Dynamics of Spacing Selection for Lamellar Eutectics in Directional Solidification

Profile and its splitting features of solidifying interface of lamellar eutectic in directional solidification have been investigated by solving numerically the nonlinear coupling equation of solidification. It is argued that critical splitting point of the solidifying interface Is marginally stable, and therefore is the possible operating point of spacing selection dynamics. Three modes of the dynamics are proposed, and a new scaling law of the lamellar array is derived, which has a more general form than the classic one.