A. V. Stolbovsky, V. V. Popov, E. N. Popova, S. A. Murzinova

SPECIFIC FEATURES OF THE GRAIN STRUCTURE IN Ni-Cu ALLOYS AT THE SATURATION STAGE UNDER HIGH-PRESSURE TORSION

Effect of doping in the Ni-Cu system on the structure formed under room-temperature high-pressure torsion is studied, and the statistical analysis of the grain structure under steady-state deformation (saturation stage) is done. It is demonstrated that in all the alloys considered (with 10, 34, and 90 at. % of Cu) there are two groups of crystallites, in one of which a pronounced effect of relaxation processes is observed, whereas in the other one they are not revealed. The ratio of the volume fractions of these groups depends on the alloy composition and, correspondingly, on its melting temperature. It is shown that the final average grain size is formed under the effect of dominating crystallite group depending on the alloy melting temperature. The non-linearity in the crystallite sizes and volume fractions of the crystallite groups dependently on the alloy composition is observed, indicating the noticeable effect of stacking-fault energy on the structure forming under the deformation.

Acknowledgment: The work was performed within the state assignment on the theme Function, No. g/r AAAA-A19-119012990095-0 and supported by the Basic Research Program of UB RAS, project No. 18-10-2-37.

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