Effects of hot rolling on microstructure, macrotexture and mechanical properties of pre-extruded AZ31/SiC nanocomposite sheets

AZ31-1 vol% SiC nanocomposite sheets were fabricated by hot rolling with pre-extrusion. Nanocomposite sheets exhibited significantly enhanced tensile strength with respect to as-annealed extruded sheet. 50% strength improvement and relatively high ductility were realized in the sheet after 4 passes rolling, which resulted from the complicated interaction of the uniform microstructure, the fine mean grain size of 5.2 mu m, the strong basal texture and the continuous nanoparticle bands. Additionally, strength along rolling direction and transverse direction in this sheet showed slight variation. Comparison with previous work showed that the 4 pass hot rolled sheet we obtained here with pre-extrusion exhibited the comparable mechanical strength and much better ductility, demonstrating that pre-extrusion can promote the deformation efficiency of hot rolling in magnesium nanocomposite sheets fabrication and achieve good combination of reasonable strength and remarkable ductility. Correlation of the mechanical performance with texture and microstructure evolution was investigated.