Process design of Warm-Forging with extruded Mg-8Al-0.5Zn alloy for differential case in automobile transmission

This paper mainly concerns a warm-forging with Mg-8Al-0.5Zn alloy for the differential case which covers differential gears in the transmission assembly of the automobile. The optimum forging process has been proposed with numerical simulations, which has been validated and compared with experiments conducted in the 1600-ton press shop. In order to validate the applicability of the Mg differential case into the automobile, its microstructure including texture evolution and mechanical properties in tension and compression have been analyzed. It does not only show substantial light-weight design in the total weight of 50% compared with conventional ductile iron, but also demonstrate the net-shape in the outer surface as well as internal volume. However, insufficient mechanical properties and tension-compression asymmetry of the Mg-8Al-0.5Zn differential case are huge obstacles in adopting Mg alloys into the automobile parts, successfully.