In vitro corrosion behavior of multilayered Ti/TiN coating on biomedical AISI 316L stainless steel

Multilayered Ti/TiN coatings were deposited on biomedical AISI 316L stainless steel using arc ion plating. The electrochemical behavior of the coatings, characterized in neutral Troydeʹs simulated body fluid at 37±1 °C shows enhanced free corrosion potentials than that of the substrate. The protection is more effective using multilayered Ti/TiN films than that of the TiN film due to denser film structure, better surface quality and higher adhesion strength. Besides, the thin but well-bonded Ti and TiN layers play an important role in the re-distribution of corrosion current, which contributes to the inhibition of corrosion attack and to the modification of the pit propagation mechanism.