Персона: Шеляков, Александр Васильевич
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Институт лазерных и плазменных технологий
Стратегическая цель Института ЛаПлаз – стать ведущей научной школой и ядром развития инноваций по лазерным, плазменным, радиационным и ускорительным технологиям, с уникальными образовательными программами, востребованными на российском и мировом рынке образовательных услуг.
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- ПубликацияОткрытый доступХОЛОДНОКАТАНЫЕ БЫСТРОЗАКАЛЕННЫЕ ЛЕНТЫ ИЗ СПЛАВА TiNiCu С ПАМЯТЬЮ ФОРМЫ(НИЯУ МИФИ, 2025) БОНДАРЕВ, Н. А.; БОРОДАКО, К. А.; ТАТАРНИКОВ, Н. Н.; ШЕЛЯКОВ, А. В.; Шеляков, Александр Васильевич; Бородако, Кирилл АнатольевичТонкие ленты из быстрозакаленного сплава TiNiCu являются прекурсором для создания микро- и нанопинцетов для систем манипулирования микро- и нанообъектами. Для уменьшения их толщины в работе использовалась холодная прокатка образцов лент в аморфном состоянии. После прокатки с усилиями на валках до 12 тонн толщина лент уменьшилась в 1,2-1,5 раза. Показано, что после изотермической кристаллизации в прокатанных лентах наблюдается эффект памяти формы . Установлено, что прокатка приводит к уменьшению характерных температур мартенситного превращения, сужению гистерезиса превращения, снижению величины эффекта памяти формы, а также к уменьшению шероховатости поверхности лент как с их контактной, так и со свободной стороны.
- ПубликацияТолько метаданные3D nano-manipulation and nano-assembling by the smallest and the fastest shape memory alloy nano-tools(2019) Koledov, V.; Von, Gratowski, S.; Lega, P.; Cotta, M.; Shelyakov, A.; Шеляков, Александр Васильевич© 2019 IEEE.The shape memory alloys (SMAs) have recently been recognized as reliable basement of the technology of mechanical nanotools with still non determined minimal size. Among them the intermetallic alloy Ti(NiCu) give promising possibilities to create the reconfigurable micro- and nanostructures with shape memory effect (SME) capable to produce mechanical work on nanoscale. In the present report the review of the basic physical phenomena, which provide the possibility for the application of nanostructured SMA Ti(NiCu) for creating of micro and nanotools is given. The preliminary strained layered composites of SMAs are discussed which provide the multiple reversible actuation of a SMA based tool. Fundamental studies devoted to search for minimal size, at which martensitic phase transition and controllable actuation of SMA based tools take place are described. The technology of SMAs treatment by FIB-CVD gives the possibility to create different kinds of micro and nanotools, like nano- tweezers, grippers, pinchers, screws etc. These micro-nanotools have active SME layer with the thickness from tenths nm to 1 μm The continuous bending actuation threshold frequency of the SMA based thermally controlled nanoactuator is proved to exceed 8000 Hz. The new mechanical nanotools with SME give possibility to provide 3D nanomanipulation of the real nano-objects such as CNTs, different nanowires, nanowhiskers and also bio-nanoobjects such as DNA, etc. One of very interesting fundamental physical question which arises at nano-manipulation is the restriction due to influence of Casimir and van der Waals forces between the interacting nanotools and objects to be manipulated.
- ПубликацияТолько метаданныеVariation in the structure of the amorphous NiTi-based alloys during mechanical vibrations(2020) Belyaev, S.; Rubanik, jr, V.; Resnina, N.; Rubanik, V.; Shelyakov, A.; Шеляков, Александр Васильевич© 2020 Elsevier B.V.The aim of the present work is to study the influence of the vibration temperature, frequency and amplitude on the structure of amorphous NiTi-based shape memory alloys. The Ti40.7Hf9.5Ni44.8Cu5, Ti40.7Hf9.5Ni41.8Cu8 and Ti50Ni25Cu25 melt-spun amorphous thin ribbons were subjected to low-frequency mechanical vibrations in a Dynamical Mechanical Analyser or ultrasonic vibrations in anvil. The results of the study have shown that the mechanical vibrations lead to a structural relaxation and initiate the beginning stage of the crystallisation in the amorphous NiTi-based shape memory alloys. During the vibrations with an amplitude of 4 μm, crystalline clusters, with a size of 4–6 nm, appear in the amorphous matrix. On an increase in the vibration temperature or frequency, the size of the crystalline clusters hardly changes. The clusters that form during the vibrations do not influence the crystallisation temperature but decrease the crystallisation enthalpy.
