Search

Metal-polymer composite materials were tested at ambient temperatures of 20 and 60 °C. The most modern composite wear-resistant materials used in mechanisms as sliding bearings were used. The relevance of the tests is determined by the application of worldwide trends to mechanisms without maintenance for the entire life cycle. The influence of temperature on the wear resistance of metal-polymer composite materials that can be used in aviation spherical plane bearings is determined. It was determined that heat generation caused by both the friction process and dynamic load as a result of reverse motion has the greatest influence on the wear intensity. Increasing the test temperature affects polymer composite materials to a greater extent than metal-polymer tape. At this stage, a significant role in wear resistance is played with the ability of the material to dissipate heat, which occurs in the contact zone from reversible sliding. It has also been established that the carbon fabric of the Fluroglide material can withstand higher temperatures than the babbitt of the metal-polymer tape. A key role in the durability of spherical plane bearings that work in non-standard temperatures will be played by the composite materials design selection and the polymer materials themselves for specific operating conditions [ABSTRACT FROM AUTHOR]

The analysis of the defects of parts of the friction units of aviation equipment under the conditions of abrasive wear was carried out. Types of electrode materials for modification of parts by electrospark alloying are considered. The mechanisms of wear under the influence of free abrasive of electrospark coatings of 1.1645 and 1.3355 steels, HG30 alloy and ZLAB-1 ceramics on structural steels 30HGSA and 45 were analyzed. The dependence of the intensity of wear of electrospark coatings on the hardness of carbides and borides and the ratio of the strengthening phase in the matrix was determined. The low wear resistance of the ceramic coating ZLAB-1 is due to the presence of the boride component ZrB2 of increased microhardness in the matrix phase, which leads to the brittleness of the coating. The predominance of brittle fracture of ESC of 1.1645 steel is caused by the presence of iron carbide up to 16% in the structure of secondary cementite and pearlite of the steel. The increase in wear resistance of ESC made of 1.3355steel is due to the presence of a large amount of W, V and Mo carbides. The phase inhomogeneity of ESC made of HG30 alloy, established by X- ray structural and phase analysis of the coating diffractograms and the activation of oxidation processes during friction lead to an increase in the wear resistance of ESC due to the appearance of W2C tungsten semi-carbide and WC1-x tungsten semi-carbide phases. The obtained results indicate the prospects of ESC made of 1.3355 steel and HG30 alloy with the necessary level of properties to increase the wear resistance of structural steels. [ABSTRACT FROM AUTHOR]

The object of the study is the process of changing tribological efficiency according to tribotechnical characteristics (wear intensity, friction coefficient, temperature in the contact zone) of composites based on phenylone C-1 and polyamide PA-6 with arimide-T filler and fullerene C-60. The study solved the problem of obtaining composites with high wear resistance. Based on the results of research, it was found that varying the content of arimide-T makes it possible to obtain composites with different patterns of changes in tribotechnical characteristics under conditions of dry friction, lubrication with water and I-50 oil. Composites with the composition: phenylone C-1+15 wt. have the maximum tribological efficiency. % arimide-T+3 wt. % fullerene C-60 and polyamide PA-6+30 wt. % arimide-T+3 wt. % fullerene C-60. Phenylone C-1 has destructive properties when working in the environment of water and temperature in the friction zone. Its reinforcement with arimide-T and fullerene C60 gave positive results of a complex of tribotechnical characteristics under these conditions. It was found that the wear of composites based on phenylone C-1 in I-50 oil is two orders of magnitude lower than in water. Research of samples from the obtained composites based on phenylone C-1 and polyamide PA-6, reinforced with the optimal content of arimide-T and fullerene C60, showed that their wear resistance when lubricated with oil is 3.5...4.0 times greater than the wear resistance of bronze. An applied aspect of the reported results is the introduction of manufacturing technologies and restoration of machine parts from the proposed composites. It has been proven that their optimal composition contributes to high tribological efficiency and could provide the required level of wear resistance and reliability of resource-determining nodes, systems, and machine assemblies. The results could be used by machine-building and repair-technological enterprises [ABSTRACT FROM AUTHOR]

