Phase Field Simulation of Dendrite Growth of Fe-C Alloy in a Forced Flow

摘要

Based on the KKS model, the phase-field model is built by coupling with the concentration field and flow field, we simulate the dendrite growth during isothermal solidification of Fe-C alloy in a forced flow. The results show that the tip of dendrite arm is parabola shape, the secondary branch appear at the root of main branch, the dendrite growth presents obvious symmetry under the pure diffusion conditions. Because of fluid flushing, the solute concentration of the upstream dendrite arm is low, which lead to the dendrite grow fastly, thus the developed side-branch structure is formed, the tip velocity at steady state increased about 22.05% compared with the case without flow. Solute accumulate in the downstream of dendrite, which hindered the side-dendrite appear, the tip velocity at steady state decreased about 46.49% compared with the case without flow. The horizontal preferred direction of the dendrite is changed by fluid flow, hence horizontal main stem tilts towards the upstream direction.