Characterization of TiAlSiON coatings deposited by plasma enhanced magnetron sputtering: XRD, XPS, and DFT studies

Abstract

The results of characterization of TiAlSiON hard coatings deposited on ferric-chromium AISI 430 stainless steel by plasma enhanced magnetron sputtering are presented. The coating with maximum hardness (of 43GPa) was obtained at the following optimal values of elemental concentrations: Si ~5at.%, Al ~15at.%, and Ti ~27at.%. The value of gaseous mixture (Ar-N2) pressure was of 0.13Pa and the value of partial pressure of oxygen (O2) was 1.3·10-3Pa. The X-ray diffraction (XRD) measurements showed the presence of Ti(Al)N. High-energy resolved XPS spectra of core levels revealed the formation of Ti-N, Ti-O-N, Si-N and Al-O-N bonds. Comparison of XPS valence band spectra with specially performed density functional theory calculations for disordered Ti0.5Al0.5N1-xOx (0≤x≤0.3) phases demonstrated that a Ti(Al)OxNy phase is formed on the surface of AISI430 steel upon the plasma enhanced magnetron sputtering, which can provide a good combination of high hardness and additional oxidation resistance of this material. © 2015 Elsevier B.V.