Microstructure, corrosion resistance and biocompatibility of titanium incorporated amorphous carbon nitride films

Abstract: Titanium incorporated amorphous carbon nitride films were deposited by direct current magnetron sputtering. The films change from amorphous to nanocomposite structure, the relative fraction of sp 3 C–N bonding decreases significantly from 2.17 to 1.64 with the increase of Ti content from 2.7at.% to 12.3 at.%. For the films with high Ti content, the nanocrystalline TiN embedded in a-CN x matrix, while principally TiN did not appear to be well formed for the film containing low Ti content. Potentiodynamic polarization, in vitro human osteoblasts and murine fibroblast cell adhesion tests were employed to assess the corrosion performances of Ti6Al4V alloy coated with the films in Tyrode''s solution, and the biocompatibility of Ti-incorporated a-CN x films, respectively. Titanium incorporation increases the corrosion resistance of a-CN x films, and the higher corrosion potential and lower corrosion current density are observed for the alloy coated with the film containing lower Ti content. The high osteoblast adhesion and activation demonstrate the enhanced biocompatibility of Ti alloy coated with Ti-incorporated a-CN x films. The improved biocompatibility in biological environment is attributed to structural change after titanium introduction. [Copyright &y& Elsevier]