Problemi tribologii最新文献

{"title":"Study of frictional properties, long-term (cyclic) strength of materials of brake pads of motor vehicles","authors":"V. Makarenko, O. Kliuiev, O. Voitovych, Yu.Ye. Mieshkov, Yulia Makarenko","doi":"10.31891/2079-1372-2023-107-1-13-19","DOIUrl":"https://doi.org/10.31891/2079-1372-2023-107-1-13-19","url":null,"abstract":"Fractogram analysis shows that deep scratches, particles of titanium and chromium carbides and other elements were found on the friction surfaces. Moreover, in the braking devices there was damage to the large size of the brake pads of trucks. The transfer of particles of borides and carbides to the surface of the wheels can be explained by the processes of metal flooding with their subsequent embrittlement, which inevitably leads, as a rule, to the destruction of friction wheel pairs. It is established that such types of wear as fretting corrosion significantly (by 1.5-2 times) reduce the fatigue limit of parts. Also significantly reduce the cyclic strength of metal friction pairs oxide films on their surface in the absence of lubricant. The service life of friction wheel pairs has a particularly strong impact on fatigue strength. The main reason for the decrease in endurance due to the processes of setting on the working surfaces of friction units is a high concentration of stresses caused by deep tears, cuts, microcracks. The process of destruction of brake pads from fatigue begins from the surface of the part. In this regard, the quality of the surface, its structural-phase composition, physical and mechanical properties of the surface layer in most cases are decisive for the intensity of the development of wear processes of parts from fatigue of the tribosystem (friction wheel pairs), which are operated under cyclic loads. The peculiarity of the influence of friction and wear processes on the fatigue strength of metal is that at the time of running-in there is a change in surface roughness, structure and properties of surface layers. As the analysis of literature sources has shown, the effectiveness of the influence of friction and wear processes on the characteristics of fatigue resistance in the case of repeatedly alternating (cyclic) loads is essential, and therefore ignoring this effect during the traditional assessment of the reliability of parts by individual criteria, for example, wear resistance, often leads to an incorrect assessment of the operational durability of the elements of the tribological system of road or rail transport. The long-term (cyclic) strength of brake pads was determined on a specialized unit model 1251 by Instron company (Great Britain). The basis for spraying and surfacing of different types of coatings was normalized steel 35. Tensile-compressive deformations at zero average stress and a cycle frequency of 20 Hz were studied on the laboratory unit. Most of the tests were carried out in salt solutions (NaCℓ of industrial purity was used).The process of destruction of brake pads from fatigue begins with the surface of the part. In this regard, the quality of the surface, its structural-phase composition, physical and mechanical properties of the surface layer in most cases are decisive for the intensity of the development of wear processes of parts from fatigue of the tribosystem (friction wheel pairs), which a","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":"48384576","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":"Tribomonitoring of the quality of aviation hydraulic oils according to lubricity and rheological indicators","authors":"O. Ilina, O. O. Mikosianchyk, O. Yashchuk, R.H. Mnatsakanov, N.M. Berezivskyi","doi":"10.31891/2079-1372-2023-107-1-34-40","DOIUrl":"https://doi.org/10.31891/2079-1372-2023-107-1-34-40","url":null,"abstract":"The study proposes a diagnostic control method for assessing the quality of commercial batches of hydraulic oils based on the kinetics of changes in the thickness of lubricating layers, shear stresses of the lubricating material, and effective viscosity in tribotechnical contact. Timely and high-quality tribomonitoring of lubricants provides a perspective on their rational use and reduced wear of equipment parts. The developed methodology simulates the operation of gears in rolling conditions with a slip of 30% using a roller analogy. Samples of AMG-10 oil from two manufacturers were analyzed. For \"Bora B\" AMG-10 oil (sample 1) with gradients of the sliding speed of the lubricating layer in contact from 5.63·103 to 5.73·105 с-1, the effective viscosity is set at the level of 4249 and 5039 Pa·s at a bulk oil temperature of 20 and 100 oС, respectively, which indicates the resistance of oil components to destruction under conditions of increasing shear rate gradient. For AMG-10 oil (sample 2), the effective