中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 30 No. 1 January 2020 |
（1. School of Resources and Materials, Northeastern University at Qinhuangdao, Qinhuangdao 066004, China;
2. School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China;
3. Key Laboratory of Advanced Metal Materials and Forming Technology in Qinhuangdao, Northeastern University at Qinhuangdao, Qinhuangdao 066004, China）
Abstract:Mg-5.88Zn-0.53Cu-0.16Zr (wt.%) alloy was solidified at 2-6 GPa using high-pressure solidification technology. The microstructure, strengthening mechanism and compressive properties at room temperature were studied using SEM and XRD. The results showed that the microstructure was refined and the secondary dendrite spacing changed from 35 μm at atmospheric pressure to 10 μm at 6 GPa gradually. Also, Mg(Zn,Cu)2 and MgZnCu eutectic phases were distributed in the shape of network, while under high pressures the second phases (Mg(Zn,Cu)2 and Mg7Zn3) were mainly granular or strip-like. The solid solubility of Zn and Cu in the matrix built up over increasing solidification pressure and reached 4.12% and 0.32% respectively at 6 GPa. The hardness value was HV 90 and the maximum compression resistance was 430 MPa. Therefore, the grain refinement strengthening, the second phase strengthening and the solid solution strengthening are the principal strengthening mechanisms.
Key words: high pressure solidification; Mg-Zn-Cu-Zr alloy; strengthening mechanism; eutectic transformation
