Effect of antimony addition on the microstructure and mechanical properties of ZA84 magnesium alloy

The effect of antimony addition (0.2, 0.5 and 1 wt%) on the microstructure and mechanical properties of Mg–8Zn–4Al–0.2Mn alloy has been studied. Sb-addition to ZA84 alloy refines the ternary Mg32(Al,Zn)49 phase besides forming Mg3Sb2 precipitates and having a little effect on the grain refinement. Both the room and elevated temperature strength properties (yield and ultimate tensile strengths) are found to increase in Sb added alloys with slight reduction in ductility. However, the maximum strength properties are obtained with 0.2 wt% Sb-addition. Fractograph of the tensile tested ZA84 alloy shows intergranular and brittle type failure, whereas 0.2% Sb-addition facilitates transgranular fracture, relating to high strength.