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

Abstract

Although A356 aluminum alloy exhibits ductility and strength, the refinement of the initial α-Al phase has shown promise in improving these properties. The microstructure of A356 aluminum alloy has not been well analyzed by the grain refinement mechanism. In this paper, we constructed a phase field lattice-Boltzmann model to explore the influence of the refinement mechanism on the growth of α-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 α-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.