Microstructure and mechanical properties of as-cast AZ31 with the addition of Sb

Microstructures and mechanical properties of as-cast AZ31 with Sb addition (0.3 wt.%, 0.45 wt.% and 0.6 wt.%) were investigated. The results show that the microstructure of AZ31 with Sb addition consists of two phases, equiaxed grains of α-Mg with a bigger grain size (about 200 μm) and rod-shaped precipitates of α-Mg3Sb2, the stable intermetallic compounds with high melting point, homogenously distributed in matrix, which is significantly different from that of AZ31. Tensile tests indicated that the tensile strength and elongation of alloys with Sb addition appreciably decrease with the increase in Sb addition because of stress concentration occurring in the ends of rod-shaped precipitates.