ON THE ROLE OF INTERFACIAL DEBRIS MORPHOLOGY IN A CONFORMING CONTACT TRIBOSYSTEM

Studies were made of the friction and wear behaviour of polymeric- and ceramic-based materials sliding in an annular conforming contact in high vacuum simulating conditions in space mechanism friction brakes. Extended sliding under low rubbing severity (load, 43 N; mean sliding speed, 0.18 m s-1) produced various frictional torque outputs from the system. The third-body debris morphology which develops in the interface correlates with friction level: a "full" debris layer implying high friction and an "empty" interface, with lesser debris features and interfacial "screens", implying low friction. Wear can also be related to the debris morphology. Although friction trends were often material specific, some ceramics developed either type of interface morphology and hence either high or low friction behaviour. Friction from the tribosystem depends on the location of the active velocity accommodation sites in the interface and the results support the interface tribology view of sliding systems.