Ce、Y 和Gd对Mg-3Sn-2Sr镁合金铸态组织和力学性能的影响.pdf

Trans. Nonferrous Met. Soc. China 24(2014) 2497−2506 Effects of Ce, Y and Gd additions on as-cast microstructure and mechanical properties of Mg−3Sn−2Sr magnesium alloy Ming-bo YANG1,2,3 2 2 3 , Meng-dan HOU , Jia ZHANG , Fu-sheng PAN 1. Key Laboratory of Manufacture and Test Techniques for Automobile Parts, Ministry of Education, Chongqing University of Technology, Chongqing 400054, China; 2. Materials Science and Engineering College, Chongqing University of Technology, Chongqing 400054, China; 3. National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400030, China Received 22 July 2013; accepted 19 October 2013 Abstract: The effects of Ce, Y and Gd additions on the as-cast microstructure and mechanical properties of Mg−3Sn−2Sr alloy were investigated and compared by scanning electron microscopy, X-ray diffraction, differential scanning calorimetry analysis, tensile and creep tests. The results indicate that the Mg−3Sn−2Sr ternary alloy is mainly composed of α-Mg, primary and eutectic SrMgSn, and Mg Sn phases. After the additions of 1.0% Ce, 1.0% Y and 1.0% Gd to the Mg−3Sn−2Sr alloy, the Mg Ce, YMgSn, GdMgSn and/or 2 12 Mg Sr phases are formed, respectively. At the same time, the formation of the primary SrMgSn phase is suppressed and the coarse 17 2 needle-like primary SrMgSn phase is modified and refined. In addition, the additions of 1.0% Ce, 1.0% Y and 1.0% Gd to the Mg−3Sn−2Sr alloy can simultaneously improve the tensile and creep properties