Phase composition, thermal stability, physical and mechanical properties of superhard nanocomposite coating on Zr-Ti-Si-N base

The report presents investigation results for Zr-Ti-Si-N coatings of 2.8 to 3.2μm thickness deposited using a vacuum-arc method with a high frequency discharge (HF). It was demonstrated that some deposition conditions formed ZrN and TiN phases (of 29 to 30 GPa and 47 GPa hardness, respectively) under compression deformation Σ = -1.1%. Other deposition conditions formed ZrN, Zr2N, Si3N4, TiN phases (the coating hardness reached 56 GPa). It was found that annealing of steel samples coated with Zr-Ti-Si-N (72% Zr; T≅ 10%; Si ≅ 8%; N ≅ 10%) in air and in vacuum, under 850 C and 1180 C, respectively, resulted in that a grain size increased from 15 nm to 25 nm, and formed a thin ZrO2 film and β - Si3O4 crystallites. SEM with EDS, WDS, RBS with a microbeam, a nanobeam of electrons, nanoindentation, XRD, X-ray strain measurements (sin2φ-method), AES (in some cases), methods of recoil nucleus and nuclear reactions were applied for analyses. Also we applied testing of wear and corrosion in acidic medium.(authors)