Distinct tribological behaviors of polyimide composites when rubbing against various metals

Abstract Friction and wear of polyimide tribo-composites when rubbing against various metal alloys, i.e. aluminum alloy, bronze and bearing steel, were compared. Results demonstrated that counterpart types exerted important influences on wear rates comparing with friction coefficients. When sliding against bronze, wear rate of polyimide reinforced with aramid particles and polytetrafluoroethylene was almost one order of magnitude lower than those obtained rubbing against aluminum alloy and bearing steel. The composite exhibited much faster wear when rubbing against aluminum alloy under elevated pv (pressure × speed) conditions. Comprehensive analyses of the tribo-chemistry indicated that radicals deriving from broken polytetrafluoroethylene molecules were more prone to chelate with the bronze, thus forming a robust tribofilm.