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Information × Registration Number 0218U007836, 0115U001401 , R & D reports Title Scientific basics development of obtaining and physic-mechanical properties determination of the new class nanostructural superhard nitride coatings based on high-entropy alloys popup.stage_title Head Voyevodin Victor Nicolajevich, Доктор фізико-математичних наук Registration Date 21-12-2018 Organization National Science Center "Kharkiv Institute of Physics and Technology popup.description2 The research report contains 54 pages, 15 figures, 15 tables, 40 references. The objects of study are multicomponent high-entropy alloys and coatings. The purpose of the work is to obtain high-entropy cathodes for vacuum-arc deposition of carbide, oxide and nitride coatings. Investigation of physicomechanical properties, structural state, heat resistance of high-entropic coatings. Research methods - measurement of hardness, determination of the level of elasticity and yield boundary by indentation method, determination of friction coefficients by two methods, heat resistance, X-ray diffraction, electron microscopy. It is revealed that solid solutions of WPP based on the BCC lattice are formed at an electron concentration of less than 7.2 electrons / at, and when the electron concentration is above 7.66 electrons / atms, solid solutions are formed on the basis of the fcc lattice. The lattice parameter is determined by the metal, which is more refractory. High-entropy vacuum coatings have a hardness depending on the composition and deposition method from 8 to 12 GPa. At the same time, the type and parameters of the lattice are the same as in cast rapidly cooled alloys. Vacuum-arc high-entropic coatings have a cluster structure with sizes of 2-6 nm, with each cluster differing from each other in composition. For almost all WPPs, an increase in nitrogen pressure in the chamber to 0.6 Pa leads to the formation of textured coatings ([111]), which have a hardness of 50 to 70 GPa. An increase in the negative potential of the substrate during the formation of the coating leads to a decrease in the relative content of the light component (Ti) and nitrogen, as well as an increase in the heavy component (Ta, Hf). In the range of the substrate potential from -50 to -250 V, the single-phase state takes place, but at -50 V it is a virtually non-textured state, and at -250 V, the structure [111] with the highest hardness is formed. Annealing in vacuum to a temperature of 1000 ° С practically does not change the hardness of WPP, and at 1100 ° С - 1300 ° С the hardness decreases somewhat. Annealing in air at a temperature of 800 ° C reduces the hardness by almost half. The presence of yttrium in the WEC composition increases the hardness of coatings during annealing in air by one and a half times. The coefficient of friction of solid coatings is 0.38 - 0.4. High hardness ensures low wear of the coating at low loads of scratch testing, however, the greatest value of the critical fracture load LC5 = 179.33GPa is achieved in less solid coatings obtained at Up = -50 V. Keywords: nanocrystalline coatings, multi-element coatings, oxides, carbides, nitrides, superhardness, morphology, structure. Product Description popup.authors Андреєв Анатолій Опанасович Воєводін Віктор Миколайович Доломанов Андрій Валентинович Ковтеба Дмитро Володимирович Сердюк Ірина Віталіівна Столбовий В'ячеслав Олександрович Чікрижов Олександр Михайлович Черноіванов Євген Володимирович popup.nrat_date 2020-04-02 Close