Phase-Field Modelling of Intermetallic Solidification

Many important intermetallic compounds display a faceted morphology during solidification close to equilibrium but adopt a more continuous, dendritic like morphology with increasing departure from equilibrium. We present a phase-field model of solidification that is able to both reproduce the Wulff shape at low driving force and to simulate a continuous transition from faceted to dendritic growth as the driving force is increased. A scaled ratio of the (perimeter)2 to the area is used to quantify the extent of departure from the equilibrium shape.