Effect of voltage on microstructure and its influence on corrosion and tribological properties of TiO2 coatings

Abstract To improve the corrosion resistance performance of TiO2 thin films, a coating was prepared on 316 L stainless steel substrate following the electrophoretic deposition process. The structural, surface composition and morphological compositions of TiO2 films were analyzed by Scanning electron microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and X-ray Diffraction (XRD), respectively. Micro-scratch tester was used to investigate the tribological properties and corrosion performance was examined employing electrochemical impedance spectroscopy (EIS) and Potentiodynamic polarization in 3.5 wt.% aqueous NaCl solution. Among the three coatings produced at three different applied voltages, film obtained under 30 V exhibited the lowest corrosion current density value of 0.212 µA as well as the highest charge transfer resistance (the corrosion resistance) and the double layer capacitance, which was attributed mainly to the significant decrease of micro-pore into the film.