“…It is seen from the figure that the velocity of the interface is slower for higher value of diffusivity ratio. Thus the result conforms with the statement of Dursunkaya and Nair[13] that when ratio of thermal diffusivities is small, the interface motion is rapid.Fig. 2reveals the dependence of the moving interface on dimensionless time for three values of solid Stefan number S 1 = 0.65, 0.75, 0.85 and for fixed S 2 = 0.1, a 21 = 0.7.…”