Metal Matrix Composites

Overview no. 55 Wear-Mechanism maps

Sliding wear and transfer

The wear behavior of new lead free metal matrix composite (MMC), centrifugally cast copper alloy graphite (C90300–10%graphite) composite (CG) is studied in comparison to a commonly used leaded copper (LC) alloy (18–22% Pb). Tribological tests were conducted with pins made from these materials and tested against a SAE 1045 steel counterface. The CG material showed higher wear resistance than the LC in the load range investigated (27–118 N). The CG and the LC showed similar friction coefficient (0.38) values at a low load of 27 N, where as at 118 N the CG had a slightly higher friction coefficient than the LC against the 1045 steel counterface. Transfer of material from the CG and the LC pins resulted in lowering the wear rate of the counterface as measured by the weight loss of the steel counterface. At the load of 27 N, the CG composite seems to be a viable substitute for the LC. For other loads modified versions of the CG are likely to provide optimum substitutes for the LC. Observations on structure, composition and morphology of surface, subsurface and wear debris was utilized in understanding the wear properties in each material.

V.D. Khanna

Papers

Residual stresses and sliding wear

Wear mechanism in composites: a qualitative model

On the effect of fiber orientation on the wear of composite materials