Fretting wear properties of hydroxyapatite, alumina containing high density polyethylene biocomposites against zirconia.

Considering the importance of wear on the materials performance in biomedical applications, the major objective of the present work is to investigate the friction and fretting wear behavior of various HDPE-based composites against zirconia counterbody, both in air and simulated body fluid (SBF) environment. Both Al(2)O(3) and/or HAp fillers (upto 40 vol %) have been incorporated in HDPE to improve the hardness and elastic modulus of HDPE. The fretting wear study indicates that extremely low COF (approximately 0.055-0.075) as well as higher wear resistance (wear rate in the order of approximately 10(-6) mm(3)/N m) can be achieved with the newly developed composites in SBF. A low wear depth of 3-7 microm is recorded, irrespective of fretting environment. Besides reporting the phenomenological tribological data, major focus has been on to understand the underlying mechanism of material removal at fretting contacts. Such understanding has been established in discussing the wear mechanisms in terms of deformation of polymer matrix, tribolayer formation, and wear debris generation.