Effects of Zn content on as-cast microstructure and mechanical properties of Mg-xZn-4A1 alloys containing TiC and rare earth elements

摘要

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.