Phase-field lattice-Boltzmann study on eutectic growth with coupled heat and solute diffusion

Abstract

The thermosolutal interaction influences eutectic evolution and thus properties of solidified materials. Limited by numerical capability, however, very few studies are performed on the eutectic growth with coupled heat and solute diffusion. Combining the phase-field lattice-Boltzmann approach and a parallel-adaptive mesh refinement algorithm, a novel numerical scheme is developed to efficiently simulate the thermosolutal multiphase eutectic evolution. The contact angles at the triple point agree well with the analytical solution, and the temperature always obtains the local extreme at the solid/liquid interface due to the release of latent heat. The effects of the Lewis number and imposed heat sink on the eutectic evolution are discussed in detail, which includes the change of the lamellar growth velocity and the form of lamellae creation. The dimension is further extended to 3D to investigate the evolution of plate- and rod-like eutectics. How to simulate eutectic evolution with a larger Lewis number (e.g., 106) and how to develop a more general eutectic model are also discussed. As the first attempt to solve the thermosolutal eutectic evolution, our investigation paves a way for further quantitative analysis and direct comparison with experiments.