- ПубликацияТолько метаданныеInfluence of copper content and thermal treatment on shape memory effect in rapidly quenched TiNiCu alloys(2021) Borodako, K. A.; Shelyakov, A. V.; Sitnikov, N. N.; Zaletova, I. A.; Sevryukov, O. N.; Бородако, Кирилл Анатольевич; Шеляков, Александр Васильевич; Ситников, Николай Николаевич; Севрюков, Олег Николаевич© 2021 Institute of Physics Publishing. All rights reserved.Amorphous alloys of the TiNi - TiCu system with a copper content of 25 to 40 at.% were prepared by planar flow casting at a melt cooling rate of 106 K/s. Crystallization of the alloys was carried out by isothermal annealing and by action of single electric pulse with a duration of 5 ms. Shape memory behavior and structure of the alloys was investigated by means of bending tests and X-ray phase analysis. It was found that increasing the copper content to above 30 at.% considerably reduces the plasticity and shape memory effect of the alloys. However, abrupt decreasing the annealing duration significantly improves the shape memory performance due to prevention of the formation of brittle Ti-Cu phases in the alloys structure.
- ПубликацияТолько метаданныеInfluence of the holding temperature on the kinetics of the isothermal B2 → B19′ transformation in TiNi-based shape memory alloy(2020) Demidova, E.; Belyaev, S.; Resnina, N.; Shelyakov, A.; Шеляков, Александр Васильевич© 2019, Akadémiai Kiadó, Budapest, Hungary.The aim of the present paper was to study the kinetics of the isothermal B2 → B19′ transformation in the quaternary Ti40.7Hf9.5Ni44.8Cu5 shape memory alloy in a wide temperature range to find the common features of this phenomenon in NiTi-based alloys. It was found that the isothermal B2 → B19′ martensitic transformation occurred during holding at a constant temperature both within and outside of the temperature range of the forward transformation. The holding temperature of T* influenced the maximum value of the martensite phase (ΦM) that appeared under isothermal condition and the rate of the martensite volume fraction variation. The maximum ΦM value of 80% was found when holding was at T* = Ms (the start temperature of the forward martensitic transformation on cooling), and it was two times larger than in quenched Ni51Ti49 alloy. An increase in holding temperature larger than Ms decreased the maximum ΦM value and the slope of the ΦM(t) curve. A decrease in the holding temperature less than Ms decreased the ΦM value and hardly influenced the dΦM/dt value. It was found that the variation in volume fraction of the martensite phase that appeared under isothermal holding at different temperatures in the Ti40.7Hf9.5Ni44.8Cu5 shape memory alloy was close to the binary Ni51Ti49 alloy, and hence, it was concluded that the features of the kinetics of the isothermal B2 → B19′ transformation were common for this type of transformation in non-stoichiometric NiTi-based alloys.
- ПубликацияТолько метаданныеStudy of the Structure, Phase Transformations, and Shape Memory Effect in Amorphous-Crystalline TiNiCu Alloy(2025) Shelyakov, A. V.; Sitnikov, N. N.; Khachatrian, D. A.; Zaletova, I. A.; Шеляков, Александр Васильевич; Ситников, Николай Николаевич; Хачатрян, Давид Арменович
- ПубликацияОткрытый доступStructure and functional properties of rapidly quenched TiNiCu alloys with high copper contents(2021) Shelyakov, A. V.; Sitnikov, N. N.; Borodako, K. A.; Khabibullina, I. A.; Dyadechko, A. A.; Шеляков, Александр Васильевич; Ситников, Николай Николаевич; Бородако, Кирилл Анатольевич© Published under licence by IOP Publishing Ltd.Thin materials exhibiting the shape memory effect, with a narrow temperature hysteresis, are required to create miniature and high-speed devices. Quasi-binary intermetallic TiNi-TiCu alloys with high copper contents (more than 10 at %) demonstrate the reversible martensitic transformation with a small (4-6 K) hysteresis. Alloys of the TiNi-TiCu system with a copper content of 30-40 at.% were fabricated in an amorphous state by the planar flow casting technique at a melt cooling rate of106 K/s in the form of ribbons 30-50 μm thick. The alloy samples were subjected to dynamic crystallization using a single electric current pulse with duration of 5 ms. X-ray diffraction studies revealed almost fully martensitic state of the alloys with B19 structure at room temperature. TEM examination showed their structure to contain typical B19-martensite plates with a mean size of 20-80 nm. At the same time, the alloys exhibit a one-stage phase martensitic transformation B2↔B19 in the temperature range of (55 75) C, as well as pronounced shape memory effect, whose properties are largely determined by the structural parameters of the alloys.
