Mechanisms of the copper third body as an interfacial media on copper matrix friction materials with different compositions

Abstract

This paper aims to reveal the effects of the copper third body on different copper matrix friction materials with a novel experimental way called “exogenous powder.” An accurate adding device of exogenous copper powder was designed to control the flow rate. The tribological properties with and without exogenous copper powder were investigated by a pin-on-disc tribometer during dry sliding. Experimental results indicate that the Cu addition tends to increase the friction coefficient. For pure Cu material, the exogenous copper third body exhibits poor fluidity on the friction surface, causing serious adhesive wear on the friction interface. For the Cu 90% + 10% Gr material, the plasticity of exogenous copper powder may intensify the deformation of the third body of the surface, presenting layered accumulation distribution. For the pure Cu and Cu 95% + 5% SiO₂ material, the Cu addition makes the composition and density of the third body uneven in the direction of depth. The role of the copper component on different materials is revealed from a new perspective, and the relationship between the third body structure and the friction properties is explored.