トリプルグリッド法を適用したセルオートマトン法による凝固組織形成シミュレーション

抄録

  A cellular automaton model with a triple-grid method was developed to simulate dendritic growth with less computational cost. As a new approach of the multi-grid method, temperature, solute concentration and solid fraction fields are described by three kinds of grids in the proposed model, respectively. In order to evaluate the validity of the proposed model, simulations of secondary dendrite arm growth of Al-Si and Al-Cu alloys were carried out, and the simulated results were compared with phase-field simulations and experimental data. According to comparison of secondary dendrite arm spacing, simulation results were in good agreement with phase-field simulations and experimental results during dendritic growth. Additionally, in order to investigate the capabilities of the model, the proposed model was applied to simulate the formation of multi-equiaxed dendrites of Al-7%Si alloy under practical solidification conditions. In the early stage of solidification, primary dendrite arms developed along their crystallographic orientations. As solidification proceeded, the growth and coarsening of secondary dendrite arms occurred. From this result of multi-equiaxed dendrites, it was confirmed that the proposed model can perform quantitative simulation of dendritic growth under practical solidification conditions.