Carbon fiber reinforced thermoplastic polyimide composites were prepared, and the mechanical properties and tribological behaviors at various sliding conditions were systematically investigated. The results showed that the incorporation of carbon fiber not only improves the flexural and tensile properties of polyimide but also greatly promotes the dynamic mechanical properties. Meanwhile, the introduction of carbon fiber greatly enhances the antifriction performance and wear resistance of polyimide at elevated temperatures. Notably, at high temperatures of 180 and 260°C, the composite containing 20vol% carbon fiber exhibits the lowest friction coefficients of 0.054 and 0.1 respectively, accompanied with the lowest wear rates. Moreover, the influence of applied load and sliding speed was also investigated at various temperatures. Scanning electron microscope (SEM) and optical analysis indicate that some lubricating films can be formed on the contact surfaces at high temperatures due to the softening of contact surface and the graphitization of carbon fiber, and the wear mechanism is dominant by adhesive wear.
Source: Preview Image: xieyuliang/Shutterstock