Performance of CoCrMo Alloy with Me-Doped DLC Coatings Prepared by a Magnetron Sputtering Method

To enhance the wear resistance of CoCrMo alloy used as hip joints for longer service time, the W-DLC (W doped-diamond like carbon) films and Ti-DLC (Ti doped-diamond like carbon) films were prepared by a DC magnetron sputtering method combined with ion source technique. The thickness of the as-prepared films was 1.89 μm. Results show that the coated CoCrMo alloy exhibits higher wear resistance in comparison with uncoated CoCrMo one, and the friction properties of W-DLC coated CoCrMo alloy are better than those of Ti-DLC coated CoCrMo alloy. The wear rates of uncoated CoCrMo, Ti-DLC coated CoCrMo and W-DLC coated CoCrMo are 15.25×10−6, 0.76×10−6, and 0.19×10−6 mm3m−1N−1, respectively. Raman spectrum analysis shows that the excellent wear resistance of coated CoCrMo alloys is attributed to the graphitization of the top layer of DLC films during rubbing.