Effects of properties of the fillers on the polyimide composite tribological behaviors

Thermoplastic polyimide ( TPI) composites modified by rigidity glass fillers , such as glass fiber , glassfiber powder , 5μm and 20μm glass beads , were prepared by hot-pressing. The material t ribological performanceswere measured by MPX-2000 tribo-tester , and the effect s of the fillers properties , such as shapes , size and f rictionconditions including dry sliding , water and oil lubrications , were also investigated. Based on the micro-profile of theworn surface observed by SEM , the wear mechanism was determined. The result indicates that the bigger fillershave more interfaces and bond st rength with TPI , and have a lower wear rate. The water and oil can cool the systemeffectively , and spherical particles will cause the st ress concent ration easily , which can induce fatigue wear by extending and crossovering of fatigue cracks. The degree of wear increases with increasing the filler size , so 20μm glassbead filled TPI composite has the highest wear rate under the water and oil lubrication.