Numerical Analysis to Evaluate the Effect of Cooling Rates on Microstructures in Casted Cu-Ni-Si Alloys by Phase-Field Simulation

Corson (Cu-Ni-Si) alloys were unidirectionally solidified via the Mizuta method under air or water cooling. To replicate the microstructure of a Corson alloy during solidification, phase-field (PF) simulations were performed, and the numerical results were compared with the experimental findings. The comparison between the air- and water-cooling conditions revealed that the primary dendrite trunks were thinner, and the secondary dendrites were longer and more developed under air-cooling conditions. These results were consistent with the experimental observations. Furthermore, the secondary dendrite arm spacings were evaluated via PF simulations, and the calculated results were consistent with the experimental observations. The interface energy and its anisotropy adopted in the present PF simulations were reasonable for the Corson alloy when compared with the values reported in other studies.