Corrosion and Erosion Analysis of AlCrN/CrN Multilayered Coating Applied by Cathodic Arc Physical Vapor Deposition (PVD)

A multilayered AlCrN/CrN coating was applied on stainless steel C-450 precipitation hardened stainless steel by cathodic arc vapor deposition method. The microstructure of the coating was characterized using field emission scanning electron microscope (FE-SEM). Microhardness and surface roughness (Ra) measurements revealed 2900 HV and 0.8 µm for the coating, respectively. Coating delamination occurred at 48 N applied force in scratch test. The corrosion performance of the coating was compared with the substrate in a 3.5 wt % NaCl solution at room temperature using polarization and electrochemical impedance measurements. Applying multilayered AlCrN/CrN coating enhanced the passive film and reduced the corrosion current density by 78%. Water droplet erosion resistance of AlCrN/CrN coating was evaluated, and the eroded volume equation was formulated as a function of impact numbers.