Персона:
Михальчик, Владимир Валерьевич

Научные группы

Научная группа

Лаборатория "Ядерные топливные материалы" (Кафедра №9)

Организационные подразделения

Организационная единица

Цель ИЯФиТ и стратегия развития - создание и развитие научно-образовательного центра мирового уровня в области ядерной физики и технологий, радиационного материаловедения, физики элементарных частиц, астрофизики и космофизики.

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Михальчик

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Владимир Валерьевич

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Теперь показываю 1 - 10 из 11

Только метаданные
The evolution of structure and magnetoimpedance characteristics of amorphous Co69Fe4Cr4Si12B11 microwires under heat treatment
(2020) Kutuzov, L. V.; Svetogorov, R. D.; Mashera, V. S.; Gorelikov, E. S.; Kozlov, I. V.; Elmanov, G. N.; Prikhodko, K. E.; Tarasov, B. A.; Mikhalchik, V. V.; Козлов, Илья Владимирович; Елманов, Геннадий Николаевич; Приходько, Кирилл Евгеньевич; Тарасов, Борис Александрович; Михальчик, Владимир Валерьевич
© 2019 Elsevier B.V.Amorphous Co69Fe4Cr4Si12B11 glass-coated microwires after heat treatment in the temperature range of 250–600 °C during 30 min were investigated. Changes of microstructure, phase composition, fracture morphology, and giant magnetoimpedance (GMI) properties were shown. It is confirmed that a significant increase in the GMI effect was possible not only due to the structural relaxation, but also as a result of phase transformations at the temperature close to the onset of crystallization. It is shown that at the very initial stage of the nucleation of Co nanocrystals, a sharp increase in circumferential diagonal GMI component was observed, a further increase in the amount of the crystalline Co phase was accompanied by degradation of this effect. The most significant GMI ratio was obtained for microwires annealed at 430 °C. At 450 °C and above, an irreversible decrease of the GMI ratio took place. It was caused by the formation of Co crystals, decrease in amount and composition change of the amorphous phase during primary and secondary crystallization. At the final stage of the Co crystals segregation the secondary crystallization of the residual amorphous phase occurred with formation of a metastable τ-phase with a Me23B6 type structure. Thermal stability of the τ-phase was analyzed.
Только метаданные
Special aspects of uranium oxide non-stoichiometry measurement by thermogravimetric analysis
(2020) Tenishev, A.; Kuzmin, R.; Matvenov, M.; Mikhalchik, V.; Shornikov, D.; Тенишев, Андрей Вадимович; Матвенов, Максим Евгеньевич; Михальчик, Владимир Валерьевич; Шорников, Дмитрий Павлович
© Published under licence by IOP Publishing Ltd.Thermogravimetric analyses for determining uranium dioxide non-stoichiometry have been reviewed. Parameters of oxidation in air at various temperatures have been examined. The key parameters affecting accuracy of the obtained results have been evaluated. Oxidation parameters have been proposed, both for pure uranium dioxide as well as for uranium dioxide with added gadolinium oxide, which makes it possible to determine oxygen to metal (O/M) ratio with at least ±0.002 accuracy in weighed sample portions of approximately 3 g.
Только метаданные
Determination of Density and Pore Size Distribution in Uranium Dioxide Fuel Pellet by Image Analysis of its Cross-Sectional Structure
(2019) Devyatko, Yury N.; Khomyakov, Oleg V.; Tenishev, Andrey V.; Mikhalchik, Vladimir V.; Shornikov, Dmitry P.; Хомяков, Олег Владимирович; Тенишев, Андрей Вадимович; Михальчик, Владимир Валерьевич; Шорников, Дмитрий Павлович
The paper proposes a method for reducing the true pore size in oxide nuclear fuel using a well-known histogram for the distribution of the pores cross sections across the polished section. It is shown that the problem of constructing a continuous pore size distribution function from the pore size distribution histogram is incorrect. Histograms showing pore distributions across the polished sections of oxide nuclear fuel sintered under various conditions are obtained. The Scheil-Saltykov method was used to reduce histograms for 3D pore size distributions in uranium oxide fuel.
Открытый доступ
Influence of the structural state and crystallographic texture of Zr-2.5% Nb alloy samples on the anisotropy of their thermal expansion
