Irradiation enhanced corrosion resistance of CrN/TiSiN multilayers synthesized by cathodic arc ion plating

The effect induced by irradiation is often considered as 'negative impact'. Irradiation damage normally leads to defects in materials, including vacancies, clusters and interstitials, therefore resulting in the attenuation of stability such as corrosion resistance. Here, multilayered CrN/TiSiN coatings have been fabricated by cathodic arc ion plating and the corrosion properties of prepared coatings have been investigated before and after irradiation. Microstructure of irradiated samples revealed amorphization on the surface layer induced by irradiation. The corrosion behavior was studied by electrochemical tests, and multilayered CrN/TiSiN coatings revealed enhancement in corrosion resistance as the corrosion potential increased and corrosion current decreased in all irradiated samples. It turned out that the multilayered CrN/TiSiN coatings deposited with a bias voltage of 150 V and Ti80Si20 targets revealed the best corrosion resistance after irradiation. Given that, surface morphology analysis of corroded surface was conducted to provide further evidence. This irradiation enhanced corrosion resistance of multilayered CrN/TiSiN coatings could be explained by the rapid formation of passive films upon the irradiation induced amorphous layer during corrosive process, which function as barriers between the substrate and the corrosive solution. Our results reveal profound insights into corresponding corrosion mechanism of nitride coatings based on the microstructure investigation of corroded coatings and contribute to the understanding of corrosion behaviors of irradiated nitride coatings.