Effect of Barocryodeformation Degree at 77 K on the Precipitation Structure in CuCrZr Alloy

Abstract

AbstractThe effect of severe plastic deformation by barocryodeformation at liquid nitrogen temperature on the structure of precipitation-hardened commercial CuCrZr alloy is investigated. In particular, the dependence of the microstructure, the preferential orientation of the crystallites, and the lattice period of the alloy on the deformation degree were studied. The samples were preliminarily water quenched from a premelting temperature to create a supersaturated solid solution of dopants in the copper matrix. It was shown that the evolution of the average size and distribution density of the precipitates with the degree of deformation increase indicates the occurrence of competing processes in the alloy. It was shown that the decomposition of the solid solution due to the strain-induced acceleration of diffusion processes and strain-induced dissolution of the precipitates definitely contribute to the evolution of the structure. The conclusion about the simultaneous occurrence of kinetically opposite phase transformations was confirmed by the observation of a nonmonotonic change in the lattice constant of the matrix and the precipitates density with increasing accumulated deformation.KeywordsSevere plastic deformationDeformation-induced precipitationDeformation-induced dissolutionCopper alloy