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Your search keyword '"Prokopenko, Nikita"' showing total 14 results
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14 results on '"Prokopenko, Nikita"'

4. Structure and properties of multilayer nanocrystalline ceramics based on a high-entropy alloy.

Author

Petrikova, Elizaveta, Ivanov, Yurii, Shugurov, Vladimir, Prokopenko, Nikita, and Tolkachev, Oleg

Subjects
METAL coating, CERAMICS, YOUNG'S modulus, CRYSTAL lattices, NIOBIUM nitride, ATMOSPHERIC nitrogen
Abstract

Nitride coatings based on high-entropy alloys are a significant extension of the concept of obtaining and using high-entropy materials. The purpose of this work is to analyze the regularities revealed in the study of the structure and properties of multilayer ceramics based on a high-entropy alloy, formed in the form of thin (up to 5 µm thick) coatings on a metal substrate during the deposition of a multi-element metal plasma in a nitrogen atmosphere. A deposition regime was revealed as a result of the performed studies. It makes it possible to form hard (≈50 GPa) coatings based on HEAs nitrides of non-equiatomic composition. It is shown that nitride coatings are multilayer (average layer thickness 47.5 nm) nanoscale (crystallite size 2.5-4 nm) amorphous-crystalline formations. The crystalline component of the coatings has a cubic face-centered crystal lattice, the analog of which is niobium nitride Nb0.88N with a crystal lattice parameter of 0.44588 nm. It has been established that the coatings have hardness varying from 38.4 GPa to 71.7 GPa with an average value of 50.0 GPa; Young's modulus from 430 GPa to 1100 GPa with an average value of E=806 GPa (normalized hardness H/E=0.062). The obtained results can be used in the development of scientific foundations for a new environmentally friendly, fully automated electron-ion-plasma method for the formation of HEAs nitrides with high hardness. [ABSTRACT FROM AUTHOR]

Published
2023
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8. Steel Surface Doped with Nb via Modulated Electron-Beam Irradiation: Structure and Properties.

Author

Vorobyov, Maxim Sergeevich, Petrikova, Elizaveta Alekseevna, Shin, Vladislav Igorevich, Moskvin, Pavel Vladimirovich, Ivanov, Yurii Fedorovich, Koval, Nikolay Nikolaevich, Koval, Tamara Vasil'evna, Prokopenko, Nikita Andreevich, Kartavtsov, Ruslan Aleksandrovich, and Shpanov, Dmitry Alekseevich

Subjects
ELECTRON beams, IRRADIATION, MECHANICAL wear, STEEL, PULSE modulation, SURFACE structure
Abstract

A niobium film on an AISI 5135 steel substrate was exposed to submillisecond pulsed electron-beam irradiation with controlled energy modulation within a pulse to increase the film–substrate adhesion. This modulated irradiation made it possible to dope the steel-surface layer with Nb through film dissolution in the layer, for which optimum irradiation conditions were chosen from experiments and a mathematical simulation. The irradiated system was tested for surface hardness and wear, and its surface structure and elemental composition were analyzed. The results demonstrate that the microhardness of the irradiated system is much higher and that its wear rate is much lower compared to the initial state. [ABSTRACT FROM AUTHOR]

Published
2023
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