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Volume 25 № 2 2023

1. Vladimir A. Aleksandrov. Waveguide Waves on the Water Surface in an Open Channel with a Built-in Source and a Capillary Waves Resonator. Chemical Physics and Mesoscopy, 2023, vol. 25, no. 2, pp. 135-148. Download

Wave processes on the free surface of water in a channel are considered when semicylindrical capillary waves are excited by a source and a quarter-wave resonator inside the channel. It is shown that the experimentally detected accelerating surface flows on the water surface in channels with installed sources and resonators of semicylindrical capillary waves are associated with the excitation of waveguide waves in the channel. Waveguide waves with a distributed amplitude in the form of a standing wave are formed when semicylindrical capillary waves are excited in a section of the liquid surface in a channel. In the channel, for capillary waves the liquid surface is a waveguide open at both ends due to the reflection of part of the waves from the channel walls and their interference. Waveguide waves propagate after the waves emanating from the source with acceleration and create an accelerating flow of surface energy and, together with it, a surface flow of liquid due to the transfer of momentum to the particles of the liquid. In contrast to semicylindrical waves, the front lines of waveguide waves within the channel, are straight, as in plane waves, but the amplitude and intensity of these waves is maximum along the channel axis. The waves emanating from the source in subsequent periods of oscillations are superimposed on the flow created by waveguide waves and, as a result, their semi-cylindrical front lines are extended. The principle of generating an accelerating surface fluid flow by waveguide waves in a channel with a source and a capillary wave resonator can be used to create acoustic flows in limited media by sources of acoustic and ultrasonic semicylindrical and hemispherical waves. Using the same principle, it is possible to obtain directed flows of microwave electromagnetic energy in waveguides with open cavity ends by a source of semicylindrical waves inside the waveguide cavity.
Keywords: piezoelectric transducer, capillary oscillations and waves, surface fluid flow, channel, waveguide waves.

DOI: https://doi.org/10.15350/17270529.2023.2.13


2. Boris Ya. Bendersky, Sergey V. Grigoryev, Alena A. Chernova. Influence of Saturated Steam Humidity on Power Turbine Blade Flow. Chemical Physics and Mesoscopy, 2023, vol. 25, no. 2, pp. 149-159. Download

One of the main problems in the operation of steam turbines is erosion wear of blades resulting from steam saturation with moisture droplets during useful work performed in turbine stages; it is especially noticeable in the last stage of low-pressure cylinder. Drip erosion can lead to serious breakdowns, cause reduced time interval before overhaul and reduce  the efficiency of a steam turbine's low-pressure cylinder by up to 5-6 %. The erosion of turbine blades has a tangible negative impact on the technical and economic performance of steam turbines, therefore the process of localizing erosion effects and combating drip erosion has never stopped since their development. One of the ways to solve the problem of droplet surface erosion  is the hydrodynamic optimization of the working process associated with appropriate design changes in turbines; this requires a detailed study of hydro-elastic processes of the interaction of wet saturated superheated working steam with steam turbine blades. The present work is devoted to studying the influence of the degree of steam saturation on the flow around the blade of a power turbine. The mathematical modeling was carried out based on the numerical solution of conservation equations for a viscous, compressible, thermally conductive gas containing incompressible fluid particles, written in two-phase flow variables and augmented by volume fraction transfer equations. A quasi-stationary approach was applied: the rotation of the blade was not been taken into account. A model problem of two-phase saturated steam flowing around the profile part of the blade of the last stage of the low-pressure cylinder of a condensing power turbine was considered. The numerical research was performed by the control volume method of with the use of the VOF approach. The space discretization of the computational domain was constructed using unstructured elements - tetrahedrons. The analysis of the obtained results allowed us to identify the distribution of the mass fraction of water in local areas near the blade surface. It is shown that the mass fraction of water grows monotonically with increasing humidity of steam. It is revealed that the localization of the regions with the maximum mass fraction of water correlates with the regions of maximum pressure and density near the blade surface.
Keywords: steam power turbine, blade, saturated steam, fluid dynamics, streamline, contact stresses.

