Sliding Wear Behavior of Aluminum Matrix Composites Hybrid Reinforced by SiC_p and Spherical Graphite Particles

Spherical graphite particles (Gr) particles and (Gr+SiC_p) hybrid reinforced 6092Al composites were prepared via powder metallurgy. The dry sliding friction and wear behaviors of the composites were investigated. The results showed that as the load increased from 10 N to 20 N, the friction coefficient and wear rate of the three composites increased correspondingly; the wear sliding speed increased from 0.5 m/s to 1.0 m/s, and the friction coefficients of 15%Gr/6092Al and (5%Gr+20% SiC_p)/6092Al firstly decreased and then increased; while (5%Gr+10% SiC_p)/6092Al decreased. When the other conditions were the same, 15%Gr/6092Al composites showed higher wear rate than the hybrid reinforced composites. The results of the analysis of variance showed that the three factors, the effect of the reinforcement phase percentage alone, the interaction between the reinforcement phase percentage and the sliding rate, and the sliding speed alone, have a significant impact on the wear rate and the friction coefficient. With the increase of SiC_p content, the hardness of the material increased, and the SiC_p acted as a supporting and protective role on the Al matrix. The wear marks on the wear surface became shallow, the phenomenon of delamination exfoliation was obviously alleviated, the debris became fine, and the friction coefficient was more stable, and the wear mechanism changed from delamination wear to abrasive wear.