Defect and Diffusion Forum Vol. 394

Abstract: This study aimed to evaluate the effects of extrusion process and subsequentheat-treatment on microstructural evolution and mechanical properties of Mg-4%Y alloy. Theresults showed that the dynamic recrystallization occurred during extrusion, the microstructure istiny equiaxial grains, the shearing stripes and parallel streamlines which distribute along theextrusion direction are especially obvious. The tensile curve has obvious yield phenomenon. Afterannealing, parallel streamlines disappear, the yield phenomenon of tensile curve eliminates, theyield strength(σ0.2) and the tensile strength(σb) decrease, the plasticity increases. The underneathmechanism for mechanical properties can be ascribed to the weak pining effect of second-phaseparticles on the movement of dislocation and release of the pile-up dislocations.