Polyetheretherketone (PEEK) polymers are increasingly used in
tribological applications. An important aspect of PEEK tribology is the
surface temperature reached during sliding. However, most knowledge of
frictional heating in PEEK is based on post-hoc analysis of debris and
wear surfaces. In this study, infrared thermography was used to observe
the full field temperature map of PEEK during ball-on-disc sliding.
Although the measured temperatures were below any thermal transition, the
results matched closely to those predicted by flash temperature models.
Additionally, friction studies were performed with steel and sapphire
counterfaces. It was observed that PEEK debris was readily deposited to
steel but not on sapphire. The friction studies also indicated a greater
adhesive friction response for PEEK against steel compared to sapphire.
The transfer of PEEK material to the steel surface may elevate the
temperature at the sliding interface. Analysis of films formed on steel
suggests that the transferred PEEK was oriented in the direction of
sliding. The deposition of debris and formation of oriented films
resembled a high temperature drawing process, which was likely to be due
to localized frictional heating. The results of this study illustrate the
important role transfer films play in determining both the friction and
temperature response of the PEEK wear interface.