Genoese studies in situ. Compared to the previous design, the dimensions and weight of the cell have been reduced by almost two times, while keeping the pressure range up to 100 GPa. To demonstrate the performance of the device, a study of the possibility of using polycrystalline NaCl as a pressure sensor during diffraction studies of the sample in non-hydrostatic compression conditions was conducted.
Key words: high pressures, shear deformations, phase transformations, diamond anvils, shear cell.
UDC 620.178.1
WITH. N. Dub*, V. I. Kush, O. N. Kaidash, V. P. Wednesday, T. WITH. Panasyuk (Kyiv)
*lz@ism.kiev.ua
Initiation of plastic flow in boron carbide during nanoindentation
The generation of plastic flow during nanodeformation of a sample of crystalline boron carbide was investigated using the nanoindentation method. For the first time, a sharp elastoplastic transition (pop-in) was observed when the indenter was inserted into boron carbide as a result of the homogeneous nucleation of dislocations in the region of the imprint.The analysis of nanoindentation data for the case of homogeneous nucleation of dislocations in the contact area allowed to perform an experimental assessment of the theoretical shear strength and ultimate hardness of boron carbide.
Key words: boron carbide, nanoindentation, elastoplastic transition, theoretical shear strength, ultimate hardness.
UDC 539.23:620.18:620.17
A. A. Onoprienko*, V. I. Ivashchenko, I. I. Timofeeva, A.K. Sinelnitchenko, O.AND. Butenko (Kiev)
*onopr@ipms.kiev.ua
Characterization of Ti–B–C–N films deposited by dc magnetron sputtering of bicomponent Ti/B4C target
Quaternary Ti–B–C–N films have been deposited onto Si (100) substrates by dc magnetron sputtering of bi-component Ti/B4C target in an Ar/N2 gas mixture with different amounts of nitrogen in the mixture (from 0 to 50%). The X-ray diffraction, X-ray photoelectron spectroscopy, indentation, and scratch tests have been employed to characterize the films. The films have been found to have the nanocomposite structure composed of Ti/TiB nanocrystallites (nc) solely when sputtered in argon or of nanocrystallite nc-TiN/nc-TiBx/nc-TiOx phases embedded into an amorphous a-C/a-CN/a-BN/a-BC matrix when nitrogen is added to the gas mixture.The latter structure is specific to all the films deposited with nitrogen regardless of the nitrogen amount in the gas mixture.It has been found that the Knoop hardness of films first increased with added nitrogen reaching a maximum value of 33 GPa at 25% N2 in the gas mixture, and then decreased.The friction coefficient of films changed little with the added nitrogen, while with 25% N2 exhibited the lowest value. The Ti–B–C–N films showed increased adhesion strength on silicon compared with Ti–B–C coatings.
Keywords: magnetron sputtering, nanocomposite, structure, mechanical properties.
UDC 620.178.152:669.265.295
M. IN. Karpets, O. M. Myslivchenko*, M. AT. Krapivka, V. F. Horban, O. WITH. Makarenko, V.AND.Nazarenko (Kyiv)
*karp@ipms.kiev.ua
**zvyagina-47@yandex.ru
The influence of plastic deformation on the phase composition, texture and mechanical properties of the high-entropy alloy CrMnFeCoNi2Cu
The deformation of the multicomponent high-entropy alloy CrMnFeCoNi2Cu was studied. The distribution of elements, microstructure, phase transformations and mechanical properties of this alloy were studied using X-ray diffractometry, scanning electron microscopy and microindentation. It was shown that the CrMnFeCoNi2Cu alloy has a great potential for strengthening during cold plastic deformation.
Keywords: high-entropy alloy, deformation, mechanical properties.
UDC 539.534.9
O. V. Bondar*, B. A. Postolny (Sumy)
V. M. Beresnev (Kharkiv)
G. Abadias, P. Chartier (Poitiers, Futuroscope, France)
AT. IN. Sobol (Kharkov)
D. AND. Kolesnikov (Belgorod, Russia)
F. F. Komarov (Minsk, Belarus)
M. AT. Lysovenko (Sumy)
AND. AND. Andreev (Kharkov)
*oleksandr.bondar@gmail.com
Composition, structure and tribotechnical properties of vacuum-arc single-layer TiN, MoN and multilayer TiN/MoN coated
The results of complex studies of nanostructured coatings made of TiN and MoN, as well as multilayer coatings consisting of alternating layers of TiN/MoN, are presented.Coatings were obtained using a promising modern method of cathodic arc evaporation (Vacuum-arc method). A comparison of the elemental and phase composition of the coatings, their tribological and physical-mechanical properties: coefficient of friction, wear, adhesion, hardness, modulus of elasticity was carried out. Covered destruction mechanisms are considered.
