Plasma immersion ion implantation (PIII) has been successfully employed to improve the corrosion behavior, biocompatibility and tribological surface properties of biomaterials [1-2]. NiTi alloys have been widely used for biomedical application [1-3], because of its unique properties such as super elasticity and biocompatibility. The good biocompatibility is due to the formation of a thin passive film at natural conditions, but locally destroyed of this passive film by corrosion processing led to release of Ni [2-3]. To overcome this problem, which is strongly depended on the corrosion resistance of the metal, surface modification methods have been used to improve the biocompatible properties of NiTi alloys[1-3]. In this study, carbon plasma immersion ion implantation (CPIII) was used for surface modification of NiTi alloys to improve the corrosion behavior.
