Directional solidification: Transition from cells to dendrites

Abstract

The evolution of cells and dendrites on a solidification front is analyzed numerically by a Green's-function method. We obtain a consistent picture of the pattern-forming processes in the whole experimentally accessible range of the phase-diagram cell spacing versus growth rate. We find a smooth transition from cells to free dendrites confirming suspected scaling relations. The selection of dendritic spacings appears to occur through a tail instability.