Tribological Evaluation of Polyether Ether Ketone (PEEK) Nanocomposite Coatings Reinforced with Ceria—Effect of Composition, Load, Speed, Counterface, and UV Exposure

Ceria nanofillers were incorporated into PEEK coatings at concentrations of 0.5, 1.5, and 3 wt% and applied to mild steel samples using an electrostatic spraying technique. The tribological performance of these coatings was assessed under various loads and sliding speeds. XRD, FTIR, and microhardness tests were conducted to characterize the chemical and mechanical properties of the coatings. The 1.5 wt% ceria-reinforced PEEK coating outperformed the pristine PEEK and other concentrations in terms of wear resistance. The counterface material did not affect the wear resistance of the optimized PEEK/1.5 wt% ceria nanocomposite coating, which also demonstrated superior wear resistance after UV exposure as compared to that of pristine PEEK coatings.