Friction and Wear Behavior of PTFE-based Composites under Dry Sliding and in Liquid Nitrogen

Friction and wear behavior of Ekonol and PAB fiber reinforced PTFE composites under dry sliding and in liquid nitrogen were studied on MPX-200 wear tester.The morphologies of the worn surfaces and wear mechanisms of the PTFE composites after tests were observed and analyzed by scanning electron microscope(SEM).Effects of temperature on impact strength of composites were evaluated.The results showed that the anti-ploughing ability of PTFE increased in liquid nitrogen,wear mass loss of Ekonol/PAB/PTFE composites was much lower under low temperature than those at room temperature.The friction coefficient of composites at room temperature was much lower than that under low temperature.The load effect on wear mass loss of composites was small under low temperature.The friction coefficient and wear mass loss remain steady with sliding speed increased,the wear behavior was characterized by ploughing and brittle fracture.Under dry sliding,friction coefficient at the beginning increased and then decreased,while wear mass loss kept increasing,when sliding speed increased,load effect on wear mass loss of composites was prominent.Under the listed test conditions,when load was greater than 300 N,wear mass loss of composites went up sharply.The wear of Ekonol/PAB/PTFE composites was characterized by ploughing,adhesion and fatigue.At both room and low temperature condition,friction coefficient decreased with increasing load.The impact strength of Ekonol/PAB/PTFE composites at low temperature was about one second of that at room temperature.