Analysis Of Friction And Wear Of PTFE Based On Molecular Dynamic And Experiment Study

Polytetrafluoroethylene(PTFE) is the fabric liner lubricants of self-lubricating spherical plain bearings. When the bearing is working, some PTFE moleculars transferred to the bearing inner ring from the fabric liner, formated PTFE and PTFE friction pair, which decreased the friction coefficient and wear rate of the bearing, meanwhile, the PTFE’s wear life directly affect the bearing’s life. Therefore, it’s significant for fabric liner joints bearing to study the friction and wear of PTFE.Most research of PTFE’s tribological properties depend on macro testing, this paper presented the research of friction by molecular dynamics simulation from microscopic perspective and experiment studies. The main work is as follows,using Materials Studio software constructed the PTFE model and simulated the PTFE’s RDF and Tg, which verified the model’s reliability, what’s more, established of PTFE/PTFE micro-friction pair model. Application of molecular dynamics simulation method simulated the PTFE/PTFE friction behavior on different normal load and sliding velocity. Analyzed the ways of energy loss in the friction pair model, and studied the micro friction and wear mechanism of PTFE through micro scopic friction behavior and related data, which concluded that when PV value increases, the microscopic friction process became more intense and wear depth increases; While, The friction coefficient decreases, when the normal load increase,and the friction coefficient increases when the sliding velocity increases.The sliding friction tests of GCr15/PTFE friction pair and PTFE/PTFE friction pair was done by the UMT tester,on the same conditions with microscope simulation. Obtained the friction coefficients of friction pair and wear rates of PTFE specimen in different condi- tions, and analyzed friction and wear of PTFE material from macroscope.The text conclud that the friction coefficients of microscopic experiments are closely to macroscopic simulation results under the same work condition, Which verified the rationality of the results of microscopic simulation.