An analytical model for solute diffusion in multicomponent alloy solidification

•We develop a model for multicomponent diffusion during alloy solidification.•The model takes into account the local-nonequilibrium diffusion effects.•The model takes into account the interaction between the solutes.•The solute distributions in the liquid phase are calculated.•We discuss the influence of the interaction between the species on solute redistribution.

An analytical model describing steady-state plane front solidification of multicomponent alloys has been developed, taking into account both the diffusive interaction between the solutes and the local nonequilibrium diffusion effects in the bulk liquid. These effects strongly affect the solute distributions in the liquid phase ahead of the interface. At relatively low interface velocity the strong diffusional interaction between the species leads to a minimum or a maximum of solute concentration ahead of the interface. In ternary systems the model predicts two-step transition to diffusionless solidification.