Heat Resistance, High-Temperature Tribological Characteristics, and Electrochemical Behavior of Arc-PVD Nanostructural Multilayer Ti–Al–Si–N Coatings

Abstract

The present paper has aimed at studying heat resistance, electrochemical behavior, and tribological characteristics at high temperatures of superhard (~48 ± 2 GPa), multilayered with a modulation period of 17–18 nm, and nanostructured (nc)AlN-(am)Si₃N₄/(nc)TiN coatings obtained with an ion-plasma vacuum arc. The heat resistance of the coatings studied in the temperature range of up to 800°C inclusive was mainly determined by the oxidation of their surface layers without the substrate intrusion. Having a high coefficient of friction from 0.6 at 20°C to 0.8–0.85 at elevated temperatures, the coatings are characterized by virtually no wear, which was confirmed by profilometry measurements of friction zones. The obtained results concerning electrochemical behavior indicate that the Ti–Al–Si–N coatings are highly efficient in the protection of a cutting tool from corrosion in both acidic and alkaline media.