Effect of Antimony and Yttrium Addition on the High Temperature Properties of AZ91 Magnesium Alloy

The effect of individual and combined additions of Y and Sb on the microstructure and mechanical properties of AZ91 alloy has been studied. The results indicate that the additions introduce new Al2Y and Mg3Sb2 phase along with the Mg17Al12 -β phase besides, refining the grains significantly. It can be seen that the β phase in Y added AZ91 + Sb alloy becomes much finer and distributed more uniformly than that of any other alloys. Minimum grain size 140 μm is observed in AZ91alloy with 0.6 yttrium and 0.5 antimony additions. Moreover, improved room- and high-temperature mechanical properties are obtained in Sb added AZ91 + xY alloys. The maximum tensile properties are obtained with the alloy having the combined additions of 0.6 yttrium and 0.5 antimony.