Reactive diffusion between solid Fe and liquid Zn was studied experimentally using Fe/Zn diffusion couples prepared via an immersion technique. Using this technique, a pure Fe sheet was immersed in a pure molten Zn bath at a constant temperature of 723K for times of up to 2h. The microstructure of the cross-section of the Fe/Zn diffusion couple was observed using scanning electron microscopy, and the chemical composition of each phase was determined using electron probe microanalysis. The interface concentrations of Fe for the ζ-FeZn13 and δ-FeZn7-10 phases at the ζ/δ interface, cζδ and cδζ, and for the liquid-Zn (L) phase at the ζ/L interface, cLζ, as determined from the diffusion couples, were found to be much higher than the corresponding equilibrium values; especially in the early stages (up to 300s). The difference gradually decreased during immersion. The deviations from the equilibrium values of cζδ and cLζ were proportional to the interdiffusion flux across the ζ-phase layer.

Reactive Diffusion between Solid Fe and Liquid Zn at 723K. R.Kainuma, K.Ishida: Iron and Steel Institute of Japan International, 2007, 47[5], 740-4