Methods of direct and indirect assessment of the quality of mixing dispersed solid-phase components in a liquid polymer binder are considered. It is shown that a number of methods for the quantitative estimation of mixing (associated with the extraction of solid-phase components), which have been developed in other areas of the technology of materials, are not suitable for controlling an energy-saturated heterogeneous composite material (EHCM). An experimental method revealed the criteria values (a range) of the EHCM density and determined the main groups of the EHCM characteristics, ensuring their acceptable operational properties. By means of modern research equipment using proven methods, a series of studies was carried out to establish the uniformity of the distribution of particles of solid-phase components in the EHCM, the presence, the shape, sizes and distribution in the volume of defects in the structure of the material, the physicomechanical properties of the EHCM after polymerization. According to a comparison of the results of instrumental determination of the main characteristics of the EHCM (structural, physical) with the operational properties of the material, depending on the duration of the mixing process on a specific equipment under otherwise equal conditions, it was found that for the successful solution of technological tasks it is acceptable to assess indirectly the quality of mixing according to the results of density determination of the EHCM after its polymerization. This can provide operational output quality control of the final product that does not require significant material and time costs during the development of technological processes and during the production of the EHCM.

Examples of the implementation of powder metallurgy methods and their individual elements in the processes of producing materials with special properties and products thereof are considered. The possibility is shown and the results of producing radar-absorbing and radar-transparent materials in the form of solid bodies and coatings are evaluated. The addition of technological transitions, traditional for powder metallurgy, providing in general the production of radar-transparent materials, with the processes of mechanically activated synthesis and mechanically activated self-propagating high-temperature synthesis at the stages of preparing powders for molding, makes it possible to make the transition to the production of radar-absorbing materials. The high efficiency of both has been confirmed experimentally. The transition from a single-component composition of the initial charge mixture through the formation of the phase composition of the material due to the inclusion of powder components into the mixed charge, the composition and crystal structure of which remain unchanged at all stages of its preparation, to the synthesis of the required phase composition due to the interaction of powder components at one of the stages of technological conversion makes it possible to synthesize, for example, silicon carbide ceramics directly in practically useful products, particularly, substrates of optical mirrors for remote sensing of the Earth. The technological operations developed in powder metallurgy have become a background for the production of energy-saturated heterogeneous composite materials. Actively developing additive technologies, as a relatively new branch of powder metallurgy, expands its capabilities practically boundless.

One of the ways to increase the efficiency of the implementation of ion-plasma technologies of exposure to the surfaces of various materials is partial or full compensation of the positive charge of ions in the stream or on the treated surface, for which additional emitting systems are used that create compensating electron flows in the discharge space, accelerating gap or on the processed surface. It was previously shown that for the implementation of such a compensating effect, it is possible to use plasma sources of charged particles, capable of forming beams of both signs when the polarity of the accelerating voltage is changed. The main problem in this case is the difficulty in achieving simultaneously high emission efficiency of ions and electrons, since the conditions for their emission from plasma are significantly different. This article proposes a concept and a design developed on its basis for a prototype of a multi-discharge plasma electron-ion source for the joint or alternating formation of electron and ion beams. It is shown that the proposed design realizes the possibility of increasing the perveance by compensating for the space charge by particles of the opposite sign. A number of characteristics of the developed model of a plasma electron-ion source (current-voltage characteristics of the extraction of electrons and ions) are presented and its prospects for further development of an electron-ion source for industrial use on its basis are shown. Combined or alternating ion-electron beams formed in the presented source can be used to implement the technology of applying thin-film layers of metals, semiconductors, and dielectrics to maintain ionization processes and ensure stable discharge burning, compensation of both the space charge in the beam and the surface charge on the formed film.

