88 research outputs found
Application of Laser Radiation for Fabrication of Micromechanical Actuator Based on Two-Way Shape Memory Effect
The work deals with production and research of experimental samples of micromechanical actuator based on the rapidly quenched TiNiCu alloy, in which a two-way shape memory effect is formed as result of impact of the laser radiation. By the technique of focused ion beams an element with thickness of 5 microns, width of 7 microns and 100 microns in length was obtained, bending reversibly to 2.5 microns in the heating-cooling cycle.
Keywords: shape-memory alloy, thin ribbon, two-way shape memory effect, laser treatment, micromechanical actuato
Thermal energy conversion by coupled shape memory and piezoelectric effects
International audienceThis work gives experimental evidence of a promising method of thermal-to-electric energy conversion by coupling shape memory effect (SME) and direct piezoelectric effect (DPE) for harvesting quasi-static ambient temperature variations. Two original prototypes of thermal energy harvesters have been fabricated and tested experimentally. The first is a hybrid laminated composite consisting of TiNiCu shape memory alloy (SMA) and macro fiber composite piezoelectric. This composite comprises 0.1 cm3 of active materials and harvests 75 µJ of energy for each temperature variation of 60 °C. The second prototype is a SME/DPE 'machine' which uses the thermally induced linear strains of the SMA to bend a bulk PZT ceramic plate through a specially designed mechanical structure. The SME/DPE 'machine' with 0.2 cm3 of active material harvests 90 µJ over a temperature increase of 35 °C (60 µJ when cooling). In contrast to pyroelectric materials, such harvesters are also compatible with both small and slow temperature variations
RESEARCH OF RAPIDLY QUENCHED RIBBONS OF TINICU ALLOYS WITH HIGH COPPER CONTENT
Amorphous alloys of the TiNi–TiCu system with a copper content of 25 to 40 at. % were obtained by melt spinning technique in the form of 30–50 µm thick ribbons. It is shown that, compared to isothermal annealing, high.speed electropulse heat treatment leads to a dramatic improvement in the ductility of alloys and characteristics of shape memory effects.Аморфные сплавы системы TiNi–TiCu с содержанием меди от 25 до 40 ат. % получены методом спиннингования расплава в виде лент толщиной 30–50 мкм. Показано, что по сравнению с изотермическим отжигом высокоскоростная электроимпульсная термообработка приводит к резкому улучшению пластичности сплавов и характеристик эффектов памяти формы.Работа выполнена за счет гранта РНФ (проект № 19-12-00327)
Laminated Amorphous-Crystalline Rapid Quenched Ribbons of Ti50Ni25Cu25 alloy with Two-Wae Shape Memory Effect
Alloys with shape memory effect are promising materials for the creation actuators of various devices. For the miniaturization of devices it becomes relevant to obtain thin-dimensional materials with the effect of two-way shape memory (TWSME). This work is devoted to the study of the properties of rapid-quenched amorphous-crystalline thin ribbons from the TiNi–TiCu alloy system, possessing TWSME.Сплавы, обладающие эффектом памяти формы, являются перспективными материалами для создания приводов различных устройств. Для миниатюризации таких устройств, создания микро- и, возможно, наноустройств является актуальным получение тонкомерных материалов с эффектом обратимой памяти формы (ЭОПФ). Данная работа посвящена исследованию свойств быстрозакаленных аморфно-кристаллических тонких лент из сплава системы TiNi–TiCu, обладающих ЭОПФ.Работа выполнена по гранту при финансовой поддержке РНФ, проект № 19-72-00145
Thermal strain parameters of the rapidly hardened alloy Ti50Ni25Cu25 upon cycling in the martensitic transformation range
Fiber-Optic Thermosensor Based on Shape Memory Effect
A fiber-optic thermosensor using thin shape memory ribbons of rapidly quenched TiNiCu alloy as thermosensitive element is described. It is shown that the developed thermosensor is optically passive, resistant to corrosion and to radio and electromagnetic noise. Also it has a fast response (less than 1 sec), a high reliability and durability (more than 105 cycles), a small size and high simplicity of thermosensitive part. Its switching temperature can be varied in a wide region (273-353 K) with alloy composition
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