- ПубликацияТолько метаданныеTwo-Way Shape Memory Effect in Rapidly-Quenched High-Copper TiNiCu Alloys Deformed in the Martensitic State(2020) Shelyakov, A. V.; Sitnikov, N. N.; Borodako, K. A.; Sevryukov, O. N.; Шеляков, Александр Васильевич; Ситников, Николай Николаевич; Бородако, Кирилл Анатольевич; Севрюков, Олег Николаевич© 2020, Pleiades Publishing, Ltd.Abstract: The effect of martensitic deformation on the two-way shape-memory effect (SME) of quasi-binary high-copper TiNi–TiCu alloys (with 25–40 at % Cu) is studied. The alloys are prepared by rapid quenching from the melt in an amorphous state in the form of ribbons 30–50 μm in thickness. The alloys crystallize during isothermal annealing, the time of which is varied from 100 to 300 s, and during a single current pulse 10 ms in duration. The relatively low bending strains (1.5–3%) are shown to cause two-way SME in TiNiCu alloys; as the strain of martensite increases, the reversible strain in the martensitic transformation range increases markedly. An increase in the copper content is found to cause a substantial decrease in the value of two-way SME, which is related to the formation of the brittle TiCu phase. At the same time, a decrease in the heat treatment time causes an increase in the reversible strain, which reaches the maximum value (2.35%) for the alloy with 25 at % Cu subjected to high-rate electric pulse treatment.
- ПубликацияТолько метаданныеThe influence of neutron irradiation in amorphous state on the crystallization and martensitic transformation in the NiTi-based shape memory alloys(2019) Belyaev, S.; Chekanov, V.; Konopleva, R.; Nakin, A.; Shelyakov, A.; Шеляков, Александр Васильевич© 2019 Elsevier B.V. The influence of neutron irradiation on the amorphous Ti 40.7 Hf 9.5 Ni 44.8 Cu 5 and Ti 50 Ni 25 Cu 25 thin ribbons, their crystallization behaviour and martensitic transformations that occur after crystallization have been studied. The critical fluence value of 1⋅10 19 cm −2 was found. If the fluence was 1⋅10 19 cm −2 or less, the crystallization parameters and the temperatures of the martensitic transformation that took place alloy after crystallization hardly changed. Otherwise, a huge increase in the crystallization temperature and enthalpy occurred and the degradation of the martensitic transformation in crystallized samples was observed.
- ПубликацияОткрытый доступInvestigation of thermal-structural characteristics at two-way shape memory effect of rapid quenched laminated amorphous-crystalline ribbons of Ti50Ni25Cu25alloy(2020) Sivtsova, G. V.; Khabibullina, I. A.; Sitnikov, N. N.; Shelyakov, A. V.; Ситников, Николай Николаевич; Шеляков, Александр Васильевич© Published under licence by IOP Publishing Ltd.The work is devoted to the study of processes of structural changes leading to the realization of the two-way shape memory effect (TWSME) in the rapid quenched amorphous-crystalline alloy Ti50Ni25Cu25. The object of the study was a rapid quenched laminated amorphous-crystalline Ti50Ni25Cu25 alloy ribbon with a thickness of about 39 um and with a thickness of surface crystal layer about 10 µm was present on the non-contact side relative to the quenching wheel. In the ribbon under study, without any additional heat treatments the TWSME with bending deformation from a rectilinear shape during heating and cooling in the range of martensitic transformation is manifested. The samples were characterized by means: scanning and transmission electron microscopy; X-ray diffraction analysis; differential scanning calorimetry; measuring the characteristics of the crystalline layer during the implementation of TWSME and the temperature dependence of the form change. It was shown that the formation of a laminated amorphous-crystalline composite occurs due to the martensitic transformation of B2~B19 in the crystal layer and the accompanying TWSME as a result of which the crystal layer is reduced.