Influence of Differential Speed Rolling Process on Microstructure and Mechanical Properties of AZ31 Magnesium Alloy Sheet

The microstructure and mechanical properties of AZ31 magnesium alloy sheet produced by differential speed rolling process at the conditions of different rolling temperature, reduction in pass and rolling route were studied. The results show that when the rolling temperature increases from 623 K to 723 K, the grains grow up and twins disappear, and the ultimate tensile strength decreases from 275 MPa to 250 MPa,while the elongation increases from 14.5% to 18%. The ultimate tensile strength increases from 265 MPa to 300 MPa and the elongation decreases from 18% to 15% with increasing reduction in pass from 5% to 20%. The rolling routes affect the quantity of twins in the sheets. Twins in the sheet processed by route A are more than that by other routes, which induces higher ultimate tensile strength and lower elongation. On the other hand, the sheet prepared by route D exhibits higher elongation and lower ultimate tensile strength.