Effect of temperature and atmosphere on the tribological behavior of a polyether ether ketone composite

Polyether ether ketone (PEEK) is a high-performance thermoplastic, which is often selected for hightemperature tribological applications under chemically aggressive environments. The present work investigates the tribological behavior of a high-performance PEEK composite under conditions that are often found inside hermetic compressors. Therefore, an AMTI tribometer equipped with a hermetic chamber and a heating system was used to conduct sliding tests of PEEK cylinders on AISI 304 stainless steel polished discs (Sq <10 nm) with reciprocating movement and a normal force of 175 N. The tribological behavior of the PEEK/AISI 304 stainless steel system was investigated as a function of ambient temperature (30 °C and 80 °C) and atmosphere (atmospheric air and tetrafluoroethane). Wear and surface roughness analyses were performed with white light interferometry and optical microscopy. Raman spectroscopy was used to investigate transfer films on the counter body surface. Temperature was observed to have a strong influence on the tribological behavior of the samples tested under atmospheric air, with a 25% decrease in the friction coefficient associated with a 100% increase in the wear rate. However, the friction measured from the samples tested under a tetrafluoroethane atmosphere showed no significant temperature dependence.