Composition, structure and adhesion of cathodic-arc and glow-discharge deposited TiN/TiO2 coatings: a case study

Abstract

Abstract Titanium-based vacuum coatings, such as TiN and TiO2, are being widely used for functionalization of the surfaces and for forming protective surface layers for a number of applications. In this study, TiN/TiO2 coatings were deposited by two physical vacuum deposition (PVD) methods: cathodic-arc (for TiN) and glow-discharge (for TiO2) deposition. We studied the bilayer film composition, structure and properties by means of X-ray diffraction (XRD) analysis, X-ray photoelectron spectroscopy (XPS), and scratch test analysis. The XRD spectrum indicated the presence of both anatase and rutile TiO2 phases, together with TiN reflections. The Ti 2p, O 1s and N 1s core level of XPS spectra in the depth of the oxide up to the oxide-nitride interface indicated intimate heterojunction between the layers. This results in a lower coefficient of friction and improved adhesion strength of the TiN/TiO2 film compared with pristine TiN coating.