WEAR AND FRICTION BEHAVIOR OF METAL IMPREGNATED MICROPOROUS CARBON COMPOSITES

Metal-matrix composites have been prepared by pressure-infiltration ca sting of copper-base alloy melts into microporous carbon preforms. The carbon preforms contained varying proportions of amorphous carbon and graphite. Load dependence of the wear and friction behavior of the co mposite pins has been examined under ambient conditions against cast-i ron plates, using a pin-on-plate reciprocating wear tester. The wear r esistance of the composite is significantly improved, as compared with the base alloy. Contrary to the normally expected behavior, the addit ion of graphite to the amorphous carbon does not reduce the friction c oefficient, especially at high loads. The wear and friction behavior o f the composites is very sensitive to the size and distribution of the microstructural constituents.