Corrosion resistance of CrAlN and TiAlN coatings deposited by lateral rotating cathode arc

Abstract In this work, CrAlN and TiAlN coatings were deposited on stainless steel substrates by a vacuum arc reactive deposition process from two lateral rotating elemental aluminum and chromium or titanium cathodes in a flowing pure nitrogen atmosphere. The composition and crystalline structure of the as-deposited coatings was analyzed by energy dispersive analysis of X-rays (EDX) and X-ray diffraction (XRD), respectively. The corrosion resistance of the CrAlN-coated and TiAlN-coated samples in a 3 wt.% NaCl solution was evaluated and compared by electrochemical potentiodynamic polarization method. It was found that both the CrAlN and TiAlN coatings exhibited their best corrosion resistance, respectively, at a composition with Cr/Al or Ti/Al atomic ratio of around 1:1, while the CrAlN coatings showed an evidently better corrosion resistance than the TiAlN coatings.