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

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.     

Optimization of Steel-Surface Hardening by Carbon Nanostructures Followed by Treatment with High-Intensity Energy Sources

The effect whereby a steel surface is modified by its covering with a nanocarbon material followed by fast electron- or laser-beam irradiation is studied. The initial material is low-carbon steel. Soot produced via the thermal sputtering of graphite electrodes in an electric arc with the subsequent extraction of fullerenes is used as the nanocarbon coating. Due to the fact that nanocarbon-coated samples are irradiated with a 60-keV electron beam, the material microhardness enhances considerably. The dependence between the microhardness and the irradiation energy is nonmonotonic and reaches its maximum (about 600 ± 20 HV) under the condition that the electron-irradiation energy is 460 J/cm² and the intensity is 1.53 kW/cm². This corresponds to a fourfold increase in the microhardness. Electron-beam irradiation of the treated surface is accompanied by a 1.5–2-fold decrease in the friction coefficient. Experimental results are compared with data obtained under laser irradiation of the nanocarbon-coated steel surface.     

Laser Strengthening of a Steel Surface with Fullerene Coating

Doklady Physics - Modification of a steel surface by coating with fullerenes C60 and subsequent treatment by intense laser radiation has been investigated. The initial samples are made of...     

Evolution of Phase Composition and Structure in Sapphire Implanted with <Superscript>64</Superscript>Zn<Superscript>+</Superscript> Ions and Heat-Treated in Oxygen

Single-crystal Al₂O₃ substrates are implanted with ⁶⁴Zn⁺ ions using doses of 5 × 10¹⁶ cm^–2 and an energy of 100 keV. The samples are annealed in oxygen with a stepwise increase in temperature from 400 to 1000°C. The changes on the surface and in the bulk of the sample are analyzed via scanning electron microscopy, energy-dispersive analysis, transmission electron microscopy, and Auger electron spectroscopy.