Department of Materials Science and Engineering,Monash University,Victoria,3800,Australia

出　　处：《Journal of Materials Science & Technology》2021年第25期133-138,共6页材料科学技术（英文版）

基　　金：financially supported by National Natural Science Foundation of China(51771036 and 51421001)。

摘　　要：Aberration-corrected scanning transmission electron microscopy has been used to study a novel metastable phase,designated asβ’’phase,induced to form by electron beam irradiation in a Mg-9.8 wt.%Sn alloy.This phase is spherical in three dimensions,having a D019 structure with the lattice parameters of a=0.642 nm,c=0.521 nm and space group of P63/mmc.Its chemical formula is Mg_(3)Sn,like theβ’metastable precipitate phase.The orientation relationship between theβ’’phase and theα-Mg matrix is such that■_(β)’’//■_(α)and(0001)_(β)’’//(0001)_(α).Its formation involves solely the ordering of Sn atoms in the solid solution magnesium matrix.First-principles calculations indicate that the formation of theβ’’phase is energetically favored.

关 键 词：Mg-Sn alloys Metastable phase IRRADIATION HAADF-STEM Density functional theory 

分 类 号：TG146.22[一般工业技术—材料科学与工程]