DOI: https://doi.org/10.15350/17270529.2023.2.14


3. Alexander V. Vakhrushev, Fedor A. Vinogradov, Aleksey Yu. Fedotov, Anatolie S. Sidorenko. The Simulation of the Interface Enhancement of Multilayer Niobium-Cobalt Nanosystems by Pressing. Chemical Physics and Mesoscopy, 2023, vol. 25, no. 2, pp. 160-169. Download

This article describes the process of the formation of clear interfaces between the components of a multilayer nanocomposite. The experimental studies and modeling show that the quality of the interface noticeably deteriorates with an increase in the number of layers, which is associated with the accumulation of the number of defects and an increase in their size on the surface of each subsequent deposited nanolayer of a multilayer system. The preparation or modernization of the surface, on which the atoms of the next layer of the nanosystem are deposited to improve its quality, has a positive effect on the formation of a high-quality interface between the layers. The article considers the method of pressing for the surface modernization. The modified embedded atom method (MEAM) was used as a method for studying the surface structure and relief. The computational experiment was carried out using molecular dynamics simulation. The LAMMPS software package was used in the simulation. The simulation of the process of pressing the substrate, which enables to improve the interface of the nanosystem, and the process of the nanofilm deposition were carried out. The simulation of deposition took place in a stationary temperature regime. The computational experiment was carried out at five temperature regimes: 300, 250, 200, 100, and 50 K. The analysis of the effectiveness of the proposed technique is given.
Keywords: magnetic materials, interface improvement, multilayer nanofilms, mathematical modeling, molecular dynamics.

DOI: https://doi.org/10.15350/17270529.2023.2.15


4. Nikolay G. Galkin, Aleksandr V. Shevlyagin, Vladimir M. Il’yashchenko, Dmitriy T. Yan, Konstantin N. Galkin. Growth, Structure, and Optical Reflection of Magnesium Silicide Films Grown on Porous Silicon under High Vacuum Conditions. Chemical Physics and Mesoscopy, 2023, vol. 25, no. 2, pp. 170-185. Download

The growth of magnesium silicide on porous silicon was first tested under high vacuum conditions (10-5 – 10-6) without chemical removal of silicon oxide and in a limited temperature range of preliminary annealing (Ta = 450 °C). It is found that the minimum substrate temperature at which deposited magnesium begins to destroy silicon oxide and interact with silicon by forming magnesium silicide (Mg2Si) is 290 °C. In the solid-phase reaction of magnesium with porous silicon, after the destruction of silicon oxide, the optimum temperature, at which the formation of a continuous Mg2Si film begins, is 350 °C. It is shown that at the annealing temperature Ta = 420 °C only island Mg2Si films with good crystalline quality is formed. For all the cases, the formation of magnesium silicide is confirmed by X-ray diffraction, scanning electron microscopy, Raman spectroscopy, or Raman micromapping. It is established that the reflection spectrum of the Mg2Si/PS/Si system corresponds to the reflection from porous silicon with its partial increase at 500 – 900 nm due to the contribution to the reflection from magnesium silicide, which increases with increasing film thickness. It is proved that after the thermal treatment of porous silicon and the growth of magnesium silicide with a thickness of up to 90 nm, PS photoluminescence is retained. The radiation of PS is recorded with partial attenuation in the Mg2Si film without a change in the spectral composition, both immediately after growth and after long-term storage under atmospheric conditions (up to 8 months).
Keywords: mesoporous silicon, magnesium silicide, film growth, vacuum, reflection spectra.

DOI: https://doi.org/10.15350/17270529.2023.2.16


5. Aleksey M. Lipanov, Sergey A. Karskanov. Asymptotically Weighted Method for the Numerical Solution of Partial Differential Equations. Chemical Physics and Mesoscopy, 2023, vol. 25, no. 2, pp. 186-196. Download

An algorithm for the method of numerical solution of differential equations with partial derivatives is presented. The computational process begins with the use of an explicit difference scheme at each timeintegration step for half of the nodal points. This allows to reduce the amount of calculations based on two layers implementing a pseudo-implicit method for solving nonlinear partial differential equations when finding the parameter values at the next time layer. Two examples of solving linearized Euler equations are considered as test problems. Calculations are carried out using dimensionless variables. In both problems, the calculation was carried out on a uniform grid with a step of 0.1. In the first case, a wave of a complex shape propagates in an open area under the influence of the main flow. The centers of acoustic impulse, entropy impulse and vorticity impulse do not coincide. Over time, the impulses interact with each other, merging into a single structure. In the second case, the acoustic pulse interacts with a solid impenetrable wall. During the calculation time, the wave does not have time to reach the upper boundary; however, it is reflected from the wall, becoming much more geometrically complicated. In both examples, good agreement was obtained between the numerical and known theoretical data. The maximum deviations between the results are observed in the areas of the parameter extrema. The numerical values of the parameters and analytical values in time are compared, and absolute integration errors are shown.
Keywords: right-hand side method, linearized Euler equations, nonlinear differential equation, implicit method, acoustic wave.

