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EN
The paper presents the study of Ni-based coatings deposited by plasma detonation onto a steel substrate after direct current low-energy electron beam irradiation and proposes explicit parameters of the electron beam for modification of coatings by irradiation. The choice of irradiation modes is based on the calculation of the temperature profile in the Ni-Fe two-layer absorbents using numerical simulation methods. It was found that the exposure of coatings to irradiation according to the recommended modes leads to the evolution of the structural-phase state of coatings and substantial improvement of performance properties of modified surfaces. The wear resistance of modified surfaces increases 3 times, the microhardness increases on the average 25%.
EN
New classes of high-entropy alloys, which consist of at least 5 main elements with atomic concentrations 5-35 at.%, are under great interest in modern material science. It is also very important to explore the limits of resistance of high-entropy alloy nitrides to implantation by high-energy atoms. Structure and properties of nanostructured multicomponent (TiHfZrNbVTa)N coatings were investigated before and after ion implantation. We used the Rutherford backscattering, scanning electron microscopy with energy dispersive X-ray spectroscopy, high resolution transmission electron microscopy and scanning transmission electron microscopy with local microanalysis, X-ray diffraction and nanoindentation for investigations. Due to the high-fluence ion implantation (N⁺, the fluence was 10¹⁸ cm¯²) a multiphase structure was formed in the surface layer of the coating. This structure consisted of amorphous, nanocrystalline and initial nanostructured phases with small sizes of nanograins. Two phases were formed in the depth of the coating: fcc and hcp (with a small volume fraction). Nitrogen concentration reached 90 at.% near the surface and decreased with the depth. Nanohardness of the as-deposited coatings varied from 27 to 34 GPa depending on the deposition conditions. However, hardness decreased to a value of 12 GPa of the depth of the projected range after ion implantation and increased to 23 GPa for deeper layers.
EN
TiAlN, TiSiN, and TiCrN composite layers were deposited by magnetron sputtering and sliding - angle ion beam sputtering of the inner surface of hollow truncated cones of different compositions. The composition of both type coatings and component depth distributions were studied by the Rutherford backscattering spectrometry. The structural and phase analyses of the deposited films were performed by transmission electron microscopy and diffraction. Microhardness, wear resistance and friction coefficient of the coatings were also measured and discussed in the relationship with the structure and composition. Microhardness tests showed that the registered data varied in the range 10 to 50 GPa, depending on composition and concentration of components. The best wear protection results from the magnetron deposited Ti-Al-N systems in a narrow range of component concentrations. A minimal friction coefficient was revealed for the magnetron sputtered layers.
EN
Current paper presents the results of investigating of nanostructured cathode arc vacuum evaporation coatings, based on (Ti, Hf, Nb, Si)N. Several methods of the structural and elemental analysis were used: proton microbeam, nano- and micro-electron beam, X-ray diffraction analysis. To determine tribological properties (scratch resistance, adhesive and cohesive strength) of the coatings, scratch testing were conducting. Influence of thermal annealing at temperatures 300, 500, 800, 1000C on elemental composition, microstructure, residual stress, phase composition, profiles of atomic distribution in the coatings were investigated.
EN
Nanostructured thin-film coatings based on titanium nitride, doped with silicon, chromium and aluminium were the object of this study. The creation of a smooth transition layer was carried out by the changing of a supplying nitrogen flow to the vacuum chamber during the application. TiSiN, TiCrN and TiAlN coatings were deposited. The studies of the structure, elemental and phase composition of the coatings were carried out. Also, the performance of coatings was investigated. The results can be used in today's technology, such as mechanical engineering.
EN
The paper deals with the investigations of structural properties of Zn_{1-x}Mn_xTe films, which were fabricated under various deposition conditions using the thermal evaporation method in a closed volume. The surface morphology of the samples was studied, the phase analysis of their structures was performed, the elemental analysis of the films and the crystal lattice constant were investigated. The texture perfection of the films before and after copper ion implantation was evaluated.
