Elevated-Temperature Wear and Friction of PTFE/PEEK Composite

Abstract

A study was conducted on elevated-temperature tribological behavior of a PEEKmatrix composite with 15% (by volume) PTFE particulates. Neat PEEK and PTFE were also investigated at the elevated temperature to provide reference information. Tribological experiments on neat PEEK, neat PTFE and the PEEK/PTFE composite (C15) were carried out with a pin-on-disk tribometer with its contact surfaces heated at 200C. Friction and wear mechanisms of the composite were studied based on SEM and optical microscopic observations of test samples and steel counterfaces. At 200C, friction coefficient of C15 composite decreased by about 30% from that at 45 C. The specific wear rate of the composite at elevated temperature (200C) was lower by 500% than that at low temperature (45C). The C15 composite exhibited lower friction and wear than those of neat PEEK and neat PTFE at both low and elevated temperatures. The synergistic effect of solid-state lubrication of PTFE in C15 composite was also found at high temperature. Dominating friction and wear mechanisms in the composite at the elevated temperature were identified to include PTFE adhesion, viscoplastic flow, and most importantly, formation of transfer films under combined compression and surface traction.