Phase Field Simulation Of Binary Alloy Solidification Process

Phase field method is an effective tool to describe the complicate solid-liquidinterface in non-equilibrium state. In this paper, according to free energy function, the phase-field model of binary single-phase alloy with isothermal and non-isothermal condition deduced, with the interface anisotropy and a term of noise to produce the side-branches introduced into the phase-field model.The governing equations of phase-field models are discretized using the Finite Difference method on uniform grids. The phase equation is solved by coupling solution equation and temperature equation. Since the phase field parameter, the solute field parameter and the temperature change not at the same rate, multi-grid method, especially the double grid method can be applied to save time, which greatly decreases the computing time.The anisotropy intension and the disturbance intension and the mesh size are three important parameters which greatly influence the simulation results and their effects are investigated and the optimized values are deduced.On the basis of the key parameters chosen reasonably, the solidification of Al-6.5wt%Cu alloy on the isothermal condition is simulated. Comparing the numerical simulation results with the real casting experiments, we found out that the dendrite morphologies and the solute profile agreed well with each other qualitatively.