A microstructural model of competitive growth in nickel based superalloys

A microscale cellular automaton-finite difference model was developed to simulate the solidification process of binary alloys. The velocity of the solid/liquid interface is determined by solute diffusion and local equilibrium at the dendrite tip. The crystallographic orientation of grains is simulated using a modified implementation of the decentred square growth technique first developed by Gandin & Rappaz.(1) The relationship between the tip undercooling of columnar dendrites and the misorientation was obtained. The model was applied to simulate converging and diverging competitive grain growth, with good agreement to experimental results.