A 3D CELLULAR-AUTOMATON ALGORITHM FOR THE PREDICTION OF DENDRITIC GRAIN-GROWTH

Two- and three-dimensional (3D) Cellular Automaton (CA) algorithms are proposed for modelling the growth of dendritic grains from the liquid phase. These CA growth algorithms are validated for simple thermal si tuations by comparing the predicted grain shapes with those deduced fr om analytical models. The insight obtained by the 3D approach is demon strated by studying the extension of a single dendritic grain in a squ ared platform (i.e. at a section change of a casting mould) under vari ous conditions. In particular, the effects of crystallographic orienta tion, thermal gradient, velocity of the isotherms and growth kinetics are shown. This 3D CA growth algorithm, coupled with finite element he at flow calculations, will become a major tool for the prediction of d endritic grain structures in solidification processes. (C) 1997 Acta M etallurgica Inc.