Cellular Automaton Approach on Micro Morphology Generation with Nucleation-Grain Growth Kinetics in Solidification Process

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In this paper, an approach to the mathematical modeling of grain structure formation in micro solidification processes is proposed at first. Based on the kinetics of heterogeneous nucleation and of grain growth, the dendrite and the equiaxial micro-morphologies are automatically generated using the Monte-Carlo simulation. Nucleations occurring in the vicinities of vessel wall, vessel corner as well as in the liquid metal are simulated by two steps of calculations using macro- and micro-discretized cell configurations. The growth kinetics of the dendrite tip and the preferential growth directions of cubic metals are taken into account.The computer system has been developed, and the solidification process and the grow of the associated micro-morphology are solved by varing such parameters as the constitutive undercooling due to the local solute increase in frontal of the solid-liquid interface, compatibility for interference with the adjacent dendritic structure, and macroscopic heat transfer with latent heat discharge.The grow of morphology in Al-Si binary alloy in 2D region is calculated for numerous conditions of solidification processes and the applicability of the method is clarified.In the next place it is examine hole the heterogeneous dendritic morphology changes to the equiaxial one due to the fluid dynamic force induced by electromagnetic excitation.The micro and macro solidification process with or without magnetic stirrer have been solved, and the results are compared with morphologies obtained from actual continuous casting apparatus, such as twin roll casting and horizontal casting and the applicabilities of the method developed arc clarified.