contact viscosity decreases by 1.53 times both at an oil temperature of 20 oС and at 100 oС and is 2764 Pa·s (at 20 oС) and 3309 Pa·s (at 100 oС), which indicates the destruction of the components of the lubricant. For \"Bora B\" AMG-10 oil, effective lubricating properties have been established both during the start-up period and at maximum revolutions in conditions of rolling with slipping. It was shown that at start-up, regardless of the temperature of the lubricant, the mixed lubrication mode dominates. At the maximum revolutions of the tested samples, the hydrodynamic lubrication mode dominates, which indicates the effective lubricating properties of the Bora B AMG-10 oil. According to the kinetics of changes in the rheological parameters of oils, it was established that the resistance of the lubricant's components to mechano-thermal destruction under non-stationary lubrication conditions contributes to the effective formation of a lubricating layer in contact with a high bearing capacity","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":"42167239","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 of structural steels nitrided in a cyclically switched discharge with dry friction","authors":"M. Stechyshyn, M. Skyba, A. Martynyuk, D.V. Zdorenko","doi":"10.31891/2079-1372-2023-107-1-20-24","DOIUrl":"https://doi.org/10.31891/2079-1372-2023-107-1-20-24","url":null,"abstract":"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. \u0000Unlike 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. \u0000According to the results of previous experiments, such a compromise pressure value can be 16 MPa. \u0000Another 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. \u0000For 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.","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":"42288827","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":"The regularity of the change in the coefficient of friction of the coupling of \"shaft-sleeve\" parts using polymeric materials","authors":"V. Aulin, S. Lysenko, A. Hrynkiv, A. Tykhyi, O. Kuzyk, O. Livitskyi","doi":"10.31891/2079-1372-2023-107-1-81-91","DOIUrl":"https://doi.org/10.31891/2079-1372-2023-107-1-81-91","url":null,"abstract":"For the conjugation of samples and parts of the \"shaft-sleeve\" type, from the theoretical and experimental points of view, the laws of the change of the coefficient of friction for the combined polymer-metal material and coating were considered. Based on the law of energy conservation and transformation in the friction zone, expressions for estimating friction coefficients for polymer coatings and combined polymer-metal materials were obtained, taking into account the properties of thermal conductivity and elasticity and the geometric dimensions of the polymer and metal components. The consistency of the patterns of change in the friction coefficient has been clarified in tribocouplings of samples and parts from load and sliding speed in modes without lubrication and at extreme friction. To substantiate the effective operation of tribocoupling of parts made of combined polymer-metal materials, a criterion was introduced - the coefficient of wear, which is used to evaluate the tribological efficiency. It is shown that the obtained experimental results do not contradict the theoretical justification","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":"48603523","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":"Optimization of the technology for applying discrete coatings in restoration of bronze parts by electrospark alloying","authors":"E. Solovykh, I. Shepelenko, M. Chernovol, S. Mahopets, A.E. Solovuch, S. Katerynych","doi":"10.31891/2079-1372-2023-107-1-51-58","DOIUrl":"https://doi.org/10.31891/2079-1372-2023-107-1-51-58","url":null,"abstract":"In this work, a multicriteria optimization of the technology for applying discrete coatings by electrospark alloying in the restoration of bronze parts is carried out. As criteria for optimizing the process of electrospark alloying, tribotechnical characteristics were chosen – the wear intensity and friction coefficient of the coating. As adjustable parameters, those design, technological and operational factors that have the greatest influence on the value of optimization criteria are used: coating material; lubricant; operating current; amplitude of electrode oscillations; sliding speed; specific load. As a result of experimental studies, experimental dependences of wear intensity and friction coefficient for various coating materials, sliding speeds and lubrication conditions were obtained. The use of multicriteria optimization of the electrospark alloying technology made it possible to obtain various alternative coating options and technological parameters of their application for various