Formation of intermetallic particles in an Fe-Ni-Al alloy during annealing and electron irradiation

Abstract

The behavior of intermetallic nanoparticles, such as Ni3Al, and vacancy defects in an fcc Fe-Ni-Al alloy during annealing and electron irradiation is studied by measuring residual resistivity. It is shown that, during annealing at early stages, Ni3Al zones are formed in the quenched Fe-Ni-Al alloy, which increase residual electrical resistance, and during annealing above 700 K, nanosized (~4.5 nm) intermetallic precipitates are formed from them, uniformly distributed in the alloy matrix, whose growth leads to a decrease in residual resistivity. Under irradiation at room temperature, vacancy defects accumulate in the alloy in the form of vacancy complexes. The dissociation of these complexes at about 400 K causes the appearance of freely migrating vacancies and enhances self-diffusion forming Ni3Al bands. At about 600 to 700 K, the solid solution is decomposed thermally. At higher temperatures, the formation of intermetallic particles occurs, which is characterized by a decrease in electrical resistance.