The use of polymer composite materials allows significantly reduce the labor intensity of manufacturing friction unit parts due to high-performance and economical resources. According to the definition, a composite material consists of one or more continuous phases of a homogeneous matrix with one or more dispersive phases. In this regard, the reliable operation of metal-polymer tribosystems primarily depends on the structural and morphological factor influencing the tribomechanical characteristics of materials. The principle of producing composite materials consists of a pre-created combination of two different phases (fillers and matrix) using certain technological techniques. As a result of filling, materials are obtained whose physical and mechanical properties differ from the matrix. The choice of fillers for metal-polymer materials depends on the purpose of the material, the need to change some tribomechanical characteristics and the type of polymer matrix. Plain spherical bearings with metal-polymer tribosystems are very popular in the aviation industry. They are made from stainless and corrosion-resistant steels and do not require maintenance. Compacts have an extremely high payload-to-weight ratio and are used in primary and secondary flight control systems. They have a hinged type design. The work identifies modern antifriction composite materials for use in plain spherical bearings. The structures and wear resistance characteristics of polymer materials under special operating conditions - vibration, reverse movements - have been determined. It has been established that the design of the composite material is of paramount importance under increased loads in low-frequency vibration tests. It has been determined that the Fluroglide material, consisting of carbon fibers with the addition of PTFE material with functional additives, shows high tribological characteristics comparable to classic metal fluoroplastic tape. At extreme loads of metal-polymer composite materials, a key role is played by relaxation processes and the ability of the base of the composite material to restrain polymer materials and fillers from crushing and from the action of reverse movements. Under these critical operating conditions, Fluroglide exhibits superior wear resistance to metal fluoroplastic tape. [ABSTRACT FROM AUTHOR]

The issues of ensuring the durability and reliability of equipment, increasing wear resistance and expanding the range of operation of friction pairs in extreme operating conditions require solutions related to innovative technologies for the formation of wearresistant surfaces that can significantly increase the efficiency of using hardening methods, creating new ones and improving existing ones. A brief review of the combined methods of engineering contact surfaces of tribological systems is carried out. The perspective of using this direction to expand the range of use of discrete protective structures, namely in the conditions of fretting, fretting fatigue, and limit friction, is shown. [ABSTRACT FROM AUTHOR]

The fretting corrosion machine has been modernized for testing spherical bearings under vibration conditions. The method of research of anti-friction composite materials and coatings for low-frequency reversible movements has been developed. A method for laboratory resource tests of aviation spherical sliding bearings with metal-polymer composite materials in conditions close to real has been developed. [ABSTRACT FROM AUTHOR]

The analyzed properties of polymer materials related to wear resistance and vibration absorption capabilities, utilized in the production of sliding pairs, have been explored. The perspective of employing polymer-metal friction pairs in industrial machinery, pharmaceuticals, and the food industry has been substantiated. To effectively control any mechanical system with sliding motion under optimal parameters, indicating tribological characteristics for materials in frictional contact is a convenient means for swiftly characterizing tribological behavior when operating conditions are variable. Through experimental investigation, factors influencing the wear of polymer specimens in contact with metal have been analyzed. The materials subjected to tribological analysis are polymer materials such as Sustamid 66 gray, Sustapei, and SusTamid 6G OL, manufactured by the Röchling Group, in contact with steel 30KhGSA. All selected polymer materials are designed for use in pairs with sliding contact. [ABSTRACT FROM AUTHOR]