(2021) Isaenkova, M. G.; Tenishev, A. V.; Krymskaya, O. A.; Stolbov, S. D.; Mikhal'chik, V. V.; Fesenko, V. A.; Klyukova, K. E.; Исаенкова, Маргарита Геннадьевна; Тенишев, Андрей Вадимович; Крымская, Ольга Александровна; Михальчик, Владимир Валерьевич; Фесенко, Владимир Александрович
Zirconium remains the main structural material for thermal reactors due to the small capture cross section of thermal neutrons. In the period of stricter safety requirements for reactors with a simultaneous increase in operating parameters, predicting the behavior of the material in emergency situations has gained greater urgency. In this work, we measured the temperature dependence of the thermal expansion of samples cut from thick-walled tubes made of Zr-2.5% Nb alloy that were deformed and annealed in different modes. The analysis of the physical processes responsible for the shaping of the material is carried out. It was found that the anisotropic change in the linear dimensions of cubic samples both during heating and cooling is due to a change in the zirconium content in the beta-phase, phase transformations alpha + beta-Zr -> alpha + beta-Nb -> beta -> alpha + beta-Zr, as well as the preferred orientation of the grains of the alpha-phase, characterized by high anisotropy of linear expansion. It is shown that the expansion of the investigated samples upon heating in the alpha -phase is determined exclusively by the integral texture parameters of Kearns, and the coefficients of thermal linear expansion (TLEC) in different directions vary over a wide range from 3.10-6 to 12.10-6 K-1. During cooling at the stage of the reverse phase transformation of the beta-phase into alpha, an increase in the size of the cubic samples in the tangential direction up to 2.3 % and a decrease in the radial direction to 1.3 % are noted, which is associated with the orientation of the alpha-phase grains formed during cooling in the beta -matrix and anisotropy of the TLEC of the alpha-grains. It is shown that the orientation of the alpha-phase grains in the reverse beta -> alpha transformation is determined not only by the orientation of the basal axes in the initial material, but also by the spatial distribution of the prismatic axes relative to the external directions in the tube. Significant size fluctuations in different directions of the samples obtained using the technology of manufacturing channel tubes for CANDU reactors should lead to the development of significant macrostresses both during heating and cooling of the tube. The structural state of the samples deformed or annealed at 400-530 degrees C does not significantly affect the temperature dependence of the TLEC, but is manifested only in some of its features. In this case, completely recrystallized samples, i.e., with a recrystallization texture, in which the 1120 directions are oriented along the tube axis, are characterized by a significantly lower variation in dimensions in different directions in the temperature range 20-1200 degrees C.
Только метаданные
Regularities of Thermal Expansion of Cladding Tubes and Rods Made of E110opt Alloy within the Temperature Range of 273–1473 K (20–1200°C)
(2021) Fedotov, P. V.; Kuznetsov, V. I.; Isaenkova, M. G.; Tenishev, A. V.; Perlovich, Y. A.; Stolbov, S. D.; Mikhalchik, V. V.; Novikov, V. V.; Исаенкова, Маргарита Геннадьевна; Тенишев, Андрей Вадимович; Михальчик, Владимир Валерьевич; Новиков, Владимир Владимирович
© 2021, Pleiades Publishing, Ltd.Abstract: The regularities of the thermal expansion of cladding tubes and rods from the E110opt alloy, as well as the anisotropy of their thermal properties in the case of layer-by-layer texture inhomogeneity are studied. The thermal linear expansion coefficients (TLEC) of rods and cladding tubes were measured in the axial, radial and tangential directions during heating and cooling in the temperature range of 293–1473 K (20–1200°C). It is shown that as a result of α → β → α phase transformations in the samples, a stable texture of phase transformations is formed which is preserved during subsequent heating and cooling cycles. Analytical expressions are obtained that describe the temperature dependence of the thermal expansion coefficient in the first cycle of heating products from the