Problems of Tribology = Проблеми трибології - 2023 рік
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Документ Performance analysis of turbocharger rotor friction pairs of an automobile engine(Хмельницький національний університет, 2023) Fasolia, V.; Hetman, M.; Staryi, A.Turbochargers are used in modern engines to increase their performance by increasing the amount of air supplied. To increase wear resistance, researchers and engineers are improving integrated technologies for strengthening turbocharger assemblies. The purpose of this study is to evaluate and analyze the influence of integrated strengthening technologies on the wear resistance of the turbocharger assembly. Integrated strengthening technologies include the use of new materials, coatings, design changes and manufacturing processes that improve the strength, thermal stability and wear resistance of the turbocharger assembly. A comprehensive analysis was carried out, including experimental tests, mathematical modeling and numerical simulations. Analyzed tests of wear resistance on specially designed stands simulating the real operating conditions of turbocharger units. The results can be used to analyze the effect of integrated strengthening technologies on wear resistance, considering various parameters such as temperature, torque and operating time.Документ Uninterrupted control of coating thickness during the wear process of vehicle units(Хмельницький національний університет, 2023) Makovkin, O.M.; Vychavka, A.A.; Valchuk, I.K.In the course of this research in the field of automotive technology, systematic patterns and features of wear of structural materials with wear-resistant coatings that were applied using various technologies, depending on the change in friction modes, were revealed. Our research led to the identification of physical parameters of tribological properties and their changes in the friction process. An interesting property discovered in the course of our work is the fact that changing the contact area several times does not significantly affect the change in the friction coefficient. Instead, changes in the coefficient of friction are mainly related to the chemical composition of the secondary structures that are formed during friction. An important aspect of our findings is that the change in the coefficient of friction is usually due to the chemical composition of the secondary structures, which in turn depend on the chemical composition of the base material, the characteristics of the coating, the characteristics of the environment and the temperature conditions in the friction zone. An analysis of the chemical composition of secondary structures formed during friction was carried out, which allows for a deeper understanding of wear mechanisms and creates opportunities for optimizing materials and coatings in the field of automotive technology.Документ Vibration diagnostics of machine friction units: analysis of the current state and prospects(Хмельницький національний університет, 2023) Lytvynov, O.; Dykha, O.Vibration diagnostics makes it possible to detect defects in the friction parts of the machine at the early stages of their development, which provides for the repair or replacement of parts before they fail. In this work, an analysis of modern research on the use of vibration diagnostics in tribology is carried out, which includes aspects: vibration diagnostics in technology and tribology; vibration during friction and wear; vibration assessment methods; theoretical approaches in the analysis and modeling of vibrations. It is noted that an important aspect is the development and implementation of theoretical approaches in the analysis and modeling of vibrations, which allows a deeper understanding of the dynamics of friction and wear. This approach makes it possible to develop accurate and adaptive strategies for maintenance and optimization of tribotechnical parameters. It is shown that vibration diagnostics is not only a tool for detecting malfunctions, but also a key element for ensuring the long-term and efficient functioning of friction units of machines. The effective use of vibration diagnostics can significantly reduce maintenance costs, increase the reliability and productivity of equipment, which becomes an indispensable condition for the effective functioning of modern technical systems.Документ Friction and wear of current-transmitting contact elements of electric transport with the use of metal-graphite composite materials(Хмельницький національний університет, 2023) Kovtun, O.; Dykha, O.The work provides an analysis of research devoted to the problem of manufacturing and operation of current-transmitting elements of electric transport, namely, the durability of contact parts according to operational and tribological characteristics. The work of current-transmitting elements of electric transport consists in the continuous sliding of one element on the surface of another and is accompanied by wear. At the same time, two types of wear are distinguished: mechanical and electrical. It has been established that the correct choice of materials has the greatest impact on reducing friction and wear of electrical contact elements. The basis for this is graphite material, which has the best current-conducting characteristics, but has insufficient strength and wear resistance. Approaches to the creation of materials for electrical contact elements using composite metallographite materials based on copper, aluminum, lead and other materials are analyzed.