5th International Conference on Advances in Solidification Processes (ICASP-5) 5th International Symposium on Cutting Edge of Computer Simulation of Solidification, Casting and Refining (CSSCR-5)

The interaction between the capillarity and the thermal-solute-convection fields determines the microstructure evolution during solidification, which significantly influences the eventual mechanical properties of materials. However, to achieve the coupled thermal-solute-convection microstructure evolution with a realistic Lewis number (Le ~ 104) and Prandtl number (Pr ~ 10-2), the computing overhead is gigantic. In this work, the multi-physical microstructure evolution was simulated via a phase-filed lattice-Boltzmann approach, which enhanced the time step by 2-3 orders of magnitude in comparison with the explicit finite difference method. A parallel and adaptive mesh refinement algorithm was developed to further improve the computational efficiency. Accordingly, the fully coupled 3-D thermal-solute-convection dendritic and eutectic growth for Al-Cu alloys was first reproduced with a realistic Lewis number and Prandtl number. It was confirmed that the domain temperature and the presence of convection have significant influence on the final morphology. The simulated results agree well with the experimental findings.