The role of graphite particles in the high-temperature wear of copper hybrid composites against steel

Copper matrix composite reinforced with SiC and graphite (Gr) particles was prepared by a powder metallurgy method. Dry sliding wear properties were tested in the temperature range 373-723 K, compared with the SiC/Cu composite. The addition of graphite particles simultaneously decreased the wear rates of the composite and the counterpart, and effectively avoided the occurrence of severe wear up to 723 K. The friction coefficient of copper hybrid composite was more stable and lower than that of SiC/Cu. Microstructural analysis showed that a uniform graphite microcrystals layer on the top of worn surface helped to decrease the plastic deformation in subsurface region and alleviate adhesion wear. It showed that graphite particle was an effective addition agent for copper matrix composite applied in high-temperature sliding wear condition. (c) 2004 Elsevier Ltd. All rights reserved.