Radial solute segregation during unidirectional solidification

Based on the symmetry of an actual unidirectional solidification system, the slightly curved liquid-solid interface related radial solute distribution inhomogeneity during diffusion-controlled steady-state unidirectional solidification of a binary alloy is calculated by means of linear approximation in a cylindrical coordinate system. The results show that the radial solute segregation is qualitatively proportional to the solute Peclet number, relative interface depth h·R^-1 and (1-k), where k is the equilibrium solute partition coefficient. Also, it is slightly quantitatively smaller than Corielle's result gotten from the planar rectangular coordinate system.