Corrosion behaviour of tetrahedral amorphous carbon (ta-C) filled titania nano tubes†
TiO2 nanotubes were formed by anodic oxidation on Ti–6Al–7Nb and the nanotubes were filled with tetrahedral amorphous carbon (ta-C) by cathodic arc evaporation (CAE). The samples were characterized by field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS) and micro Raman studies. The corrosion behaviour of the Ti–6Al–7Nb substrate, substrate with self-organized TiO2 nanotubes (TNT) and ta-C filled TiO2 nano tubes (ta-C TNT) were investigated through electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization studies in simulated body fluid (Hanks' solution). The investigations show that the native oxide on the sample is replaced by a self assembled nano array by an anodisation process and the pores can be filled with ta-C. Potentiodynamic polarization and electrochemical impedance studies of ta-C filled TNT sample show that the corrosion resistance is comparable with TNT samples.