Influence of alloying elements on hot tearing susceptibility of Mg–Zn alloys based on thermodynamic calculation and experimental

Abstract

Based on the hot tearing index |∆T/∆(fs)0.5| recently proposed by Kou and the thermodynamic calculations of Pandat software, Al, Cu, and Mn elements were picked up and their influence on hot tearing susceptibility of Mg–xZn (x = 6, 8, 10, wt%) alloys was studied by experiments. The results indicate that Al addition can significantly reduce the hot tearing susceptibility of Mg–Zn alloys. Either 0.5Cu or 0.3Mn addition individually can reduce the HTS of the Mg–6Zn–(1, 4) Al alloys, while adding together increases the susceptibility. The addition of 0.5Cu and 0.3Mn both individually and together increases the HTS of Mg–8/10Zn–1Al alloys. Based on the experimental and calculation results, the index can be modified to |∆T/∆(fs)0.5|(d)2 for more accurate prediction on the hot tearing resistance of Mg–Zn based alloys. Grain refinement significantly improves the hot tearing resistance of Mg–Zn based alloys. Keywords: Hot tearing susceptibility, Mg–Zn, Alloying element, Thermodynamic calculation, Grain size