Effect of Antimony on Microstructure of Mischmetal-Containing AZ31 Magnesium Alloy

Effect of antimony on the microstructure, especially on the morphologies of rare earth-enriched phases, of mischmetal -containing AZ31 alloy was studied. The results showed that, by the addition of 0.8%Sb, the rare earth-enriched phases in AZ31-1.0%MM were transformed to dispersive tiny sphere-like Al-rare earth-Sb phases from coarse needle-like Al-rare earth phases. Meanwhile, rare earth-enriched phases transferred into alpha-Mg crystal grains from grain boundaries. On the other hand, the distribution of beta-Mg17Al12 phases became more dispersive.