Effects of contact area and stress on the volumetric wear of ultrahigh molecular weight polyethylene

The effects of contact area and contact stress on the wear of ultrahigh molecular weight polyethylene (PE) articulating with a polished surface of cobalt–chromium alloy were evaluated using a pin-on-disk apparatus implementing bi-directional movement. Within a relevant range of contact stresses, volumetric wear rate increased with increasing contact area. Volumetric wear was found to be independent of normal load within this range. Mechanistic issues related to these findings are discussed.