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Information × Registration Number 0221U103202, 0118U003109 , R & D reports Title Physical mechanisms of inelastic deformation of nanostructural crystalline materials, high-entropy alloys and polymer compositions under conditions of moderate and deep cooling. popup.stage_title Head Pal-Val Pavel P., Доктор фізико-математичних наук Registration Date 16-02-2021 Organization B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine popup.description2  The physical mechanisms of grain boundary hardening of nanocrystalline titanium at temperatures of 4.2-400 K, obtained by the original method of cryomechanical fragmentation of grain structure, are elucidated. A theoretical substantiation of the violation of the classical Hall-Petch ratio detected at low temperatures for the dependence of the yield strength on the grain size is proposed. In the study of the influence of the microstructure on the parameters of abrupt plasticity in the microgranular alloy AZ31 subjected to intense plastic deformation and annealing, we found a nonmonotonic dependence of the hardening coefficient on deformation and low amplitude of abrupt deformation at 4.2 K, which is a consequence of It is established that the controlling mechanism of plastic deformation in the CoCrFeNiMn nanocrystalline WES obtained by torsion under high pressure at temperatures of 300 and 77 K is the overcoming by dislocations of local barriers (clusters of atoms of atomic scale). When studying the micromechanical properties of AZ31 alloy and the influence of previous low-temperature plastic tensile deformation to failure, it was found that the modes of preparation of AZ31 alloy significantly affect the parameters of plastic deformation: its homogeneity, strain hardening, yield strength and deformation. As a result of the study of the influence of annealing on the evolution of the dislocation structure in copper, conducted by acoustic and X-ray methods, it was found that the most intense change in the density of mobile dislocations occurs at temperatures 30-40 C below the temperature of their total density. Spontaneous flexoelectric polarization of dislocations in quantum He and H crystals is envisaged, which occurs due to mutual polarization of electroneutral He atoms and H2 molecules in combination with a high level of asymmetry of their configurations in the dislocation nuclei. Product Description popup.authors popup.nrat_date 2021-02-16 Close