The article discusses the issue of antiwear properties of traditional and alternative diesel fuels. The main goal of this work was the theoretical and experimental studies on the effect of alternative biodiesel fuels (on a plant basis) on the change in the antiwear properties of traditional diesel fuels. Also, the goal was to study the effect of the magnetic field on the antiwear properties of diesel and alternative diesel fuels. Experimental studies have been conducted for the antiwear properties of traditional and alternative diesel fuels based on biocomponents obtained from rye oil. The studies showed that the addition of methyl esters of fatty acids of rye oil led to an increase in the amount of wear by 1.8 (10% esters) and 2.2 (20% esters) for the diesel samples and their mixtures with biocomponents, respectively. During the treatment of fuels with a magnetic field of 0.1 T and 0.4 T, it was established that the amount of wear is 1.2 and 1.5 times (10% esters, a magnetic field of 0.1 T and 0.4 T, respectively); 2.2 and 1.15 times (20% esters, magnetic field of 0.1 T and 0.4 T, respectively) times, respectively. It was established that the treatment with a magnetic field stabilizes the antiwear properties of diesel fuels in the case of addition a biological component to them. The results of studies can be applied in the chemical industry, the transport industry, in particular, in the operation of diesel vehicles. The article results can be useful to tribologists, chemical experts, as well as scientists involved in the development and implementation of alternative engine fuels. [ABSTRACT FROM AUTHOR]

The reasons for the destruction of parts of the friction units of aircraft and ground aviation equipment, which are made of iron-based alloys, were analyzed, and it was established that during operation, various processes develop on their working surfaces, namely: abrasive wear, seizure, fretting - corrosion, fatigue wear. The analysis of modern technological methods of surface strengthening of machine parts was carried out, the prospects of electrospark alloying of iron-based alloys were determined. Research on the wear resistance of coatings was carried out using a complex methodology, which includes metallographic, electron microscopic, durometric, and other methods of analysis of physical and mechanical methods. The influence of electrode materials on the wear resistance of ESD coatings has been established. Practical recommendations for surface strengthening of parts of automatic transmission systems operating under conditions of abrasive wear are indicated. [ABSTRACT FROM AUTHOR]

Analysis of methods and installations for assessment of wear and research of tribometric parameters of various materials was carried out. The purpose of the work is to create a tribometric machine and a method of testing the anti-friction and anti-wear properties of polymers and composite materials. That includestemperature registration in frictional contact and in the nearsurface layers of triboelements. The main structural diagram of the installation of the tribometric machine, developed at the National Aviation University, is presented. The main characteristics of the installation, the method of testing samples and the parameters of work related to the relevant research of polymer materials and composites based on them are provided. The standardized method specified in ISO 7148-2:2012 is used when testing materials. The proposed elliptical contact form of the triboelements ensures the constancy of the contact load during the experiment. The installation is equipped with a sensor system that allows you to control the speed of rotation and the moment of friction. The rotation speed is measured using a Hall sensor. The system of thermoresistive sensors provides monitoring of environmental conditions and temperature of testing objects. The developed installation can be used for express testing of materials for tribotechnical purposes, which provides an opportunity to develop more effective tribological solutions regarding the structural adjustment of tribo-coupling elements. [ABSTRACT FROM AUTHOR]

The article considers the efficiency of applying electric spark coatings with the aim of studying the effective influence on the tribological properties of eutectic alloys. Friction and wear tests of electrospark coatings made of the developed eutectic alloy on a steel substrate were performed. In order to compare the effectiveness of the influence on the tribotechnical properties of eutectic alloys, both the coatings in the initial state and the coatings annealed under two different modes were tested. Based on the results of the study of the chemical composition of the films formed in the process of friction, regularities were established by qualitative assessment. The dependences of tribotechnical properties for the initial and heat-treated coatings were determined. These studies indicate the feasibility of using electrospark coatings for different friction conditions. [ABSTRACT FROM AUTHOR]

