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 доступFormation of structure of TiNiCu alloys with high copper content upon producing by planar flow casting(2020) Shelyakov, A. V.; Sevryukov, O. N.; Sitnikov, N. N.; Borodako, K. A.; Khabibullina, I. A.; Шеляков, Александр Васильевич; Севрюков, Олег Николаевич; Ситников, Николай Николаевич; Бородако, Кирилл Анатольевич© Published under licence by IOP Publishing Ltd.The rapidly quenched alloys of the quasibinary intermetallic TiNi-TiCu system with a high copper content (more than 25 at.%) are of great interest as shape memory materials due to the possibility of a significant decrease in the temperature and deformation hysteresis in comparison with the binary TiNi alloy. To obtain alloys with a copper content of 25 to 40 at.%, the planar flow casting technique was used. The alloys were fabricated at a melt cooling rate of about 106 K/s in the form of ribbons 30-50 µm thick and wide in the range from 7 to 20 mm. The study of the structure of the alloys was carried out using X-ray diffraction analysis, scanning and transmission electron microscopy. It was shown that from the ribbon side, contacting the quenching wheel, all alloys are amorphous, while on the non-contact side of the ribbons of alloys with 25 and 30 at.% Cu, a thin surface crystalline layer with a B2 structure is observed. Using energy dispersive X-ray spectroscopy, it was found that the content of the alloy components in the amorphous and crystalline phases coincides.
- ПубликацияОткрытый доступApplication of laser radiation for creation of metamaterial based on rapidly quenched shape memory TiNiCu alloy(2020) Sitnikov, N. N.; Irzhak, A. V.; Tabachkova, N. Yu.; Koledov, V. V.; Borodako, K. A.; Shelyakov, A. V.; Ivanov, A. A.; Бородако, Кирилл Анатольевич; Шеляков, Александр Васильевич; Иванов, Андрей Анатольевич© 2020 IOP Publishing Ltd.The work deals with application of laser radiation for creation of metamaterial - layered structural composite based on rapidly quenched TiNiCu thin ribbon. Structural properties of the composite were examined by transmission and scanning electron microscopy. Considerable two-way shape memory effect was achieved and studied.
- 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.
- 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.
- ПубликацияОткрытый доступInvestigation of the effect of electric pulse heat treatment of rapid-quenched Ti50Ni25Cu25 alloy ribbons with a thin surface crystal layer on the structure formation from an amorphous state(2020) Khabibullina, I. A.; Mashchenko, V. I.; Sivtsova, G. V.; Sitnikov, N. N.; Shelyakov, A. V.; Ситников, Николай Николаевич; Шеляков, Александр Васильевич© Published under licence by IOP Publishing Ltd.This work is devoted to the study of the influence of electric pulse heat treatment of rapid-quenched Ti50Ni25Cu25 alloy ribbons (at. %) with a surface crystal layer. The object of the study was a rapid-quenched layered amorphous-crystal ribbon with a thickness of about 30 GMSH. A three-dimensional finite element mesh generator with built-in pre-and post-processing facilities. http://gmsh.info/m and a width of about 1.5 mm, in which a thin surface crystal layer (2.5 μm) was present on the non-contact side relative to the quenching wheel. The alloy samples were subjected to electric pulse treatment by passing a single pulse of electric current through the sample with a variable duration. For comparison, samples of the alloy were obtained, crystallized by standard isothermal heat treatment. The samples were characterized by means of scanning electron microscopy techniques, energy dispersive X-ray analysis and differential scanning calorimetry. It was shown that electric pulse treatment with an exposure time of less than 1 second leads to a significant change in the formed crystalline structure in comparison with the structure obtained by isothermal treatment. The microstructure of such samples in cross section is characterized by an uneven distribution of crystals over the thickness of the ribbon: columnar crystals are observed from the contact and non-contact sides of the ribbon, and large crystals are present in the inner part of the ribbon.