В работе представлены исследования, направленные на изучение трибологических показателей тонких металломатричных покрытий в условиях ограниченной смазки. Рассмотрены два типа покрытий, отличающиеся металлической основой, в контакте с различными антифрикционными сплавами. Металломатричные покрытия получены методом короткоимпульсного лазерного сплавления с использованием металлической основы – кобальта и никеля. В качестве упрочняющей фазы использована керамическая композиция на основе карбида бора. Использование карбида бора дает положительный трибологический эффект, доказанный многочисленными исследованиями зарубежных и отечественных ученых. Металлическая матрица никеля и кобальта обоснована их особыми физико-механическими свойствами, среди которых можно отметить химическую стойкость и термопрочность. Полученные покрытия подвержены сравнительным трибологическим испытаниям в условиях масляного голодания, соответствующих граничному трению. В процессе трения исследована динамика эволюции коэффициента трения в паре трения с бронзой БрАЖ9-4 и серым чугуном СЧ-18. Выполненные исследования выявили разную эффективность и работоспособность полученных металломатричных покрытий в условиях сухого трения. Независимо от материала контртела наиболее привлекательным с точки зрения коэффициента трения выглядит металломатричный композит на основе кобальта. Износные испытания выявили высокую стабильность коэффициента трения в диапазоне динамической нагрузки и отсутствие заедания и схватывания контактирующих поверхностей. Коэффициент трения колеблется в интервале от 0,1 до 0,2. The paper presents the studies aimed at examination of the tribological characteristics of thin metal-matrix coatings under the conditions of limited lubrication. Two types of coatings with different metal base in contact with various antifriction alloys are considered. Metal-matrix coatings are obtained by short-pulse laser melting using a metal base - cobalt and nickel. A ceramic composition based on boron carbide was used as a hardening phase. The application of boron carbide gives a positive tribological effect, proven by numerous studies of foreign and domestic scientists. The metallic matrix of nickel and cobalt is substantiated by their special physical and mechanical properties, among which chemical resistance and thermal strength can be noted. The resulting coatings were subjected to comparative tribological tests under oil starvation conditions corresponding to boundary friction. In the process of friction, the dynamics of the evolution of the friction coefficient in a pair of friction with bronze BrAZh9-4, gray cast iron SCH-18 was studied. The conducted studies revealed the different efficiency and performance capability of the obtained coatings under dry friction conditions. Regardless of the material of the opposite element, the cobalt-based metal-matrix composite appears to be the most attractive in terms of friction coefficient. Wear tests revealed a high stability of the coefficient of friction in the dynamic load range and the absence of seizing of the contacting surfaces. The friction coefficient ranges from 0.1 to 0.2.

A technology for renewal and strengthening of a working valve face of a gas distribution mechanism of an internal combustion engine is discussed. A route-and-operational map of the valve repair process has been compiled. Among the main features, the surfacing method (selective laser melting—SLM) and the method of diamond smoothing the surface of a protective-and-renewal coating are highlighted. The processing modes of the part are described. Data on the physical-mechanical characteristics of the coating were obtained. According to the test results, it was concluded that the valve life became double.

Современное ремонтное производство развивается в направлении получения тонких восстановительных покрытий преимущественно из композитов, основанных на применении керамических материалов. Однако использование керамических составов в массовом производстве затруднено в связи с отсутствием достоверных данных об их антифрикционных свойствах. Данная работа посвящена изучению триботехнических свойств восстановительных покрытий на основе оксидной матрицы FeO, дополнительно легированных оксидом бора B2O3. Покрытия получены высококонцентрированной короткоимпульсной лазерной обработкой порошковых композиций, предварительно нанесенных на металлические поверхности. Полученные покрытия подвержены износным испытаниям в условиях сухого трения скольжения с фиксацией коэффициента трения, в зависимости от прилагаемой нагрузки и состава порошковой композиции. Полученные результаты исследований подтверждают высокие антифрикционные свойства керамических покрытий на основе оксидных соединений. Оксидные структуры благоприятно влияют на антифрикционные свойства покрытий, в частности, введение оксида бора в диапазоне от 2 до 4 % в состав керамической композиции снижает коэффициент трения до уникальных 0,09–0,1 в условиях сухого трения. При этом наблюдается формирование устойчивых трибоструктур между контактирующими поверхностями. Modern repair production is developing in the direction of obtaining thin recovering coatings mainly from composite materials, based on the use of ceramic materials. However, the use of ceramic compositions in mass production is hindered by the lack of reliable data on their antifriction properties. This work is devoted to the study of the tribotechnical properties of recovering coatings based on the FeO oxide matrix additionally doped with boron oxide B2O3. The coatings are obtained by highly concentrated short-pulse laser processing of powder compositions previously deposited on metal surfaces. The resulting coatings are subjected to wear tests under conditions of dry sliding friction with fixation of the friction coefficient, depending on the applied load and the formulation of the powder composition. The obtained research results confirm the high antifriction properties of ceramic coatings based on oxide compounds. Oxide structures have a positive impact on the antifriction properties of coatings, in particular, the introduction of boron oxide in the range from 2 to 4 % into the formulation of the ceramic composition reduces the friction coefficient to unique 0.09–0.1 under dry friction conditions. In this case, the formation of stable tribological structures between the contacting surfaces is observed.