The analysis of antifriction and antiwear additives to lubricants has been carried out and the mechanisms of formation of protective films on tribocombination elements have been considered. An increase in the antifriction and antiwear characteristics of lubricants due to their additional modification with graphite, molybdenum disulfide, fullerenes, nanotubes or a repair composition has been established. The mechanism for increasing the efficiency of lubricants with friction modifiers is to create a protective surface layer in the process of tribosystem self-organization during friction. It has been established that by empirical analysis it is possible to choose the optimal concentration of the repair and restoration compound RVS, the addition of which to the gear oil provides an increase wear resistance of steel under rolling conditions with slippage. Reducing the wear of contact surfaces is facilitated by mechanical chemical processes that manifest themselves during structural adaptability of finely dispersed components of the geomodifier friction RVS, boundary lubricating films and metal surface layers at friction under dynamic loading conditions. For the main indicators providing an increase in the wear resistance of friction pairs are microhardness of metal surface layers and its gradient depth distribution, microgeometry of the surface layer, formed during friction, and the formation of boundary lubricating layers on friction-activated contact surfaces. These processes are a manifestation of structural adaptability structural materials under study, the consequence of which is qualitative and quantitative change in the microgeometry of surfaces friction. Fullerenes and nanotubes are elementary objects of nanotechnologies, on the basis of any possible macro-objects, which may be of practical importance, - materials and outbuildings. The potential of using these structures (especially nanotubes) exceeds potential of other nanostructures. [ABSTRACT FROM AUTHOR]

The mechanical and tribotechnical characteristics of polymer materials are analyzed and the possibility of their improvement by adding reinforcing substances is shown. For Teflon-based composite materials, no change in antifriction properties has been established under lubrication conditions, compared to friction conditions without lubrication, the friction coefficient is reduced by only 1-3%. Effective fillers of polymer materials include carbon fibers, MoS2., graphite, graphene, SiO2, etc. It was analyzed that the addition of silicon carbide to polyvinyl chloride increases the anti-friction characteristics, heat resistance and dielectric properties of the polymer. Antifriction materials based on polyvinyl chloride have a relatively low coefficient of friction, but it can be improved if silicon carbide is dispersed on the surface of the polymer. It is substantiated that knowledge of the mechanical and tribotechnical characteristics of interacting tribomaterials is necessary for their selection from the point of view of the safety and efficiency of sliding bearings in the machine-building industry. [ABSTRACT FROM AUTHOR]

High-velocity air-fuel (HVAF) spraying and detonation spraying (DS) methods are used to produce the Al-Cu-Fe-Sc coatings from a water-atomized powder on a low-carbon steel (Q235/SS330) substrate. X-ray diffraction phase analysis shows that the protective AlCuFeSc coatings produced by these methods contain different volume fractions of quasi-crystalline (QC) iphase. Wear and friction behaviour of the produced AlCuFeSc coatings is studied in the dry and wet conditions depending on the loading type (quasistatic or dynamic) for various counter-bodies (Si3N4, WC-Co hard alloy, or 52100 bearing steel). The effects of the coating-surface roughness and the QC i-phase content are also analysed. [ABSTRACT FROM AUTHOR]

The article deals with the study of the possibility of using AlB12--50 wt.% Al aluminium-matrix composite material electric spark (ES) coatings to protect titanium alloys during wear under fretting. Fundamental possibility of such coatings obtaining is estimated by theoretical calculation of Palatnik's criterion (1.22). Thermal conductivity coefficient and heat capacity of the composite were calculated or determined from an experiment. The coatings were deposited on ALIER-52 setup. Fretting corrosion tests were carried out on MFK-1 setup according to 'the coating--counterbody' system (counterbody--hardened Steel 45). Phase composition of the coating was studied with DRON-3M diffractometer and elemental x-ray spectrum analysis of the friction track surface was carried out using a JEOL JAMP9500F (SEM) microanalyzer equipped with an energy-dispersive x-ray microanalysis. The following phases namely TiB2, Ti aluminides, Ti, TiO, TiO2 and AlB10 were revealed by x-ray analysis in the coating. The absence of the AlB12 phase is noteworthy. It can be explained by thermal-oxidative destruction of aluminium dodecaboride under severe conditions of ES alloying (ESA). Regardless of the deposition mode, the wear of the sample with ES-coating is shown to be significantly less than that of the uncoated one. A conclusion is made about the prospect of using this electrode material for ESA of titanium alloys operating under fretting corrosion. [ABSTRACT FROM AUTHOR]

