Electrochemical impedance study of TiAlN film coating on a Ni-based alloy in 0.9% NaCl

TiAlN films were deposited on Ni-based alloy by RF sputtering technique. Electrochemical impedance spectroscopy was employed as in situ technique to investigate the evolution of the TiAlN films on exposure in biological media. After immediate- to short-term exposure, the biological media was further evaluated with inductively coupled plasma-atomic emission spectrometer (ICP-AES) to measure the release of metal ions, such as nickel. The results of ICP-AES analysis showed that TiAlN coated on a Ni-based alloy effectively reduced metal ion release levels, as compared to the uncoated Ni-based alloy. The effect of the nitride films was also reflected in corrosion resistance and the corrosion rate. It was demonstrated that the TiAlNcoated Ni-based alloy revealed a higher corrosion resistance than uncoated substrates. Furthermore, the impedance of nitride films on a Ni-based alloy was larger than that of the metal’s charge transfer reaction at shortterm immersion.