Mechanical and tribotechnical properties of three-component solid lubricant UHMWPE composites

Three-component composites with an ultra-high-molecular-weight polyethylene (UHMWPE) matrix reinforced with short carbon fibers (SCF) and filled with solid-lubricant particles of finely dispersed polytetrafluoroethylene (PTFE) are studied. It is shown that, under dry sliding friction at moderate sliding velocity and load (P = 60 N, V = 0.3 m/s), the optimal composition providing maximum wear resistance (it is doubled) is UHMWPE + 5 wt% fluorolite + 5 wt% SCF. Under more severe triboloading conditions (P = 140 N, V = 0.5 m/s), a two-fold increase in wear resistance has been attained for the blend UHMWPE + 5 wt% fluorolite + 10 wt% SCF. Wear mechanisms of three-component UHMWPE composites are discussed in view of the data on structure formation, as well as tribocontact temperature, variations of the friction coefficient and wear track surface topography.