The work is devoted to development of the method of restoration of worn press tools from 3Kh3M3F steel for extrusion of non-ferrous alloys by mechanized hardfacing with self-shielded flux-cored wire. The advantages and disadvantages of different classes of hardfacing materials are considered and use of 50Kh6V2GSMFA steel is proposed. In the case of hardfacing with selfshielded flux-cored wire the alloying part of this steel provides a higher hardness at high working temperatures of pressing, due to a complex hardening of the martensite matrix with carbides of tungsten, chromium and other elements, as well as additional hardening by vanadium nitride. It allowed increasing the tool life. Moreover, alloying by chromium at the level of 5.5 – 6.0% improved adhesion to the processed metal. Resistance to thermal erosion and thermal fatigue strength of the deposited layer was increased by selection and optimization of gas-slag-forming components. Industrial trails of hardfaced steel 50Kh6V2GSMFA, first applied for restoration and hardening of the hot pressing matrices from 3Kh3M3F steel, were conducted at LLC “ZCM” (city of Bakhmut). Compared to new unsurfaced matrices, those restored by hardfacing demonstrated 2.4…2.5 times higher durability, while working diameter drawdown after 5 pressing cycles decreased three times. Total cost of matrix restoration by surfacing is 1.5 – 20 times lower than that of a new matrix from 3Kh3M3F steel. [ABSTRACT FROM AUTHOR]

Copyright of Problems of Friction & Wear is the property of National Aviation University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Problems of Friction & Wear is the property of National Aviation University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Problems of Friction & Wear is the property of National Aviation University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The conditions of operation of the parts and components of mining equipment, which are made mostly from 110G13L steel, are considered. Limited possibilities for application of this steel to improve the equipment service life are noted. The possibility of application of electroslag surfacing in a current-conducting mould by different high-carbon materials is shown as an alternative. High-chromium cast irons should be considered the most promising surfacing material. They have a good combination of higher mechanical properties and resistance to abrasive and shock-abrasive wear. 24 Ref., 2 Tabl., 1 Fig. [ABSTRACT FROM AUTHOR]

Copyright of Problems of Friction & Wear is the property of National Aviation University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Problems of Friction & Wear is the property of National Aviation University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Анотація. Супроводжуючі гарматні постріли хімічна дія порохових газів та високі температури активно руйнують поверхневий шар матеріалу каналу ствола. Це призводить до порушення геометрії каналу ствола і, як наслідок, пониження точності прицільної стрільби гармати. Приведено опис принципово нової технології зміцнення поверхневим пластичним деформуванням внутрішньої робочої поверхні каналу стволів крупнокаліберних артилерійських і танкових гармат. Ця зміцнювальна технологія базується на проклепуванні металу каналу ствола деформівними тілами із сферичною ударною поверхнею, які встановлені на масивному циліндричному зміцнювачі. Циліндричному зміцнювачу в процесі обробки від електродвигуна приводу надають планетарного обкочувального руху по оброблюваній внутрішній поверхні каналу ствола. Одночасно зміцнювач переміщають вздовж геометричної осі оброблюваного ствола гармати. Результатом цієї зміцнювальної обробки є формування у товщі матеріалу каналу ствола залишкових напружень стиску, підвищення його поверхневої мікротвердості. Це забезпечує підвищення опору матеріалу каналу ствола його вигоранню, а також зношуванню під час гарматних пострілів. Створена конструкція зміцнювального пристрою для здійснення цієї обробки. Він складається із циліндричного зміцнювача із деформівними тілами, механізму передачі крутного моменту від валу двигуна до зміцнювача та електродвигуна приводу. Під час обробки зміцнювальний пристрій переміщається вздовж каналу ствола гармати. Його циліндричний зміцнювач обкочується по оброблюваній внутрішній поверхні ствола та проклепує його матеріал. Забезпечувана товщина зміцнення сталевих деталей 0,15–0,20 мм. Сформований у процесі обробки зміцнений поверхневий шар матеріалу каналу ствола гармати володіє підвищеною мікротвердістю, завдяки чому надійно протистоїть формуванню в ньому експлуатаційних мікротріщин. При цьому сформовані в товщі зміцненого металу каналу ствола напруження стиску надійно протистоять температурному розростанню мікротріщин. Це забезпечує підвищення опору зміцненого металу ствола експлуатаційному руйнуванню, завдяки чому підвищуються надійність та довговічність вартісного артилерійського озброєння.

