LAUSR

Abstract In this study, the CrN x coatings were deposited by reactive magnetron sputtering at varying sputtering power from 200 to 300 W. The chemical composition, phase structure, surface and cross-sectional morphologies, and mechanical properties of the coatings were respectively investigated by electron probe microanalysis, X-ray photoelectron spectroscopy, X-ray diffraction, Raman spectroscopy, scanning and transmission electron microscopy, and nano-indentation measurements. The results show that the coating deposited at a sputtering power of 200 W is a single-phase fcc CrN with columnar structure, while the coatings deposited at sputtering powers of 250 and 300 W are consisted of hexagonal Cr 2 N and fcc CrN with nano-composite structure. As compared with the single-phase Cr 2 N or CrN coatings, the composite coatings exhibit both higher hardness and superior resistance to plastic deformation and cracking, which is attributed to their unique nano-composite structure.