Simulation of atypical dendrite growth in Ni-Cu binary alloy with phase-field method

摘要

Two dimensional non-facet formations during <110> dendrites growth of Ni-Cu binary alloy are simulated with a phase-field model. The gradient terms for both phase field and solute field are considered in the model. The finite difference method is adopted with uniform grid, and the C Programming Code is implemented to complete the phase-field simulation. We focus on effect of the interface kinetics coefficient on dendritic morphology, tip operating state and concentration profile across the liquid-solid interface. The simulation results indicate that the symmetry of crystal growth does not depend on the kinetics coefficient without flow. With increasing of kinetics coefficient, the steady-state dendrite tip velocities increase accordingly, and the level of solute trapping is severe. The crystal growth patterns are formed including a sector form and a plate formation, but the symmetry of dendrite morphology is not disrupted.