Effect of unequal channel angular pressing on microstructure and mechanical properties of Mg–Zn–Y–Mn–Ti magnesium alloy enhanced by lamellar LPSO phase and spherical W phase

In this paper, DEFORM-3D numerical simulation software was first used to numerically simulate the unequal channel angular technology for Mg–Zn–Y–Mn–Ti alloy under different deformation conditions (temperature, speed and extrusion ratio). Next, a mold was self-made according to the optimized parameters and the pressing experiments were carried out under the conditions of the pressing ratio of 9, the pressing speed of 1 mm/s and the pressing temperature of 350 °C, 400 °C and 450 °C to analyze its variations in microstructure and mechanical properties. The results indicate that with the increase of pressing temperature, the volume fraction of dynamically-recrystallized grains and the size of recrystallized grains increase continuously, the volume fractions of 14H LPSO phase and W phase decrease continuously and the texture of (0002) basal plane weakens continuously. The yield strength and tensile strength of the alloy increased first and then decreased, while the elongation increased all the time. The 400 °C-pressed sample showed the best comprehensive mechanical properties, with a yield strength of 278 MPa, a tensile strength of 375 MPa and an elongation of 22.8%.