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Information × Registration Number 0203U002467, 0100U003287 , R & D reports Title Influence of the structural and external factors on the localization of the plastical deformation and the destruction of the materials popup.stage_title Head Andronov V.M., Registration Date 23-06-2003 Organization Kharkov National University named after V.N. Karazin popup.description2 Objects of experimental research are the constructional aluminum-lithium alloys 1450 (Al-2,64 wt.%Cu-2,2 wt.%Li-0,12 wt.%Zr), 1421 (Al-3,0 wt.%Mg -2,2 wt.%Li-0,15 wt.%Zr-0,2 wt.%Sc), modeling alloys Al-(3-12)wt.%Mg, thread-like crystals of cooper and amorphous materials Ni78Si8B14 and 11XCP. The purpose of the work is to study the influence of structural changes and temperature-rate conditions of deformation on stability and mechanisms of plastic deformation of materials, in particular, superplastic flow of aluminum alloys, unstable plastic deformation of threadlike crystals and also to investigate the kinetics of the ageing processes by the method of internal friction. Under the tests in the creep regime in the range of temperatures Т = 723ё803 К for an alloy 1421 superplasticity is realized. It is shown, that at temperature Т і 773 К in superplastically deformed samples of the alloy 1421 the liquid phase is present. The direct proof of it is the presence of bunches of threadlike formations in surface cavities of deformed specimens. Thus in the range of temperatures 723ё773 К the activation energy of superplastic deformation is108±14 kJ/mol, and in the range of temperatures 773 ё 803 К the value of activation energy grows and becomes 152±16 kJ/mol. The proposition is made that the increase of the activation energy of the superplastic deformation is connected to the change of the micromechanism of realization of the grain boundary sliding, caused by the local melting on the grain boundaries. Research of ageing kinetics of alloys Al-(3-12) wt.% Mg is carried out directly in the relaxator. It is shown, that at ageing in situ the minimal values of internal friction connected with dispersoid hardening, are reached earlier on the contrary to the existing before understandings. The little amplitude decrease of internal friction is revealed during the long ageing connected to movement with low friction of dislocation segments in areas, free from segregations and impurities. Product Description popup.authors popup.nrat_date 2020-04-02 Close