Exploration of Effect of Thermal Cycling Treatment on Mechanical and Tribological Performance of Polyimide Composites

Polyimide (PI) and PI composites reinforced with glass fiber (GF), and aramid fiber (AF) were fabricated with hot-pressing technology. Then polyimide and its composites were treated with a thermal cycling (TC) condition from -50 degrees C to 150 degrees C with 300 cycles continuously. Compared with the samples without TC treatment, the fracture morphologies, mechanics, and tribological properties of the samples were studied. The results showed that, based on the fractographic morphologies, the phenomenon of fiber stripping could be obviously observed in the PI composite materials after TC treatment. Compared with before TC treatment, the friction coefficients (FC) and wear rates (WR) of PI and PI composites showed different variations, respectively. In conclusion, TC treatment had a great influence on the morphologies of the worn surface and the composition of transfer film. As the shear force increased, the elemental analysis demonstrated that GF was extruded into the groove.