A lattice Boltzmann model with sharp interface tracking for the motion and growth of dendrites in non-equilibrium solidification of alloys

A lattice Boltzmann model (LBM) with sharp interface tracking is developed to simulate the motion and growth of dendrites in non-equilibrium solidification of alloys. The model is validated through comparative analysis with the drafting-kissing-tumbling (DKT) phenomena of two and three particles and the continuous growth model (CGM), and demonstrates its computational efficiency advantage without compromising accuracy by comparison with the multi-phase field (MPF) model. Subsequently, the model is utilized to investigate the dendrite morphology transition and primary dendritic arm spacing (PDAS). It is found that the velocity dependent solute partition and the resulting changes in constitutional undercooling strongly influence the estimated morphology region and PDAS. Moreover, the segregation and microstructure evolution during the rapid solidification were studied. And the results revealed that free dendrites lead to significant changes in microstructure and segregation under the influence of non-equilibrium effects. This work illustrates the great potential of the proposed model in simulating dendrites and microstructure evolution under a wide range of solidification conditions. Its suitability for extreme conditions and non-equilibrium solidification can contribute to the understanding of microstructure formation patterns and solute segregation in rapid solidification. • A lattice Boltzmann model with sharp interface tracking is proposed for the motion and growth of dendrites in non-equilibrium solidification of alloys. • Melt flow, solute transport, dendrite growth/motion and rapid solidification kinetics are coupled. • The multiple dendrites are labeled by sharp interface tracking instead of multi-phase field method. • The underlying mechanism of microstructure morphology transition, segregation and the primary dendrite arm spacing are discussed.