Purpose. Study of the composition, structure, adhesive strength and corrosion resistance of gas-dynamic coatings based on electroerosion Aluminum powders.
Methods. The object for applying gas dynamic coatings were Aluminum nickels with a diameter of 40 mm and a thickness of 5 mm. Electroerosion Aluminum powder materials were obtained from waste electrical wire on equipment developed and patented by employees of the Southwest State University Scientific and Educational Center. Gasdynamic coatings were applied on the DIMET-405 installation. To achieve the goal set in this paper, the corresponding tasks were solved using modern research equipment.
Results. Based on experimental studies aimed at studying the composition, structure and corrosion properties of gas dynamic coatings based on electroerosive Aluminum powders, the following has been established: the coating is formed uniformly, without cracks and in the absence of discontinuities; the elemental composition of the gas dynamic coating includes the following basic elements: Al (64.5%), Si (17.6%); C (10.8%); O (6.3%), Fe (0.5%); Mn (0.3%); the phase composition of the gas dynamic coating includes the following main phases: Al, Al2O3 and Al(OH)3; The hardness of the gas-dynamic coating is on the order of 105.4 NV; the coefficient of friction of the coatings on the 500 m friction path is on the order of 0.35; higher indicators of adhesive strength and corrosion resistance of gas-dynamic coatings have been experimentally established compared with those of the substrate.
Conclusion. High economic efficiency indicators of the developed technology for the restoration and hardening of gasdynamic coatings based on electroerosive Aluminum powders are associated with resource conservation and import substitution.

Purpose. A study was conducted on the cyanidation of R6M5 high-speed steel using baths composed of urea and sodium carbonate within the temperature range of 550–580°C.
Methods. The microstructure of the diffusion layer of steels was studied on cross sections using a Quanta FEG-650 scanning electron microscope equipped with an EBCD microanalysis system with a focused ion beam. This technique allowed for detailed visualization and analysis of the phase composition and morphology of the surface layers. To evaluate the performance characteristics of the cyanidized samples, wear tests were performed under conditions simulating friction during cutting tool operation. Testing was performed to establish a correlation between microstructural features of the diffusion layer and its resistance to abrasive action.
Results. The conducted experiments confirmed the significant efficiency of the new salt bath composition for cyanidation of high-speed steel P6M5 under the given temperature conditions. In the process of treatment, modified layers enriched with ε-phases (solid inclusions) are formed on the surface of the material, which provide unique performance characteristics: increased microhardness, reduced friction coefficient and resistance to wear.
Conclusion. The possibility of using cyanide-free salt baths for low-temperature cyanidation of P6M5 steel has been established, which expands the technological possibilities of tool production. The combination of high wear resistance and hardness of the treated steel makes the method promising for manufacturing of cutting tools and parts operating under intensive loads. The results of the study demonstrate that the use of the developed composition allows not only to improve the quality of cyanided layers, but also to introduce resource-saving technologies in industry, while maintaining high standards of environmental safety.

Purpose. Study of the elemental and phase compositions, as well as the microhardness of the surface of the cutter body of the KZTS A6/20 road milling machine made of 30KhGS steel, in order to use nitrocarburizing for its surface hardening.
Methods. Modern methods and equipment were used to achieve the set goal. Using the X-ray analyzer built into the Quanta 600 FEG scanning electron microscope, X-ray spectra were determined at specific points on the sample surface. The phase composition of the sample was studied by X-ray diffraction on a Rigaku Ultima IV diffractometer in Cu-Kα radiation using Soller slits using the ICCD PDF-2 DB (2014). The diffraction maxima were described using a superposition of the Gaussian function and the Lorentz function. Using the DM-8 automatic microhardness analysis system using the micro-Vickers method, the microhardness of the samples was studied by transverse section.
Results. The following were obtained as a result of the study: an X-ray diffraction pattern of the elemental composition of the cutter body of the KZTS A6/20 road milling machine, showing that the ratio of the elements corresponds to the composition of alloyed structural steel 30KhGS; a diffraction pattern showing the crystalline phases of α-Fe and Fe2O3 with different sizes of crystallites, as well as data on the position and interplanar distances of all reflections. The microhardness of the sample surface was determined: HV0.01 = 437.6.
Conclusion. The completed study will allow the development of recommendations for the practical application of chemical-thermal treatment methods, by means of which it is possible to carry out surface hardening of parts made of 30KhGS steel, in particular the body of a road milling cutter.