operating conditions. Of the studied coatings, the most effective is a two-layer coating with the first layer SP-2 and an outer layer of the base material bronze BrAZhMts 10-3-1.5, which is explained by the formation of wear-resistant areas based on Mn and Ni. Multiparametric optimization of the electrospark alloying technology made it possible to reveal a combination of structural and technological factors that ensure the formation of discrete coatings with high operational properties in the restoration of bronze parts.","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":"44994934","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 1. Development of a mathematical model","authors":"A. Voitov","doi":"10.31891/2079-1372-2022-107-1-25-33","DOIUrl":"https://doi.org/10.31891/2079-1372-2022-107-1-25-33","url":null,"abstract":"The paper further developed the methodological approach in obtaining mathematical models that describe the running-in of tribosystems under boundary lubrication conditions.The structural and parametric identification of the tribosystem as an object of simulation of running-in under conditions of extreme lubrication was carried out. It has been established that the processes of running-in of tribosystems are described by a second-order differential equation and, unlike the known ones, take into account the limit of loss of stability (robustness reserve) of tribosystems. It is shown that the nature of tribosystems running-in conditions of extreme lubrication depends on the gain coefficients and time constants, which are included in the right-hand side of the differential equation. It is shown that the processes of running-in of tribosystems depend on the type of the magnitude of the input influence on the tribosystem, the first and second derivatives. The input influence is represented as a product of coefficients and a time constant К0·К2·Т3. This allows us to state that the processes of the tribosystem running-in will effectively take place when the input action (load and sliding speed), will change in time and have fluctuations with positive and negative acceleration of these values from the set (program) value. This requirement corresponds to the running-in program \"at the border of seizing\".The left part of the equation is the response of the tribosystem to the input signal. Tribosystem time constants Т2 and Т3  have the dimension of time and characterize the inertia of the processes occurring in the tribosystem during running-in. Increasing the time constants makes the process less sensitive to changes in the input signal, the warm-up process increases in time, and the tribosystem becomes insensitive to small changes in load and sliding speed. Conversely, the reduction of time constants makes the tribosystem sensitive to any external changes","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":"44305796","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":"The influence of alloying with manganese and chromium of steel hardened and tempered auger on its relative wear resistance during dehydration in a municipal solid waste truck","authors":"O. Bereziuk, V. Savulyak, V. Kharzhevskyi","doi":"10.31891/2079-1372-2022-106-4-51-57","DOIUrl":"https://doi.org/10.31891/2079-1372-2022-106-4-51-57","url":null,"abstract":"The article is dedicated to the study of the influence of alloying with manganese and chromium followed by hardening and tempering of the auger on its wear resistance during the dehydration of municipal solid waste truck. The use of a mathematical apparatus and appropriate regression analysis programs made it possible to determine the dependence of the wear resistance of the auger on the content of manganese and chromium in the steel of the auger for the case of its quenching and tempering. Constructed graphical dependences of relative wear resistance with the indicated alloying and heat treatment of the screw revealed a significant influence of the concentration of manganese and chromium in steel, sufficient convergence of the obtained patterns was confirmed. It was established that after operation and wear on the path s = 56850 m during the dehydration of solid waste in a garbage truck, an increase in the manganese content in the steel of the heat-treated screw from 0.32% to 1.8% leads to a decrease in energy intensity by 10 kWh/tons, and an increase chromium content in screw steel after similar heat treatment from 0% to 6% leads to a decrease in energy consumption by 11.5 kWh/tons and to a reduction in the cost of the solid waste dehydration process in the garbage truck. It was determined that tempering the chromium-manganese screw steel after its hardening allows reducing energy consumption by 1.26...2.56 kWh/tons, depending on the chromium content. The expediency of conducting further