Tribological Properties of Graphite-Fiber-Reinforced,Partially Fluorinated Polyimide Composites

Graphite-fiber-reinforced polyimide (GFRPI) composites were formulated form three new partially fluorinated polyimides and three types of graphite fiber. Nine composites were molded into pins and evaluated in a pin-on-disk tribometer. Friction coefficients, wear rates, pin wear surface morphology, and transfer film formation were assessed at 25 and 300°C. Also assessed was the effect of sliding distance on friction and the effect of constantly increasing or decreasing temperature on friction. Wear was up to two orders of magnitude lower at 25°C and up to one order of magnitude lower at 300°C than with previously formulated NASA GFRPI composites.