{"title":"Theoretical Substantiation of the Initiation and Direction of Crack Development under Impact Loading of the Elastomer Surface by Solid Particles","authors":"V. G. Kopchenkov","doi":"10.3103/S1068366623010063","DOIUrl":"10.3103/S1068366623010063","url":null,"abstract":"<p>A theoretical model of the formation of the stress-strain state in elastomers under the action of a concentrated load is considered. Experimental studies were carried out using the polarization-optical method. As a sample, transparent L-83 polyurethane with physical and mechanical characteristics corresponding to typical rubbers was used. It is shown that the stress-strain state of the surface layer calculated as a result of the theoretical solution of the mathematical model coincides with the experimental data. When loading, zones of compressive and tensile stresses are created. The magnitude of the tensile stress determines the likelihood of surface destruction (tearing). Simulation of an oblique impact confirmed the qualitative picture of the stress-strain state in elastomers under the action of a concentrated load. A theoretical study made it possible to establish that the potential energy of deformation is distributed over the depth of the surface layer in inverse proportion to the square of the distance from the point of application of the force, i.e., the point of contact of the solid particle with the surface of the elastomer. This makes it possible to mathematically calculate the level and distribution of energy dissipation in the wear volume of the surface layer. Theoretical and practical studies have shown that in the practical use of elastomer linings, it is recommended to install them at an angle close to 90° to the direction of solids flow.</p>","PeriodicalId":633,"journal":{"name":"Journal of Friction and Wear","volume":"44 1","pages":"58 - 62"},"PeriodicalIF":0.7,"publicationDate":"2023-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4863243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Synergism and Antagonism of Anti-Wear Additives as a Method of Confirming the Mechanism of Their Action","authors":"G. F. Pavelko","doi":"10.3103/S1068366623010099","DOIUrl":"10.3103/S1068366623010099","url":null,"abstract":"<div><div><h3>\u0000 <b>Abstract</b>—</h3><p>The effect of 2,2,6,6-tetramethylpiperidine (TMP), 2,6-di-<i>tert</i>-butyl-4-methylphenol (DTBMP), <i>para</i>-cumylphenol (PCP), 2,2,6,6-tetramethylpiperidine-1-oxyl (TMPO), and dicumyl peroxide (DCP) on the anti-wear properties of dodecanethiol (DdSH), didodecyl disulfide (Dd<sub>2</sub>S<sub>2</sub>), and dibutyl disulfide (Bu<sub>2</sub>S<sub>2</sub>) in a solution of purified Vaseline oil (PVO) has been investigated. The anti-wear properties of 23 two-component compositions of additives from 28 possible combinations were studied. A rule was proposed: synergy is when the effectiveness of a mixture of additives is greater than the average result of the sum of anti-wear efficiencies of each component separately, and antagonism is when the effectiveness of a mixture of additives is less than the average result of the sum of anti-wear efficiencies of each component separately. The practical significance of the proposed method for studying two-component additives is that it can be used to confirm or refute the mechanism of action of additives.</p></div></div>","PeriodicalId":633,"journal":{"name":"Journal of Friction and Wear","volume":"44 1","pages":"53 - 57"},"PeriodicalIF":0.7,"publicationDate":"2023-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4863876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. A. Polyakov, L. I. Kuksenova, E. M. Kuleshova, A. V. Medovshchikov
{"title":"Evaluation of Dynamic Parameters and Improvement of Wear Resistance of Involute Gears when Using Film-Forming Lubricants","authors":"S. A. Polyakov, L. I. Kuksenova, E. M. Kuleshova, A. V. Medovshchikov","doi":"10.3103/S1068366623010105","DOIUrl":"10.3103/S1068366623010105","url":null,"abstract":"<div><div><h3>\u0000 <b>Abstract</b>—</h3><p>The article describes the problems of existing methods for assessing the durability of involute gears (IGs) associated with determining the maximum permissible wear and predicting the occurrence of sudden failure. The relationship of dynamic indicators with wear processes in IGs is described, which makes it possible to predict resource limitation by the nature of the growth of the dynamic coefficient due to the increase in the probability of jamming. The results of the analysis of the amplitude-frequency response of the transmission by the fast Fourier transform method are presented, which allowed us not only to evaluate the dynamism of the transmission with different lubricants, but also to rank these materials by their extreme pressure action depending on the magnitude of the loading moment, at a given limit value of the dynamic coefficient. It is shown that as the antifriction properties of the lubricant increase, the growth of the dynamism coefficient decreases as the loading moment increases (when using