Comparative Investigation on the Tribological Performances of TiN, TiCN, and Ti-DLC Film-Coated Stainless Steel

TiN, TiCN, and Ti-diamond-like carbon (DLC) films were coated on 316L stainless steel surfaces by physical vapor deposition. All films exhibited uniform and dense surfaces with good adhesion. The Ti-DLC film demonstrated the lowest surface roughness. TiC and free C were observed in both the TiCN and Ti-DLC films. Among the three films, the TiCN film demonstrated the highest hardness and elastic modulus, followed by the Ti-DLC film and finally the TiN film. Under dry conditions, all films exhibited significantly lower coefficients of friction than stainless steel. The Ti-DLC film showed the lowest coefficient of friction and is thus considered an ideal anti-wear material for orthodontic applications. The friction mechanisms of the three films were also compared. Therefore, this study provides experimental data and a theoretical basis that may guide the production and modification of dental braces.