Electrohydrodynamic crystalline anisotropic solidification based on a hybrid lattice Boltzmann model

Electrohydrodynamics is an efficient approach to control the solidification process. While most studies focus on isotropic solidification, the effects of crystalline anisotropy on Electrohydrodynamics solidification remain unexplored. This study uses numerical simulations based on a hybrid lattice Boltzmann method to examine the effects of varying electric field strengths and physical properties on electrohydrodynamic crystalline anisotropic solidification, focusing on dendrite growth rate and solid-liquid interface morphology. It is found that large electrical Rayleigh numbers enhance flow motion, sharpening the upstream concentration gradient, and promoting frontal branch growth while suppressing lateral growth. Material properties, including the diffusion coefficient ratio and ionic mobility ratio, significantly affect the local solid-liquid interface morphology by modifying electric charge transport. Low diffusion coefficient ratios lead to multiple vortices, while higher ones result in simpler flow structures. Ionic mobility ratio controls the interfacial charge gradient. When the solid phase exhibits higher ionic mobility than the liquid, interfacial charge accumulation induces flow motion, triggering the Mullins-Sekerka instability. In directional solidification, the ionic mobility ratio influences the onset of the interface Mullins-Sekerka instability, while the electric strength enhances competition among dendritic tips. These results provide an avenue for the application of electrohydrodynamics in the smart control of material manufacture.