DOI: https://doi.org/10.15350/17270529.2023.2.17


6. Vladimir G. Lebedev, Konstantin Y. Shklyaev, Mikhail G. Vasin. The Model of the Slow Relaxation Processes During Melting of Glass-Forming Eutectic Solutions. Chemical Physics and Mesoscopy, 2023, vol. 25, no. 2, pp. 197-208. Download

The purpose of the study of the present work is to understand the nature of the slow relaxation processes observed in glass-forming eutectic melts after melting. The nonlinearity of diffusion processes in a heterogeneous melt with inclusions of refractory stoichiometry (compound) is considered as the cause of the phenomenon under study. The origin of nonlinearity is related to thermodynamic instability, similar to that which occurs during spinodal decomposition. A prerequisite for the considered approach is the initial inhomogeneity of the solid solution. To confirm the assumptions made, relaxation processes were studied within the framework of a liquid solution model of a binary system, the evolution of which is described by an equation similar to the Kahn-Hilliard equation with an effective Gibbs potential taking into account the presence of stoichiometric phase residues after melting of the solid solution. Using Al-Y alloy as an example and on the basis of the Gibbs potentials for Al-Y known from experiments and presented in the standard database, it is shown that, under the condition of initial inhomogeneity, instability can develop in these systems leading to slow relaxation processes, and the boundaries of the region of this instability are determined on phase diagrams. The practical significance of the work is in assessing the boundaries of nonmonotonic relaxation in melting processes near the liquidus and the possibility of predicting this phenomenon in metal alloys, which may be of interest in the technology of designing new materials.
Keywords: intermetallic alloys, relaxation, melts, viscosity.

DOI: https://doi.org/10.15350/17270529.2023.2.18


7. Anatoliy A. Shakov, Marina A. Eryomina, Svetlana F. Lomayeva. Mechanochemical Method for Preparation of Highly Dispersed Gadolinium Powder. Chemical Physics and Mesoscopy, 2023, vol. 25, no. 2, pp. 209-216. Download

Highly dispersed gadolinium particles present great interest due to their use as a contrast agent in magnetic nuclear tomography and for the storage and use of hydrogen. The production of highly dispersed gadolinium particles is a complex problem. The main problem is the preservation of the powder in the metallic state in the air, since many finely dispersed metals are pyrophoric, especially powders of active metals (alkaline earths, lanthanides). The purpose of this work was the production of highly dispersed gadolinium powders and the study of their morphology and structure depending on the medium and milling time. A cheap and efficient method has been developed for obtaining highly dispersed gadolinium powders by short-term (1-3 h) ball milling of a gadolinium – potassium chloride mixture in an argon atmosphere in a Fritsch P7 planetary ball mill followed by washing away KCl. The proposed method enables to obtain highly dispersed gadolinium powders (0.1-1 microns) with the metal phase content of 70-90 wt.% depending on the milling duration. After 1 hour milling, the particles have the shape of plates with sizes from 0.1 to 2 microns (the average size is 1 micron); there is 90 wt.% of gadolinium and 10 wt.% of gadolinium hydride in the phase composition of the powder; the powder is not pyrophoric, including in contact with water. After 3 hours of milling, the average particle size decreases to 0.2 microns (varied from 0.1 to 1 micron); the amount of gadolinium hydride phase increases to 27 wt.%; the powder is stable under a layer of petroleum ether.
Keywords: highly dispersed gadolinium powder, mechanical grinding, planetary ball mill, XRD phase analysis, scanning electron microscopy.

DOI: https://doi.org/10.15350/17270529.2023.2.19


8. Andrey A. Shushkov, Pavel V. Bykov, Vasiliy L. Vorobʼev, Alexander V. Vakhrushev, Vladimir Ya. Bayankin, Stepan V. Suvorov. The Effect of Aluminum Ion Implantation on the Physical and Mechanical Properties of the Surface Layers of Stainless Steel AISI 321. Chemical Physics and Mesoscopy, 2023, vol. 25, no. 2, pp. 217-230. Download

