Evaluating high-temperature mechanical behavior of cast Mg-4Zn-xSb magnesium alloys by shear punch testing

High-temperature shear punch test (SPT) was employed to investigate the effects of 0.15, 0.4 and 0.7 wt.% Sb additions on the microstructure and mechanical properties of an as-cast Mg-4%Zn alloy. The shear behavior of the alloys was investigated in temperature range of 25-250 °C. The results showed good reproducibility of the data obtained by the SPT for these cast alloys. The dendritic structure of the base alloy was refined after Sb additions, the effect being more pronounced in Mg-4%Zn-0.4%Sb. This alloy had the highest shear strength among all materials tested, mainly due to the formation of the thermally stable Mg3Sb2 second-phase particles. These particles are believed to increase the material's resistance to the applied shear stresses in the deformation zone during deformation SPT of the investigated system. However, when antimony content was increased to 0.7 wt.%, a slight decrease in strength of the alloy was observed, which was attributed to the formation of coarse Mg3Sb2 particles.