中國有色金屬學報(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 29 No. 6 June 2019 |
（1. National Engineering Research Center of Light Alloy Net Forming and Key State Laboratory of Metal Matrix Composite, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China;
2. Shanghai Innovation Institute for Materials, Shanghai 200444, China;
3. Shanghai Spaceflight Precision Machinery Institute, Shanghai 201600, China;
4. Shanghai Engineering Technology Research Center of Near-Net-Shape Forming for Metallic Materials, Shanghai 201600, China）
Abstract:The as-cast Mg-8Li-xZn-yGd (x=1, 2, 3, 4; y=1, 2; wt.%) alloys were prepared in a vacuum induction furnace and their microstructure and mechanical properties were investigated. The results show that the increase of Zn content results in the volume fraction of W-phase (Mg3Zn3Gd2) increasing while that of Mg3Gd phase decreasing. The strength of Mg-8Li-xZn-1Gd alloys is improved with the increase of Zn content, which is ascribed to the second phase strengthening of fine strip-like W-phase and the solid solution strengthening of Zn element. For Mg-8Li-4Zn-yGd alloys, the increase of Gd content leads to the appearance of coarse and discontinuous net-like W-phase, which decreases the strength. The Mg-8Li-4Zn-1Gd alloy exhibits an optimum comprehensive performance with the yield strength, ultimate tensile strength and elongation of 154.7 MPa, 197.0 MPa and 12.4%, respectively. In addition, the aging behavior of the typical alloys was also investigated.
Key words: Mg-Li-Zn-Gd alloy; W-phase; microstructure; mechanical properties; aging behavior
