WEAR OF UHMWPE SLIDING AGAINST UNTREATED, TITANIUM NITRIDE-COATED AND HARDCOR-TREATED STAINLESS-STEEL COUNTERFACES

A pin-on-plate reciprocating machine has been used to assess the wear performance of ultrahigh molecular weight polyethylene when sliding against untreated, titanium nitride-coated, and 'Hardcor'-treated stainless steel counterfaces. The initial surface roughness of the stainless steel counterfaces was smooth (R(a) approximate to-0.01-0.02 mu m). Following the surface treatments the surfaces were significantly roughened. In the first set of wear tests run in water the wear rates of the UHMWPE on the roughened treated surfaces were significantly greater than on the smooth untreated stainless steel surface. Both sets of treated surfaces were then polished to the same smoothness as the initial untreated surface. In the second set of tests, run with bovine serum as a lubricant, there was no significant difference in the wear rates between the three counterfaces.