Effects of heat treatment on microstructure evolution and mechanical properties of Mg-6Zn-1.4Y-0.6Zr alloy

作     者：Jing Wang Xiao-gang Fang Shu-sen Wu Shu-lin Lü 

作者机构：State Key Lab of Materials Processing and Die & Mould Technology Huazhong University of Science and Technology Wuhan 430074 China 

出 版 物：《China Foundry》 (中国铸造（英文版）)

年 卷 期：2017年第14卷第3期

页      面：199-204页

核心收录：

学科分类：08[工学] 0806[工学-冶金工程] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 

基　　金：financially supported by the National Natural Science Foundation of China(Grant No.51275183:Non-equilibrium structure control of RE-containing Mg allloys with ultrasonic vibration and high pressure rheo-forming) 

主　　题：镁合金 加热处理 微观结构 机械性质 TG146.22 A 

摘      要：To investigate the effects of solution temperature and the decomposition of I-phase on the microstructure, phase composition and mechanical properties of as-cast Mg-6Zn-1.4Y-0.6Zr alloy, solution treatment at 440 oC, 460 oC and 480 oC and further aging treatment were conducted on the alloy. The results indicate that the net-like intermetallic compounds(mainly I-phase) dissolve into the α-Mg matrix gradually with the increase of solution temperature from 440 oC to 480 oC. Besides, the I-phase decomposes completely at 480 oC, with the formation of fine W-phase(thermal stable phase) and Mg_7Zn_3 phase. In addition, a great number of fine and dispersive Mg-Zn binary phases precipitate in the α-Mg matrix during the aging treatment. Due to the increase of solute atoms and the precipitation of strengthening phases, such as W-phase and Mg-Zn phases, the optimal strength is obtained after solution treatment at 460 oC for 8 h and aged at 200 oC for 16 h. The yield strength(YS), ultimate tensile strength(UTS) and elongation are 208 MPa, 257 MPa and 3.8%, respectively. Compared with the as-cast alloy, the increments of YS and UTS are 117% and 58%, respectively, while the decrement of elongation is 46%.