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The paper compares the microstructure and tribotechnical characteristics of composite coatings of 70 wt.% Ni -20 wt.% Cr -5 wt.% Si -5 wt.% B. These coatings are produced by slip casting and unidirectional solidification. The coating composition is substantiated and coating restructuring mechanisms in the forming process are discussed. Natural composite Ni -Ni 3 B forms the basis of the coating. The fine lamellar eutectic, which occupies ~50.5% of the coating, consists of Ni 3 B, a nickel solid solution doped with chrome and silicon, and CrB crystals. The microhardness of the coating and phase constituents are determined. The method of contact eutectic vacuum melting with controlled cooling permits obtaining the nonporous coating without slag inclusions and with homogeneous oriented structure. The mechanism of 3 to 5 times increase in the wear resistance of homogeneous nonporous coatings and their potential application in friction units of machinery are discussed.Strong and stable protective coatings are needed to improve the wear-and heat-resistance of structural materials used in corrosive environments and at high temperatures [1-3]. The formation of composites consisting of a solid (with high creep strength) intermetallide and a more plastic metal phase is a prospective area for improving the properties of brittle materials and associated coatings. This approach can be implemented using eutectic reactions [4-6] between coating components: refractory oxides and borides of transition metals.Contact eutectic melting extends the structure-formation capability of the initial powder mixture: a considerable amount of the liquid phase at the final stage of coating formation results in the appropriate mobility of the molten layer, adhesion with the substrate, and a high speed of the process (10 2 -10 3 sec). However, high cooling rates substantially contribute to the porosity and cracking of coatings. Three-component and more complex eutectics are known to have lower melting temperatures than two-component ones. When the liquid phase appears, doping components in alloys (powder mixtures) may chemically react with base materials or with each other, often resulting in new phases with higher melting temperatures than those of the initial components. Of particular interest is an opportunity to produce antifriction and wear-resistant surface layers in this way [6,7]. The wear-and heat-resistance of heterogeneous and heterophase age-hardened or amorphous-crystalline coating materials can be increased through the structure formation processes (the literature on these processes [3,[8][9][10][11][12][13][14] needs to be carefully analyzed and summarized.)The objective is to examine the slip casting formation of the composite coating 70 wt.% Ni -20 wt.% Cr -5 wt.% Si -5 wt.% B, analyze the potential use of contact eutectic melting to obtain nonporous wear-resistant coatings, and study their effect on the tribotechnical characteristics of subsequent controlled thermal treatment.The reason for studying this system is high strength...

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Авторское право 2013 г., Общество инженеров нефтегазовой промышленности Этот доклад был подготовлен для презентации на Конференции SPE по разработке месторождений в осложненных условиях и Арктике 15-17 октября 2013 года в Москве, Россия.Данный доклад был выбран для проведения презентации Программным комитетом SPE по результатам экспертизы информации, содержащейся в представленном авторами реферате. Экспертиза содержания доклада Обществом инженеров нефтегазовой промышленности не выполнялась, и внесение исправлений и изменений является обязанностью авторов. Материал в том виде, в котором он представлен, не обязательно отражает точку зрения SPE, его должностных лиц или участников. Электронное копирование, распространение или хранение любой части данного доклада без предварительного письменного согласия SPE запрещается. Разрешение на воспроизведение в печатном виде распространяется только на реферат объемом не более 300 слов; при этом копировать иллюстрации не разрешается. Реферат должен содержать явно выраженную ссылку на авторское право SPE.