Influence of Equal-Channel Angular Pressing on Grain Structure and Internal Stresses of Technically Pure Nickel
| Parent link: | Russian Physics Journal Vol. 65, iss. 9.— 2023.— [P. 1436-1442] |
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| Other Authors: | , , , |
| Summary: | Title screen Using transmission electron microscopy, the structure, phase composition, defects, amplitude of internal stresses and their sources are studied in the ultrafine-grained technically pure nickel produced by the method of equal-channel angular pressing (ECAP). During ECAP, the samples are subjected to shear deformation by compression along two intersecting channels of equal diameters at an angle of 120° and a temperature of T = 400°C without intermediate annealing within four passes, n = 4. An examination of the grain structure demonstrates that all grains are anisotropic. According to the dislocation structure, the grains are classified into three types: 1) the smallest grains with no substructure (practically no dislocations) – dislocation-free grains, 2) larger grains containing chaotically distributed dislocations or a net substructure, and 3) the largest grains with a cellular or fragmented substructure. The average value of the scalar dislocation density in the grains of each type is calculated. It is found out that equal-channel angular pressing results in the formation of nanosized particles of secondary phases localized inside the grains, at grain boundaries and at grain junctions of ultrafine-grained nickel. The sources of internal stresses are revealed and their amplitude is determined. The amplitude of the internal stresses is calculated using the amplitude of the crystal lattice curvature-torsion from the bending extinction contours Режим доступа: по договору с организацией-держателем ресурса |
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2023
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| Subjects: | |
| Online Access: | https://doi.org/10.1007/s11182-023-02788-5 |
| Format: | Electronic Book Chapter |
| KOHA link: | https://koha.lib.tpu.ru/cgi-bin/koha/opac-detail.pl?biblionumber=669200 |