Morphological development of solidification structures under forced fluid flow: a Monte-Carlo simulation

A Monte-Carlo simulation of microstructural development under forced convection is presented. The model takes into account both diffusive and forced fluid flow, kinetics of atomic attachment at the solid-liquid interface and structural modification under the influence of capillary forces. It has been shown that the nature of fluid flow has a very significant influence on the morphology of the solidification structure. A laminar type flow is shown to destabilize the solid-liquid interface promoting dendritic growth for solid growing from fixed substrate. Particle rotation under streamlined flow, or a periodic change in the fluid flow direction around the growing solid is, however, shown to produce the rosette type solidification morphology. A turbulent type flow penetrating into the interdendritic region produces fine and compact solidification structures with or without liquid entrapment. (C) 2002 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.