Abstract:
AZ31 magnesium ribbons are prepared by the single roll rapid solidification method at different rolling speeds, and the microstructures are analyzed. The mechanical properties of AZ31 magnesium rods extruded at 250 ℃ from the ribbons are investigated. Results indicate that the rapid cooling directionally solidification region and gradual cooling equiaxed grain region are found in the cross-sections of the AZ31 magnesium ribbons, which is a thermal-gradient driven microstructure partition phenomenon. The heat insulation zone forms due to the gas entrapment in the melt pool, leading to the decline of microstructural homogeneity of the ribbons. It is found out that when the rolling speed is 17.58 m/s, the AZ31 magnesium rods extruded at 250 ℃ from the ribbons have the optimal performance, with the yield strength up to 360 MPa and the elongation up to 14.47 %.