Influence mechanism of organic-modified ?-zirconium phosphate on tribological properties of UHMWPE

Ultra-high molecular weight polyethylene (UHMWPE) is prone to deformation and wear under harsh conditions of dry friction with high contact stress, and failing friction parts. In this work, CZrP/UHMWPE composites with different organic-modified alpha-zirconium phosphate (CZrP) contents were prepared. The tribological properties of the GCr15/composites friction pair under dry friction conditions were studied by ball-on-disk tribology experiments, and the wear mechanism was analyzed. The results show that when the content of CZrP is 5 wt%, the friction coefficient and wear loss of CZrP/UHMWPE composites are the smallest, which are about 30% and 58% lower than those of pure UHMWPE. In the process of dry sliding friction and wear, CZrP will gradually accumulate on the friction surface of the composite material, and a protective layer with certain strength and lubricity will be formed through the unique interlayer sliding effect of CZrP. The hydrogen bonding between the molecular chains of the surface coupling agent and the physical entanglement with the molecular chains of UHMWPE make the accumulated CZrP not easy to be worn and peeled off. This work aims to provide an effective strategy to improve the tribological properties of UHMWPE under severe conditions with high contact stress.