Abrasive wear of silicon carbide particulate— and whisker-reinforced 7091 aluminum matrix composites

Abstract

The abrasive wear behavior of silicon carbide particulate- and whisker-reinforced aluminum matrix composites was investigated under two-body abrasion conditions utilizing a pinon-disk apparatus. Both SiC particulate- and SiC whisker-reinforced composites exhibited greater wear resistance than the unreinforced 7091 alloy. The whisker reinforcement was more effective than the particulate reinforcement in improving the wear resistance of the matrix alloy. Further, whisker reinforcements oriented normal to the contact surface were, at small abrasive sizes, more effective than whiskers oriented within the contact surface. At larger abrasive sizes the opposite effect was observed. It was found that, at constant reinforcement volume fraction, the ratio of the average abrasive penetration depth to the characteristic size of the reinforcement was the critical parameter controlling the relative abrasive wear resistance of composites reinforced with SiC.