Problemi tribologii最新文献

{"title":"Nitriding in a cyclically switched glow discharge","authors":"M. Stechyshyn, O. Dykha, V. Oleksandrenko, N. Stechyshyna","doi":"10.31891/2079-1372-2023-108-2-20-27","DOIUrl":"https://doi.org/10.31891/2079-1372-2023-108-2-20-27","url":null,"abstract":"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. \u0000The 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.","PeriodicalId":34638,"journal":{"name":"Problemi tribologii","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45477202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mathematical model of running-in of tribosystems under conditions of boundary lubrication. Part 2. Simulation results","authors":"A. Voitov","doi":"10.31891/2079-1372-2023-108-2-44-55","DOIUrl":"https://doi.org/10.31891/2079-1372-2023-108-2-44-55","url":null,"abstract":"The paper presents the results of mathematical modeling of tribosystems running-in processes when various factors are changed: design parameters of tribosystems, which are taken into account by the form factor; tribological properties of the lubricating medium; rheological properties of composite materials in the tribosystem; roughness of friction surfaces; load and sliding speed. By comparing the theoretically obtained results, by modeling according to the developed models, with experimental data, it was established that the mathematical model adequately reflects the running-in processes taking into account the changes in constructive, technological and operational factors. Applying the Cochrane criterion, it was established that the obtained experimental results are homogeneous and reproducible. The maximum value of the coefficient of variation of the values of the volumetric wear rate and the coefficient of friction is within the limits v = 12,3 - 26,5%. The value of the simulation error is within the limits v = 7,7 - 12,9%. \u0000A rating of factors that maximally affect the processes of running-in of tribosystems in the conditions of extreme lubrication has been obtained. In the first place is the roughness of the friction surfaces, the coefficient of variation v = 26,5%. In the second place – the load on the tribosystem during running-in, the coefficient of variation v = 20,8%. In third place is the value of sliding speed during running-in, the coefficient of variation v = 18,6%. The conclusion made must be taken into account when developing a rational program for running-in tribosystems in conditions of extreme lubrication. \u0000The methodical approach of applying the acoustic emission method in the study of tribosystem running-in processes is presented. It is proved in the work that in order to determine the volume rate of wear during tribosystem running-in, it is necessary to register and analyze the fourth cluster from the general acoustic emission signal. The sources of signal generation of the fourth cluster are microcutting and plastic deformation of protrusions of the roughness of the friction surface, which is characteristic of the first stages of running-in.","PeriodicalId":34638,"journal":{"name":"Problemi tribologii","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43858455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dependence of the wear rate on the microhardness of the coating of the auger hehydration in a garbage truck for municipal solid waste","authors":"O. Bereziuk, V. Savulyak, V. Kharzhevskyi, I. Vishtak","doi":"10.31891/2079-1372-2023-108-2-56-61","DOIUrl":"https://doi.org/10.31891/2079-1372-2023-108-2-56-61","url":null,"abstract":"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.","PeriodicalId":34638,"journal":{"name":"Problemi tribologii","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49001419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Features of Increasing the Wear Resistance of Machine Parts by Treatment with a Concentrated Heat Flow","authors":"Iuliia Sokolan, O. Romanishina, K. Sokolan, P. Maidan, V. Karazey","doi":"10.31891/2079-1372-2023-108-2-37-43","DOIUrl":"https://doi.org/10.31891/2079-1372-2023-108-2-37-43","url":null,"abstract":"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 near-surface 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","PeriodicalId":34638,"journal":{"name":"Problemi tribologii","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47290554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Wear Resistance Research and Its 2-factor Modeling of Nanoscaled Silicon Carbide Detonation Coatings","authors":"A.H. Dovgal, L.B. Pryimak, V.V. Varijukhno","doi":"10.31891/2079-1372-2023-108-2-6-14","DOIUrl":"https://doi.org/10.31891/2079-1372-2023-108-2-6-14","url":null,"abstract":"This research is related to the spheres of wearproof coating testing. The SiC coating has been deposited on the medium carbon steel using detonation deposition using the magnet coil flux of back direction. It has been established that only nanoscaled particles are deposited on the surface which had been accumulated in aggregates of different shape. The structure of the obtained coating has been thoroughly researched on the electronic microscope in previous publication. The obtained coating has been developed for testing on the friction bench modeling the friction process that is taking place in the couple of main and rod journals of internal combustion engines. The coating has also the corrosion protection properties. The nanoscaled coating on mild carbon steel had been tested under specified conditions and their friction surfaces had been researched on electronic microscope with the view of determination of wear mechanism. The two-factor modeling of the wear rate and friction factor has been done and three-dimensional diagrams have been plotted and analyzed.","PeriodicalId":34638,"journal":{"name":"Problemi tribologii","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136287214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of the properties of coatings obtained by electric arc spraying","authors":"A. Lopata, I. Smirnov, M. Holovashchuk, V. Lopata","doi":"10.31891/2079-1372-2023-107-1-73-80","DOIUrl":"https://doi.org/10.31891/2079-1372-2023-107-1-73-80","url":null,"abstract":"The paper considers possibilities to increase the wear resistance, corrosion resistance, and service life for parts of machines and mechanisms via their hardening and renovating using electric arc coatings characterized by high density, adhesion strength, and micro hardness. Also, the possibility of controlling the properties of restored surfaces owing to choice of the related equipment with required structure and characteristics in order to prolong the service life of machinery parts is shown. The right choice of equipment for spraying makes it