Nanocomposites and nanomaterials

Effects of the substrate bias voltage and gas pressure on electrical conductivity and microhardness of the nanostructured TiON coatings
Podhurska V.Ya.1, Ostash O.P.1, Kyrysha A.A.1, Kuprin A.S.2, Kovtun Yu.V.2
1 Department of Hydrogen Technologies and Alternative Energy Materials, Karpenko Physico-Mechanical Institute of the NAS of Ukraine, 5 Naukova str., Lviv 79060, Ukraine.
E-mail: podhurskavika@gmail.com
2 National Science Center Kharkiv Institute of Physics and Technology, 1 Akademicheskaya str., Kharkiv 61108, Ukraine.

Good mechanical properties, high resistance to corrosion and low density make titanium and its alloys the materials of choice for many applications in the aeronautical, marine and chemical industries. However, titanium displays poor tribological properties (highly unstable friction coefficients and low wear rate) which must be improved for some technological applications [1]. Titanium also is a widely used material for medical devices because of its inertness and high biocompatibility as compared to other metals, including stainless steel [2]. Transition metal oxynitride films represent a particular class of materials that possess the superior properties of oxides (chemical stability and biocompatibility) and nitrides (hardness and resistance).
The aim of this work was to study the effect of the steel substrate bias voltage and gas pressure on the microstructure, electrical conductivity, and microhardness of the TiON coatings. These coatings have been deposited on steel substrates in a “Bulat-3” cathodic arc system. Variable parameters of the deposition process were the negative potential on the substrate Ub = -50...-200 V. It is shown that TiON coatings represent nanostructure, high electrical conductivity, and microhardness depending on the magnitude of the bias potential on the substrate and gas pressure.

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2.	Beshchasna N., Ho A. Ye. K., Saqib M. et al. Surface evaluation of titanium oxynitride coatings used for developing layered cardiovascular stents // Materials Science & Engineering C. – 2019. – 99. – P.405-416.