Copyright of Mechanics & Advanced Technologies is the property of National Technical University of Ukraine KPI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The peculiarities of manufacturing drill bits and cutters are considered and studied. The carried out analysis of operation of working bodies of drill bit frames showed that during drilling most often a wear of cutters, a protective coating of sitters and a calibrating surface of frames of drilling bits occur. It was investigated that in arc surfacing using TIG method, low rates of heating and cooling of metal during preheating of working bodies of a bit allow reducing residual stresses and avoiding the formation of cracks in coatings and base material. It was established that the optimal thickness of surfacing the protective coating should be within 2.0…3.0 mm, where a uniform distribution of tungsten carbides throughout the volume of the deposited layer is observed, which effectively resists wear of the working bodies of blades and frames of bits in the conditions of alternating and shock loads, hydroabrasive wear, corrosion, erosion, etc. It was established that bits with a protective coating, having a high wear and corrosion resistance, increase the mechanical speed of drilling and solve the most important task of reducing the number of lowering and lifting operations when drilling gas and oil wells. As a result of carried out production tests of manufactured drill bits, it was found that protective coating of working bodies allows extending the service life. 18 Ref., 1 Tabl., 8 Fig. [ABSTRACT FROM AUTHOR]

У статті представлені теоретичні та експериментальні дослідження трибосистем, які працюють в умовах аномального тертя та зношування при зміні зовнішніх умов їх роботи. Виконано порівняльний аналіз механізмів самоорганізації трибосистем, які працюють в умовах нормального механохімічного і аномально низького тертя та зношування для визначення умов переходу до такого режиму. Визначено ще один мож-ливий спосіб переведення трибосистем до умов аномально низького тертя та зношування шляхом модифі-кації поверхневого шару бронзових зразків фінішною обробкою мінералом групи амфіболів (нефрити).

This work is a comprehensive study of the structure and properties of plasma eutectic coatings after thermal cyclization. This kind of treatment significantly increases the adhesive-cohesive strength of coatings. According to the results of the conducted research, the resistance against the operation of two-layer coatings in the whole temperature range is higher than for single-layer ones. This effect is achieved by the increase in adhesion properties, a decrease in the hardness gradient along the depth of the coating, and the increase in the coating's thermal stability due to the barrier properties of the doped boride layer. By controlling the size of the dispersed crystals of the penetration phases and at the same time the state of the metal matrix, it is possible to select the TCO modes in which the coatings receive optimal tribotechnical properties. [ABSTRACT FROM AUTHOR]

It is shown that under the conditions of hard abrasive wear, characteristic for parts of mining industry equipment, hardfacing with wear-resistant materials, in particular high-chromium cast iron, should be used. Such lining layers can be applied by electroslag hardfacing in a current-conducting mould of different cross-sections. Here, it is possible to apply both restorative and fabrication hardfacing. Features of hardfacing by each of these methods are shown. Industrial tests of deposited lining were performed in the case of components of jaw crusher SMD-11 and loader bucket. [ABSTRACT FROM AUTHOR]

