Statistical analysis of grain structure features in Ni-Cu alloys at the saturation stage under high-pressure torsion

Abstract

Statistical analysis of the Ni-Cu system grain structure formed at room temperature under high-pressure torsion at 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 they are not revealed in the other one. 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 the dominating crystallite group depending on the alloy melting temperature.