Sliding wear of polyetherimide matrix composites

The tribological behaviour of polyetherimide (PEI) and its short-carbon-fibre (SCF) composites were studied using both a block-on-ring and a pin-on-disc rig under dry sliding conditions. The influence of the contact pressure and the experimental temperature on both the specific wear rate and the coefficient of friction were investigated. It was found that the addition of 5-20 vol.% SCF could reduce the coefficient of friction, and improve the wear resistance significantly, especially at elevated temperatures. With respect to the neat PEI, increases in both the contact pressure (0.25-3 MPa) and the temperature (25-150 °C) deteriorated the wear resistance dramatically, while the coefficient of friction kept unchanged with temperature. However, the SCF composites exhibited a slightly linear increase of the wear rate as the contact pressure varied from 1 to 9 MPa, and a remarkable reduction of the coefficient of friction at elevated temperatures. Assisted by micrographs of the worn surfaces, corresponding wear mechanisms are discussed.