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In coated tools, the grain boundaries and coating layers are areas of intense energy dissipation, which hardens the coating material by increasing its toughness and its resistance to the formation and development of cracks. An increase in the efficiency of the coatings was achieved by applying nano-dispersed multilayer composite structure. This paper proposes using nano-scale multilayer composite coating based on TiN-CrN compound to improve thermal stability, where, barrier layers based on ZrNbN have been introduced. The ZrNbN barrier does not interact with TiN and CrN at temperatures around 1000°C. The influence of process parameters of the filtered cathodic vacuum arc deposition on the composition, structure and properties of the coatings based on variation of TiAlN-ZrNbN-CrN was analyzed. The results presented here show that the hardness of the developed coatings was as high as 38 GPa. Subsequently, the carbide tools used in this study with the new coatings had an increased lifetime of 1.5-2.0 times compared to tools with commercial coatings. The coated tools were tested in turning and milling of steels, nickel and titanium alloys.

The challenges facing the development of environmentally friendly dry cutting technologies for various materials is investigated. The system used for the study includes a cutting tool equipped with inserts from layered composition ceramic with nano-scale multilayer coatings, an ionized gas medium which is supplied into the zone of cutting and the ultrasonic vibrations, which are placed to a cutting tool in the direction of the cutting speed. It is shown, that elaborated ecologically friendly dry machining not only does not match efficiency of standard machining technology with application of cutting fluid, but also in some cases surpasses it.

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В работе представлены результаты исследований режущих свойств и механизма изнашивания лезвийного режущего инструмента, оснащенного сменными многогранными пластинами (СМП) из режущей керамики (РК) с наноструктурированными многослойно-композиционными покрытиями (НМКП) при резании высокотвердой стали. Показано, что применение НМКП позволяет управлять контактными процессами за счет изменения трения и длин плотного и полного контакта стружки и передней поверхности инструмента, что способствует снижению нормальных контактных напряжений и вероятности макро-и микро хрупкого разрушения контактных площадок инструмента.Ключевые слова: режущая керамика (РК); покрытие; контроль контактных процессов, режущие свойства инструмента, механизм изнашивания ВведениеВ настоящее время все большее применение в металлообрабатывающих производствах получают лезвийные режущие инструмента, оснащаемые сменными многогранными пластинами (СМП) из режущей керамики (РК), не содержащие в своем составе дефицитных элементов и обладающие высокой сопротивляемостью изнашиванию, особенно при повышенных температурах, возникающих в процессе резания.При производстве лезвийных режущих инструментов из РК наиболее широко используют оксиды алюминия Al2О3 и нитрид кремния Si3N4, которые являются основой для одно -и многокомпонентных систем. Добавление в оксидную керамику оксидов циркония, карбидов титана и армирование «нитевидными» кристаллами SiC существенно улучшает её свойства (рис. 1).Рис.1. Основные типы режущей керамики, используемые при производстве режущих инструментов.

-In this paper, we consider the development of the methodology for the formation of nanostructured multi-layered composite coatings to improve the cutting properties of carbide cutting tools in the high-performance machining of various materials. The methodology for the formation of the composition, structure, and properties of developed composite coatings with a three-layered architecture was based on the phenomenological theory of the thermodynamic criteria for the evaluation of adhesion, and the assumption of the prevailing adhesion-fatigue wear of carbide cutting tools. The synthesis of coatings was carried out through filtered cathodic vacuum-arc deposition. The hardness, adhesion, and cutting properties of the developed coatings deposited on the carbide substrates were studied. It was found that the synthesized coatings had a nanoscale grain structure and thickness of sublayers, which significantly increased the area of intergranular and interlayer boundaries and provided a considerably balanced relation of the most important characteristics of the coating, such as "hardness-heat resistance". Such structures are characterized by increased toughness and resistance to the formation and development of "brittle" cracks and more efficient resistance to fractures in conditions of complex stress from external influences. It is revealed that, in the longitudinal turning of steel, carbide tools with the developed coatings demonstrated a tool life of five times higher than the tool life of uncoated tools and up to three times higher than the tool life of tools with standard coatings.

The functional role of nanostructured multilayer composite coatings (NMCC) deposited on the operating surfaces of replaceable faceted cutting inserts (CI) from cutting ceramics based on aluminum oxides with additives of titanium carbides is studied. It is shown that the developed NMCC not only raise substantially the endurance of the ceramic tools under high-speed dry treatment of quenched steels but also improve the quality and accuracy of processing of the parts and the ecological parameters of the cutting process.

Developed a process of assisted filtered cathodic-vacuum-arc deposition (AFCVAD). We used a special emitter (implantor) to generate Cr, Mo ions with high energy. Such key parameters of coatings as composition, structure, a thickness, hardness, adhesion in relation to a substrate obtained at various energy of chrome ions have been studied. A phenomenological (physical) model of assisted filtered cathodic-vacuum-arc deposition (AFCVAD), allows to predict the properties of the coatings formed on the basis of binary compounds as a function of the relationship Ra, characterizing parameters of ion implantation.