Effects of Process Parameters of Semisolid Stirring on Microstructure of Mg–3Sn–1Mn–3SiC (wt%) Strip Processed by Rheo-rolling

Abstract

A novel semisolid stirring and rheo-rolling process for preparing Mg–3Sn–1Mn–3SiC (wt%) composite strips was proposed, and the effects of process parameters of semisolid stirring on microstructures of Mg–3Sn–1Mn–3SiC (wt%) composite strips were investigated. The average grain size and roundness decrease, and the distribution of SiC becomes more homogeneous with the decrease in stirring temperature and the increase in the stirring speed. When the stirring time is increased, the distribution of SiC particles tends to be homogeneous, and the average grain diameter and roundness of α-Mg grain decrease. Under the following process parameters: the stirring temperature at 640 °C, the stirring speed at 1100 rpm, the stirring time at 30 min and the roll speed at 0.2 m/s, Mg–3Sn–1Mn–3SiC (wt%) strip with a cross-sectional size of 4 mm × 160 mm was prepared. The ultimate tensile strength and elongation of Mg–3Sn–1Mn–3SiC (wt%) composite strip reached 226 ± 6 MPa and (7.4 ± 0.2)%, which are obviously improved in comparison with Mg–3Sn–1Mn (wt%).