Deposition and characterization of nitrogen containing stainless steel coatings prepared by reactive magnetron sputtering

Abstract

Nitrogen containing austenitic stainless steel coatings were deposited with nitrogen concentrations up to 14.1 at% using electron enhanced closed field unbalanced DC magnetron sputtering. The reactive gas flow was controlled with an optical spectrometer. The effect of the nitrogen to argon flow ratio on the chemical composition, microstructure and hardness of the coatings was investigated. The nitrogen concentration in the coating was measured by Auger Electron Spectroscopy (AES), and was found to be linearly dependent on the relative optical intensity of the iron 428.2 nm line, used as control signal for the reactive gas concentration at the source. Chemical state information was gathered by X-ray photoelectron spectroscopy (XPS). X-ray diffraction (XRD) was used to evaluate the lattice parameter, and peak shape parameters as a function of the nitrogen content. The influence of the nitrogen concentration on the hardness was investigated by nanoindentation measurements. Copyright © 1996 Elsevier Science Ltd.