中國有色金屬學(xué)報(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 20 No. 4 April 2010 |
（1. Materials Science and Engineering College, Chongqing University of Technology, Chongqing 400050, China;
2. National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400045, China）
Abstract:The as-cast microstructure, tensile and creep properties of Mg-3Sn-1Ca and Mg-3Sn-2Ca magnesium alloys were investigated and compared by using optical microscopy and scanning electron microscopy, X-ray diffraction analysis and tensile tests. The results indicate that the as-cast microstructures of Mg-3Sn-1Ca and Mg-3Sn-2Ca alloys are different. The former is mainly composed of a-Mg, eutectic CaMgSn and solid state precipitation of Mg2Sn, whereas the latter is mainly composed of a-Mg, primary CaMgSn, eutectic CaMgSn and Mg2Ca phases. As a result, the two alloys obtain different tensile and creep properties. Mg-3Sn-1Ca alloy shows relatively higher ultimate tensile strength and elongation at room temperature and 150 ℃ than Mg-3Sn-2Ca alloy, however, the yield strengths of Mg-3Sn-1Ca alloy at room temperature and 150 ℃ are relatively low. In addition, the creep properties of Mg-3Sn-1Ca alloy at 150 ℃ and 70 MPa for 100 h are obviously lower than those of the Mg-3Sn-2Ca alloy.
Key words: magnesium alloy; CaMgSn phase; Sn; Ca; mechanical properties