The article is concerned with the determination of physical plasticity δH (the ratio of the plastic strain to the total strain) and yield stress σS by indentation and the application of these characteristics for analysis of the wear rate W during the friction. The experimental part of the work is performed on the AISI O2 and AISI D2 steels, the surface layers of which were hardened by combined thermomechanical treatment consisted of sequential use of laser heat treatment and ultrasonic impact treatment. For the metals, W is shown to be proportional to δH and inversely proportional to σS. The general scheme for the dependence of W on δH is proposed and based on experimental results for tool steels and hard alloys. For the steels, whose wear is caused by the plastic deformation, W increases with increasing δH, and it decreases conversely for hard alloys worn predominantly by the fracture mechanism. The use of physical plasticity δH and yield stress σS, which are calculated using the hardness and Young's modulus, characterizes both the hardening extent and the wear rate of the surface layers in more full measure and more accurately than the hardness magnitude itself. [ABSTRACT FROM AUTHOR]

A new concept of creating steels to provide high resistance to wear and damageability to the rolling surface of wheels was proposed, requirements for a set of mechanical characteristics of such steels were developed and chemical composition of steel for a new generation of railway wheels, as well as heat treatment mode during their repair surfacing was substantiated. [ABSTRACT FROM AUTHOR]

The peculiarities of wear of operating elements of the bodies of steel, matrix drill bits and heads were considered and studied, and repairability criteria were determined. Performed analysis of worn areas of operating elements of used drill bit bodies showed that at drilling wear of cutters and seats is the most common, and wear of flushing components of the drill bit bodies occurs less often. Metallographic examination showed that the deposited layer and the base metal are connected by a thin transition layer of diffusion origin, which shows that base metal melting and filler metal dissolution did not occur in it. It is established that the drill bit repair is cost-effective in those cases, when the cost of such repair does not exceed one third of the cost of the bit proper. Multiple repeated reconditioning of operating elements of worn areas reduces the cost of manufacturing new drill bits several times. Conducted production trials of reconditioned drill bits showed that repair of worn areas of the operating elements allows considerable extension of the service life and saving 30…50 % of the initial cost of a specific drill bit type. 12 Ref., 2 Tabl., 8 Fig. [ABSTRACT FROM AUTHOR]

Copyright of Problems of Friction & Wear is the property of National Aviation University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Problems of Friction & Wear is the property of National Aviation University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Problems of Friction & Wear is the property of National Aviation University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Metallophysics & Advanced Technologies / Metallofizika i Novejsie Tehnologii is the property of G.V. Kurdyumov Institute for Metal Physics, N.A.S.U and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The analysis of the state of the problem with the development of wear and durability calculation methods of metal, metal-polymer and polymer gears is presented. Known methods in the literature are characterized for gears with metal wheels. The basic author's method of calculating cylindrical gears has been provided. Impact factors were described by which modified gear calculation methods were formed based on the basic method. These are the following factors: operational - change in the curves of involute teeth profiles due to their wear, structural - parity of the teeth, technological - correction of teeth, tribological - wear resistance of materials. According to the developed methods, the estimation of contact pressures, wear and durability of spur and bevel straight and helical gears, worm gears made of metal structural materials was carried out. The modified method was used to calculate a spur straight-tooth metalpolymer transmission (hybrid transmission) with steel gear and a glass or carbon fiber reinforced polyamide wheel. [ABSTRACT FROM AUTHOR]

Copyright of Scientific Bulletin of National Mining University is the property of National Mining University, State Higher Educational Institution and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