The purposes. The process of forming a heat-protective coating on the surface of turbine blades of gas turbine engines involves a complex of complicated technological equipment. The purpose of this work is to systematize, identify the causes and possible ways to eliminate manufacturing defects of thermal barrier coatings produced by electron beam evaporation in vacuum.
Methods. To achieve this goal, of thermal barrier coating formed on the turbine blades from a single-crystal nickel superalloy ZHS32-VI were analyzed. The metal sublayer in the thermal barrier coating system was deposited by the ion-plasma method on the MAP1-M equipment. The ceramic thermal insulation layer was formed by electron beam evaporation with condensation from the vapor phase on the L-8 installation. Optical and electron microscopy and metallography were used to study defects in the ceramic coating. The chemical composition of the phase components in the surface layer and thermal barrier coatings of the blades was performed using an energy dispersive analyzer included in an electron microscope.
Results. The causes of coating defects at different stages of production have been identified. The classification of defects and measures for their elimination and prevention of their occurrence are carried out.
Conclusion. After analyzing the experience of serial technology, it can be concluded that defects of thermal barrier coatings can be divided into two groups: defects formed during deposition as well as defects formed during auxiliary coating manufacturing operations. Defects detected by visual inspection can be eliminated, despite the increase in the production time at the same time as its price increase. However, the greatest danger is hidden defects, which cannot be detected at the manufacturing and control stage. Such defects appear only during testing or operation, endangering the performance of the entire engine as a whole.

The purpose of this work was to optimize the conditions of spark plasma sintering of powders obtained by electrodispersion of metal waste of the TN20 alloy for the production of nonporous and high-hardness tungsten-free hard alloys.
Methods. Dispersible metal waste is made up of 20x20x5 mm pieces of TN20 alloy. The chemical composition in accordance with GOST 26530-85 is as follows: Ni up to 15%; Mo up to 6%; Nb up to 0.1%; TiC the rest. The working fluid is isopropyl alcohol. The plant for metal waste dispersion is an experimental and patented one. The modes for dispersing metal waste are 61.5 UF (capacity), 130 V (voltage), at 130 Hz (pulse frequency). Powder fusion plant ‒ SPS 25-10 "Thermal Technology". The BVTS microstructure was studied using a scanning electron microscope QUANTA 600 FEG. Optimization of the conditions of spark plasma fusion of powders obtained by electrodispersion of metal waste of the TN20 alloy for the production of porous and high-hardness tungsten-free hard alloys was carried out using a factor experiment and the method of steep ascent by Box and Wilson.
Results. In accordance with the goal set, aimed at optimizing the conditions of spark plasma sintering of powders obtained by electrodispersing metal waste from a TN20 alloy for the production of nonporous and high-hardness tungsten-free hard alloys, an optimal hardness of 95.2 HRA was established at the following values of factors: temperature 1250 °C, pressure 40 MPa, holding time 15 minutes.
Conclusion. Thus, the goal has been achieved. The results of the work can find practical application in the organization of resource-saving and import-substituting technologies.

Purpose. Experimental study of the vibration characteristics of a passive damper using an elastomer with ferromagnetic powder filler as a working body.
Methods. Measurement of amplitude-frequency characteristics of a uniaxial damper on a vibration test bench in a wide range of frequencies of harmonic action. Laboratory tests of the damper were performed in the loaded and unloaded conditions, varying the simulated payload from 0 to 600 g in 200 g increments.
Results. Uniaxial dampers of the original design of Stepanov G.V., consisting of two cylindrical magnetizable elastomers located between three ring permanent magnets facing each other with same poles, were manufactured. The elastic elements are placed inside an assembled supporting housings equipped with flanges for bolting to the vibration test platform. The housings were made of plastic by 3D printing. In a wide range of vibration loads the influence of the magnetic field on the vibration-protective characteristics of the damper by replacing permanent magnets with nonmagnetic washers was investigated. The amplitude-frequency characteristics of the dampers are typical for similar industrial products with a small bandwidth in the lower frequency region and a resonance peak after which the transfer function monotonically decreases. The measured characteristics demonstrate that the presence of permanent magnets in the damper design leads to a significant reduction of the transmission coefficient at the resonant frequency while increasing the bandwidth.
Conclusion. Elastomers with powder ferromagnetic filler are promising materials for manufacturing dampers of new designs. The use of magnetic interaction forces of filler particles in the polymer matrix enhances dissipative properties of the damper, which reduces the response of the system at its own resonant frequency, which demonstrates the prospects of their application for the protection of electronic devices under vibration loads.

