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Effect of pressure of the reaction gas on the texture, structural stress state and mechanical properties (hardness and resistance to abrasive wear) in vacuum-arc coatings based on Ti-V-Zr-Nb-Hf-Ta nitrides of high entropy alloys were investigated in this work. At a bias potential of – 200V, an increase in nitrogen pressure during deposition from 2.5·10 – 4 to 4.5·10 – 3 Torr leads to an increase in the content of nitrogen atoms in the coating, and the formation of a bittexture state [111] + [311] is established. The formation of a biaxial texture occurs due to the presence in alloys of atoms with very different masses (Ti, V and Hf, Ta). The use of a multi-element composition in a single-phase state with a simple cubic lattice allows to achieve high values of microstrain (up to 1.4 %) with a low deposition pressure. It is determined that the increase of nitrogen pressure during deposition leads to an increase in macrostresses. The highest hardness of 53 GPa is achieved in coatings obtained at a pressure of 2·10 – 3 Torr. It has been established that coatings with high resistance to abrasive wear are found to be: crystallite grain size 12-25 nm, absent of texture (or a low level of texture perfection), and also rather high microstrain in crystallites. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Nano- & Electronic Physics is the property of Sumy State University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Nano- & Electronic Physics is the property of Sumy State University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Nano- & Electronic Physics is the property of Sumy State University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Nano- & Electronic Physics is the property of Sumy State University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Nano- & Electronic Physics is the property of Sumy State University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Nano- & Electronic Physics is the property of Sumy State University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The nitrides of high-entropy alloys, (TiZrAlYNb)N, fabricated by cathodic vacuum arc evaporation are studied with electron microscopy, atomic force microscopy, laser scanning microscopy; energy-dispersive X-ray analysis, X-ray phase analysis, time-of-flight secondary-ion mass spectrometry; and hardness measurements. It is found that the deposition parameters influence the structure, surface morphology, element distribution, and mechanical properties. The structural-phase state of the coatings before and after the ion implantation of heavy negative gold ions Au are compared. [ABSTRACT FROM AUTHOR]

Frictional properties of multi-element nanocomposite coatings by means of tribometry method have been studied. The obtained nitride nanostructured coatings include only a single phase of solid solution with the fcc lattice and NaCl structural type with (111) preferred orientation. The influence of annealing temperature on the tribological characteristics has been studied. It has been determined that the wear resistance (wear factor) of the coatings after annealing was 1.03 ×10-5 mm3 N -1 m -1 which is higher than before the annealing 7.8 10 -5 mm3 N -1 m -1. [ABSTRACT FROM AUTHOR]

This paper presents the results of investigation multilayer TiN / MoN coatings. Coatings were fabricated using Arc-PVD method. Period thickness of nanoscale layers in coatings was λ = 8, 25, 50 and 100 nm. The total thickness of coatings was up to 8.4 μm. Samples were studied using SEM, TEM, EDS, RBS, XRD, SIMS and nanoindentation. The actual thickness of the layers has a few larger values than expected (in most cases per 25 %). The formation of two phases was found: stoichiometric TiN (fcc) and cubic γ-Mo2N (fcc). Maximum values of hardness and elasticity modulus were obtained for coating with λ = 8 nm: H = 47 GPa, E = 470 GPa. Plasticity index and its dependence on the thickness of layer period (λ) were calculated. The most plastic coating was the sample with H / E = 0.1. [ABSTRACT FROM AUTHOR]

In order to develop the direction of "structural engineering nitride coatings" in the work conducted systematic analysis of the impact of the negative bias potential (direct and high-voltage pulse) on the structure, substructure and mechanical properties of ZrN coatings obtained by vacuum arc evaporation. Defined boundary value of (– 100 V) DC potential applied to the substrate, below which a high-voltage pulse potential (– 1200 ... – 2000 V quantity that allows to form peaks bias) makes a decisive contribution to the formation of preferred orientation of the crystallites with the [110] axis. The highest values of hardness 43 GPa are achieved at a constant potential -70 V. Supply high-voltage pulse shifts the maximum hardness in the direction of a greater value of the constant potential. [ABSTRACT FROM AUTHOR]

Arc vacuum deposition of nitride coatings in the Ti-Si-N system is carried out in an argonnitrogen mixture with variable gas concentration ratios. The resulting condensates are studied by fractographic analysis, X-ray diffraction analysis, and high-resolution scanning electron microscopy. Studied also are the elemental composition and microhardness of the condensates. At gas mixture pressure p > 5 × 10 Torr, conditions are found under which the hardness of the condensates is maximal, and the dependence of the hardness on the argon percentage in the mixture is obtained. At an argon percentage of 8-12%, the hardness of the coatings reaches 50 GPa. This value is 1.7 times higher than the hardness of coatings obtained in a nitrogen atmosphere. This superhard state is explained by the nanometer size (25-30 nm) of nitride grains and a specific growing texture with a family of {100} planes that is parallel to the growth plane. Such a configuration minimizes the surface energy. Mechanisms that may increase the ionization of film-forming particles and activate chemical bonds in the presence of argon are discussed. [ABSTRACT FROM AUTHOR]

The reproducibility of the single-phase structural state of the Ti-V-Zr-Nb-Hf multielement system (a high-entropy alloy) is demonstrated using the vacuum-arc method to prepare coatings based on this system. Single-phase high-entropy compounds with a bcc lattice typical of the molten state result from vacuum deposition; preparation in nitrogen atmosphere yields single-phases nitride superhard nanocrystalline coatings based on the fcc metallic lattice. [ABSTRACT FROM AUTHOR]

High-entropy alloy and nitride coatings (TiHfZrVNb)N were prepared by the cathodic-arc-vapor-deposition method under various deposition conditions. The composition, crystal structure, strain-stress state, profiles of defects and atoms in-depth and at surfaces of the (TiHfZrVNb)N coatings were characterized by EDS and SEM analysis, X-ray diffraction with "α-sin²ψ" method of measurements and slow positron beam. The oxidation behavior of nitride films after annealing at 600 °C temperature was studied. The results indicate that nitride coatings show the face-centered cubic crystal structure. The redistributions of elements and defects, their arrangement (segregation) due to the thermally stimulated diffusion and termination of the spinodal segregation near the interfaces, around the grains and subgrains were found. The peak hardness and modulus of the nitride films were 44.3 and 384 GPa, respectively. The tribological properties of the (TiHfZrVNb)N coatings against AISI 1045 were evaluated by a ball-on-disc tribometer with a 3.0 N applied load. [ABSTRACT FROM AUTHOR]