3D STOCHASTIC MODELING OF THE COLUMNAR-TO-EQUIAXED TRANSITION DURING THE SOLIDIFICATION OF ALLOY 718

An efficient three-dimensional (3D) stochastic model for simulating the evolution of dendritic crystals during the solidification of alloys was developed. The model includes time-dependent computations for temperature distribution, solute redistribution in the liquid and solid phases, curvature, and growth anisotropy. The 3D model can run on PCs with reasonable amount of RAM and CPU time and therefore no parallel computations are needed. 3D mesoscopic computations at the dendrite tip length scale were performed in this study to simulate the formation of the columnar-to-equiaxed transition in alloy 718. Comparisons between microstructure predictions obtained via 2D and 3D stochastic modeling are also presented.