The results of studies of the effect of ultra-high cooling rates of the melt equal to 10⁵ K/s on the phase composition, microstructure, grain structure and mechanical properties of the Sn – 14 at.% In – 6.5 at.% Zn alloy are presented. To prepare the samples, the rapid quenching from the melt technique was used. A drop of melt was injected onto the inner surface of a rapidly rotating copper cylinder and solidifing in the form of a foil with a thickness of 30–90 μm. Investigations of the phase composition, carried out by the method of Х-ray diffraction analysis, made it possible to establish that the foil consists of a solid solution of zinc in the γ -phase (Sn4In) and zinc. Observations of the microstructure of the foil using scanning electron microscopy showed that the decomposition of a supersaturated solid solution proceeds at room temperature with the release of dispersed zinc particles. The character of the grain structure and texture of the foil is studied by the electron backscatter diffraction technique. A mechanism of the formation of elongated grains is proposed, which consists in the fact that at a high solidification rate, comparable to the rate of movement of the melt over the surface of the mold, grain growth can occur not only in the direction opposite to the direction of heat removal, but also in the direction of movement of the spreading. The formation of the preferred growth of grains, in which the most closely-packed plane (0001) is parallel to the foil surface, provides the maximum rate of decrease in the enthalpy of the alloy during crystallization. The features of the influence of the microstructure and grain structure on the mechanical properties of the foil are revealed. The microhardness of the rapidly solidifing Sn – 14 at.% In – 6.5 at.% Zn alloy is 105 MPa. The stress–strain curve of the Sn – 14 at.% In – 6.5 at.% Zn foil, obtained at room temperature, has a shape specific for the stress–strain curve of metals at high temperatures, which is due to the low melting point of the γ-phase.

The paper presents the results of a study of the formation features on a large-pore substrate of a SiC-containing layer of pre-processed in a bead mill products of grinding porcelain fight with anthracite (10 wt.%). It is shown that the alloying of aluminosilicate powder with carbon leads to the formation of cubic and hexagonal silicon carbide (moissanite) in the sintered material. The main source of silicon for the formation of SiC when sintering doped powder Al₂O₃−SiO₂, is quartz. The process of SIC formation at temperatures of 850−950 °C becomes possible due to the formation of structural defects on the surface and in the volume of mechanically activated porcelain particles; partial transition to a more active, amorphous state of brittle SiO₂ (always present as grains in the structure of milled aluminosilicate particles) when doped with carbon. The process of manufacturing multilayer tube samples included pressing and sintering of a large-pore aluminosilicate substrate at a temperature of 1200–1250 °C with successive application and heat treatment of the intermediate and membrane layers. It was found that at 950 °C, the formation of a membrane layer from a mechanically activated Al₂O₃−SiO₂–C powder with a particle size of less than 1 µm is accompanied by the formation of SIC in an amount of 36 %. The structural and filtering characteristics of the obtained three-layer tubular samples with A SIC-containing membrane layer were determined: the pore size of 0.4−0.5 microns; water capacity of 0.012 m³ /m²  ∙ s; the degree of retention of particles smaller than 0.5 microns, including microorganisms, − 100 %. It is shown experimentally that three-layer samples are characterized by an almost constant filter cycle during filtration.

The main factors of the process of diamond smoothing are considered in the work: the force of the contact interaction of the tool and the part in the deformation zone and the friction on the contact surface of the part and the smoother. The technique of analytical determination of the optimal smoothing force for the finishing-hardening treatment mode is presented. The calculated values were obtained for some characteristic grades of materials of small and medium hardness (≤ 210 HB, indenter radius 3.4 mm) and a number of hardened steels of high hardness (indenter radius 2.0 mm). The force values are also determined using expressions for the deformation component of the friction coefficient. A comparative analysis of the results indicates that the calculation options are adequate for practical purposes. On specific examples of processed materials, graphical dependencies are shown, which reflect the relationship between the coefficient of friction, including its deformation component, and the smoothing force. With an increase in the leveling force, the friction coefficient increases, this is explained by an increase in the depth of penetration of the diamond tip and, consequently, an increase in the deformation component. The depth of penetration of the indenter into the surface to be treated, and therefore the coefficient of friction during ironing, depends on the hardness of the material being processed. With increasing hardness, the penetration depth decreases, which leads to a decrease in the deformation component and in general the coefficient of friction. The friction coefficient is also affected by the radius of the working part of the tool, since the indenter penetration depth also depends on its value. The research results can be used in the development of technology for finishing and hardening diamond smoothing, the development of the process and its introduction into production.

