Tribological and Electrochemical Behavior of CrN/ZrN multilayer Coatings Produced by Arc-PVD

In this study, CrN/ZrN multilayer nanostructured coatings with different bilayers (10, 20, and 30) were fabricated by the cathodic arc evaporation. The electrochemical behavior of samples was evaluated by polarization and impedance spectroscopy tests in the Ringer medium. In addition, the pin on disk test was used to investigate the tribological behavior of the samples. The results showed that the electrochemical and tribological behavior of the coatings were dependent upon the number of bilayers such that with the increase in the number of bilayers, the coatings showed higher corrosion resistance and better tribological performance. Field emission scanning electron microscopy (FE-SEM) images of the specimens after exposure to the corrosion medium showed that the number of surface cavities formed on the coatings with the highest number of bilayers were few in number and smaller in diameter. The results of the pin on disk test showed that by increasing the number of bilayers from 10 to 30, the coefficient of friction and wear rate decreased and the 30L coating showed better wear resistance.