不同方法表面改性碳纤维增强热塑性聚酰亚胺复合材料的摩擦磨损性能

采用硝酸氧化改性和涂层复合改性法分别对碳纤维(CF)进行了表面处理,并制备了CF增强热塑性聚酰亚胺(TPI)复合材料;对CF的表面形貌进行了观察,研究了表面改性方法对复合材料摩擦磨损性能的影响,并利用扫描电子显微镜观察了磨损表面形貌。结果表明:硝酸氧化改性增大了CF的表面粗糙度,随处理时间的延长粗糙度增大;经涂层复合改性后,CF表面包覆了一层聚酰亚胺(PI),保护了CF并提高了其与基体界面的结合强度;经表面改性后的CF增强TPI复合材料的摩擦磨损性能均得到提高,以涂层复合改性的效果最好;硝酸氧化改性后的CF在摩擦过程中易断裂,复合材料的磨损形貌以磨粒磨损为主,而涂层复合改性后的CF断裂得到抑制,与基体结合更为牢固,磨损表面较为平整。

Friction and Wear Performance of Carbon Fiber Reinforced Thermoplastic Polyimide Composites Prepared by Different Surface Modification Methods

Carbon fibers(CF) treated by the methods of nitric acid oxidation modification and coating composite modification separately were used to prepare CF reinforced thermoplastic polyimide(TPI) composite.The surface morphology of CF was observed and the effect of surface modification on friction and wear performance of the composite was studied.The wear surface morphology was observed by scanning electron microscopy.The results show that the surface roughness of CF was increased by nitric acid oxidation modification and increased with treating time.After coating composite modification,the CF surface was coated by a layer of polyimide(PI),which could protect CF and increase the interface strength between CF and substrate.The friction and wear performance of CF reinforced TPI composite was increased after surface modification,and the effect of coating composite modification was the best.Nitric acid oxidation modified CF ruptured easily during friction,and wear morphology of the composite was abrasive wear mainly.The rupture of coating composite modified CF was restrained,the combination between CF and substrate was even firmer,and wear surface was flat.