possible to increase the speed and temperature of the spraying gas and particles, reduce the droplet diameter, increase the density and reduce the oxidation of coatings. The influence of spray factors such as the flow rate and pressure of working gases, composition of combustion mixture, spraying distance, dispersion of the spray, properties of wire material, etc. on the properties of the coatings obtained has been investigated.","PeriodicalId":34638,"journal":{"name":"Problemi tribologii","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43700585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of microgeometry in the point contact zone of rest friction on fatigue life for friction bearing units","authors":"A. Milanenko","doi":"10.31891/2079-1372-2023-107-1-6-12","DOIUrl":"https://doi.org/10.31891/2079-1372-2023-107-1-6-12","url":null,"abstract":"A comprehensive methodology has been developed to assess the maximum contact stresses and deformations in the point contact zone and the maximum tangential stresses, including their position in the subsurface zone in depth and in the rolling direction when the microgeometry of the rest contact.","PeriodicalId":34638,"journal":{"name":"Problemi tribologii","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41686532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Increasing the Wear Resistance of Restored Car Parts by Using Electrospark Coatings","authors":"D. Marchenko, K. Matvyeyeva","doi":"10.31891/2079-1372-2023-107-1-65-72","DOIUrl":"https://doi.org/10.31891/2079-1372-2023-107-1-65-72","url":null,"abstract":"The work scientifically substantiates the application of effective technology for the restoration of worn car parts by applying new electrospark coatings based on electroerosion nanomaterials. The developed technology is characterized by technological flexibility, cheapness, simplicity, does not require the use of expensive and scarce materials and equipment, and also meets the requirements of environmental safety. The proposed technology can be used to restore a wide range of parts for cars, tractors and other machines. Experimentally established dependences of the effect of the properties of electroerosive materials on the properties of electrospark coatings of restored car parts. It is shown that the content of nano-sized particles in the electrode material contributes to the improvement of the physical and mechanical properties of electrospark coatings. The dependences of the influence of the properties of electrospark coatings on the resource of restored car parts were experimentally established. It is shown that the resource of the shafts of turbocompressors restored according to the recommended technology is higher than the resource of new shafts by an average of 1.5 times. Experimentally established rational modes of applying wear-resistant coatings to worn shafts of turbocompressors, which provide the necessary complex of physical and mechanical properties of the coating and the given resource of the shafts as a whole (rotation frequency of the part, min - 1 - 50; electrode feed, mm/min - 0.4 ... 0.5). The characteristics of wear resistance of electrospark coatings of turbocompressor shafts, obtained using electroerosion nanomaterials, were studied. It is shown that the average value of the coefficient of friction of the electrospark coating was 0.146 instead of 0.486 without coating, which is 3.3 times lower. According to the results of production tests, it was found that the duration of operation of the turbocharger, with the restored method of electrospark treatment with a nanostructured electrode shaft, increased by 2.1 times compared to a new industrially manufactured shaft. Thus, when abrasive material containing a fraction of 0.1...0.4 mm was introduced, the operating time of the turbocompressor with a restored shaft was 12.8 hours, and the operating time of the turbocompressor with a new shaft without wear of the nominal size was 8.1 hours.","PeriodicalId":34638,"journal":{"name":"Problemi tribologii","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43624841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Establishing the peculiarities of tire wear of garbage trucks during the transportation of municipal solid waste","authors":"O. Bereziuk, V. Savulyak, V. Kharzhevskyi","doi":"10.31891/2079-1372-2023-107-1-59-64","DOIUrl":"https://doi.org/10.31891/2079-1372-2023-107-1-59-64","url":null,"abstract":"The article is dedicated to the establishment of peculiarities of tire wear of garbage trucks during the transportation of solid waste. Using the planning of the first-order experiment with the first-order interaction effects using the Box-Wilson method, adequate dependencies of wear of garbage truck tires on the front and rear axles due to the transported mass of municipal solid waste and the mileage 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 garbage truck tires on both the front and rear axles is most affected by the transported mass of municipal solid waste, and the least – by the mileage of the garbage truck. The response surfaces of the objective functions – tire wear of the garbage truck on the front and rear axles and their two-dimensional sections in the planes of the impact parameters are shown, which allow to visually illustrate the indicated dependences of the objective function data on individual impact parameters. The dependencies of the number of routes of the garbage truck to the maximum allowable tire wear on the front and rear axles were obtained. The response surfaces of the target functions – the number of routes of the garbage truck to the maximum permissible wear of the tires on the front and rear axles and its two-dimensional sections in the planes of the influence parameters, which allow to visually illustrate the specified dependencies, are obtained. The expediency of conducting further research on the influence of speed, unevenness of the road surface, weather conditions and other factors on the wear of garbage truck tires has been revealed.","PeriodicalId":34638,"journal":{"name":"Problemi tribologii","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43299701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal and stress-strain state of friction pairs in ventilated disc brakes of lightweight vehicles","authors":"O. Dykha, K. Holenko, J. Padgurskas, O. Babak","doi":"10.31891/2079-1372-2023-107-1-41-50","DOIUrl":"https://doi.org/10.31891/2079-1372-2023-107-1-41-50","url":null,"abstract":"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 brakes","PeriodicalId":34638,"journal":{"name":"Problemi tribologii","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49626950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}