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Information × Registration Number 0217U007289, 0117U003885 , R & D reports Title Investigation of the mechanical behavior regularities of shape memory alloys taking into account the loading regimes and hydrogen action popup.stage_title Head Yasniy Oleg Petrovych, Registration Date 27-12-2017 Organization Ternopil National Technical Ivan Puluj University popup.description2 The design of specimens for investigation the mechanical, corrosion-mechanical and electrochemical properties of NiTi is proposed. The methodology approaches for determining the strength and plastic characteristics of the NiTi alloy, the stresses of the start and the end of structural transformations for stretching, the resistance of the alloy to hydrogen embrittlement and corrosion cracking, as well as the electrochemical behavior in fluoride-containing aqueous media, have been developed. The ductile type of fracture on the macro and microscale of the nitinol spacimens under uniaxial tension in the air at room temperature was found. The macrofracture of the specimen is oriented normally to the action of the external load and only near the lateral surface of the specimen (up to 100 micrometers) the shear zone was found. The origin of the fracture is located near the surface of the specimen. For a hydrogenated alloy, a pseudoelastic structural transformation begins at a significantly lower stresses compared to an non-hydrogenated one. On the initial stage the structural transformation proceeds with increasing of stress and then reaching a certain maximum is accompanied by stress relaxation and ends at almost the same level of stress as it began. The destruction of the hydrogenated alloy occurs at a much lower stress than for a non-hydrogenated alloy (about 800 MPa). It was found that the cyclic uniaxial loading increases the residual deformation of the alloy at a minimum load value and reduces the area of the hysteresis loop in comparison with first cycle. Product Description popup.authors Дивдик Олександр Васильович Студент Олександра Зіновіївна Цимбалюк Любов Іванівна Цирульник Олександр Тимофійович Ясній Олег Петрович popup.nrat_date 2020-04-02 Close