A Modified Cellular Automaton Model for Simulation of Dendritic Microstructures in Solidification of Alloys

摘要

A two-dimensional modified cellular automaton (MCA) model was developed to predict the evolution of the microstructures in solidification of alloys. Different from the classical cellular automata in which only the temperature field was calculated, the MCA model is coupled with the curvature and the solute redistribution both in liquid and solid during solidification. The effects of constitutional undercooling and curvature undercooling are incorporated on the equilibrium interface temperature. The relationship between the growth velocity of a dendrite tip and the local undercooling is calculated according to the KGT (Kurz-Giovanola-Trivedi) model. This MCA model was applied to simulate the free dendritic growth from an undercooled melt as well as the competitive dendritic growth and non-dendritic structure evolution in practical casting solidification.