a film-forming additive, the limiting value of the dynamism coefficient is reached at a loading torque of 2.47 N m, and in the case of using pure synthetic oil, the limiting value of the dynamism coefficient is reached at a loading torque of 2.39 N m), this in turn leads to an increase in the maximum permissible wear and to an increase in the resource according to the wear criterion (in the case of using synthetic oil with a film-forming additive, the IG resource is 10–11 times higher than in the case of using pure synthetic oil).The dependence of the amplitude of the torque oscillations on the high-speed shaft of the IG transmission on the type of lubricant is revealed. Analytical dependences of the dynamic coefficient on the load for different lubricants are obtained. The dependence of the wear limit on the type of lubricant is proposed. A new method of predicting the resource of an IG is proposed taking into account the growth of the dynamic coefficient.</p></div></div>","PeriodicalId":633,"journal":{"name":"Journal of Friction and Wear","volume":"44 1","pages":"47 - 52"},"PeriodicalIF":0.7,"publicationDate":"2023-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4863236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. D. Sidorov, V. A. Burakov, V. D. Zorin, A. S. D’yachkovskiy, E. Yu. Stepanov
{"title":"Refinement of Piston Friction Parameters in a Smooth Barrel","authors":"A. D. Sidorov, V. A. Burakov, V. D. Zorin, A. S. D’yachkovskiy, E. Yu. Stepanov","doi":"10.3103/S1068366623010130","DOIUrl":"10.3103/S1068366623010130","url":null,"abstract":"<div><div><h3>\u0000 <b>Abstract</b>—</h3><p>This article describes fine tuning of wear diagnostics of a laboratory smooth barrel with a length of 5 m and diameter of 30 mm during tests. The devices are developed for measurements of internal diameter and force of pulling a piston prototype through the entire barrel length. An analog–digital instrument for measurement of internal diameter allows one to detect and to measure defects of arbitrary deformed barrel. The dimensions of the sensors used in the device allow us to scale it up for measurements of barrel of both lower and higher diameter. The device of force measurements allows us to estimate the friction parameters before experiments to clarify the mathematical model of gas dynamic processes accompanying the shot and to adjust loading conditions, if necessary. It has been demonstrated that their use allows us to estimate wear and to diagnose the state of the barrel system. Significant broadening of bore on the side of the breech end of the barrel has been detected. There is a correlation of measured data from both instruments. A ballistic experiment has been carried out using the updated measuring and recording complex. On the basis of the results the friction parameters of the piston–barrel couple obtained before the experiments have been accounted in the mathematical model of gas dynamic processes. This has allowed us to reduce the number of matching parameters upon simulation and to perform more accurate analysis of gas dynamic processes accompanying a shot with plotting respective time dependences of piston pressure and speed as well as distribution of maximum gas temperatures and pressure along the barrel length. Thus, the coefficient of the law of gunpowder burning has increased by 10%.</p></div></div>","PeriodicalId":633,"journal":{"name":"Journal of Friction and Wear","volume":"44 1","pages":"30 - 33"},"PeriodicalIF":0.7,"publicationDate":"2023-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4863237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Tribotechnical Characteristics of Lubricant under Conditions of High Temperatures","authors":"O. Yu. Elagina, A. G. Buklakov, S. I. Dumansky","doi":"10.3103/S106836662301004X","DOIUrl":"10.3103/S106836662301004X","url":null,"abstract":"<p>This article discusses the issues of maintaining operability of hinged friction joints operating at 500°C. The object of study is the hinged joint of a pipe dryer operating contact loads in the friction joint up to 100 kN and operation temperatures in the range from 200 to 500°C. The studies have been performed with WOLFRAKOTE TOP FLUID high temperature lubricant comprised of solid lubricants suspended in base mineral oil. The experimental results of the lubricating composition upon heating in mold have demonstrated that burn up of the liquid component is intensified at 450°C being accompanied by transfer of lubricating medium into powdered form. Assessment of changes in tribological properties of high temperature lubricant in various aggregate states has demonstrated that heating and transfer of lubricant from liquid to solid state at low contact loads and velocities does not impair its tribotechnical properties. However, the increase in load and velocity parameters causes sharp increase in friction forces with the use of lubricating medium in powdered form. Based on the performed studies recommendations are presented aimed at improving the operability of hinged joints operating at higher temperatures.