Effect of counterpart material and water lubrication on the sliding wear performance of crosslinked and non-crosslinked ultra high molecular weight polyethylene

This paper deals with the effects of counterpart material and aqueous environment on the wear of ultra high molecular weight polyethylene (UHMWPE). Specimens of radiation crosslinked and non-crosslinked UHMWPE were exposed to unidirectional sliding against austenitic stainless steel, a hardened 100Cr6 steel coated with a diamond like carbon layer (DLC), a CoCrMo alloy and against alumina. The tests were performed in normal atmosphere and in distilled water. The results revealed that the UHMWPE(C) (cut from the core of the non-crosslinked UHMWPE block) has a better wear resistance than UHMWPE(S) (cut from the surface of the non-crosslinked UHMWPE block), UHMWPE-X (crosslinked UHMWPE) has a higher wear resistance than UHMWPE(C). One exception is dry sliding against Al2O3 where UHMWPE(C) is superior to UHMWPE-X. Under wet conditions, the lowest wear rate was achieved with UHMWPE-X sliding against CoCrMo. The results show that the wear of the material strongly depends on the type of counterpart material. The effect of water lubrication varies from pairing to pairing.