Efficacy of surface microtexturing in enhancing the tribological performance of polymeric surfaces under starved lubricated conditions

The efficacy of microtexturing on the tribological performance of Aromatic Thermosetting CoPolyester (ATSP) and Ultra High Molecular Weight Polyethylene (UHMWPE) were investigated under oil-lubricated starved conditions. Nominal contact pressures of 5.02 and 10.04 MPa were applied over a range of sliding velocities, 0.008-2.278 m/s. Static and kinetic coefficients of friction (COF) for untextured and textured surfaces were obtained and compared. Reduction in the average kinetic COF up to 29% for microtextured ATSP and 25% for microtextured UHMWPE were obtained. Static COF did not exhibit a notable change as a result of microtexturing. The core void volume was identified as a reliable indicator of the wear intensity of the dimples and consequently lubricant retention capacity for texturing. While both microtextured polymers illustrated reduction in the kinetic COF, only ATSP showed mechanical integrity for applications that experience high contact load under starved conditions. Microtextured UHMWPE experienced mechanical failure due to fluid pressure build up in the dimples under high load tests.