A comparative analysis was conducted of the physical and mechanical characteristics (hardness, reduced modulus of elasticity, ratio of hardness to reduced modulus of elasticity characterizing the degree of hardening of the material, index of plasticity, elastic recovery, stiffness) of the surface layer up to 2.2 μm thick of stainless steel AISI 321 in the initial state and after aluminum ion implantation  (dose 1017 ion/cm2, energy 80 keV). It is found that for the irradiated sample th e average value of hardness is 4.6 times higher, reduced modulus of elasticity is 2.0 times higher, ratio of hardness to reduced modulus of elasticity is 2.4 times higher, elastic recovery is 31 % higher and stiffness is 43 % higher compared to those of the non-irradiated sample of stainless steel AISI 321 at the average penetration depth of the diamond tip into the irradiated sample of ≈45 nm. With a diamond tip indentation depth in the range of ≈80 nm  ≈2200 nm, there is a tendency to the improvement of the physical and mechanical characteristics by up to 20 %. The use of ion-beam mixing with aluminum ions at a dose of 1017 ion/cm2 and the irradiation energy of 80 keV leads to a  considerable improvement in all physical and mechanical characteristics of AISI 321 stainless steel, especially in the active working layer up to ≈80 nm and to a depth of 2200 nm. This is a promising method for practical implementation in the industry of the Russian Federation.
Keywords: hardness, reduced modulus of elasticity, elastic strain index, hardening degree, elastic recovery parameter, nanoindentation, AISI 321 stainless steel, Al ions, ion-beam mixing.

DOI: https://doi.org/10.15350/17270529.2023.2.20


9. Valeriya V. Aksenova, Olga M. Kanunnikova, Ivan N. Burnyshev, Vladimir I. Lad’yanov. Decomposition of Toluene During Processing in a Planetary Ball Mill Together with Aluminum and Magnesium Powders. Chemical Physics and Mesoscopy, 2023, vol. 25, no. 2, pp. 231-238. Download

To avoid agglomeration of plastic particles during mechanical activation (MA), a process control agent (PCA) is usually used, which is deposited on the surface of the particles and prevents the Me-Me interaction. At the same time, the crushed powders are polluted by the PCA decomposition products – carbon and hydrogen. The aim of the work was to study the effect of metal on the structural and chemical transformations of the liquid phase during the MA of toluene together with metal powders. To study the interaction of metal and toluene under the MA conditions, the powders of hydride-forming magnesium and carbide-forming aluminum were used in the present work. High-energy grinding was carried out in a planetary mill at a rotational speed of 600 rpm and processing time of 30 hours. The solid phase was studied by hydrogen thermal desorption spectroscopy (TDS) and for studying the liquid phase attenuated total reflection (ATR) was used. Based on the joint analysis of the TDS and ATR data, it is shown that the intensity of the structural and chemical transformations of the liquid phase depends on the interaction of the toluene decomposition products with the metal powder. In the process of mechanical cracking of toluene, the transformation of toluene → alkenes → alkanes occurs because of hydrogenation reactions of the aromatic ring. At the same time, the metal powder present in the reaction medium at MA and sorbing the toluene decomposition products has a significant effect on the structural and chemical transformations of the organic phase. Magnesium absorbs hydrogen, thereby preventing the hydrogenation of the benzene ring, and the toluene decomposition does not occur even after 30 hours of treatment. In the presence of aluminum, the decomposition of toluene begins after 20 h. The particle sizes of the aluminum and magnesium powders after 5 hours of processing  by grinding practically do not differ.
Keywords: toluene, decomposition, aluminum, magnesium, IR spectroscopy, thermal desorption of hydrogen.

DOI: https://doi.org/10.15350/17270529.2023.2.21


10. Aleksandr V. Zhikharev, Sergey G. Bystrov, Vladimir Ya. Bayankin, Evgeniy V. Kharanzhevskiy, Vladimir F. Kobziev. The Laser Influence on the Formation of Ni-Al Compounds in the Nickel Foil Surface Layers Depending on the Laser Radiation Power Density. Chemical Physics and Mesoscopy, 2023, vol. 25, no. 2, pp. 239-249. Download

The possibility was studied of obtaining the Ni3Al intermetallic compound using laser radiation by irradiating a nickel matrix with a 99.9% aluminum layer about 20 nm in thickness deposited on its surface by sputtering. The samples had a square shape with dimensions of 12´12 mm and thickness of ~50 mm. Before sputtering, the surface of initial samples was subjected to grinding, polishing and cleaning in organic solvents in an ultrasonic bath. The sample side with the deposited aluminum layer was treated by a focused laser beam in an argon atmosphere. The surface treatment of the samples was carried out with one pulse, but with different laser power densities. XPS, AFM, and microhardness measurements were used for studying the physicochemical sample properties. The experiment shows that under the selected irradiation modes, high-temperature heating of the irradiated surface occurs leading to the surface high-temperature oxidation with the formation of a complex spinel-type NiAl2O4 oxide. High-temperature heating occurs due to an increase in the laser radiation flux density from mode to mode, thus ensuring an increase in the amount of energy absorbed by the irradiated material during the pulse. As a result, the chosen modes of the laser treatment do not ensure the Ni3Al intermetallic compound formation in the samples under study. Apparently, after the termination of the laser action in the zone of the sample irradiation, a rapid cooling of the strongly heated region takes place with the "freezing" of all the processes occurring in the heated layer.
Keywords: intermetallic compounds, Ni-Al, nickel aluminide, X-ray photoelectron spectroscopy, microhardness, scanning probe microscopy.

