Decomposition of crystal-growth equations in multicomponent melts

• A new variational method describing crystal growth has been developed.
• The equations can be applied to crystal growth out of supercooled, multicomponent melts.
• The model was applied to the process of crystal growth when annealing amorphous tapes of the FINEMET® alloy Fe73.5Cu1Nb3Si13.5B9.

Using a variational approach, the macroscopic laws of the growth of a new-phase, multicomponent particle are compared to the physicochemical laws of processes in the “new phase – initial melt” system. A suitable equation-based method has been developed to calculate the growth of a new-phase particle under the conditions of diffusion growth and non-equilibrium solute trapping by the quickly growing front of a new phase. The laws of crystal growth have been studied while annealing the amorphous alloy FINEMET® Fe73.5Cu1Nb3Si13.5B9.