research on determining the rational composition and structural state of the auger material and ways to increase its wear resistance has been revealed","PeriodicalId":34638,"journal":{"name":"Problemi tribologii","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42400583","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":"Effect of fullerene-like nanoparticles on the tribological properties of industrial lubricants for steel rolling","authors":"I.M. Kartun, O. Remez, O. Haidai, O. Spaska, O. Yanchenko, V. S. Pyliavsky, Y. Polunkin","doi":"10.31891/2079-1372-2022-106-4-45-50","DOIUrl":"https://doi.org/10.31891/2079-1372-2022-106-4-45-50","url":null,"abstract":"The paper shows the results of studying the possibility of using fullerene-like nanoparticles as a lubricating additive in the composition of technological lubricant MT-216 M. The lubricity properties were evaluated on a laboratory rolling mill DUO-180 during cold rolling of strips of steel 08kp. The rolling force, the coefficient of friction in the deformation zone were measured, the values of the elongation coefficient and the parameter reflecting the costs of the rolling force per unit deformation of the metal were calculated","PeriodicalId":34638,"journal":{"name":"Problemi tribologii","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42113139","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":"Theory and experiment of tribological test methods","authors":"O. Dykha, A. Staryi, M. Getman, V. Fasolia","doi":"10.31891/2079-1372-2022-106-4-27-38","DOIUrl":"https://doi.org/10.31891/2079-1372-2022-106-4-27-38","url":null,"abstract":"Based on the analysis of the current state of test methods for wear of friction pairs and the need for methods with certain operating conditions, the problem of developing a theory of test methods for wear of friction pairs according to the ball-cylinder scheme was solved, which makes it possible to determine the parameters of wear models and the general characteristics of the wear resistance of materials. It is shown that the type of wear within the range of properties of the friction pair parameters ensures compliance with the basic conditions in contact: materials, lubrication, pressure, speed, temperature, type of movement, and other less significant factors. It has been established that one of the fundamental issues in the development and conduct of wear tests is to take into account the influence of the stationarity of the wear mode at a point. Test methods in steady and unsteady modes (transient mode) are different. The test method should be based on the solution of the contact problem for a friction pair sample-counter-sample. Based on the solution of wear-contact problem for the \"ball-cylinder\" scheme, a theory has been developed for identifying the parameters of the wear pattern. To solve the inverse problem, a method of approximating function is proposed and implemented. The power approximation of the experimental function after substitution into the resolving equation gives simple expressions for calculating the model parameters. The results obtained make it possible to predict the intensity of wear of tribocouples under given initial operating conditions: according to loads, sliding speed, characteristics of lubricants and structural materials.","PeriodicalId":34638,"journal":{"name":"Problemi tribologii","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45632410","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":"Nanostructural glasscomposite self-lubricant coatings","authors":"N. Fialko, V. Shchepetov, S. Kharchenko, S.I. Kovtun, Ya. N. Hladkyi, S. Bys","doi":"10.31891/2079-1372-2022-106-4-6-12","DOIUrl":"https://doi.org/10.31891/2079-1372-2022-106-4-6-12","url":null,"abstract":"The results of the study of glass-composite nanostructured self-lubricating coatings are presented. The structural components of these coatings significantly affect the graphitization process and provide an antifriction surface layer of α-graphite. The formation of this layer makes it possible to significantly minimize the contact parameters in the friction region. \u0000A significant effect of aluminoborosilicate in the form of a glass phase on the tribological properties of coatings is noted. An increase in adhesive strength is achieved by forming a surface layer of glassy sodium silicate. The presence of near-surface particles in the graphite layer does not affect the tribotechnical characteristics of the coatings. The developed glass-composite nanostructured self-lubricating coatings have high antifriction characteristics throughout the entire load-speed range","PeriodicalId":34638,"journal":{"name":"Problemi tribologii","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43721332","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}