The purpose of the study in this paper is to take into account the influence of magnetic wave oscillations of magnetization generated in a moving domain wall in a magnetic field in yttrium orthoferrite on a transverse sound wave.
Methods. Solutions of wave equations describing the influence of magnetization oscillations in a moving domain wall and a transverse acoustic wave using the methods of slowly varying amplitudes, perturbation theory and Lagrange.
Results. The influence of magnetic wave oscillations of magnetization accompanying a moving domain boundary, with and without taking into account their absorption in a magnetic field, on a transverse acoustic wave excited in a plate sample of yttrium orthoferrite is described analytically. Taking into account the crystalline and magnetic properties of yttrium orthoferrite (YFeO3) during the movement of a domain boundary in it, estimates are obtained for the contributions of the effect of magnetic wave oscillations of magnetization to the displacements of transverse sound waves. Without taking into account absorption in a magnetic field, the contribution is of the order of 10–7 m, which is comparable with the theoretical thickness of the domain boundary D3 ≈ 10–8 m, and taking into account absorption, it is of the order of 10–14 m.
Conclusion. To develop logical and memory devices whose operation is based on magnetization reversal due to the movement of domain walls at transonic speeds, the mechanisms of the influence of magnetic wave oscillations of magnetization on excited transverse acoustic waves in a YFeO3 plate were studied. Such interaction can significantly affect the quality and accuracy of information processing. The obtained estimates of the contributions of these interactions are important for creating the element base of devices for processing and recording information with magnetic memory based on weak ferromagnets.

Purpose of the study. Obtaining ablated Cerium dioxide nanoparticles in a narrow size range with specified maximum and minimum values to determine the dependence of particle morphology on the size factor.
Methods. Nanodispersed solutions of ablated cerium dioxide particles characterized by a narrow-size distribution were obtained using a specially developed technique. The morphology of ablated cerium dioxide nanoparticles obtained by sequential dispersion and centrifugation was studied using transmission electron microscopy. The crystal structure of narrow-size groups of CeO2 nanoparticles was studied using X-ray diffractometry and their coherent scattering regions were calculated.
Results. The studies have shown that with increasing average sizes of ablated cerium dioxide nanoparticles, their morphology becomes spherical. It has been established that with increasing particle size, the intensity of the X-ray diffraction reflection from the (111) crystallographic planes decreases, while the intensity of the reflection from the (200) crystallographic planes increases. It has been established that the sizes of the coherent scattering regions of ablated cerium dioxide nanoparticles for the (111) crystallographic planes vary in the range from (21.8±0.2) nm to (38.2±0.2) nm, and for the (200) crystallographic planes, vary in the range from (22.9±0.2) nm to (42.5±0.2) nm with increasing particle size. The difference between the average sizes of cerium dioxide nanoparticles and the sizes of their CSRs is due to the presence of an amorphous surface layer.
Conclusion. According to the results of the studies presented in this paper, it follows that with an increase in the size of ablated cerium dioxide nanoparticles, their morphology changes predominantly from a cubic shape to a spherical one, which is manifested in a change in the ratio of the intensities of reflections from various crystallographic planes in their structure

Purpose of research. Characterization of n-type bismuth telluride nanofilms from the Bi2Te2,7Se0,3 target formed by high-frequency magnetron sputtering in Ar on a silicon substrate.
Methods. High-frequency magnetron sputtering on a silicon substrate was carried out depending on changes in the control parameters (power P = 50 – 80 W and time t = 1800 – 2700 s) of sputtering. Characterization of magnetron nanofilms was carried out by X-ray phase analysis, atomic force microscopy, scanning electron microscopy, energydispersive X-ray microanalysis, digital holographic microscopy and Raman scattering. Statistical processing of AFM images of MNFs with the construction of autocorrelation functions using the direct Fourier transform, analysis of changes in the fractal dimensions of MNFs
Results. Thicknesses were measured with precision using AFM, DHM, SEM and a specially developed EDS technique, and the growth rates of MNFs were calculated, their linear increase depending on P, and t was proven. According to the Raman and XRD data, it was found that polycrystalline MNFs are formed in the process of RF MR of Bi2Te2,7Se0,3, the crystallinity of which was achieved after annealing at 623 K. The sizes of the coherence regions, texturing, microstrains and interplanar deformation distortions of MNFs were calculated using the XRD patterns. Statistical processing of AFM images of MNFs was carried out with the determination of the fractal dimension and the construction of the ACF using the DFT. It is proved that MNFs have 3D dimensions and are formed by the mixed Stranski – Krastanov mechanism.
Conclusion. In magnetron sputtered Bi2Te3 nanofilms with n-type conductivity, deformations of both signs were found: both compressive (∆а < 0) and tensile (∆a > 0). The calculated coherence sizes are consistent with the low level of crystallinity and weakly depend on the growth of both P and t. According to measurements by the “step” method of MNF thickness, the rate of their formation was V ≈ 0,6 nm/s.

