Working Out the Processes of Deposition “MetalMetal“ Multi-Layer Coatings (Cu-Mo, Cu-MoN, Cu-C) and Studying the Tribological Characteristics of Friction Pairs

Abstract

As part of the program to search for new materials with high characteristics according to Avinit vacuum-plasma technologies, based on the complex use of coating methods (CVD + PVD), stimulated by nonequilibrium low-temperature plasma, the technological parameters of applying tightly bonded high-quality multilayer and nano-layer "metalmetal coatings" were worked out:  metal PVD coatings of Mo, Cu;  multi-layer PVD coatings based on Cu-Mo-N;  multi-layer PVD coatings on the basis of (Cu-C) (with different carbon content). Studies of samples with coatings were performed (micro-grinding, coating hardness, determination of surface geometry after coating). The thickness of multilayer coatings is 1...2 microns. with coating hardness of 250-400 kg/mm2. The developed regimes ensure high adhesion and preservation of the hardness of steel DIN 1.2379 within the specified limits. Distortions of the geometry and roughness of the coated surfaces, compared to the condition before the coating, were not detected. Tribological tests of coated samples were carried out. All tested coatings were completely worn out when rubbing steel DIN 1.2379 at very low loads (max up to 300N, then the load did not increase). All coatings had a high coefficient of friction Kfr ≥ 0.15. The use of such coatings in tribocombinations with steel in the form of independent wear-resistant coatings is impractical. They can be considered as soft layers in the development of new structures of antifriction wear-resistant coatings to increase the performance of friction pairs in the "coating-steel" and "coating-coating" tribosystems.