EN
Using the vacuum-arc evaporation method we fabricated periodic multilayered TiN/MoN structures with different bilayer periods λ 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.
EN
First results in the field of synthesis and research of the multicomponent (Ti-Zr-Hf-V-Nb)N nanostructured coatings are presented in the paper. Influence of processes of spinodal segregation and mass-transfer on single-layered or multilayered crystal boundary (second phase) forming were explored. Superhard nanostructured coatings were investigated before and after annealing at the temperature 600°C using unique methods (slow positron beam, proton microbeam particle induced X-ray emission-μ, Rutherford backscattering-analysis, scanning electron microscopy with energy dispersive X-ray spectroscopy, X-ray diffraction analysis was performed using DRON-4 and nanoindentor). Diffraction spectra were taken point-by-point, with a scanning step 2Θp=0.05 to 0.1°. We detected that positron trapping by defects was observed on the nanograins boundaries and interfaces (vacancies and nanopores which are the part of triple and larger grain's boundary junction). The 3D distribution maps of elements obtained by the proton microbeam (particle induced X-ray emission-μ) together with the results obtained by slow positron microbeam gave us comprehensive information about physical basis of the processes, connected with diffusion and spinodal segregation in superhard coatings.
EN
This work presents the first results on forming of multi-layered superhard coatings Ti-Hf-Si-N/NbN/Al_2O_3 and their properties as well as structure. Microstructure, elemental and phase compositions of multi-layered coatings obtained by different methods were investigated. There were used such methods as: scanning electron microscopy EDS JEM-7000F microscope (with microanalysis) for research of cross-section of coatings, with subsequent Auger-electron spectroscopy, X-ray diffraction analysis, optical inverted microscope Olympus GX51, electron-ion microscopes Quanta 200 3D and Quanta 600 (scanning electron microscopy), equipped by the detector of X-ray radiation of the system PEGASUS 2000. It was stated that hardness of coatings has reached 56 GPa, and at the same time the factor of wearing during friction was the smallest - 2.571×10^{-5}. It was also noted that nitrogen pressure in the chamber at the deposition of the top layer significantly influences on the properties of samples. For example, the coefficient of friction at P=0.3 Pa from 0.2 at the beginning of track to 0.001 (during the tests), and at the pressure of nitrogen P=0.8 Pa, the coefficient of friction was equal to 0.314 at the beginning of track and 0.384 at the end (during the tests).
EN
Results of structure, phase composition, physical and mechanical properties and tribological properties investigations of nitride high-entropy coatings (TiZrHfVNb)N are presented in the paper. Proton microbeam (μ-PIXE), X-ray diffraction method, including method of X-ray strains measurements, energy dispersive X-ray spectroscopy and scanning electron microscopy analysis, microhardness testing and nanoindentation were used. Thermal annealing (t=600°C) influence on defect profiles, structure and element distribution in the coatings was investigated. It was found that thermal treatment of coatings leads to changing of defect profiles and to element redistribution. Also we can say that it influences less on grain size changing. Investigated (TiZrHfVNb)N coatings demonstrate high values of hardness and excellent wear resistance.
EN
This work presents the results of TiN/MoN coatings studying. These multilayer nanostructured coatings demonstrate dependence on depositions conditions on nanometer level. The influence of nanosized monolayer thickness on structure changing and properties of nanocomposite multilayer coatings TiN/MoN was found. Multilayer TiN/MoN coatings of the total thickness from 6.8 to 8.2 μm were obtained using C-PVD method. Thicknesses of monolayers were 2, 10, 20, 40 nm. The structure of samples was studied using X-ray diffraction (Bruker D-8 Advance) in Cu K_{α} radiation, high resolution transmission electron microscopy with diffraction CFEI EO Techai F200, scanning electron microscopy with energy dispersive X-ray spectroscopy (JEOL-7001F), and microhardness measurements in dependence on indenter load. Scratch tests (friction, wear, etc.) were also provided using Rockwell-C diamond indenter (CSM Revetest Instruments) with a tip radius of 200 μm. Friction and wear behavior were evaluated using ball-on-plate sliding test on a UMT-3MT tribometer (CETR, USA). With decreasing monolayer thickness the hardness value increases, and the size of nanograins reduces. The values obtained for the friction coefficient of the multilayer system is much smaller than in nanostructured coatings of TiN (nc) or MoN (nc). Annealing showed formation of a (Ti,Mo)N solid solution and small growth of nanocrystals.
