Hard metal nitrides: Role in enhancing the abrasive wear resistance of UHMWPE

Enhancing the abrasive wear resistance (WR) of polymer composites is an extremely difficult task since the particles or fibers are easily dug out or broken leading to a deterioration of their wear resistance. Exploration of hard particles in the right amount, size and compatibility with the matrix may lead to the reduction in micro-cutting and micro-ploughing of the matrix. Very few successful efforts are reported in the literature. Nitrides of metals are known for their high hardness. However, their potential for enhancing wear resistance of polymers has not yet been explored. In this paper, the potential of nitrides of Aluminum, Silicon, and Titanium based on a constant amount (2 wt%) was explored by preparing composites with Ultra high molecular weight polyethylene (UHMWPE) and investigating their abrasive wear performance using a pin on disc test with a single rotation and under various loads. Further efforts were focused on investigating the optimum amount of best-performing nitride particles (Si3N4) for highest possible wear resistance by developing a series with 2, 4, 6, 8, 10 and 12 wt% Si3N4 particles. 10 wt% of filler loading was found to be optimum for highest wear resistance and the improvement was ≈45%. The efforts were then focused on investigating the wear-property correlation and wear mechanisms.