Multilayer CrN/CrAlN coatings were deposited on the 420-SS by the cathodic arc evaporation system with different duty cycles of bias-voltage. The deposited films were characterized by XRD and FESEM techniques. Mechanical, electrochemical, and surface properties of deposited films were studied by nano-indentation, electrochemical, and AFM analysis. Microstructure investigation confirmed the formation of adhesive and dense nanostructure multilayer film.Increasing the duty cycle led to the decrease in the coating grain size and promoted the hardness to 34.1 ± 4 GPa. A clear reduction of size and distribution of macroparticles was observed by using large repulsive force at a high duty cycle. By increasing the duty cycle, the coating deposition rate was increased from 1.23 to 1.38 µm/h and the surface roughness was decreased from 155 to 70 nm. The lower corrosion current density was obtained for the film applied at the 40% duty cycle (0.59 µA cm −2 ), which was about 10-order of magnitude less than the substrate.

The Multilayer CrN/CrAlN film was deposited on the SS420 substrate by cathodic arc evaporation technique. The effect of substrate bias‐voltage was investigated on the microstructure, surface morphology, and mechanical and electrochemical corrosion properties of the deposited film. The deposited CrN/CrAlN coatings were characterized by XRD and FESEM techniques. Mechanical properties, corrosion resistance, and surface morphology of the coated samples were studied by nano‐indentation, polarization method, electrochemical impedance spectroscopy, and atomic force microscopy, respectively. Adhesive and dense nanostructure CrN and CrAlN phases were successfully deposited on the substrate. The refinement of the coating crystallite was observed from 31.2 to 24.3 nm by increasing the substrate bias voltage, this improved the mechanical properties of the coating. The number of macroparticles, the number of pinholes and porosities, and the surface roughness of coatings significantly decreased by increasing the substrate bias voltage. The CrN/CrAlN coating reduced the corrosion current density in contrast to the SS420 substrate. Better corrosion resistance was obtained for the coating deposited at 150 V of bias voltage due to lower defects in the film structure.This article is protected by copyright. All rights reserved