Atomic structure and enhanced thermostability of a new structure MgYZn4 formed by ordered substitution of Y for Mg in MgZn2 in a Mg-Zn-Y alloy
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2019年第9期
论文作者：Lifeng Zhang Shangyi Ma Weizhen Wang Zhiqing Yang Hengqiang Ye
文章页码：2058 - 2063
摘 要：A new phase MgYZn4 in Mg-Zn-Y alloy was studied using aberration-corrected scanning-transmission electron microscopy and first-principles calculations.Nanometer-sized MgYZn4 precipitates were formed through ordered substitutions of Y with 50% Mg atoms in MgZn2.MgYZn4 has an orthorhombic structure with a space group of Pmnn,and lattice parameters a =5.2965 A,b =9.4886 A,and c =8.5966 A.Importantly,both size and structure of MgYZn4 are stable at 625 K for 5 h,showing higher thermostability than MgZn2,which should be important for applications at elevated temperatures.The enhanced thermostability of MgYZn4 is attributed to the lower formation energy and bonding enhancement due to Y substitution.
Lifeng Zhang1，Shangyi Ma1，Weizhen Wang2,1，Zhiqing Yang1，Hengqiang Ye1
1. Shenyang National laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, School of Materials Science and Engineering, University of Science and Technology of China2. School of Materials Science and Engineering, Northeastern University
摘 要：A new phase MgYZn4 in Mg-Zn-Y alloy was studied using aberration-corrected scanning-transmission electron microscopy and first-principles calculations.Nanometer-sized MgYZn4 precipitates were formed through ordered substitutions of Y with 50% Mg atoms in MgZn2.MgYZn4 has an orthorhombic structure with a space group of Pmnn,and lattice parameters a =5.2965 A,b =9.4886 A,and c =8.5966 A.Importantly,both size and structure of MgYZn4 are stable at 625 K for 5 h,showing higher thermostability than MgZn2,which should be important for applications at elevated temperatures.The enhanced thermostability of MgYZn4 is attributed to the lower formation energy and bonding enhancement due to Y substitution.
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