Effects of Y and Zn/Y on hot tearing susceptibility of Mg-Zn-Y-Zr alloys

摘要

The effects of Y and Zn/Y on hot tearing susceptibility (HTS) of Mg-6.5Zn-xY-0.5Zr (x = 4, 9, 12 and 18) and Mg-5Zn-13.5Y-0.5Zr alloys were investigated herein. The results illustrated that HTS of the investigated alloys decreased in the following order: Mg-6.5Zn-4Y-0.5Zr > Mg-6.5Zn-18Y-0.5Zr > Mg-6.5Zn-9Y-0.5Zr > Mg-6.5Zn-12Y-0.5Zr > Mg-5Zn-13.5Y-0.5Zr. The results also showed that HTS of the alpha-Mg-based alloy containing only LPSO phase was lower than that of the alloy containing only W-phase and (I+W) or (W+LPSO) mixed secondary phases. This was attributed to the coherence relationship between LPSO phase and alpha-Mg, and the bridging effect of LPSO phase.