Enhanced Tribological Performance of UHMWPE Composites Reinforced With Wollastonite: Biocompatibility and Wear Behavior

Abstract

Ultra-high molecular weight polyethylene (UHMWPE) is often limited by poor tribological properties in artificial joints, leading to high wear-rates compared to metals and ceramics. This study explores the use of wollastonite, a natural mineral, as a filler to enhance the tribological performance of UHMWPE composites. X-ray diffraction (XRD) analysis revealed that wollastonite content and particle size inversely affected the crystallinity of the composite due to heterogeneous nucleation and stress concentration. The incorporation of wollastonite significantly improved the tribological performance, with wear-rate reductions of 71%, 69.81%, and 50.73% under dry friction, normal saline (NS) lubricant, and new-born calf serum (NBCS) lubricant conditions, respectively. The wear mechanisms in the composite were predominantly slight fatigue and abrasive wear, contrasting with the extrusion deformation and severe fatigue wear observed in neat UHMWPE. Additionally, simulated body fluid (SBF) immersion tests demonstrated the composite's ability to form a surface apatite-like deposition. These findings suggest that wollastonite reinforcement effectively enhances both mechanical and tribological properties of UHMWPE.