The Computer Simulation Research on Evolution of Solidification Microstructure

Phase-field method is the effective method to simulate microstructure as a kind of numerical computer simulation technology. On the basis of the free energy functional, the anisotropy is introduced into the phase-field model which applied to the solidification process, and the side-Branch competitive growth, ripen and solute micro-segregation in the free dendrite growth are realized. The simulation results show that the instability and morphology selection of dendrite are influenced by anisotropy strength. If the anisotropy coefficient is 0 or little, equiaxed dendrite will not bring. Under the same condition, the dendrite will grow faster with the increase of anisotropy coefficient. But if the anisotropy coefficient value (0.06) is over large, dendrite variation will appear, the simulation conclusion is consistent with theoretical predictions.