Action of transfer film in improving friction and wear behaviors of iron- and copper-filled poly(ether ether ketone) composites

The composites of poly(ether ether ketone) (PEEK) filled with micrometer-si zed Cu and Fe particles were prepared by compression molding. The friction and wear behaviors of the composites were examined on a pin-on-disc frictio n-and-wear tester by sliding PEEK-based composites against tool steel at a sliding speed of 1.0 m s(-1) and a normal load of 19.6N. Optical microscopi c analysis of the transfer film and of the worn pin surfaces and wear debri s was performed to investigate the wear mechanisms of the composites. It wa s found that Cu and Fe used as filler considerably decreased the wear rate of PEEK. A thin, uniform, and tenacious transfer film was formed when Cu wa s used as the filler, and a nonuniform and thick transfer film was formed w hen Fe was used as the filler. The transfer film played a key role in incre asing the wear resistance of the PEEK composites. Plastic deformation was d ominant for wear of PEEK-Cu, while abrasion and adhesion were dominant for wear of PEEK-Fe. Because of the strong affinity between Fe as filler and it s identical counterpart in the counterface tool steel surface, the adhesion between the PEEK-Fe composite surface and the counterface tool steel surfa ce was thus severe. This contributed to the generation of a thicker transfe r film for PEEK-Fe. (C) 2000 John Wiley & Sons, Inc.