填料特性对聚酰亚胺复合材料摩擦学性能的影响

采用不同特性玻璃质刚性填料(玻璃纤维、玻璃纤维粉、5μm 和20μm 玻璃微珠) 填充改性热塑性聚酰亚胺( TPI) , 利用MPX-2000 摩擦试验机测定了干摩擦、水润滑和油润滑条件下材料的摩擦磨损性能, 考察了不同形态、尺度填料的影响, 用扫描电子显微镜(SEM) 观察磨损表面形貌, 分析材料磨损机理。结果表明, 大尺寸填料的单位个体与基体的界面面积和结合强度大于小尺寸填料, 其磨损率比小尺度填料的材料低。在水和油起到良好冷却作用后, 球形颗粒易出现应力集中, 疲劳裂纹向四周扩展、交汇, 产生疲劳磨损, 其程度随颗粒尺寸增大而提高, 表现为20μm 玻璃微珠填充材料磨损率最大。 

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.