INFLUENCE OF THE INITIAL STRUCTURAL STATE OF THE CU-0.6CR ALLOY ON RECRYSTALLIZATION IN THE PROCESS OF SPD

Abstract

An alloy of the Cu-Cr-Zr system is a promising high-strength electrically conductive material. Inturn, due to the significant refinement of the structure, SPD methods can significantly increase themechanical characteristics. Therefore, the study of structural and phase changes in this system of alloysunder SPD conditions is of particular interest. It is known that deformation treatment at temperaturesabove 450–500 °C can be accompanied by recrystallization processes. The type of recrystallizationunder deformation conditions depends on the characteristics of boundaries and grains. In this paper,we study the issue of the influence of the initial type of structure on the nature of recrystallizationunder conditions of warm ECAP conform at 450 °C in the Cu-0.6Cr alloy. Coarse-grained equiaxed,obtained after high-temperature annealing at 1050 °C and subsequent quenching in water, and astripe structure, obtained by drawing, were used as the initial state. It has been established that in thecase of initial equiaxed grains, the centers of recrystallization during ECAP will be predominantlytriple junctions of grains. In the case of elongated grains, the character of continuous dynamicrecrystallization was observed. That is, the nucleation of recrystallized grains occurs along elongatedgrain boundaries. The main reason can be considered a more stressed state of the boundaries in theoriginal structure after drawing.