Microstructure and mechanical properties of an Mg-10Al alloy fabricated by Sb-alloying and ECAP processing

The effect of the addition of 0.5 wt% Sb and equal channel angular pressing (ECAP) on the microstructures and mechanical properties of Mg-10Al alloy was investigated. The results show that the addition of Sb has little effect on the as-cast microstructures of the alloy except for encouraging the formation of rod-shaped Mg3Sb2 particles. However, the microstructures of the Sb-alloyed Mg-10Al alloy were greatly improved after ECAP processing. The coarse rod-shaped Mg3Sb2 particles are broken into finer particles during ECAP, which then hinder the grain growth and thereby enhance the refinement function of ECAP processing on the α-(Mg) matrix and the β-Mg17Al12 phase. Relative to the as-cast alloys and as-ECAPed Mg-10Al, the as-ECAPed Mg-10Al-0.5Sb alloy exhibited superior mechanical properties at both room temperature and elevated temperatures due to the alloy structure optimization as a result of the combination of Sb-alloying and ECAP processing.