The purpose of the study. Assessment of the quantitative accumulation of damage in the C/C composite and the effect of damage on the bearing capacity of the endoprosthesis during continuous loading. The need to assess the impact of damage on load-bearing capacity is due to the heterogeneous structure of the C/C composite. The reason for the inhomogeneity of the C/C composite is the pyrocarbon matrix, which is a stochastic medium at the level of the crystallite dimension. Due to the specific structure of the C/C composite, damage to the grains may occur under low loads caused by accidental circumstances during human movement. Damage to the grains leads to a change in elastic properties in the area of damage to the pyrocarbon matrix and C/C composite. Such changes lead to pseudoplastic deformation of the C/C composite product.
Methods. The model for analyzing the effect of damage accumulation on the bearing capacity of the endoprosthesis, developed as part of the study, is a synthesis of two methodologically different models. The first level of the model is an algorithm that allows us to obtain solutions to the integral equation for deformations in polycrystal grains of pyrolytic carbon, determine the probabilities of damage to the matrix grains for each of the criteria, calculate the volume fractions of destroyed, partially damaged and undamaged crystallites, and determine the elastic properties of the pyrocarbon matrix at two scale levels within the framework of the generalized singular approximation and the polydisperse model. The second level is a finite element model of the femoral component of the hip arthroplasty, created in the ANSYS package. The second level model makes it possible to evaluate the effect of matrix damage at the dimensional level of crystallites on the macroscopic mechanical condition of the structure. The interconnection of the two-level model is ensured by the continuous exchange of data between the two levels.
Result of investigation. A piecewise linear diagram demonstrating the nontrivial pseudoplastic nature of the C/С composite deformation.
Conclusion. A two-level model of the femoral component of the hip joint endoprosthesis showed that the C/C composite exhibits subcritical pseudoplastic deformation, which indicates the survivability and positive mechanical response of the structure.

Research objective. This work considers the issues of using carbon nanotubes as fillers in order to improve the strength properties of polymer materials based on polypropylene, which are used in various industries, oil and gas production, metallurgy, electric power engineering, etc.
Methods. A method for creating a new polymer composite material based on polypropylene with the addition of carbon nanotubes has been developed. Experimental tests of the strength of prototypes made of the "polypropylene-carbon nanotubes" composite were conducted in accordance with GOST 25.601-80 "Calculations and Tests for Strength".
Results. In the course of experimental studies, it was found that ultrasonic exposure of carbon nanotubes with a properly selected solvent and exposure conditions is an important condition for using CNTs as a nano-additive. To obtain a composite granular polymer material by introducing carbon nanotubes, it is most advisable to use a twin-screw extruder with pre-selected temperature regimes in each heating zone and the speed of rotation of the screws. It has been established that the introduction of carbon nanotubes in microquantities (0.2–0.4 wt. %) into the polymer matrix leads to an increase in the maximum allowable load to ~0.03–0.05 kN, the plastic deformation coefficient ~2.2–7.1% and the tensile strength ~1–2.5 N/mm2.
Conclusion. The results obtained allow us to conclude that the use of carbon nanotubes as nanoadditives in the polymer matrix of polypropylene allows us to create special polymers with unique properties without significantly increasing the cost of their production. In addition, the control of the percentage of CNTs allows us to design custom materials with precise control of their properties.

Purpose. Investigation of the physico-mechanical properties of a polymer obtained by adding a carbon black concentrate based on low-density linear polyethylene.
Methods. The process of coloring the thermoplastic polymer was carried out by adding a carbon black concentrate based on linear low-density polyethylene on equipment including a paddle mixer, dryer, and extruder. The obtained colored samples were analyzed using modern research methods for thermoplastic materials, which made it possible to obtain reliable information on the assessment of their certain physical and mechanical properties. To obtain samples, polymer crumbs coming out of the strand extruder were crushed on an HSS230-A mechanical crusher. The melt mass flow rate was determined by extruding the molten material from an IIRT type device (extrusion plastometer). The tensile and strength parameters were determined on a SEM-type machine for testing structural materials. The hardness index of the test sample was determined by the Shore method using a durometer.
Results. Based on the results of the work, the most optimal concentration of the added composition was identified to impart a stable black color to the thermoplastic polymer. The dependence of changes in the physico-mechanical parameters of a thermoplastic polymer depending on the amount of soot concentrate additive based on linear low-density polyethylene has been established.
Conclusion. The conducted studies revealed the patterns of the process of coloring a thermoplastic polymer with a souper concentrate based on linear low-density polyethylene and carbon black at different quantitative ratios. As a result of the study, it was found that with a quantitative increase in the concentrate in the thermoplastic polymer, the physical properties of the colored material change. A change in the amount of the additive in the range from 0.2 to 5 ppm leads to a change in the values of the physico-mechanical parameters of the studied samples compared with the initial polymer.