Keywords: vacuum-arc evaporation, Ti–Mo–N, phase-element composition, friction, hardness, wear, adhesion.
UDC 544.032.4, 544.723+661.183.2
K.AND. Veselovska, V. L. Veselovsky*, O.M. Zaderko, V.THERE ARE. Diyuk, O. IN. Ishchenko (Kyiv)
*veselovskyi.v@gmail.com
The influence of oxidation and heat treatment on the bromination of activated carbon
It has been shown that the same active surface centers of carbonaceous atrici. Heat treatment of oxidized activated carbon samples partially or completely restores the surface reactivity by removing oxygen-containing functional groups. It was found that it is the number, not the nature of the removed groups, that determines the increase in the surface reactivity of the activated carbon. Heat treatment of oxidized activated carbon samples at 800 °C almost completely restores their reactivity to the addition of bromine.
Keywords: activated carbon, gas-phase bromination, liquid-phase bromination, surface modification, oxidation, heat treatment.
UDC 621.922.025:661.657.5
V. K. Starkov*, E. G. Polkanov (Moscow)
*v.starkov@stankin.ru
The influence of the recipe composition on the hardness of the grinding wheel with a reduced concentration of cubic boron nitride
Recipe compositions of abrasive-ceramic compositions based on cubic boron nitride with a concentration of less than 100% are proposed for the technological manufacture of a tool with a given hardness. Statistical analysis of experimental data obtained a regression model of the relationship between the hardness measured by the ball indentation method and the content of the main components of the composition, which includes an abrasive filler in the form of grains of microcrystalline corundum, particles of ground fruit stones and hollow aluminosilicate microspheres.
Keywords: reduced concentration, cubic boron nitride, ceramic bond, composition of abrasive-ceramic composition.
UDC 621.623
Yu. D. Filatov*, A. G. Vetrov, V.I. Sydorko, A. Yu. Filatov, S. IN. Kovalev, V. D. Kurylovich, M. AND. Danylchenko, T. AND. Prykhna, A. I. Borymskyi, A. M. Kutsai, V. G. Poltoratskyi (Kyiv)
*filatov@ism.kiev.ua
Polishing of elements of optical and electronic technology from monocrystalline silicon carbide
The expediency of using polishing suspensions made of diamond micropowders, boron nitride powders, and Ti3AlC2 MAX phase when studying the regularities of polishing monocrystalline silicon carbide and using as criteria for the efficiency of the processing process the reduced amount of transfer energy, the density of transfer energy, and the density of vibrational energy spent on the formation of sludge particles is substantiated. As a result of computer modeling of the micro- and nanoprofile of the treated surface, profilograms were constructed, according to which the values of the roughness parameters and the characteristic ratios connecting them with the most probable size of the sludge particles were determined.
Keywords: polishing, slime particle, transfer energy, roughness.
UDC539.4
IN.IN.Hvorostyan*, A.IN.Panasenko (Kyiv)
*plt2002@ukr.net
Assessment of the damageability of carbide tool edges under local loads
Experimentally investigated the damage of the edges of a carbide cutting tool under local contact loads. Various parameters for assessing the damage of materials are used and the regularity of their changes is shown depending on the methods of modifying the surface of hard alloy plates and the level of the applied load. Statistical processing of the test results using the Weibull distribution was carried out.
Key words: hard alloy, local contact loading, edge damage, damage parameter, Weibull distribution.
UDC 621.762.52:544.778.4
D. Yu. Kosyanov*, P. IN. Mateichenko, I. AT.Vorona, R. P. Yavetskyi, A. IN. Tolmachev (Kharkiv)
*kosjanovdenis@rambler.ru
The trajectory of sintering of powders of different sizes 2.88Y2O3–0.12Nd2O3–5Al2O3
The relationship between the relative density and the average grain size of the 4% (at.) Nd3+:Y3Al5O12 ceramics obtained by reaction sintering of powders of different sizes 2.88Y2O3–0.12Nd2O3–5Al2O3 was established. It is shown that the anomalous course of the sintering trajectory at T > 1700°С can be caused by the suppression of the mobility of the intergrain boundaries of ceramics. A partial decomposition of the garnet phase with the precipitation of an unidentified impurity phase along the grain boundaries of Nd:YAG at a ceramic sintering temperature of 1800°С was detected.
Key words: reaction sintering, grain size, recrystallization, sintering trajectory, optical ceramics.