Wear transitions in particulate reinforced copper matrix composites

Abstract

The effects of applied load, sliding velocity and SiC volume fraction on the transitional behavior between mild and severe wear in SiC particulate reinforced copper matrix composites were studied under dry sliding wear condition. Increasing SiC fraction or decreasing sliding 1 velocity delays the occurrence of severe wear up to higher transition load. Mechanically mixed layer (MML), which is markedly harder than that of the bulk material, is absent in the post-transition regime. The coverage rate of MML is affected by applied load and sliding velocity. SiC particulates act as load-bearing components and lessen the frictional deformation extent in the subsurface region. In the pre-transition regime, microcrack propagation induced detachment of MML and subsurface material are the primary wear mechanism. In the severe wear process, thermally activated subsurface deformation plays a significant role in the tear of surface layer from the substrate material.