Документ Determination of the dependencies of the wear influence of the cylindrical brush on the operational characteristics of the garbage truck’s mounted sweeping equipment(Хмельницький національний університет, 2023) Bereziuk, O.V.; Savulyak, V.І.; Kharzhevskyi, V.О.; Harbuz, Ye.S.The article is dedicated to the establishment of dependencies of the influence of the wear of the cylindrical brush on the operational characteristics of the mounted sweeping equipment of the garbage truck. By using the planning of the second-order experiment with the first-order interaction effects, using the Box-Wilson method, the adequate dependencies of the influence of the wear of the cylindrical brush on the performance characteristics of the mounted sweeping equipment of the garbage truck were determined. It was established that, according to the Student's criterion, among the investigated factors of influence, the wear of the cylindrical brush has the greatest effect on the deformation of the cylindrical brush, and the width of the contact spot has the least influence. The required pressing force of the cylindrical brush is most affected by the width of the contact spot, and the least by the wear of the cylindrical brush. The response surfaces of the target functions are shown – the amount of deformation and the required pressing force of the cylindrical brush and their two-dimensional cross-sections in the planes of influence parameters, which make it possible to visually illustrate the specified dependences of target function data on individual influence parameters. It was established that the wear of the cylindrical brush of 50% of cases leads to an increase in the deformation of the cylindrical brush by 1.3 times, and the necessary force of pressing of the cylindrical brush – by 3.1...3.6 times, depending on the width of the contact spot. It is shown the expediency of conducting further researches of the effect of antifriction materials on the wear of the friction pairs of the mounted sweeping equipment of the garbage truck.Документ Analysis of the influence of shaker table rigidity on the accuracy of vibration test results for electronic equipment(Хмельницький національний університет, 2023) Goroshko, A.; Zembytska, M.During vibration tests of structurally complex equipment on electrodynamic shakers, the measured vibrations on the shaker table, test fixtures and various places of the tested product may differ. One of the reasons is the deformable shaker table, the stiffness of which can significantly affect the results of vibration tests. The electronic equipment being tested, as a rule, does not have an axisymmetric shape and therefore, during testing, it is very difficult to align the center of gravity of the product and the vibrating table or equipment with the axis passing through the center of the shaker table. The paper theoretically shows that the shaker table can be considered a rigid body only if there is no displacement of the weight of the tested product from the center of the table, as well as at excitation frequencies significantly lower than the critical frequency of the table. For theoretical analysis, the disc-shaped shaker table is presented in the form of a thin plate. Vibrography of the vibrating platform experimentally confirmed the effect of increasing vibrations when moving away from the center of the shaker table. If during vibration tests it is not possible to place the electronic unit coaxially with the center of the vibrating table, it is necessary to monitor the value of vibrations at different points of the tested product, for example, at the points farthest from the center.Документ The influence of hinges wear on the dynamic load of the articulated boom of a garbage truck’s manipulator(Хмельницький національний університет, 2023) Bereziuk, O.V.; Savulyak, V.І.; Kharzhevskyi, V.О.; Yavorskyi, V.Ye.The article is dedicated to establishing the relationship between the maximum impact dynamic stresses in the most loaded section of the garbage truck manipulator boom and the wear of the manipulator's hinge and its load level. By utilizing a first-order experimental design with first-order interaction effects using the Box-Wilson method, an adequate dependence of maximum impact dynamic stresses in the most loaded section of the manipulator boom on the wear of the manipulator’s hinge and its load level was determined. It has been found that, according to the Student’s criterion, among the investigated influencing factors, hinge wear has the most significant impact on the maximum impact dynamic stresses in the most loaded section of the manipulator boom, while its load level has the least impact. The response