A layer of TiN was firstly deposited on the surface of titanium alloy by a deposition system to strength the hardness. Then, different proportions of Ca and Ag ions were respectively implanted into the surface of TiN by a plasma immersion ion implantation system to achieve the antibacterial properties and enhance biological properties. The surface morphology, chemical state and depth distribution of the samples and water contact angle were respectively measured by scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and water contact angle tester before and after the ion implantation. The biocompatibility and antibacterial properties of the samples were evaluated by cell proliferation and antibacterial experiments in vitro.
There are different ratios of Ca and Ag which exist on the surface of samples, they are uniformly distributed and without changing the surface morphology of the samples. Meanwhile, water contact angle test indicates that the wettability of the sample（Ag:Ca=1:3) is improved by PIII. Based on the improvement of hydrophilicity, the ion implanted samples can effectively promote cell adhesion, spreading and proliferation. Moreover, results indicate that Ag/Ca implanted TiN (Ag:Ca=3:1) exhibits the strongest excellent antibacterial ability[1]. The experiments results show that titanium nitride layer enhances the hardness and wear resistance of material. Ag/Ca can be evenly distributed on the surface of the samples after Ag/Ca ions were implanted on the surface of titanium nitride. Thus, the modified samples surface had better antibacterial activity and biocompatibility.
 

ion implantation; Ca and Ag ratio; cell adhesion; antibacterial activities