FRICTION AND WEAR PROPERTIES OF POLYMERIC COMPOSITE-MATERIALS FOR BEARING APPLICATIONS

This paper presents a study of the tribological properties of two locally developed polymeric composite materials for bearing applications. Unidirectional reinforcements by linen and jute fibres are used, each in turn, in unsaturated polyester resin. Friction and wear tests are carried out, in dry conditions, on a pin-on-disc machine. The experimental results, backed by scanning electron microscope examination, revealed that the reinforcement volume fraction as well as orientation have considerable effect on the friction and wear of polyester composites. An increase of fibre volume fraction to 33% increased the coefficient of friction of the tested material by about 14% and decreased its wear rate by about 95% at both low and high values of pressure-velocity product (PV limit) when the fibres were oriented normal to the specimen surface. The same increase in volume fraction of the fibres when oriented in the longitudinal and transverse directions resulted in almost the same increase in the coefficient of friction (16%) while the wear rate decreased only by 65% at low PV value. For the same orientations at high PV value, the results showed no significant effect on the coefficient of friction while the wear rate decreased by 72%.