中國有色金屬學(xué)報(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 25 No. 3 March 2015 |
（1. Chongqing Mold and Die Engineering Technology Research Center, Chongqing University of Technology,
Chongqing 400054, China;
2. College of Materials Science and Engineering, Chongqing University of Technology, Chongqing 400054, China;
3. National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400030, China）
Abstract:The as-cast microstructures and mechanical properties of Mg-4Zn-xY-1Ca (x=1.0, 1.5, 2.0 and 3.0, mass fraction, %) alloys were investigated and compared. The results indicate that all the as-cast alloys are mainly composed of α-Mg, Mg2Ca, Ca2Mg6Zn3, I (Mg3YZn6) and W (Mg3Y2Zn3) phases. However, with Y content increasing from 0.86% to 2.68%, the amount of the Ca2Mg6Zn3 phase gradually decreases but that of the I (Mg3YZn6) and W (Mg3Y2Zn3) phases gradually increases. Furthermore, an increase in Y content from 0.86% to 2.68% also causes the grain size of the as-cast alloys to gradually decrease. In addition, the tensile and creep properties of the as-cast alloys vary with Y content. Namely, with Y content increasing from 0.86% to 2.68%, the creep properties gradually increase, whereas the tensile properties firstly increase and attain the maximum at 1.77% Y, beyond that they decrease. Amongst the as-cast alloys with 0.86% Y, 1.19% Y, 1.77% Y and 2.68% Y, the alloy with 1.77% Y exhibits the relatively optimal tensile and creep properties.
Key words: magnesium alloy; Mg-Zn-Y alloy; Mg-Zn-Y-Ca alloy; microstructure; mechanical properties
