Phase separation of solid solution in Fe-Ni and Fe-Ni-P alloys during irradiation, deformation, and annealing

Abstract

Measurements of residual resistivity and thermal expansion coefficient have been used to study processes of phase separation in the solid solution of the Fe-34.7 at % Ni and Fe-34.7 at % Ni-0.1 at % P alloys that occurred during deformation, electron irradiation, and subsequent annealings. It has been shown that during both deformation and irradiation, vacancy clusters appear with various multiplicities. In both the deformed alloys and alloys irradiated at room temperatures, the presence of phosphorus atoms in the solid solution facilitates the formation of the vacancy clusters and increases the fraction of vacancies that survive in the form of vacancy clusters. After deformation, irradiation, and subsequent annealings, the same changes are observed in the electrical resistance and thermal expansion coefficient. A nearly linear dependence of the increment in the electrical resistance on the thermal expansion coefficient has been obtained. The results agree well with the matrix model of the phase separation of the solid solution.