Microfriction of various phases in a carbon fiber, polytetrafluoroethylene, graphite and polyetheretherketone composite blend as measured by atomic force microscopy

Atomic force microscopy and friction force microscopy have been used to con duct microfriction studies on short carbon fiber reinforced PEEK/PTFE compo site blends. The relative micro-scale coefficients of friction of different filler particles (PTFE, CF in normal and anti-plane orientation, and graph ite) have been compared with the matrix PEEK. The order of the nanoscopic c oefficients of friction was: carbon fiber in normal orientation > carbon fi ber in plane orientation > PEEK matrix > graphite flake > carbon fiber in p arallel orientation > PTFE particle. Additional microhardness studies resul ted in qualitative hardness comparisons of the various phases. Their order of the form: carbon fibers >> PEEK and graphite > PTFE also reflects the co ntribution of the various phases to the wear resistance of the composite bl end. The latter can be estimated from the AFM-topography traces of the poli shed composite surfaces. (C) 1999 Published by Elsevier Science Ltd. All ri ghts reserved.