It is made an attempt to propose some appropriate models of the friction and wear processes that could happen in the considered structural elements of the engineering units. The uncertainty measure in the given consideration is the entropy of the special hybrid-optional effectiveness functions. Such kind of entropy originates from the Jaynes' principle, being adapted to the subjective entropy maximum principle, with the implementation possibilities to the applicable fields of aviation industry as that follows the readings of the references. The paper theoretically considers the possibility of the multi-optional hybrid functions entropy conditional optimization doctrine applicability with the purpose of discovering a substantiated reason for the special hybrid-optional effectiveness functions existence, as well as the reasons for the formula optimality. The order of the kinetic reaction as a model function, or the socalled dependence of the tribological process order as a function, formula is obtained with taking into account the degree of uncertainty for a certain type hybridoptional effectiveness functions. With the help of the variational principle it is shown the optimality of the formula. The evolution of the proposed at this paper approach from the subjective analysis to the hybrid multi-optional functions optimization doctrine implies the use of the hybrid multi-optional functions, as an objectively existing characteristic of a phenomenon, instead of the subjectively preferred, by a human, functions, since no one chooses the objectively existential reality. The approach has a significance of a plausible explanation for the phenomena stipulated by multioptionality. [ABSTRACT FROM AUTHOR]

Copyright of Metallophysics & Advanced Technologies / Metallofizika i Novejsie Tehnologii is the property of G.V. Kurdyumov Institute for Metal Physics, N.A.S.U and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the article there are the results of tribological researches of ferromagnetic friction pair of ball-bearing steel ШХ-15-Ст45 in the conditions of a reciprocating motion in M10Г2к oil environment under the influence of a magnetic field. An overview of literature sources in the field of the repair of mobile compounds shows that studies related to the restoration of moveable parts of the friction pairs are relevant. In the course of the research, a significant increase of the friction pairs efficiency due to the direct transfer of wear particles to the working surfaces of the friction part under the action of a magnetic field has been established. Using topographic and metallographic analyzes the mechanism of deterioration of contacting surfaces in an environment of oil M10G2k is disclosed and the role of the direction of the magnetic field is determined. This is confirmed by the results of research on the distribution of wear products, which indicate, that when the magnetic field is directed to the sample area, a film from deposited flocculates and single (non-coagulated) particles, which is formed on its working surface, is much thicker than that on the surface of the counterpart. In this case, the part of the products of wear that is located on the counterpart under the action of a magnetic field is directed to the friction path, which causes the film to increase and as a result of reducing the wear of the sample. It is shown that the selective mechanism of deposition the wear particles depends on their ability to be magnetized. It is established that wear products are particles that possess a variety of magnetic properties. Such, the components of the films will be ferromagnetic, paramagnetic and diamagnetic, the chemical composition and physical and mechanical properties of which will determine the wear resistance of the friction pair. [ABSTRACT FROM AUTHOR]

It is made an attempt to propose some appropriate models of the friction and wear processes that could happen in the considered structural elements of the engineering units. The uncertainty measure in the given consideration is the entropy of the special hybrid-optional effectiveness functions. Such kind of entropy originates from the Jaynes' principle, being adapted to the subjective entropy maximum principle, with the implementation possibilities to the applicable fields of aviation industry as that follows the readings of the references. The paper theoretically considers the possibility of the multi-optional hybrid functions entropy conditional optimization doctrine applicability with the purpose of discovering substantiated reason for the special hybrid-optional effectiveness functions existence, as well as the reasons for the formula optimality. The neuron model activation function, or a squashing function, of a sigmoid type function like logistic function, formula is obtained with taking into account the degree of uncertainty for a certain type hybrid-optional effectiveness functions. With the help of the variational principle it is shown the optimality of the formula. The evolution of the proposed at this paper approach from the subjective analysis to the hybrid multi-optional functions optimization doctrine implies the use of the hybrid multi-optional functions, as an objectively existing characteristic of a phenomenon, instead of the subjectively preferred, by a human, functions, since no one chooses the objectively existential reality. The approach has a significance of a plausible explanation for the phenomena stipulated by multi-optionality. Theoretical speculations are illustrated with a plotted diagram presenting conducted numerical simulations. [ABSTRACT FROM AUTHOR]