Chromium nanostructured coatings formed by the PVD method

Abstract

Practical interest in materials with high physicomechanical properties has increased in nanomaterials and, in particular, nanocoating. First of all, it is the protection of metals from corrosion, the increase in wear resistance of parts and tools, and reflective properties. Environmentally friendly technologies are used in the vacuum sputtering process of producing chromium-based coatings. Consider the technological capabilities of a magnetron-sputtering vacuum system. It was proposed to pretreat the surface of the substrate with argon ions before applying the chrome plating. For this purpose, a designed ion source and a magnetron sputtering device for the chromium cathode are located in the chamber. Chromium-based nanostructured coatings formed by magnetron sputtering with preliminary treatment of the surface with an ion source are investigated. During the measurements, the thickness, adhesion strength, and corrosion resistance of chromium coatings were deter-mined. The strong corrosion resistance of samples with chromium-based coatings was demonstrated by their chemical resistance in nitric and hydrofluoric acid solutions. The novelty of this work was the effect of the thickness of the chromium-based nanostructured coating on the corrosion resistance. With an increase in coating thickness, the corrosion resistance of chromium coatings changes several times. For coatings less than 1 micron thick, the number of corrosion points (pores in the coating) was 5-10 times larger than for coatings 2.3-2.5 microns thick. The size and surface appearance of nanoparticles in the chromium coating structure were examined using electron microscopy. It was revealed that, depending on the formation modes, the coatings consist of crystallites with sizes ranging from 45 nm to 200 nm.

Keywords

• magnetron sputtering
• vacuum chamber
• adhesive strength
• physicochemical properties
• technological regimes
• electron microscopy