The Grain-Boundary Diffusion of Zn in α-Fe

Using semi-infinite amounts of pure Zn and pure Fe as the diffusing media and maintaining constant boundary conditions, the diffusion of Zn into αFe has been experimentally studied at temperatures of 400, 500, and 725 °C. Long diffusion times (4 days) were used to allow the various intermetallic phases to become well developed. It was determined that diffusion of Zn into Fe is not “anomalously rapid,” but follows normal diffusion behavior for polycrystalline metals in that both lattice diffusion and grain-boundary diffusion contribute to mass transport for the temperatures investigated. The grain-boundary diffusion coefficients determined are consistent with those for many other metal systems.