Comparative study of tribological properties of carbon fibers and aramid particles reinforced polyimide composites under dry and sea water lubricated conditions

摘要

Moving components used under air and lubricated conditions are constantly subjected to friction and wear, which poses a challenge to their reliability and service life. This work addressed the influence of short carbon fibers (SCF) and aramid particles (AP) on tribological performance of polyimide (PI) composites adding with polytetrafluoroethylene under dry and sea water lubrication conditions. A systematic study on the tribological mechanisms of SCF- and AP-reinforced PI composites was carried out. Under the controlled sliding conditions (i.e., velocity, pressure, and working conditions), the AP was more effective than SCF for enhancing the tribological performance under dry condition, but reversed under lubrication. Hard SCF exposed to the sliding interface could cause removal of the wear debris, thereby the tribofilm was patchy to lose excellent lubricated property. When sliding occurred under sea water lubrication, the weak interfacial interaction was beneficial to the formation of a robust boundary film for SCF-reinforced PI composite rather than AP-reinforced PI composite. Moreover, tribo-chemical reactions occurring between polytetrafluoroethylene and copper sustained the lubrication property of tribofilm and prevented tribo-corrosion when subjected to lubricated condition.