Phase-field Simulation of Dendrite Morphologies of Fe-C Alloy in Isothermal Solidification

Based on KKS model, the phase-field model coupled with solute-field was used to simulate the microstructural dendrite growth of alloy Fe-0.5%C(mole fraction). The grain growth process and the influence of anisotropic intensity and noise intensity on dendrite morphologies were investigated. The results show that during the early stages of growth, the morphology of crystal grain is spherical, with the increase of time, the grain morphologies transforms into star shape from spheric shape, and then changes into complex dendrite morphologies. With the increase of anisotropic intensity, the morphology of grain transforms from spheric shape into quadrilateral, and then into dendrite. The morphology of grain becomes dendrite because of the effect of anisotropic intensity. The main reason of dendrite side-branches is caused by the noise intensity.