EN
The coatings investigated in this paper were deposited via the magnetron sputtering of AlN-TiB_2-Ti-Si_2 target in Ar atmosphere. The investigation of structural-phase composition, element composition, morphology and mechanical properties before and after annealing up to 1350°C was carried out. The concentration of elements in the coating was changed after annealing at 900°C and further annealing at 1350°C (especially after annealing at 1350°C). The hardness of as-deposited coatings was 15 GPa, but after annealing at 1350°C the value of hardness increased up to 22÷23.5 GPa. The value of the viscoplastic index was 0.07. All this provide high damping properties of the coating, and amorphous-like structure makes promising the use of these coatings as diffusion barriers in the form of independent elements, and as a contacting layer in multilayer wear resistant coatings.
EN
Using the two technologies: plasma-detonation and vacuum-arc deposition, we fabricated two types of coatings: Ti-Si-N/WC-Co-Cr/steel and Ti-Si-N/steel. We found that the top coating of Ti-Si-N was nanostructured one with 12 to 15 nm grain sizes and H = 40 to 38 GPa hardness. A thick coating which was deposited using the pulsed plasma jet, demonstrated 11 to 15.3 GPa hardness, an elastic modulus (E) changing within 176 to 240 GPa, and tungsten carbide grain dimensions varying from 150 to 350 nm to several microns. An X-ray diffraction analysis shows that the coating has the following phase composition: TiN, (Ti,Si)N solid solution, WC, W_2C tungsten carbides. An element analysis was performed using energy dispersive spectroscopy (microanalysis) and scanning electron microscopy, as well as the Rutherford backscattering of ^4He^{+} ion and the Auger electron spectroscopy. Surface morphology and structure were analyzed using scanning electron microscopy and scanning tunnel microscopy. Tests friction and resistance (cylinder-plane) demonstrated essential resistance to abrasive wear and corrosion in the solution. The decrease of grain dimensions ≤ 10 nm occurring in the top Ti-Si-N coating layer increased the sample hardness to 42 ± 2.7 GPa under Ti_{72}-Si_8-N_{20} at.% concentration.
EN
This paper presents the first results on formation and study of structure and properties of micro- and nanocomposite combined coatings. By means of modeling the deposition processes (deposition conditions, current density-discharge, plasma composition and density, voltage) we formed the three-layer nanocomposite coatings of Ti-Al-N/Ti-N/Al_2O_3. The coating composition, structure and properties were studied using physical and nuclear-physical methods. The Rutherford proton and helium ion backscattering, scanning electron microscopy with microanalysis, grazing incidence X-ray diffraction, as well as nanohardness tests (hardness) were used. Measurements of wear resistance and corrosion resistance in NaCl, HCl and H_2SO_4 solutions were also performed. For testing mechanical properties such characteristics of layered structures as hardness H, elastic modulus E: H^3/E^2 etc. were measured. It is demonstrated that the formed three-layer nanocomposite coatings have hardness of 32 to 36 GPa and elastic modulus of 328 ± 18 to 364 ± 14 GPa. Its wear resistance (cylinder-surface friction) increased by factor of 17 to 25 in comparison with the substrate (stainless steel). The layers thickness was in the range of 56-120 μm.
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