Phase-field study for the influence of solute interactions on solidification process in multicomponent alloys

The industrial alloys, such as steel and aluminum alloy, always contain more than two main solutes. The phase equilibrium and solute diffusion behaviors in multicomponent alloys will be no longer the same as that in binary alloys because of the solute interactions. In order to study the influence of solute interactions on the solidification process, we develop a phase-field model for multicomponent alloy coupled with thermodynamic and diffusion mobility database, which can accurately predict the phase equilibria and solute diffusion transportations. The model is applied to Al–Cu–Mg and Al–Cu–Si systems respectively. There are totally different solute interactions in these two systems, that is, attractive interactions in Al–Cu–Mg alloy and repulsive interactions in Al–Cu–Si alloy. Their influences on the solidification process are quantitatively analyzed from the phase-field simulation results.