surface of the objective function is shown – the maximum impact dynamic stresses in the most loaded section of the manipulator boom and their two-dimensional sections in the planes of the impact parameters, which allows to visually illustrate the specified dependence of this objective function on individual impact parameters. It was established that the wear of the hinge by 1000 μm leads to an increase in the maximum impact dynamic stresses in the most loaded cross-section of the boom of the garbage truck manipulator by 2.6...4 times, depending on the level of its load. The expediency of conducting further studies of the effect of antifriction materials on the wear of the friction pairs of the mechanism for loading municipal solid waste into the garbage truck is shown.Документ Simulation model of contact interaction during surface strengthening of steel parts(Khmelnytskyi National University, 2023) Holenko, K.; Dytyniuk, V.; Dykha, M.In the processes of surface strengthening of steel parts, the stress-strain state is decisive for explaining the physical processes of strengthening, forming the dimensions of the contact area. Analytical dependences of contact parameters are quite approximate. In this work, based on the Ansys software complex, a simulated model of the contact of a truncated torus with a cylinder is proposed, which demonstrates the kinetics of the process of pressing a hard alloy tool into a steel workpiece - a cylinder. The experiment was conducted for 4 seconds in order to determine the maximum level of stresses, the distribution of stresses and the amount of residual stresses after removing the load. The clamping force was applied mainly in the zone of elastic deformations. The results showed an uneven stress distribution with a maximum in the center of the contact spot of 1082 MPa. After changing the load direction, small residual deformations at the level of 0.00311 μm were observed in the center of the contact patch. This indicates a violation of the elastic region on a small contact area, which does not affect the general nature of the stress distribution and can be removed during the finishing process. The results of simulation of the stressed state are used for the correlation with the observed structural changes of the material during the action of thermal and power stresses. The stress peak was formed at a distance of 200 μm, which contributes to the formation of maximum values of microhardness at this depth.Документ Review of aspects of processing and use of waste cooking oils as effective lubricants(Хмельницький національний університет, 2023) Dykha, O.; Hetman, M.; Staryi, A.; Kalaczynski, T.; Диха, О.; Гетьман, М.; Старий, А.; Калачинський, Т.In connection with environmental pollution and the depletion of oil reserves, biologically based lubricants have received great interest as a replacement for mineral oil-based lubricants. Biolubricants have a number of advantages over mineral lubricants, including high biodegradability, low toxicity, lubricating properties and minimal environmental impact. The presented review describes the main characteristics and properties of biological lubricants, various vegetable oils, which are used as raw materials for the production of biolubricant materials. The physicochemical properties of biological lubricants were analyzed from the point of view of improvement. The technological processes used for the chemical modification of vegetable oils, ensuring the lubricity and anti-wear properties of the obtained biolubricants are determined. Various additives used to improve the properties of biolubricants are also recommended. This review material will provide researchers and practitioners with additional information on the practice of using biolubricants.Документ Dependence of the wear rate on the microhardness of the coating of the auger hehydration in a garbage truck for municipal solid waste(Хмельницький національний університет, 2023) Bereziuk, O.V.; Savulyak, V.І.; Kharzhevskyi, V.О.; Vishtak, І.V.; Березюк, О.В.; Савуляк, В.І.; Харжевський, В.О.; Віштак, І.В.The article is dedicated to the study of the influence of the microhardness of the auger coating on its wear resistance during the dehydration of municipal solid waste in a garbage truck. The use of mathematical tools and appropriate regression analysis software allowed to determine the dependence between the auger wear rate and the microhardness of the coating. A graphical representation of the change in auger wear rate based on the microhardness of the coating was made up, confirming a significant convergence with the obtained dependence. The graphs illustrating the impact of the microhardness of the screw coating on its wear rate demonstrate the feasibility of increasing it. It was found that after operating and wearing out over a distance of s = 56850 m during the dehydrating of solid municipal waste in a garbage truck, increasing the microhardness of the coating from 2.7 GPa to 33.2 GPa leads to a decrease in energy consumption by 19 kWh/tons or 12% and reduces the cost of the dehydrating process. The feasibility of conducting additional research to determine further ways to increase the wear resistance of the auger was established.