E110opt alloy, taking into account possible α → β phase transformations and the resulting α-Zr crystal lattice deformation along the a and c axes. It was established that the presence of layer-by-layer inhomogeneity in the samples leads to the appearance of stresses between layers with different crystallographic textures and, as a result, affects the orientation dependence of phase transformations that are sensitive to the stress state in the material. The results obtained indicate the need to take into account the internal stresses arising in textured anisotropic materials during heating and cooling, and to separate the contributions of thermal expansion and plastic deformation when analyzing data from dilatometric measurements of sample sizes.
Открытый доступ
Пределы растворимости водорода в циркониевых сплавах Э110ОПТ и Э635
(2023) Плясов, А. А.; Федотов, А. В.; Сабуров, Н. С.; Михеев, Е. Н.; Тенишев, А. В.; Исаенкова, М. Г.; Михальчик, В. В.; Исаенкова, Маргарита Геннадьевна; Тенишев, Андрей Вадимович; Михальчик, Владимир Валерьевич
В работе представлены результаты определения пределов растворимости водорода при растворении (TSSD) и при выделении (TSSP) в необлученных циркониевых сплавах Э110опт на основе губчатого циркония и Э635 на основе электролитического циркония. Измерения проводились с помощью методов дифференциальной сканирующей калориметрии (ДСК) и горячей вакуумной экстракции (LECO). Показано, что в пределах погрешности TSSD и TSSP в сплавах Э110опт и Э635 совпадают, т.е., технология получения циркония не влияет на пределы растворимости водорода. Проведено сравнение полученных величин TSSD с данными для других циркониевых сплавов. Показано, что в пределах погрешности проведенного в настоящей работе эксперимента TSSD в циркониевых сплавах Циркалой-2, Циркалой-4, Zr−1%Nb, М5, ZIRLO, Э110опт и Э635 совпадают. Получены аппроксимационные зависимости от температуры пределов растворимости TSSD и TSSP для сплавов Э635 и Э110опт, необходимые для расчетного обоснования циркониевых комплектующих ТВС.
Только метаданные
Hydrogen Solubility in Zirconium Alloys E110opt and E635
(2022) Plyasov, A. A.; Tenishev, A. V.; Isaenkova, M. G.; Mikhalchik, V. V.; Fedotov, A. V.; Saburov, N. S.; Mikheev, E. N.; Тенишев, Андрей Вадимович; Исаенкова, Маргарита Геннадьевна; Михальчик, Владимир Валерьевич
Только метаданные
Differential Scanning Calorimetry Determination of the Hydrogen Solubility in E110opt and E635 Zirconium Alloys
(2022) Tenishev, A. V.; Petrov, M. I.; Isaenkova, M. G.; Mikhal’chik, V. V.; Fesenko, V. A.; Тенишев, Андрей Вадимович; Петров, Марк Игоревич; Исаенкова, Маргарита Геннадьевна; Михальчик, Владимир Валерьевич; Фесенко, Владимир Александрович
Открытый доступ
Термохимическая стабильность модельного нитридного ядерного топлива на основе урана
(НИЯУ МИФИ, 2019) Михальчик, В. В.; Михальчик, Владимир Валерьевич; Тенишев, А. В.
Только метаданные
Effect of the Stressed State on the Phase Transformations in Zirconium-Based Alloys
(2022) Korotitskii, A. V.; Stolbov, S. D.; Isaenkova, M. G.; Tenishev, A. V.; Mikhal'chik, V. V.; Krymskaya, O. A.; Fesenko, V. A.; Исаенкова, Маргарита Геннадьевна; Тенишев, Андрей Вадимович; Михальчик, Владимир Валерьевич; Крымская, Ольга Александровна; Фесенко, Владимир Александрович
© 2022, Pleiades Publishing, Ltd.Abstract: The crystallographic aspects of the phase transformations in zirconium alloys under compressive stresses are studied, and the changes in the sizes of cladding tubes, rods, and rings made of E110opt and E125 alloys at compressive stresses and without them are determined. The temperature of the onset of the phase transformation on heating is found to shift toward low temperatures under a load applied to a cladding tube ring in the diametral direction, and a noticeable strain leading to the appearance of ellipticity of the rings are detected. Some of the versions of the Burgers orientation relationship are operative during the reverse β‒α phase transformation under compressive stresses, which manifests itself in the suppression of growth of texture maxima in the applied load direction during cooling. Deformation is shown to be accelerated on heating in the two-phase α + β region under compressive stresses, and the parameters of high-temperature creep are calculated using the temperature dependences of the strain.