Effect of Pouring and Mold Temperatures on Hot Tearing Susceptibility of WE43 Magnesium Alloy

Abstract

The effects of different pouring temperature and mold temperature on the hot tearing susceptibility of WE43 magnesium alloy were studied using computer numerical simulation, hot tearing test and differential thermal analysis experiment. The microstructure of the hot tearing zone of the casting was observed using SEM, and the phase composition was analyzed using EDS. Numerical simulation results show that the change in pouring temperature and mold temperature could affect the hot tearing susceptibility (HTS) of WE43 alloy, and the influence of mold temperature was more significant with the conditions of pouring temperature (Tp) of 710–730 °C and mold temperature (Tm) of 240–320 °C. The experimental results are in good agreement with the simulation results. At the lower pouring temperature, the dendrite coherency began at a higher solids fraction, which could enhance the resistance to hot tearing at the end of solidification and reduce HTS of WE43 alloy. At the same pouring temperature, with the increase in the mold temperature, the number of dispersed eutectic phases in the alloy increased obviously, so that hot tearing could be well filled with the eutectic phase to reduce the HTS of WE43 alloy. In experimental conditions, the WE43 magnesium alloy had the lowest HTS at a pouring temperature of 710 °C and a mold temperature of 320 °C.