中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 21 No. 4 April 2011 |
in Mg97Y2Zn1 alloy
（1. School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China;
2. Faculty of Materials, Optoelectronics and Physics, Xiangtan University, Xiangtan 411105, China;
3. Light Alloy Net Forming National Engineering Research Center, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200030, China）
Abstract:The microstructure of the 18R-type long period stacking ordered (LPSO) phase in Mg97Y2Zn1 alloy was investigated by the first principles calculation. The arrangement rule of Zn and Y atoms in the LPSO structure is determined theoretically. The calculation results reveal that the additive atoms are firstly located in the fault layers at the two ends of the 18R-type LPSO structure, and then extend to fault layers in the interior, which is in good agreement with the experimental observations. This feature also implies the microstructural relationship between 18R and other LPSO structures. The cohesive energy and the formation heat indicate the dependence of the stability of 18R LPSO structure on contents of Y and Zn atoms. The calculated electronic structures reveal the underlying mechanism of microstructure and the stability of 18R LPSO structure.
Key words: Mg97Y2Zn1 alloy; 18R LPSO structure; the first principles; microstructure; electronic structure