Документ Features of Increasing the Wear Resistance of Machine Parts by Treatment with a Concentrated Heat Flow(Хмельницький національний університет, 2023) Sokolan, Iu.; Romanishina, O.V. ; Sokolan, K.; Maidan, P.; Karazey, V.; Соколан, Ю.С.; Романішина, О.; Соколан, К.; Майдан, П.; Каразей, В.The article discusses the possibility of using surface treatment of parts with a concentrated heat flow to increase the wear resistance of parts. This method provides conditions for the rapid crystallization of the metal structure after zonal surface melting of the sample surface with electric arc plasma. It has been found that the wear resistance of steel increases significantly with increasing scanning speed and decreasing current strength. The nearsurface layers on the cross-sectional grinds of the melting areas were studied in comparison with the initial (without melting) state on the basis of diagrams of the method of continuous indenter immersion. The values of a number of micromechanical parameters characterizing the resistance to microplastic deformation and elastic-viscous properties of steel after strengthening heat treatment were obtained. It should be noted that with a fourfold increase in hardness, the wear resistance of the steel increased almost 10 times. This indicates that the wear resistance of metals under friction is determined not only by macroscopic strength and hardness, but also by the ability to relax local peak stresses under dynamic contact interaction.Документ Resistant Properties of Lubricating Materials with Fullerene Nanoadditives(Хмельницький національний університет, 2023) Oleksandrenko, V.P.; Yefymenko, V.V.; Kalmykova, N.G.; Efimenko, O.V.; Budiak, R.V.; Nelyubin, Yu.M.; Олександренко ., В.П.; Єфименко, В.В.; Калмикова, Н.Г.; Єфіменко, О.В.; Будяк, Р.В.; Нелюбін, Ю.М.The purpose of this article is to study the possibility of using fullerene additives and their effect on the antiwear properties of aviation mineral and synthetic oils. The method of increasing the anti-wear properties of mineral MK-8p and synthetic Mobil Jet Oil 254 oil for turbojet aircraft engines by adding fullerene additive C60 is considered. It has been shown that the anti-wear properties of synthetic Mobil Jet Oil 254 oil for turbojet aircraft engines exceed MK-8p mineral oil by more than 10%. Increasing the concentration of fullerene additive in oils increases the wear resistance of conjugated surfaces. It was established that the increase in the concentration of the fullerene additive in oils shifts the critical load to higher values for both mineral and synthetic oils. The intensity of this growth is observed in mineral oil to a greater extent than in synthetic oil. The use of fullerenes as an antiwear additive to oils for turbojet engines is proposed, which improves anti-friction properties and reduces the wear of parts of machines and mechanisms. Scientific progress is determined mainly by experimental research, the conduct of which in this direction is quite relevantДокумент Nitriding in a cyclically switched glow discharge(Хмельницький національний університет, 2023) Stechyshyn, M.S.; Dykha, O.V.; Oleksandrenko, V.P.; Stechyshyna, N.M.; Стечишин, М.С.; Диха, О.В.; Олександренко, В.П.; Стечишина, Н.М.The paper shows the prospects of nitriding in a cyclically switched discharge, the classification of nitriding processes in a glow discharge according to the criteria of the characteristics of the power source is given. A comparison of the advantages and disadvantages of nitriding processes with constant and cyclically switched discharge is given.From a theoretical point of view, the process of nitriding in a cyclically switched glow discharge is considered based on the concept of an energy model. In accordance with this model, tasks for further theoretical and experimental research are formulated. It is shown that the process of surface modification in a cyclically switched discharge opens up new possibilities associated with variants of the CSD itself, which is characterized by: frequency, period and pulse shape. The implementation of the process of adjusting the switching frequency, pitch - the ratio of the cycle period to the duration of the signal, and the shape of the signal itself opens up wide opportunities to significantly influence the results of surface treatment. The influence of the shape of the discharge power signal on the kinetics of the nitriding process and its results opens up wide opportunities for studying the process itself. The presence of surges at the beginning and at the end of the cycles can, in principle, significantly affect both the nature of the nitriding process itself and the structure and phase composition of the modified surface layer, since short-term and sufficiently powerful voltage surges should lead to intensive surface sputtering. The destruction of the monolayer of nitrides, which has just formed on the surface, will contribute to the increase of the depth of the nitrided layer due to the diffusion of nitrogen particles, as well as to a certain extent leveling off the blocking effect of the surface nitride layers.