Influence of silicon content on the microstructure and hardness of CrN coatings deposited by reactive magnetron sputtering

CrN and CrSiN films were deposited on the stainless steel and silicon substrates by DC magnetron sputtering and their microstructural features were investigated by X-ray diffraction (XRD), scanning electron microscope (FE-SEM/EDS), and atomic force microscopy (AFM). The influence of Si content along with process parameters such as power on the microstructural characteristics of Cr–Si–N and CrN films were investigated and compared between each other. The power and increasing Si contents strongly influence the microstructural and hardness of the deposited films. XRD analysis of the coatings indicates a grain refinement with increase in Si content during deposition of coatings, which is tandem with AFM and SEM results. Also, the surface roughness and particle size are decreasing with addition of Si in the films. The hardness of CrN and CrSiN was measured by microhardness tester and found that introduction of Si content in the CrN system increases its hardness from 1839 Hv to 2570 Hv.