</p>","PeriodicalId":633,"journal":{"name":"Journal of Friction and Wear","volume":"44 1","pages":"42 - 46"},"PeriodicalIF":0.7,"publicationDate":"2023-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5165673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Influence of the Fiber Bedding Direction on the Fiber Composite Wear","authors":"A. G. Shpenev, P. O. Bukovskiy","doi":"10.3103/S1068366623010129","DOIUrl":"10.3103/S1068366623010129","url":null,"abstract":"<div><div><h3>\u0000 <b>Abstract</b>—</h3><p>The fibrous composite wear rate dependence on the angle between the sliding direction and the direction of the fibers on the friction surface, when fibers in the material are parallel to the friction surface was studied. For this purpose, an experiment was carried out on the wear of a composite material sample based on carbon fiber and a carbon matrix in the form of a disc with a ring-shaped counterbody made of silicon carbide ceramics. The structure of the composite made of carbon twill weave forms on the friction surface areas with fibers oriented parallel to each other and the surface of the material. Setting up the experiment according to the “ring–disk” scheme allows one to obtain a different angle between the direction of the fibers and the direction of sliding in one test. Based on the results of the friction surface relief study after the tests, the relative wear rate of the surface areas, which are characterized by different directions of the fibers, is determined. It was found that areas with fibers directed at an acute angle to the friction direction have greater wear resistance, and fibers located at a right angle to the direction of sliding are more susceptible to destruction during wear. A wear process model of an individual fiber up to its complete destruction is constructed. A phenomenological criterion for the destruction of an individual fiber is proposed, which makes it possible to estimate the effect of the angle between the direction of the fiber and the direction of sliding on the destruction of the fiber. An algorithm for determining the coefficients included in the proposed wear model, based on a limited number of tribological tests, is proposed.</p></div></div>","PeriodicalId":633,"journal":{"name":"Journal of Friction and Wear","volume":"44 1","pages":"23 - 29"},"PeriodicalIF":0.7,"publicationDate":"2023-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4864637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Electrokinetic Phenomena in Near Surface Layers of Metal Polymer Friction Elements","authors":"A. Kh. Janahmadov","doi":"10.3103/S1068366622060058","DOIUrl":"10.3103/S1068366622060058","url":null,"abstract":"<div><div><h3>\u0000 <b>Abstract</b>—</h3><p>This article discusses the near surface layers of polymer lining of a spot-type disk brake and proposes the algorithm of nonequilibrium thermodynamics, which contains thermal conductivity and electrokinetic phenomena in near surface layers of polymer lining. The possibility of application of nonequilibrium dynamics with linear regimes in tribocouplings of friction devices has been substantiated and the electrokinetic effect has been revealed. It has been demonstrated that due to the cross effect with temperature gradients there exist two equilibrium states for metal friction elements: steady state surface temperature and thermal stabilization state. For the polymer lining the equilibrium state is understood as burnout of binding components from its near surface layer with formation of fluid islands. The relations of parameters have been formed equaling the Onsager and Saxen relations, which allows one to determine the parameters by calculations. The electrokinetic effect can be used for removal of moisture from the friction surface of brakes, thus providing stability of the friction coefficient.</p></div></div>","PeriodicalId":633,"journal":{"name":"Journal of Friction and Wear","volume":"43 6","pages":"410 - 415"},"PeriodicalIF":0.7,"publicationDate":"2023-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4545435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. V. Prozhega, E. O. Reschikov, E. O. Konstantinov, M. M. Kharkov, F. A. Grigoriev
{"title":"Tribological Properties of Antifriction Molybdenum Disulfide Coatings under Extreme Conditions","authors":"M. V. Prozhega, E. O. Reschikov, E. O. Konstantinov, M. M. Kharkov, F. A. Grigoriev","doi":"10.3103/S1068366622060125","DOIUrl":"10.3103/S1068366622060125","url":null,"abstract":"<p>The tribological properties under extreme conditions, structure, and chemical composition of antifriction coatings based on molybdenum disulfide deposited by magnetron deposition and suspension spraying with various types of a film former onto the surface of samples made of 12Kh18N10T stainless steel are studied. Tribological reciprocating movement tests in accordance with the ASTM G133 standard are carried out under reciprocating movement of a ball made of ShKh15 steel with a diameter of 6.35 mm in vacuum at the temperature of the samples of 250°C. The coefficient of friction and lifetime of the coatings under extreme operating conditions are determined. Suspension deposited coatings show a coefficient of friction of 0.046–0.049, and the magnetron deposited coating of 0.061. The maximum service life of the suspension deposited coatings is 19.7–21.8 h, and of the magnetron deposited coating, 22.7 h.</p>","PeriodicalId":633,"journal":{"name":"Journal of Friction and Wear","volume":"43 6","pages":"423 - 430"},"PeriodicalIF":0.7,"publicationDate":"2023-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4545440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. G. Meliksetyan, N. K. Myshkin, S. G. Agbalyan, G. N. Meliksetyan
