Multi-phase-field lattice Boltzmann simulations of semi-solid simple shear deformation in thin film

Semi-solid deformation during casting often results in significant solidification defects, such as segregation bands. Consequently, the development of a numerical simulation tool is crucial for accurately replicating semi-solid deformation. In our previous study, we applied a multi-phase-field lattice Boltzmann (MPF-LB) model to semi-solid deformation, facilitating seamless simulation from polycrystalline solidification to semi-solid deformation in a two-dimensional (2D) problem. This study extends the 2D MPF-LB model to a three-dimensional (3D) problem and develops a simulation method for semi-solid simple shear deformation in thin films. To enhance the efficiency of the 3D semi-solid simulation, we implemented parallel computations using multiple graphics processing units. Through a discussion of the relationships among the stress–strain curve, grain rearrangement behavior, and fluid flow, we confirmed that the developed 3D MPF-LB model successfully reproduced the characteristic phenomena of semi-solid deformation, and has high potential to investigate the nuanced mechanisms of semi-solid deformation.