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.