ELECTROCHEMICAL AND MECHANICAL PROPERTIES OF COMPOSITE COATINGS FORMED ON VT1-0

10.25712/ASTU.1811-1416.2026.03.003

Abstract

In this work, composite coatings formed on VT1-0 titanium were investigated. A base oxide layer was obtained using plasma electrolytic oxidation (PEO), which was subsequently modified with superdispersed polytetrafluoroethylene (SPTFE) by a spraying method. The effect of the number of polymer layer application cycles on the electrochemical, tribological, and adhesive characteristics of the coatings was studied. It was shown that polymer treatment significantly enhances the protective properties of the system. It was found that with an increase in the number of treatment cycles from 1 to 3, the corrosion current density decreases from 1.6·10^-8 to 7.2·10^-9 A/cm², and the polarization resistance increases from 1.6·10⁶ to 9.5·10⁶ Ohm×cm² compared to the base PEO layer. Electrochemical impedance spectroscopy confirmed that the polymer effectively fills the pores of the oxide layer, especially on samples subjected to two and three treatment cycles. The highest wear resistance was recorded for the sample with triple-layer application: the wear rate decreased by more than 1500 times compared to the base PEO coating. Adhesion tests showed that the polymer film increases the critical scratch load by 43% for the sample with triple application. The obtained results demonstrate the high efficiency of the combined PEO and SPTFE spraying method for creating functional coatings on titanium.