Lamellar eutectic growth controlled by solute diffusion

Based on the planar diffusion assumption, the solute boundary layer in lamellar eutectic growth under steady-state is estimated by means of modifying the conservation of mass at solid/liquid interface. It is found that the solute boundary layer along the growth direction is related to that along the solid/liquid interface. For transparent organic system CBr₄-C₂Cl₆ with eutectic composition, the difference in average compositions of the solid and the liquid at solid/liquid interface increases with increasing in growth rate. The average composition in the liquid at solid/liquid interface still closes to the eutectic one as the initial composition of the alloy is apart from the eutectic point. In addition, for a fixed growth rate, the ratio of the difference in average composition to the lamellar width changed with initial composition of the alloy is noticeably distinct.