Документ Thermal and stress-strain state of friction pairs in ventilated disc brakes of lightweight vehicles(Хмельницький національний університет, 2023) Holenko, K.; Dykha, O.; Padgurskas, J.; Babak, O.; Голенко, К.Е.; Диха, О.В.; Падгурскас, Ю.; Бабак, О.П.The work is dedicated to the thermal behavior and stress-strain state of ventilated disc brakes installed in the lightweight vehicles (scooters, electric bikes, ATVs, etc.) using ANSYS environment in various experiment modes. Modeling of the temperature distribution in the rotor (disc) and the corresponding brake pads is determined taking into account a number of factors and input parameters during the braking operation: the amount of rotation speed, the gap between the pads and the disc, the speed of load application, thermal expansion, etc. Numerical modeling of the transient thermal and the stress fields in the area of contact between the pads and the rotor is carried out by the method of sequential thermostructural connection of the intermediate calculation states of the brake model in the ANSYS Coupled Field Transient environment. For a comprehensive assessment of brake behavior, our research considers two load approaches: constant long-term (20 s) with an influence factor in the form of thermal expansion as a result of contact pair friction; linear load from the pads on the disс with a corresponding increase in pressure up to the moment when the rotation of the system is blocked. Our research presents an assessment of the rotor ventilation channels influence on the nature of the contact spot with the brake pads (open far-field contact, sliding contact, sticking contact, etc.). In addition, it is demonstrated that despite the linear increase in pads pressure on the rotor, the graphs of temperatures, volume (thermal expansion) and stresses are of parabolic character with a disproportionate increase in indicators. Such a result forces us to come to the conclusion that it is not possible to predict the behavior of the brakes based on the analysis during a short period of time of the experiment - conducting long-term analytical studies is extremely important in the case of brakesДокумент Wear resistance of structural steels nitrided in a cyclically switched discharge with dry friction(Хмельницький національний університет, 2023) Stechishyn, M.S.; Skyba, M.Ye.; Martynyuk, A.V.; Zdorenko, D.V.; Стечишин, М.С.; Скиба, М.Є.; Мартинюк, А.В.; Здоренко, Д.В.The paper examines the method of conducting tribological studies in the dry mode of friction of nitrided and unhardened structural steels 20 and 45 in order to achieve comparable results of laboratory tests with operational characteristics. Preliminary studies of anodized steels of the same steels indicate that under conditions of extreme friction it is extremely difficult, and in some cases impossible, to use such values of specific pressure on the friction surface, at which it would be realistic to compare the results obtained for different samples made of different brands materials and processed using various technological processes. Since during the tests, constant lubrication of the friction zone was ensured, a layer of lubricant was present on the friction surface up to a certain pressure value, which led to extremely small indicators of linear wear. However, depending on the characteristics of the modified surface, there was a critical value of pressure at which the layer of lubricant was squeezed out of the friction zone, which led to instant adhesion of the surfaces. Thus, the study of wear resistance in the dry mode of friction ensures a significantly higher productivity of experiments. Unlike experiments with limit friction, dry friction can be used for different steels at the same pressure value, which eliminates the problem of comparability of results and contributes to the objectivity of conclusions regarding the effectiveness of various modification processes. According to the results of previous experiments, such a compromise pressure value can be 16 MPa. Another important phenomenon for the analysis of the influence of the modification results on the wear resistance characteristics of the surface is established - the effect of relaxation processes in the near-surface layers, which have already acquired structural transformations under the influence of pressure in the friction zone. For all steels, there is some slowing down of the intensity of wear after a break with a gradual return to the intensity characteristic of a certain brand of steel. The reason for such a phenomenon can only be the relaxation of stresses and the equalization of the characteristics of the structure in the near-surface layers. At the same time, the result is the strengthening of the surface, which explains the decrease in the intensity of the wear process. over time, as the strengthened layer breaks down, the indicators of the surface condition become equal to those before the break and the intensity of wear is restored.