DOI: https://doi.org/10.15350/17270529.2023.2.22


11. Maksim S. Konovalov, Vladimir I. Lad’yanov, Marina I. Mokrushina. On the Methodology of the Quantitative Analysis of Fe-Cr-Mn-Mo-N-C Steels with Reinforcing Particles of Oxides and Nitrides Using an X-ray Fluorescence Energy-Dispersive Spectrometer BRA-135F. Chemical Physics and Mesoscopy, 2023, vol. 25, no. 2, pp. 250-261. Download

A technique was developed for the quantitative analysis based on multiple regression of Fe-Cr-Mn-Mo-N-C composite steels with reinforcing particles of oxides and nitrides using a BRA-135F spectrometer to determine the concentrations of chromium, manganese, molybdenum, aluminum and iron. The approach to the selection of peaks for the analysis at a total content of chromium (11.50 – 15.03 wt. %), manganese (7.56 – 12.18 wt. %) and iron (66.54 – 74.08 wt. %) was considered. The optimal lines of the spectra of the considered steels were proposed for obtaining satisfactory results in qualitative analysis with regard for the peak overlap. It is shown that due to the overlap of the peaks, chromium should be determined by the peak relating to the CrKα line, manganese - by the peak relating to the MnKα line and iron - by the peak relating to the FeKβ line. An approach is described for selecting the peaks for determining the molybdenum concentrations. It is established that due to the absence of the reliable separation of the peaks relating to the lines MoKβ1 and MoKβ2.5, the molybdenum content should be determined by the peak relating to the line MoKα. As calibration samples the ingots were used, which were preliminary chemically analyzed for determining the content of metals  on an atomic emission spectrometer with inductively coupled plasma Spectroflame Modula S providing high stability and reproducibility of the analysis results in  a wide concentration range of elements, including those with lower limit of detection. The analysis for determining  the concentrations of nitrogen and oxygen in the calibration samples was performed using a METAVAK-VAK analyzer, and the carbon content was determined on a METAVAK CS-30 analyzer.
Keywords: X-ray fluorescence analysis, energy dispersive spectrometer, BRA-135F, composite steel.

DOI: https://doi.org/10.15350/17270529.2023.2.23


12. Marina A. Shumilova, Nikita E. Suksin. Regenerative Disposal Waste Solutions of Chemical Nickel Plating. Chemical Physics and Mesoscopy, 2023, vol. 25, no. 2, pp. 262-270. Download

The purpose of the presented study was to develop a regeneration method for the disposal of the spent chemical nickel plating solution (SCNPS), which would enable to obtain working solutions of chemical nickel plating (WSCNP). When developing the technological scheme for recycling, the reagent method was chosen as more economical and easier to implement. Solutions of sodium hydroxide, sodium carbonate and spent degreasing solution were used as precipitating agents. It has been experimentally established that the alkali consumption for converting the nickel salt contained in 1 m3 of SCNPS into its hydroxide at pH 12 is 19 kg of NaOH; while the degree of extraction of  nickel is 99 %. The amount of sodium carbonate required to precipitate nickel salts from 1 m3 of SCNPS at pH 10 is about 61 kg, and the degree of extraction of the metal is 97 %. Nickel recovery approaches 98 % using spent degreasing solution at pH 11, while 0.7 m3 of degreasing solution is required to precipitate Ni(II) per 1 m3 of SCNPS. The composition of the resulting nickel deposits was studied by IR-spectroscopy, which confirmed the production of nickel hydroxide. The presence of a carbonate group in the sediment is explained by the presence of carbonate impurities in the alkali; in other precipitants, the carbonate ion is included in their composition. Thermogravimetric analysis shows that the Ni(CO3) : Ni(OH)2 ratio in hydroxocarbonates is about 0.05, i.e., nickel hydroxide is the predominant component of the precipitate obtained. A technological scheme for the utilization of SCNPS using three types of precipitators was developed. The resulting nickel plating solutions were tested and their properties were judged by the quality of applied nickel coatings. It is established that solutions of sodium hydroxide and sodium carbonate can be used to obtain working nickel plating solutions.
Keywords: spent chemical nickel plating solution, nickel hydroxide, nickel hydroxocarbonate, IR-spectra, thermogravimetric and differential thermal analysis.

DOI: https://doi.org/10.15350/17270529.2023.2.24