Statistical series of economic and energy indicators had been made up according to 2017 data. It consisted of three comparable values: population and specific (capita per inhabitant in the year) gross value added (SGVA) and electricity consumption (SEC) for fifty countries, which SGVA are larger or comparable to Belarus values. Using the correlation analysis the presence of strong, positive, reliable relationship between SGVA and SEC was established. It was found, that for the innovative development of Belarusian economy and accelerated growth of SGVA, the installed electric capacities are necessary to increase by 20–25 %. It is pointed that nuclear energy is the main resource of the fifth technological setup. The solving tasks during atomic stations operation promote development of new technology, emergence and insure advanced production methods in various economy sections. It is offered to create microclimate, required by modern technologies, in working zones of plants and at workplaces in institutions by an automated system ASLOTU – the radiant system of insuring technological conditions, which had been created by Belarusian specialists. The structurer of this infrared system, principles of its calculation and specific functioning algorithm are given. The ASLOTU technical and economic indicators have been determined – cost, service life, labor intensity and frequency of maintenance, costs of fuel consumed, period of covering capital outlays. The marked indicators are the result of processing the operation data of ASLOTU, which were implemented in Belarus for the period 1997 to 2007. They formed the basis of the draft ASLOTU introduction plan until 2035. The main planned indicators are given. The results can be used in other countries in which SGVA is 4.0–15.0 thousand dollars per person and they took course toward innovative development of the economy.

A system for vector control of current in the circuit of a polyphase electric machine has been developed. For this, on the basis of the analysis of electromagnetic processes in a multiphase semiconductor converter of electrical energy, its discrete mathematical model was created, which takes into account the redistribution of electromagnetic energy by individual spatial harmonic components depending on the number of phases. Using this mathematical model and the scheme of injection of higher current harmonics, which provides a polyharmonic mode of operation of a semiconductor converter, a method for independent control of the spatial harmonic components of the input current of the converter has been developed. The formation in each of the phases of polyharmonic currents, conjugated in shape and phase with the voltage supplying the converter, is carried out by means of control actions in the form of voltage vectors of a semiconductor switch, the implementation of which is carried out by the method of multiphase space-vector modulation. To check the developed provisions, a simulation model of a nine-phase semiconductor converter of electrical energy with a vector control system was created. The results of the study of the model confirmed the adequacy of the developed technical solutions, the use of which will ensure the most complete realization of the own advantages of a multiphase electric machine in order to generally improve the weight, size and energy indicators of the autonomous power supply system.

The article discusses the results of an experimental study of the effect of pressure on the formation of charcoal during the pyrolysis of wood, carried out on a laboratory bench at pressures of 1, 3, 5, 7 atm and a temperature of 400 °C. Birch wood in the form of wood chips with a particle size of 17ç8ç6 mm was used as feedstock. Its moisture content was 14.2 % by weight, its density was 506.4 kg/m³ , and its ash content was 0.23 % by weight. It was found that an increase in pressure from 1 atm to 7 atm leads to an increase in the yield of charcoal from about 25 % weight. up to about 32 % weight. The carbon content in this case increases from 89.1 % by weight to 96.4 % by weight. The work also experimentally investigated the effect of artificial deterioration of the conditions for the exit of volatile pyrolysis components from the reaction zone on the formation of charcoal and carbon content. The data obtained suggest that the deterioration of the exit conditions of volatile components from the reaction zone leads to their decomposition with the formation of carbon deposited in the pores of the pyrolyzable material and on its outer surface. Experimental data are also presented showing that components of the pyrolysis tar decompose in the presence of charcoal with the deposition of the formed carbon on its surface. The presence of such process is indicated by the difference in masses of identical charcoal samples studied at a temperature of 600 °C in the absence and presence of pyrolysis tar. The final mass of the sample, investigated in the presence of pyrolysis resin, as established in the work, exceeds the mass of the sample, studied in its absence. These results provide indirect evidence of the correctness of the assumption about the decomposition of the pyrolysis components in the pores and on the surface of the pyrolyzable material by a delay in the release of the pyrolysis components from the reaction zone. The results of this study are of interest to specialists developing pyrolysis equipment.

The conditions for realizing the single-quantum detection mode for silicon photomultiplier tubes with the p⁺–p–n⁺ structure are studied and data on their characteristics in this mode are obtained. The structure of the experimental setup and the research technique are presented. Measurements of the counting characteristics of the photodetectors, such as the dependences of the counting rate of single-photon pulses, the speed of dark pulses, and the signal-to-noise ratio, have been performed. The dependences of the counting rate of one-photon pulses on the intensity of optical radiation recorded by a silicon photomultiplier tube are presented. It was found that these dependences had a linear section, the length of which increased with increasing overvoltage of silicon photomultiplier tubes. Also, with an increase in overvoltage, the angle of inclination of the linear section increased. The dependences of the count rate of one-photon and dark pulses, as well as the signal-to-noise ratio on overvoltage, are given. It was found that the counting rate of dark pulses increased with increasing overvoltage. It was found that the dependence of the signal-to-noise ratio on the overvoltage for these silicon photomultiplier tubes has a maximum. To obtain the maximum sensitivity of the studied silicon photomultiplier tubes, it is necessary to select the overvoltage corresponding to this maximum. As a result of comparing the sensitivity of the investigated silicon photomultiplier tubes and avalanche photodiodes, it was found that silicon photomultiplier tubes operating in the single-quantum detection mode have a higher sensitivity compared to avalanche photodiodes in the same operating mode. With a decrease in temperature, this superiority persisted. Also, a decrease in temperature led to a decrease in the minimum value of the intensity of the recorded optical radiation. Thus, the possibility of operation of silicon photomultiplier tubes in the single-quantum registration mode has been proved. These results can be applied in quantum cryptography systems when receiving an optical signal.

