Effects of Zn content on as-cast microstructure and mechanical properties of Mg-xZn-4A1 alloys containing TiC and rare earth elements
(1.重庆市重庆大学镁合金国家工程研究中心
2.Chongqing Engineering Research Center for Magnesium Alloys, Chongqing University,Chongqing 400044, China
3.Chongqing Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400030, China)
2.Chongqing Engineering Research Center for Magnesium Alloys, Chongqing University,Chongqing 400044, China
3.Chongqing Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400030, China)
Abstract: The effects of Zn content on the as-cast microstructure and mechanical properties of Mg-xZn-4A1 alloys containing TiC and rare earth elements were investigated by optical microscopy(OM), scanning electron microscopy(SEM) analysis, X-ray diffraction (XRD) analysis and tensile test. The results show that Zn content which increased from 8% to 12% does not obviously influence on the alloy phase type of the Mg-xZn-4A1 experimental alloys containing 0.25%RE and 1%TiC, but with Zn content increasing from 8% to 12%, the amount of Mg32(Al,Zn)49 phase in the as-cast microstructure of the experimental alloys increases and its distribution becomes more continuous. In addition, the Mg-10Zn-4A1 alloy containing 0.25%RE and 1TiC has the highest ultimate tensile strength at room temperature and 150 ℃ and highest yield strength and elongation at 150 ℃. Furthermore, with Zn content increasing from 8% to 12%, the yield strength and elongation of Mg-xZn-4A1 experimental alloys containing 0.25%RE and 1%TiC increase and decrease at room temperature, respectively.
Key words: Mg-Zn-Al alloys; as-cast microstructure; Mg32(Al,Zn)49 phase ; mechanical properties