UHMWPE was modified with 16 inorganic compounds as additives.Friction coefficient of pure and modified UHMWPE was investigated by an UMT-3 microtribometer against a3 mm 100Cr6 steel ball which was the upper counter-mating specimen,under load of 98 N,with rotation rate of 60.18 mm/s and rotating radius of 0.5 cm for 60 min in dry friction,respectively.Width and depth of wear scars were determined and the analysis of XRD of worn surfaces wais also observed.Results show that average friction coefficient of modified UHMWPE with 5% and 10% WS2 ,15...