Friction and wear of water lubricated PEEK and PPS sliding contacts: Part 2. Composites with carbon or glass fibre

The friction and wear characteristics of fibre-reinforced PEEK and PPS in water were studied using a face-contact sliding tester. The fibres used were glass and carbon fibres. Under boundary lubricating conditions, PEEK reinforced with glass fibre was little improved in friction and wear characteristics, since both PEEK and glass fibre had poor resistance to wear in water. In contrast, the addition of carbon fibre to PEEK made the friction and wear characteristics excellent. On the other hand, with PPS the wear characteristics were improved by adding the fibres regardless of kinds of fibres. Under mixed and hydrodynamic lubricating conditions, both PEEK and PPS were considerably improved in friction and wear characteristics by adding glass or carbon fibres. With 18 vol.% carbon fibre-reinforced PEEK and PPS, the fibre orientation affected the wear resistance in boundary or mixed lubricating regime. The fibres aligned perpendicular to sliding direction exhibited higher wear resistance than those parallel to sliding direction.