Evaluation on corrosion behavior and haemocompatibility of phosphorus incorporated tetrahedral amorphous carbon films

Phosphorus incorporated tetrahedral amorphous carbon (ta-C:P) films are deposited on biomedical titanium alloy (Ti6Al4V) by filtered cathodic vacuum arc technique. The structural properties of ta-C:P films are evaluated by X-ray photoelectron spectroscopy and Raman spectroscopy. Potentiodynamic polarization tests are employed to assess the corrosion performances of ta-C:P coated and uncoated Ti alloys in 0.89 wt.% NaCl solution. In vitro platelet adhesion measurements are performed to investigate the blood compatibility of ta-C:P films. Results indicate that phosphorus incorporation increases the corrosion resistance of ta-C films. More positive breakdown potential and lower corrosion current density than those of Ti alloy are observed for ta-C:P films. Lower platelet adhesion and activation demonstrate the enhanced haemocompatibility of Ti alloy coated with ta-C:P films. The improved interaction between ta-C:P films and biological environments is attributed to structural changes of the films after phosphorus introduction.