Characterization of TiAlSiON Coatings Deposited by Plasma Enhanced Magnetron Sputtering: XRD, XPS, and DFT Studies

TL;DR

This study characterizes TiAlSiON coatings deposited via plasma enhanced magnetron sputtering, revealing their composition, structure, and bonding, and demonstrating their high hardness and oxidation resistance through experimental and theoretical analyses.

Contribution

It provides a detailed analysis of TiAlSiON coatings' structure, bonding, and properties, combining experimental characterization with density functional theory calculations.

Findings

Maximum hardness of 45 GPa at specific elemental concentrations

Formation of Ti(Al)N, Ti-O-N, Si-N, and Al-O-N bonds

Ti(Al)OxNy phase enhances hardness and oxidation resistance

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 45 GPa) was obtained at the following optimal values of elemental concentrations: Si ~5 at.%, Al ~15 at.%, and Ti ~27 at.%. The elastic modulus of the coating was 590 GPa. The reading of gaseous mixture (Ar-N2) pressure was 1*10-3 Torr and the reading of partial pressure of oxygen (O2) was 1*10-5 Torr. 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 two ordered and few disordered TiN1-xOx (0 =< x <= 1) demonstrates that a Ti(Al)OxNy phase is formed on the surface of AISI430 steel upon the plasma enhanced magnetron sputtering, which provides this material with a good combination of high hardness and improved oxidation resistance.