The effect of carbon fibre reinforcement on the friction and wear of polymers

Thermosetting and thermoplastic polymers have been reinforced with carbon fibres of high strength and elastic modulus, and their friction and wear properties examined. During dry sliding against steel, randomly oriented chopped fibres reduce both the coefficients of friction and the wear rates of polymers to levels which are approximately independent of the matrix material. Fibre orientation is also important, and minimum wear is obtained when the fibres are normal to the sliding surface. Carbon fibre reinforced polymers are less abrasive than those containing glass, exhibit lower friction and have greater moduli of elasticity; the flexural strengths are also often greater, and particularly so with polytetrafluoroethylene (PTFE). It is concluded that the carbon fibres reduce the friction and wear of polymers by preferentially supporting part of the applied load, and in addition by smoothing the surface of the steel counterface.