The effects of popcorn-like CeO₂ decorated Cr₂AlC hybrid on the tribological properties of CF/PTFE fabric composites

In this study, cerium oxide (CeO₂) nanoflowers were uniformly grown on the surface of chromium aluminum carbide (Cr₂AlC) particles via a simple and efficient coprecipitation approach, which resulted in the preparation of the hybrids referred to as Cr₂AlC@CeO₂. The CeO₂ nanoparticles exhibited a capacity to alternate between the oxidation states of Ce³⁺ and Ce⁴⁺ under stress, forming a protective layer to repair damaged surfaces and reduce friction and wear at the nanoscale. The Cr₂AlC@CeO₂ hybrids were utilized to enhance the tribological performance of carbon fiber (CF) and polytetrafluoroethylene (PTFE) fiber blended fabric (CF/PTFE fabric) phenolic composites, and the friction test indicated that when the filler content reached 4.0 wt%, the wear rate of the fabric composites was 2.79×10⁻¹⁴ m³·N⁻¹·m⁻¹, which was 59% lower than that of the pure composites, and the coefficient of friction decreased by 39%. This enhancement was attributed to the formation of an adaptive tribofilm with a thickness ranging from 85 to 113 nm on the corresponding surface. The analysis of the worn surface and the tribofilm revealed a synergistic enhancement effect of Cr₂AlC and CeO₂. The Cr₂AlC@CeO₂-reinforced fabric composites (Cr₂AlC@CeO₂/fabric composites) exhibited the best wear resistance because of the superior load-bearing capacity of Cr₂AlC and the outstanding lubricating properties of CeO₂.