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Information × Registration Number 0304U004215, 0103U004187 , R & D reports Title Influence of structural changes and external factors on mechanical and relaxation properties of materials popup.stage_title Вплив структурних змін на механічні та релаксаційні властивості матеріалів Head Andronov V.M., Registration Date 26-03-2004 Organization Kharkov National University named after V.N.Karazin popup.description2 The objects of experimental investigations are whiskers of copper and silver, amorphous alloys Ni78Si8B14 and 11XCP; the alloys Fe-(9,4-40,0) at.% Al, Fe-34,9 at.% Ni; the 1420 Al-base alloy (mass. %): 5,0 - 6,0 % Mg; 1,9 - 2,3 % Li; 0,09 - 0,15 % Zr; 0,1 - 0,3 % Si; _ 0,3 % Fe; 0,1 % Ti; 0,3 % Mn; 0,005 % Na.The aim of this work is investigation of correlation of relaxation properties of ordering alloys on iron base with particularities of the structural state; study of influence of the structural change and temperature-speed conditions on stability and mechanisms оf ma-terials plastic deformation.The methods of the studies is a mechanical testing, mechanical spectroscopy, transmission and raster electronic microscopy, measurements in superstructure reflexes, energy dispersion X-ray microanalyses, thermal gravimetry, metallographic investiga-tions, thermal activation analysis.In quenched Fe-(9,4-40) at.% Al alloys at concentration more than 25 at.% Al ex-cept effects of the relaxation due to carbon (Snoek peak), and reorientation Al-atom pairs (Zener peak) additional Х-peak with energy of the activation 154,4-160,7 kJЧmol-1 (depending on Al content) exists. X-peak firstly in intermetallide Fe3Al at condition of sharp quenching in solution of the rock salt in water had been observed. The peak mechanism links with relaxation due to carbon, in solid solution with raised content of vacancies and ordering B2-type disposition of Al atoms. In the 1420 alloy in process of superplastic deformation inside a pores are formed and developed the filament. It is placed mainly in parallel to axis of the straining and fixed on grain borders. It is established, that magnesium concentration in filament greatly higher then average value in sample, and surface of their is covered by films of magnesium and aluminium oxides. The process of superplastic deformations is realised at presence on grain borders viscous fluid phase at the temperature which is below the temperature of equilibrium solidus. The threshold-like type effect of point defect influence on mechanical properties of copper whiskers was found out. It is shown that there exists a critical concentration of admixtures, under which the dislocations already do not reach relativistic velocities due to damping on potential relief of point defects. The relaxation spectra of investigated amorphous alloys is analysed.The results of this research can be used for improvement physical theories of internal friction and development of scientific comprehension of the nature and physics of plasticity and superplasticity and their application in creation new composite and superplastic materials. Product Description popup.authors popup.nrat_date 2020-04-02 Close