Microstructural control and hardening response of Mg–6Zn–0.5Er–0.5Ca alloy  

作　　者：Xiao-Bing Zheng Ke Liu Zhao-Hui Wang Shu-Bo Li Wen-Bo Du 

机构地区：[1]School of Material Science and Engineering,Beijing University of Technology

出　　处：《Rare Metals》2016年第7期526-531,共6页稀有金属（英文版）

基　　金：financial supported by the National Natural Science Foundation of China(No.51301006);the Projects of Beijing Municipal Science and Technology Commission(No.Z131100003213019);the Projects of Beijing Municipal Commission of Education(Nos.KM201310005001 and KM201410005014);Beijing Natural Science Foundation(No.2142005)

摘　　要：The effects of heat treatment on microstructures and hardening response of Mg-6Zn4）.5Er4）.5Ca （wt%） alloy were investigated by optical microscope （OM）, scanning elec- tron microscope （SEM）, and transmission electron microscope （TEM） in this paper. The results show that the Mg（Zn4）.5Er- 0.5Ca alloy contains Mg3Zn6Erx quasicrystalline phase （I- phase） and Ca2Mg6Zn3 phase under as-cast condition. Most of the Ca2Mg6Zn3 phases and I-phases dissolve into matrix during heat treatment at 475 ℃ for 5 h. After the as-solution alloy was aged at 175 ℃ for 36 h, a large amount of MgZn2 precipitate with several nanometers precipitate. It is suggested that the trace addition of Ca results in refining the size of the precipitate, and the presence of the nanoscale MgZn2 phase is the main factor to improve the peak-aged hardness greatly to 87 HV, which in- creases about 40 % compared with that of as-cast alloy.The effects of heat treatment on microstructures and hardening response of Mg-6Zn4）.5Er4）.5Ca （wt%） alloy were investigated by optical microscope （OM）, scanning elec- tron microscope （SEM）, and transmission electron microscope （TEM） in this paper. The results show that the Mg（Zn4）.5Er- 0.5Ca alloy contains Mg3Zn6Erx quasicrystalline phase （I- phase） and Ca2Mg6Zn3 phase under as-cast condition. Most of the Ca2Mg6Zn3 phases and I-phases dissolve into matrix during heat treatment at 475 ℃ for 5 h. After the as-solution alloy was aged at 175 ℃ for 36 h, a large amount of MgZn2 precipitate with several nanometers precipitate. It is suggested that the trace addition of Ca results in refining the size of the precipitate, and the presence of the nanoscale MgZn2 phase is the main factor to improve the peak-aged hardness greatly to 87 HV, which in- creases about 40 % compared with that of as-cast alloy.

关 键 词：Mg-6Zn-0.5Er-0.5Ca alloy Heat treatment Aging hardening 

分 类 号：TG146.22[一般工业技术—材料科学与工程] TG166.4[金属学及工艺—金属材料]