The Diffusion of Copper in Iron

Measurements of the diffusion of 64Cu in pure and impure α and γ iron show a large discontinuity in the Arrhenius plot of the lattice diffusion coefficient at the α-γ transformation, contrary to the data of Anand and Agarwala [J. Appl. Phys. 37, 4248 (1965)]. Grain-boundary diffusion predominates at T≤815°C in the α phase and at T≤1250°C in the γ phase. Trapping of the radioactive copper by inclusions or impurities in solution also appears to have a profound effect on the diffusion process.