1994 Volume 80 Issue 3 Pages 231-236
Formation and growth kinetics of Fe-Zn intermetallic phases on surfaces of Fe specimens in molten Pb containing 10 mass% Zn at 613 to 693 K were investigated. ζ phase layer was first formed on the surface and then palisade δ1, Γ, Γ1 and compact δ1 phase layers were formed successively with the lapse of annealing time. Incubation times of these phases decrease with an increase in temperature. Growth of the intermetallic phases does not follow the parabolic rate law, although their thickness increases with annealing time. The formation order, incubation times and growth kinetics of the intermetallic phases are much the same as those in Fe-Zn diffusion couple. The reason why such a result was obtained can be explained on the basis of the local equilibrium concept in reactive diffusion, because value of Zn chemical potential in the molten Pb-Zn is nearly equal to that in solid Zn.