A Study of Contact Temperature Due to Frictional Heating of UHMWPE

Contact temperature of ultra-high molecular weight polyethylene (UHMWPE) bearing was measured by the infrared radiometric microscope. Lubricant temperature near the contact band was measured simultaneously and compared with the contact temperature. Contact temperature increases of up to 12°C in 30 min were observed under a mean contact pressure 12.7 MPa and sliding speed 50 mm/s. Young's modulus of UHMWPE was estimated as 0.5 GPa from the contact dimensions. The coefficient of friction was evaluated for variety of contact conditions and material combinations for UHMWPE, CoCrMo alloy and sapphire glass. It was confirmed that the contact stress has a large effect on the coefficient of friction and the fluid film has little effect on the coefficient of friction. Under sliding conditions, the thermal property of the moving material has a large effect on an increment of lubricant temperature.