The Effect of Gradient Bias Design on Electrochemistry and Tribology Behaviors of PVD CrN Film in a Simulative Marine Environment

CrN films with various bias voltage designs (-20, -50, -80, -20 similar to-80 V gradient change) were prepared via arc ion plating. Scanning electron microscope (SEM), X-ray diffraction (XRD), nanoIndentor, electrochemistry workstation and tribo-meter were selected to evaluate the microstructure, mechanics, electrochemistry and tribology behaviors of as-prepared specimens in a simulative marine environment. By comparison, the adhesion force and anti-corrosion ability of CrN film with a gradient bias design were greatly enhanced compared with other films. The tribology behaviors of as-prepared specimens under various normal loads and sliding frequencies were deeply discussed. The result showed that the bias design played a critical role to impact the friction and wear behavior of film. Meanwhile, the CrN film with gradient bias design could bear a load of 25 N while other single CrN films failed, implying the strongest load-bearing capacity. Furthermore, at the same test condition, the lowest friction coefficient (COF) and wear loss were observed for CrN film with a gradient bias design, implying outstanding anti-friction and anti-wear abilities.