Abstract: The dependence dendritic sidebranching on phase- field parameters is studied by using a phase-field model which incorporates thermal noise quantitatively. The calculated results indicate that, with the increment of undercooling, the thermal diffusion layer collected around the equiaxed dendritic is more thin, which is advantageous to the growth of the sidebranching and the equiaxed dendritic presents the morphology of developed sidebranching; The anisotropy parameter e influence the steady state of the dendrite tip, the larger e, the quicker the dendrite tip velocity is, the more developed the side-branches are and the smaller the DAS are; The smaller coupling coefficient l, the quicker the dendrite tip velocity converges on the Green function calculation, the more developed the side-branches are; The magnitude of thermal noise influence temperature field obviously, when appropriate value is assigned to Fu, noise can enhance the emergence of sidebranching but does not influence the tip operating state.

Key words: Sidebranching, Thermal noise, Numerical simulation, Phase-field Method, Undercooling