Wear behavior of bulk oriented and fiber reinforced UHMWPE

A study of the friction and wear properties of isotropic, fiber reinforced, and bulk oriented ultra-high molecular weight polyethylene (UHMWPE) was conducted on a reciprocating wear tester. The tests were carried out with a cobalt–chromium alloy cylinder sliding against a flat sample of UHMWPE in bovine serum at 1.5 Hz for over a million cycles. In the fiber reinforced material, layers of woven UHMWPE fibers were embedded in a UHMWPE matrix. Bulk orientation of UHMWPE was produced by channel die compression of standard UHMWPE. The fiber-reinforced samples were tested in one configuration and three different degrees of consolidation. The less consolidated samples failed catastrophically, and the more consolidated sample had a wear rate twice that of the unreinforced, standard UHMWPE. The channel die oriented samples were tested in various configurations and degrees of anisotropy. They all showed similar wear behavior as the standard, with a wear rate of approximately 1×10−7 mm3/N m. The average values of the coefficient of friction of all the samples ranged from 0.08 to 0.11.