Tribological performance of some alternative bearing materials for artificial joints

In current artificial joints consisting of metal or ceramic and polyethylene (ultrahigh molecular weight polyethylene, UHMWPE) bearing surfaces, the wear debris of polyethylene is the main cause for shortening implant’s life. In order to enhance the durability of human artificial joints, alternative bearing surfaces may be needed. In the present study, the tribological performance of several candidate implant materials, including the diamond-like carbon (DLC) thin film coating on stainless steel were investigated. A pin-on-flat contact configuration in reciprocating sliding was used for preliminary materials evaluation and friction and wear testing. Test pairs were lubricated with bovine blood serum. The DLC coating sliding against uncoated stainless steel showed the lowest friction coefficient and very little, if any, wear. Wear mechanisms in tests of ceramics and steel pairs were primarily abrasive.