Eddy-currents generate heat sources in the melted volume of a ferromagnetic material placed in a moving crucible. The solidification is produced by applying a cooling system on the crucible boundary. The liquid-solid transition surface evolution and its shape define the quality of the crystallization microstructure obtained in the casting process. The computation of the nonlinear eddy current problem coupled with that of thermal diffusion field for the moving ferromagnetic pieces is required in order to obtain the temperature field distribution and the liquid-solid transition surface location at each time step. This paper presents an efficient procedure for solving this coupled field problem and obtaining the time evolution of the melted piece speed, such that the solidification surface shape preserves the imposed parameters.

Keywords: Coupled eddy current – heat diffusion problems, Fixed point polarization method, Moving ferromagnetic bodies in controlled solidification technology, Nonlinear periodic fields, Solid phase surface evolution control.