Fabrication of Titanium Nitride Thin Film on Titanium Using Cathodic Arc Plasma Evaporation for Biomedical Application.

Abstract

Commercially pure titanium (Cp-Ti) is often used for biomedical implant devices but has low hardness and wear resistance; therefore, it is not suitable for use in the sliding parts or joints. Owing to their good wear resistance and biocompatibility, titanium nitride (TiN) coatings are used to improve these surface properties of Ti. This study aims to fabricate TiN on Cp-Ti by cathodic arc plasma evaporation and to investigate the effect of Cp-Ti substrate temperature on the properties of coated TiN thin films for biomedical applications.Coated TiN thin films were deposited on Cp-Ti at different substrate temperatures of 25, 100, 175, and 250°C. The surface morphology, roughness, phase composition, hardness, coating adhesion, and biocompatibility of the TiN coatings were investigated using a digital optical microscope, scanning electron microscope, X-ray diffractometer, hardness tester, and in vitro cell studies.Statistical differences were evaluated using analysis of variance (ANOVA) and Tukey's multiple comparison analysis, with statistical significance set at p < 0.05.Thin films with a primary TiN phase were formed on the surface of the Cp-Ti substrate regardless of substrate temperatures. There was no significant difference in surface hardness between the coated samples even though the sample coated at 100 and 175°C showed a slightly higher values, ranging from 193 to 199 HV. Interestingly, surface roughness and coating adhesion were significantly influenced by substrate temperature. The higher the substrate temperature, the greater the surface roughness, while the best adhesion, with the hardness of 176 HV, was obtained at substrate temperature of 25°C. In vitro cell study indicated that the baby hamster kidney cells on the coating surface have grown and proliferated better than those on the uncoated surface.The TiN thin film was successfully coated on Ti by cathodic arc plasma evaporation at different substrate temperatures, ranging from 25 to 250°C. The adhesion of the coating at low substrate temperature (25°C) was the best compared to other substrate temperatures of 100, 175, and 250°C. In vitro cell studies have demonstrated the biocompatibility of the coated TiN thin film.