Tribological behavior of SiC reinforced AZ91D composites manufactured by semisolid injection molding

Semisolid injection molding is a novel and ideal process for manufacturing particle reinforced magnesium composites. The main purpose of this article is to reveal the wear mechanism of SiC/AZ91D composite prepared by this method. AZ91D Mg alloy and its composites reinforced with 1 % and 2.5 % SiC particles were manufactured by the semisolid injection molding method and their microstructure and wear behavior were investigated. The composites are composed of a Mg matrix, consisting of unmelted AZ91D particles distributed in a resolidified Mg base, and uniformly-dispersed SiC particles. The dry wear tests showed that adding SiC reinforcement increases the friction coefficient, enhances the wear resistance at the low loads of 5 N and 10 N, but reduces the wear resistance at the high load of 20 N. The dominant wear mechanism is abrasive wear, accompanied by small contributions from adhesive and oxidative wear.