On the Sliding Wear Behavior of PAEK Composites in Vacuum Environment
In the present study, the tribological behavior of polyaryletherketones (PAEKs) and their composites was investigated in air and vacuum environment. Polymer matrices were filled with either glass or carbon fibers and compared with a standard bearing material containing 10% carbon fiber (CF), 10% graphite, and 10% polytetrafluoroethylene (PTFE). The samples were tested in a pin-on-disk configuration under continuous sliding against a rotating steel disk (AISI 52100) at different sliding speeds. The results indicated that the tribological performance of these materials in vacuum depends on both compositions and test conditions. At low sliding speed, a very low friction and wear coefficients were obtained while at higher speed, severe wear occurred. In particular, CF filled composites showed excessive wear that led to the ignition after opening the vacuum chamber. Experimental results are discussed by analyzing the transfer film and wear debris.