A prolonged exposure of Ti-Si-B-C nanocomposite coating in 3.5 wt% NaCl solution: Electrochemical and morphological analysis

The electrochemical behaviour of magnetron sputtered Ti-Si-B-C nanocomposite coating on SS 304 substrate has been examined using potentiodynamic polarization and electrochemical impedance spectroscopy after long time immersion (1, 20, 40, 70 days) in 3.5 wt% NaCl solution. The surface morphology, elemental composition and surface topography of coated and uncoated surfaces have been analyzed using FESEM, EDX spectroscopy and AFM, respectively. The XRD study revealed the presence of TiB2 and TiSi2 phases in the film which were exposed to 70 days immersion test. It implies that the grains of TiB2 and TiSi2 have grown on the Ti-Si-B-C coating. The results obtained from the electrochemical measurements of sputtered coatings showed the increase of corrosion inhibition capability for Ti-Si-B-C coating compared to SS 304 as the immersion time increases in simulated marine environment.