Phase field simulation for grain refinement in dendrite growth of A356 aluminum alloy

Although A356 aluminum alloy has poor ductility and strength, the refinement of the initial alpha-Al phase has shown promise in improving these properties. The impact of grain refinement mechanisms on the organization and morphology of A356 aluminum alloys has not been thoroughly investigated. In this paper, we constructed a phase field lattice-Boltzmann model to explore the influence of the refinement mechanism on the growth of alpha-Al dendrites during the non-isothermal solidification process of A356 aluminum alloy. The results demonstrated that the approach of alloying by adding elements, introducing forced convection, and increasing the degree of subcooling has proven to be effective in refining the dendrites of A356 aluminum alloy. The presence of Fe element further promotes the thinning of alpha-Al dendrites, and this effect is also found after melting ultrasonic treatment at a lower initial casting temperature. These findings are expected to provide theoretical support for effectively improving the hardness, ductility, and overall performance of Al-based alloys.