中國有色金屬學(xué)報(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 31 No. 4 April 2021 |
（1. National Engineering Research Center of Light Alloy Net Forming, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China;
2. State Key Laboratory of Metal Matrix Composite, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China）
Abstract:The effects of Al/Zn ratio (mass ratio) on microstructure and mechanical properties of the Mg-8Li alloy were investigated. The results indicate that in the as-cast Mg-8Li-xAl-yZn (x+y=5) alloys (LAZ alloys), when the Al/Zn ratio is 1:4 and 2:3, the secondary phases are mainly AlLi and MgLiZn phases; when the Al/Zn ratio is 3:2 and 4:1, the secondary phases are mainly AlLi and MgLi2Al phases. The decomposition temperature of MgLiZn phase is about 300 °C and the decomposition temperatures of AlLi phase and MgLi2Al phase are higher (~350 °C). Solid solution strengthening is the main factor for the improvement of strength of Mg-8Li-xAl-yZn alloys. The Mg-8Li-3Al-2Zn alloy after solution treatment at 350 °C for 4 h has the best comprehensive mechanical properties (yield strength of 272.5 MPa, ultimate tensile strength of 315.0 MPa and elongation of 3.4%) among the studied as-cast and solid solution treated Mg-8Li-xAl-yZn alloys.
Key words: Mg-Li alloy; Al/Zn ratio; microstructure; mechanical properties
