中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 30 No. 10 October 2020 |
（1. College of Materials Science and Engineering, Chongqing University, Chongqing 400045, China;
2. National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400044, China;
3. Chongqing Academy of Science and Technology, Chongqing 401123, China）
Abstract:The microstructure revolution and mechanical properties of as-extruded and peak-aged Mg-6Zn-1Mn- 4Sn-0.5Ca (ZMT614-0.5Ca) alloy were studied by OM, SEM, TEM, hardness testing and tensile testing. The results showed that the as-cast ZMT614-0.5Ca alloy mainly consisted of α-Mg, Mg-Zn and CaMgSn phase. The hot extrusion process effectively refined the microstructure and led to a completely dynamic recrystallized microstructure. The average grain size of as-extruded alloy was ~4.85 μm. After solution treatment, remained CaMgSn with high melting point played a significant role in pinning effect and impeding the migration of grain boundary. After aging treatment, peak-aged ZMT614-0.5Ca alloy exhibited a good combination of strength and ductility, with yield strength, ultimate tensile strength and elongation being 338 MPa, 383 MPa and 7.5%, respectively. The yield strength of the alloy increased significantly by around 36% compared with that in as-extruded condition, which should be attributed to the precipitation strengthening of β'''' phase.
Key words: Mg-6Zn-1Mn-4Sn-0.5Ca; extrusion; aging; microstructure; precipitation strengthening
