Casting Defects and Mechanical Properties of High Pressure Die Cast Mg-Zn-Al-RE Alloys


  • CAST CRC was established under, and is supported in part by the Australian Government's Cooperative Research Centers scheme. The authors would like to thank Mr Gary Savage, Mr Andy Yob and Ms Maya Gershenzon for operating the high pressure die casting machine and producing the samples. Xiao also gratefully acknowledges the financial support from the China Scholarship Council (CSC).


The die casting defects and tensile properties of high pressure die cast (HPDC) Mg-Zn-Al-RE alloys with various combinations of Zn and Al were studied. The results show that die casting defects in Mg-Zn-Al-RE alloys are affected by the percentage of Zn and Al contents. The hot tearing susceptibility (HTS) of Mg-Zn-Al-RE alloys tends to increase with increasing Zn content up to 6 wt%, while a further increase of Al and/or Zn content reduces the HTS. In tensile tests, the yield strength (YS) is generally improved by increasing Zn or Al content, whereas the tensile strength (TS) and ductility appear to depend largely on the presence of casting defects. Compared with Mg-Zn-Al alloys, the mechanical properties of the Mg-Zn-Al-RE alloy are significantly improved. The Mg-4Zn-4Al-4RE alloy is found to have few casting defects and the optimal tensile properties.