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

作者：Zheng, Xiao-Bing; Liu, Ke; Wang, Zhao-Hui; Li, Shu-Bo; Du, Wen-Bo^*

来源：Rare Metals, 2016, 35(7): 526-531.

DOI：10.1007/s12598-015-0462-0

• Mg-6Zn-0.5Er-0.5Ca alloy
• Heat treatment
• Aging hardening

The effects of heat treatment on microstructures and hardening response of Mg-6Zn-0.5Er-0.5Ca (wt%) alloy were investigated by optical microscope (OM), scanning electron microscope (SEM), and transmission electron microscope (TEM) in this paper. The results show that the Mg-6Zn-0.5Er-0.5Ca alloy contains Mg3Zn6Er1 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 degrees C for 5 h. After the as-solution alloy was aged at 175 degrees C 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 increases about 40 % compared with that of as-cast alloy.

• 出版日期2016-7
• 单位北京工业大学