Investigation of the Structure and Functional Properties of Diamond-Like Coatings Obtained by Physical Vapor Deposition

Abstract

Diamond-like coatings with a total thickness of ~0.6 μm are obtained by physical vapor deposition with plasma separation and a pulsed carbon arc source with a cooled cathode and laser arc ignition; the substrates are titanium alloy (VT4), stainless steel (12Cr18N10T), and copper (M1). Scanning electron microscopy and profilometry are used to study the coatings surface and structure. The composition of the coatings and the fraction of sp3 bonds are studied using Raman spectroscopy. A wide peak in the 1580 cm-1 region is observed characteristic of diamond-like coatings. The coatings have a dense, nonporous structure. The tribological properties of the coatings are evaluated by the ball-on-disk method using a friction pair with WC and technical diamond. The strength characteristics are determined using linear scratch testing and nanoindentation measurements. The strength characteristics of the coatings vary and depend on the substrate materials. The friction coefficient of a diamond-like coating on VT4 alloy is ~0.1 in a friction pair with WC and ~0.01 with technical diamond.