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.