A research was carried out with the construction of a model of a low-pressure nozzle with aerodynamic fuel atomization, which shows the advantages of nozzles of this type. In order to reduce the time at the stage of development and calculations, modern computer design systems were used. The research was carried out in the Flow Simulation module of the SolidWorks software package, which allows you to calculate and build a model of the internal flow around the nozzle using already known parameters. These parameters were set through the program conditions panel: fuel consumption per second; air flow rate at the inlet to the nozzle; static pressure in the combustion chamber. The calculations performed by the module made it possible to evaluate the manufacturability of the design, as well as the internal processes of mixing fuel with air. To determine the quality of fine dispersion of the fuel atomization, a model of the velocity field was calculated over the entire section of the nozzle, from which it can be seen that the maximum flow rate of the fuel is achieved in the outlet channels of the fuel atomizer of the nozzle. The results obtained indicate the operation of the low-pressure principle while maintaining high-quality fuel atomization. The use of low-pressure nozzle with aerodynamic fuel atomization is possible in modern gas turbine engines of civil aircraft, as well as in gas turbine.

Annotation. An analytical expression is obtained for engineering calculation of the regularities of removing the allowance from the flat surface of the part (a rectangle in the form of a flat glass plate of considerable thickness with holes for axicon blanks), which participates in relative and portable movement on the surface of a rotating tool (faceplate) and is in a power circuit with it, which provides automatic self-installation of lapping surfaces. A scheme is proposed for dividing the lapping surfaces of a flat tool and part into ring zones and sectors, resulting in the formation of elementary platforms with reference (calculated) points in their center. Analytical expressions are obtained for calculating the coordinates of these points. The kinematics of the relative movement of the tool and the straightener without oscillation of the upper link is considered, while the sliding of the conjugate surfaces takes place due to rotation of the tool and the straightener installed with a certain eccentricity. An expression is obtained for determining the sliding speed at any point of contact of the conjugate surfaces. Modeling when dealing with relative and portable movement of the upper unit, which allowed obtaining a formula for the slip velocity of the straightener relative to the tool that allows calculation the path of friction in a particular zone in different modes of operation of technological equipment. Modeling can be used as the basis for creating a method for controlling the process of forming conical optical parts (axicons) on serial lever grinding and polishing machines with a flat tool under free lapping conditions, which provide the possibility of obtaining axicons with a deviation of the forming cone from the straightness of no more than ±0.00012 mm.

The article considers the possibility of using planned-prevention system in modern conditions. The system of vehicle telematics and remote diagnostics allows you to automate the getting of correction coefficients to determine the standard values of labor intensity of maintenance and repair and make calculations with high accuracy. The mileage before major repairs or write-off of the vehicle set by the manufacturer is also corrected for coefficients. The use tools of navigation allows you to determine the location of the vehicle in the coordinates of navigation maps with characteristics of the road surface, locality, with the definition of height above sea level and road-climate zoning. This method is an alternative solution that allows you to automate the mileage and labor intensity of technical actions and can be used to clarification parameters. To implement these principles, we propose a flowchart for processing transport telematics data for calculating correction coefficients, followed by calculating the periodicity and labor intensity. The proposed flowchart is implemented by a standard vehicle telematics system, but it can be upgraded with the possibility of remote diagnostics, which allows performing the functions of general diagnostics of individual systems and the vehicle as a whole. The use of systems of transport monitoring make it possible to improve the system of maintenance and repair. Analysis of the existing requirements regulated by documents in the perspective of the capabilities of modern transport telematics systems allows us to justify and create a new approach to the calculation of mileage before technical impacts and adjust the standards for the complexity of performing these impacts. The introduction of the general remote diagnostics function for individual systems and the vehicle as a whole makes it possible to eliminate errors in the calculation of correction coefficients, as well as to prevent the occurrence of failures during operation.