Problems of Tribology = Проблеми трибології - 2024 рік

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https://elar.khmnu.edu.ua/handle/123456789/15926

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Перегляд Problems of Tribology = Проблеми трибології - 2024 рік за Ключові слова "621"

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  • Ескіз
    Документ
    Determination of the regularity of the rate of wear of the working hydraulic cylinder of the mechanism of the sealing plate of the garbage truck from the pressing force
    (Хмельницький національний університет621, 2024) Bereziuk, O.V.; Savulyak, V.I.; Kharzhevskyi, V.O.; Alekseiev, A.Ye.
    The article is dedicated to the study of the influence of the pressing force on the wear resistance of the working hydraulic cylinder of the mechanism of the sealing plate of the garbage truck. The usage of a mathematical dependencies and appropriate software programs for regression analysis made it possible to determine the exponential regularity of the change in the rate of wear of the working hydraulic cylinder of the mechanism of the sealing plate of the garbage truck depending on the pressing force. A graphical dependence of the change in the rate of wear of the working hydraulic cylinder of the mechanism of the compacting plate of the garbage truck on the pressing force was made up, which confirmed the sufficient convergence of the obtained regularity. Graph of the influence of pressing force on wear rate of working hydraulic cylinder of the mechanism of the compacting plate of the garbage truck demonstrates the expediency of its increase. It was established that for the garbage truck of Ukrainian production of serial model KO-436, the rate of wear of the working hydraulic cylinder of the mechanism of the sealing plate of the garbage truck according to the obtained regularity will be 0.257 μm/h. The expediency of conducting additional studies to determine further ways to increase the wear resistance of the working hydraulic cylinder of the sealing plate mechanism of the garbage truck has been established.
  • Ескіз
    Документ
    Experimental installation for wear tests of materials and coatings
    (Хмельницький національний університет, 2024) Stechyshyn, M.; Dykha, O.; Oleksandrenko, V.; Tsepenyuk, M.; Kurskoi, V.; Oleksandrenko, Ye.
    On the basis of the analysis of existing tribological testing methodologies, which includes the selection of controlled wear parameters, the influence of the type of friction, contact geometry, surface roughness, the scheme of tribological research, the choice of a machine 2168UМТ for friction testing of materials is substantiated. The friction machine allows you to install three samples at the same time, change the pressure in the contact zone in a wide range, control the moment of friction, the rotation frequency of the counterbody, the number of revolutions (friction path), change the rotation frequency, respectively, the sliding speed, automatically limit the distance traveled and other functions. The method of wear is adopted according to the finger-ring scheme, linear wear is monitored using an indicator rack with a value of divisions of the measuring device of 0.001 mm. To fix the samples on the machine caliper, holders were designed and manufactured, which ensure the self-fixation of the sample on the counterbody - a spherical joint made of the rolling body of the bearing. due to the fact that the samples were pressed against the counterbody with a force corresponding to the nominal contact pressure, they were self-aligned. After the sample was self-assembled, the whole structure was fixed by tightening the nuts. The counterbody is made of a rolling bearing ring, the material is steel SHX15, the hardness of the base is HRC 61. Three devices are mounted on the caliper for permanent lubrication of the running track immediately before the approaching sample. Thus, at certain values of pressure and speed, the mode of marginal friction can be reached, which was marked by a low coefficient of friction.
  • Ескіз
    Документ
    Modeling surface structure of tribotechnical materials
    (Хмельницький національний університет, 2024) Drach, I.; Dykha, M.; Babak, O.; Kovtun, O.
    Modern tribology makes it possible to correctly calculate, diagnose, predict and select appropriate materials for friction pairs, to determine the optimal mode of operation of the tribo-joint. The main parameter for solving friction problems and other problems of tribology is the topography of the surface. The main purpose of the models in these tasks is to display the tribological properties of engineering surfaces. In the framework of the classical approach, the topography of the surface is studied on the basis of its images from the point of view of functional and statistical characteristics: the evaluation of the functional characteristics is based on the maximum roughness along the height and the average roughness along the center line, and the statistical characteristics are estimated using the power spectrum or the autocorrelation function. However, these characteristics are not only surface properties. They depend on the resolution of the device for measuring the surface geometry and the length of the scan. However, the degree of complexity of a surface shape can be represented by a parameter called the fractal dimension: a higher degree of complexity has a larger value of this parameter. Fractal dimensionality is a characteristic of surface relief and makes it possible to explain tribological phenomena without the influence of resolution. This article provides an overview of mathematical approaches to the description of the relief of engineering surfaces, in particular statistical, stochastic and topological modeling, their limitations, advantages and disadvantages. The implementation of the principles of the theory of fractal structures is discussed, which makes it possible to introduce the degree of imbalance of the tribological system into the analysis of structure formation in the surface and near-surface layers of materials and to describe the development of friction and wear processes. This is the basis for controlling the structure of the surface layers of materials with given properties. The concept of fractals, used for the quantitative description of the dissipative structure of the tribojunction zone, makes it possible to establish a connection between its fractal dimension and mechanical properties, as well as critical states of deformation of metals and alloys. The course of research and stages of fractal modeling, the classification of methods of fractal analysis of the structure of engineering contact surfaces are considered. A critical analysis of modern models based on the energy-spectral density function, which are quite similar to fractal models, is presented. Readers are expected to gain an overview of research developments in existing modeling methods and directions for future research in the field of tribology.
  • Ескіз
    Документ
    Optimization of technological parameters at discrete strengthening of steel cylindrical surfaces
    (Хмельницький національний університет, 2024) Dykha, O.; Dytyniuk, V.; Hrypynska, N.; Vychavka, A.
    The technologies of continuous strengthening of technological surfaces have practically exhausted their capabilities, which calls for the creation of fundamentally new approaches. The application of the principles of discrete-oriented strengthening of tribosystems has wide prospects for improving existing methods of strengthening due to the selection of modes and control of the geometric structure of the surface layer. The essence of the discrete-oriented strengthening method is the application of combined electromechanical processing and electrocontact cementation of cylindrical surfaces. The purpose of the work is to determine the parameters of discrete processing of cylindrical steel parts that are optimal according to the surface hardness criterion. Using the Statistica program, a factorial experiment was implemented according to the Box-Behnken plan, and the results of dispersion and regression analysis of the influence of processing parameters on microhardness were obtained. It was established that the following optimal parameters of DOZ processing are necessary to achieve the maximum values of microhardness (5950 MPa): current strength-500A, force-350 N, contact time-0.3 s.
  • Ескіз
    Документ
    Tribotechnical coatings
    (Хмельницький національний університет, 2024) Zemlyanoy, A.O.; Bys, S.S.; Shchepetov, V.V.; Kharchenko, S.D.; Kharhenko, O.V.
    Wear and tear limits the possibilities and shortens the operational life of modern technical systems. Therefore, the importance and necessity of consideration of issues aimed at reducing frictional forces and increasing wear resistance cannot be doubted. The paper summarizes the theoretical and applied results of triboresistance studies of detonation coatings of the Nb-Zr-V-Si-C-MgC2 system under conditions of constant loading in the field of sliding velocities. It has been established that the ratio of the quality of the components that make up the surface modified structures changes. It is noted that at the initial test speeds the presence of lower metal carbides that are part of the coating dominates, with an increase in speed under the current load due to solidphase and diffusion processes, higher ones are formed in the graphite matrix carbides with enhanced thermodynamic properties