Phase-field Simulation of Fe-C Alloy in the Isothermal Solidification

The phase-field model based on KKS model which is coupled with solute-field has been used to simulate the microstructural dendrite growth of Alloy Fe-C0.5mol%.The influence of undercooling,anisotropic intensity and noise intensity on dendrite growth has been investigated.The results show that with decreasing of undercooling,the morphology of dendritic trunk will become thinner,while anisotropic degree is increased,the speed of dendrite growth is decreased,thickness of solute diffusion layer is increased.The maximum solute concentration is decreased,the solute gradient is decreased.With increasing of anisotropic intensity,the grain morphology is transformed from seaweed to dendrite,and the speed of dendrite growth is increased.The noise intensity will introduce the growth of side-branches.There are some phenomena just as the side-branches competitive growth and the necking of the dendrite root.The noise intensity cannot change the steady-state behavior of dendrite tip.