Effect of the metallic substrates on the tribological performance of fused filament fabricated sliding layers made of PEEK-based materials

The motivation of this research is to explore the impact of different metallic substrates, i.e. aluminum and steel, on the tribological performance of fused filament fabricated polyetheretherketone (PEEK)-based sliding layers by means of a plate-on-ring (PoR) tribometer. The sliding wear tests were conducted under dry sliding conditions with a broad range of load conditions and the steel counterpart used is a 100Cr6 steel ring. Experimental results demonstrate that the coefficient of friction (COF) of the printed neat PEEK sliding layer does not show significant variation between the metallic substrates, while its specific wear rate on the aluminum substrate is significantly lower compared to that on the steel substrate. Interestingly, the COF and wear rate of the sliding layer manufactured by using a PEEK tribocomposite exhibit much higher values on the aluminum substrate than those on the steel substrate. By simulating the contact temperature between the sliding pair, it is revealed that different metallic substrates alter the thermal behavior of the system due to their different thermal conductivities, which affects the tribological performance, including friction and wear mechanisms. • PEEK and PEEK composite sliding layers were successfully manufactured on different metallic substrates by fused filament fabrication (FFF). • Tribological properties were influenced by the metallic substrate, with the aluminum substrate exhibiting better tribological performance for neat PEEK, while the steel substrate performed tribologically better for the PEEK composite. • Mechanical and thermal simulations revealed the local conditions of different metallic substrates, demonstrating that the substrate thermal conductivity influences the friction and wear. • The mechanisms were analyzed based on the worn surfaces, exploring the relationships between load conditions, metallic substrate, and tribological properties.