中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 24 No. 12 December 2014 |
（1. College of Mechanical Engineering, Shanghai University of Engineering Science, Shanghai 201600, China;
2. National Engineering Research Center of Light Alloy Net Forming,
Shanghai Jiao Tong University, Shanghai 200240, China;
3. State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, China）
Abstract:A Mg-14.28Gd-2.44Zn-0.54Zr (mass fraction, %) alloy was prepared by conventional ingot metallurgy (I/M). The microstructure differences in as-cast and solution-treated alloys were investigated. Sliding tribological behaviors of the as-cast and solution-treated alloys were investigated under oil lubricant condition by pin-on-disc configuration. The wear loss and friction coefficients were measured at a load of 40 N and sliding speeds of 30-300 mm/s with a sliding distance of 5000 m at room temperature. The results show that the as-cast alloy is mainly composed of α-Mg solid solution, the lamellar 14H-type long period stacking ordered (LPSO) structure within matrix, and β-[(Mg,Zn)3Gd] phase. However, most of the β-phase transforms to X-phase with 14H-type LPSO structure after solution heat treatment at 773 K for 35 h (T4). The solution-treated alloy presents low wear-resistance, because the hard β-phase is converted into thermally-stable, ductile and soft X-Mg12GdZn phase with LPSO structure in the alloy.
Key words: Mg-Gd-Zn-Zr alloy; long period stacking ordered (LPSO) structure; microstructure; friction; wear