This article explores the possibility of enhancing the functionality of TKR7С-6 turbochargers by creating new friction pairs in bearing interfaces using ultrasolid ceramic coatings. According to the tests, the most efficient combination of materials for slider bearings is the friction pair including the ultrasolid B 4 C-BN coating and BrAZH9-4 bronze. Used in the TKR7С-6 turbocharger, this pair allows reducing the friction coefficient in bearing interfaces, which decreases the wear intensity as compared with the standard bearing assemblies in the turbocharger. A low friction coefficient positively affects the spinning dynamics of the turbo shaft and the ICE crankshaft. The test results can be used in engine building and maintenance production.

Abstract—The structure and properties of the surface layers of samples of alloy E110 (Zr–1 wt % Nb) have been studied after high-speed laser dispersion of powders of magnesium oxide and titanium dioxide. The heat resistance of the surface has been determined by repeated laser treatment in air and annealing the samples in a furnace at 900°C in air. The surface layers modified by laser dispersion increase the heat resistance of the zirconium alloy. The structure and composition of the modified coatings have been determined by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy.

Nanostructured carbon materials for supercapacitor electrodes, produced by short-pulse laser treatment of a polyimide film in argon with a fiber-optic ytterbium laser, were studied. Owing to the high power density, there occurred an optical breakdown of the polyimide film and its material was destructed to give nanocrystalline graphite. The thus synthesized nanostructured carbon was used as an active electrode material for supercapacitors. The results obtained in measurements of their functional characteristics demonstrated that the materials being synthesized are highly promising.

The electric capacity of electrochemical capacitors with composite electrodes obtained by laser microstructuring was studied. The obtained electrodes allowed control of the contribution of the resistance of the electrode material and electrolyte to the total equivalent series resistance of the electrochemical capacitor. This allowed us to determine their effect on the resulting characteristics of the capacitors. The dependences of the specific electric capacity on the parameters of the composite structure of electrodes were studied, and the optimum parameters were found.

С помощью высокоскоростной лазерной обработки ультрадисперсного порошка графита, равномерно распределенного на поверхности нелегированной стали, получены тонкие, 5–7 нм толщиной, углеродные пленки имеющие структуру графита. За счет создания переходного слоя, состоящего из нестехиометрических карбидов железа, полученные пленки имеют высокую адгезию к подложке. Упомянутые пленки отличаются высокой сплошностью и в широком интервале потенциалов в боратных буферных растворах ведут себя аналогично идеально поляризуемым электродам. Катодные и анодные токи на полученных графитных пленках значительно ниже токов, измеряемых на компактных графитных материалах. Нанесенные графитные слои полностью прекращают процесс анодного растворения стальной подложки.

The effect of a focused pulsed laser radiation on the change in the composition and microhardness of surface layers of nonequilibrium copper-nickel foils coated with a carbon layer has been investigated as a function of the number of laser pulses. It has been found that the carbon concentration changes and metal oxides of the substrate (copper-nickel foil) are reduced to pure metals on the irradiated side of the samples in all cases of the laser irradiation. It has been revealed that there is a decrease in the microhardness of the irradiated surface of the samples from the initial state in all cases of the irradiation. The mechanisms explaining the changes observed in the samples under laser irradiation have been proposed.

Means of reducing the friction in slip bearings are considered, for the example of low-speed heavy-duty spiroid gears used as drives in pipeline systems.

С помощью лазерной короткоимпульсной обработки ультрадисперсного порошка оксида хрома (+3), нанесенного на поверхность стали 20, получены наноразмерные поверхностные слои, содержащие диспергированные в альфа- и гамма-железе оксиды хрома и железа, а также смешанные оксиды со структурой шпинели FeO · Cr2O3. Обнаруживается и восстановленный металлический хром. Методом снятия анодных потенциодинамических кривых в нейтральных и слабощелочных боратных буферных растворах показано, что сформированные поверхностные слои способствуют повышению коррозионной стойкости стали вследствие перехода поверхности в пассивное состояние.

Corrosion-electrochemical behavior of composite layers, obtained by laser sintering, is studied by the method of anodic potentiodynamic curves in borate neutral solution and NaOH solution. Formation of highly active nonequilibrium phases on surface results in increasing cathode activity and corrosion resistance of samples. Obtained surface layers have higher corrosion-electrochemical characteristics than iron and nickel themselves. Composition of surface layers is studied by XPS-method.

Presented here is a brief review of research of an authors' collective dealing with laser treatment of materials, sintering metallic powders, and multiscale simulation. A theoretical analysis of the processes of structure formation upon the rapid laser synthesis of composite coatings has been performed. The experimentally obtained structural and phase characteristics of the sintered layers have been explained based on an analytical and numerical simulation of the dynamics of thermal fields in the zone of treatment, processes of melting, and subsequent solidification of porous materials. Upon rapid sintering and solidification, the effect of impurity trapping has been taken into account, which determines the chemical composition of the powders under nonequilibrium conditions of their formation. It has been shown that rapid laser treatment retains the composite structure of the powder layer due to the high rates of local heating/cooling and high rate of solidification comparable with the rate of diffusion of chemical components. The results obtained are applicable in the development of a wide class of functional-gradient composite materials.