{"title":"Friction and Wear of Asbestos-Free Brake Friction Materials","authors":"N. G. Meliksetyan, N. K. Myshkin, S. G. Agbalyan, G. N. Meliksetyan","doi":"10.3103/S1068366622060101","DOIUrl":"10.3103/S1068366622060101","url":null,"abstract":"<p>The results of tribological studies of various asbestos-free brake friction materials from leading manufacturers are presented. Two main aspects of the effect of the thermal conditions on the friction and wear characteristics of the selected materials are established: a change in the physical and mechanical properties at a low thermal load of the friction contact and changes due to various structural transformations and mechanochemical processes of the surface layers at a high thermal load of the friction contact. It is shown that high-temperature friction of frictional asbestos-free polymeric materials proceeds in a multistage mode, accompanied by pyrolysis of volatile products, binder destruction, degradation of the reinforcing element, and carbonization of the friction surface, which are constant factors. The materials under study are capable of forming a frictional transfer film on the counterbody friction surface in the form of a monolithic layer or separate transferred fragments oriented along the sliding direction. The developed materials form a film on the counterbody surface at relatively high temperatures, in the region of maximum friction values. It is established that the mechanism of high-temperature destruction of the surface layers of asbestos-free brake friction materials is characterized by the accumulation of damage in the subsurface layer and the wear process is most fully explained by fatigue peeling.</p>","PeriodicalId":633,"journal":{"name":"Journal of Friction and Wear","volume":"43 6","pages":"416 - 422"},"PeriodicalIF":0.7,"publicationDate":"2023-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4549304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Tapered Roller Bearing Rib-Roller End Interaction at Hydrodynamic Contact","authors":"I. M. Klebanov, A. M. Brazhnikova, K. A. Polyakov","doi":"10.3103/S106836662206006X","DOIUrl":"10.3103/S106836662206006X","url":null,"abstract":"<div><div><h3>\u0000 <b>Abstract</b>—</h3><p>Wear of the contact surfaces is an important characteristic of rib-roller end interaction of roller bearings. The purpose of this study was to develop effective methods for calculating the wear rate of these surfaces under alternating dynamic loads. In wear rate calculations of bearing parts, as a rule, Archard’s law is used since it has been verified in hydrodynamic friction testing of bearing steels. In the paper, based on this law, a direct step-by-step wear rate calculation method for rib-roller end contact at variable loads and sliding speeds is developed. According to it, normal force, sliding velocity, and contact oil film thickness are determined in bearing dynamic modeling, and the finite element method is used to calculate contact pressure fields. A multi-mass bearing dynamic model includes a contact friction model, which allows an adequate description of hydrodynamic contact behavior of solid bodies. Using the bearing life dependence on the oil film parameter and experimentally measured steel bearing wear rates, the dependence of wear coefficient on the oil film parameter is obtained. The direct calculation method involves many computations, which makes the influence of individual factors on wear rate non-obvious. In this regard, a method of wear rate calculation with averaged parameters is also proposed. Using these two methods, rib-roller end wear calculations for a double-row tapered roller bearing are implemented. The spherical shape of the roller end and conical, toroidal convex, and concave shapes of the rib are considered. Comparison of wear rates obtained by the two methods confirms the acceptable accuracy of calculations with averaged parameters. The results in particular demonstrate that a toroidal concave rib surface allows reducing the wear rate up to three times in comparison with the tapered surface.</p></div></div>","PeriodicalId":633,"journal":{"name":"Journal of Friction and Wear","volume":"43 6","pages":"391 - 397"},"PeriodicalIF":0.7,"publicationDate":"2023-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4548948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}