Wear properties of nano-Al2O3/UHMWPE composites irradiated by gamma ray against a CoCrMo alloy

Nano-Al2O3/ultra- high molecular weight polyethylene (UHMWPE) composites were prepared by hot pressing and then radiated by a gamma ray in doses of 120 kGy, 250 kGy and 500 kGy. The hardness of the composites was tested. The friction and wear properties against a CoCrMo alloy were also tested on a knee simulator under physiological saline solution lubrication. The morphologies of worn surfaces were examined under an optical microscope. The structure of the sample was analyzed by IR and XRD tests. The results showed that the wear rate of UHMWPE decreased when filled with a proper amount of nano-Al2O3, and with an increment of the radiation dose of gamma rays. It was found that filling nano-Al2O3 into UHMWPE can inhibit the effect of oxidation during the radiation procedure.