Adaptive phase field simulation of non-isothermal free dendritic growth of a binary alloy

Efficient adaptive phase field simulation is carried out for a free dendritic growth in a nickel/copper system. The adaptive nature of the present scheme allows the simulation to be performed in an extremely large domain for thermal boundary layer, while keeping fine mesh for the diffusive interface. For isothermal cases, our calculated results agree reasonably well with those of Warren and Boettinger [Acta. Metall. Mater. 43 (1995) 689]. For non-isothermal growth, our results also agree well with those by Loginova et al. [Acta. Mater. Mater. 49 (2001) 573] for using a small domain. However, the domain size used in the previous calculations was too small for heat conduction, so that the calculated results are domain dependent and the dendrite could not grow freely. By choosing an extremely large domain, we have obtained a truly free growth simulation for the first time for a non-isothermal dendrite. The effect of supercooling is also illustrated and discussed.