Effect of composition and thickness on corrosion behavior of TiN and ZrN thin films

Abstract The corrosion behavior of TiN and ZrN coatings at thickness from 5 to 10 μm on AISI 304 stainless in 0.5 N NaCl solution was investigated. Electrochemical impedance spectroscopy, scanning electron microscopy and X-ray photoelectron spectroscopy were the techniques applied to characterize fully the corrosion behavior. From the data, TiN acts as an inert coating, while the ZrN coating reacts with the environment. It is proposed that the nitrogen in the layer is replaced by oxygen, forming a near-surface film of zirconium oxide. It is this film which possesses good corrosion resistance and is responsible for the corrosion protection thought to be afforded by the ZrN layer initially deposited on the surface.