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This work presents the results of (Zr-Ti-Cr-Nb)N superhard coatings research. The samples were fabricated by the vacuum-arc deposition method (Arc-PVD). Structure, composition and properties of these coatings were studied. The study of coatings was carried out using scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction. Hardness measurements and adhesion tests were performed. The coatings thickness was up to 6.2 μm, nanocrystallites sizes ranged from 4 to 7.3 nm. Values of hardness and cohesive strength were H = 43.7 GPa and LC = 62.06 N, respectively. The optimal conditions for coating deposition were found. [ABSTRACT FROM AUTHOR]

Using the vacuum-arc evaporation method we fabricated periodic multilayered TiN/MoN structures with different bilayer periods A ranging from 8 to 100 nm. We found that molybdenum nitride and titanium nitride layers grown on steel show local partial epitaxy and columnar growth across interfaces. A molybdenum-titanium carbide interlayer was evidenced between the substrate and the multilayer. Molybdenum nitride and titanium nitride layers contain small (5÷30 nm) grains and are well crystallized with (100) preferred orientation. They were identified as stoichiometric fcc TiN and cubic γ-M2N. Non-cubic molybdenum nitride phases were also detected. The hardness of the obtained structures achieved great values and maximal hardness was 31÷41.8 GPa for the multilayered structure with a 8 nm period. Hardness of the obtained coatings is 25÷45% higher in comparison with the initial single-layer nitride coatings, plasticity index of multilayered structure is 0.075. [ABSTRACT FROM AUTHOR]