Effect of the Deformation and Heat Treatment on the Microstructural Evolution and Mechanical Properties of Mg-4Y Alloy

摘要

This study aimed to evaluate the effects of extrusion process and subsequent heat-treatment on microstructural evolution and mechanical properties of Mg-4%Y alloy. The results showed that the dynamic recrystallization occurred during extrusion, the microstructure is tiny equiaxial grains, the shearing stripes and parallel streamlines which distribute along the extrusion direction are especially obvious. The tensile curve has obvious yield phenomenon. After annealing, parallel streamlines disappear, the yield phenomenon of tensile curve eliminates, the yield strength(σ0.2) and the tensile strength(σb) decrease, the plasticity increases. The underneath mechanism for mechanical properties can be ascribed to the weak pining effect of second-phase particles on the movement of dislocation and release of the pile-up dislocations.