Multi-phase-field lattice Boltzmann modeling and simulations of semi-solid simple shear deformation

Semi-solid deformation is a versatile phenomenon that occurs during the solidification of alloys. Semi-solid simple shear deformation is simulated using the multi-phase-field lattice Boltzmann (MPF-LB) method, which has been originally devised to capture polycrystalline solidification accompanied with melt flow and solid motion. MPF-LB simulations of semi-solid simple shear deformation, with variations in solid fractions, reveal the transition from a liquid-like behavior to a solid-like one. Especially, the shear band formed via dilatancy effects is thoroughly examined in the high solid fraction region. The relationship between grain rearrangement and mechanical behaviors during the formation process of the shear band is investigated in detail. In addition, the effect of domain size and initial grain arrangement on shear band formation is evaluated. Finally, the mechanism of shear band formation is clarified. The developed MPF-LB simulation method is promising for comprehensive evaluations of semi-solid deformation.