Study on the multiple dendrite growth of Al – Si binary alloy using phase – field method (PFM)

Abstract

Phase – field method offers the prospect of carrying out realistic numerical calculation on dendrite growth in metallic systems. The dendritic growth process of Al – 0,02mole % Si binary alloy was simulated by the coupling method of phase field and solute field. The effects of anisotropic parameters on the growth morphology of dendrite were studied. The results show that with the increase of the anisotropy magnitude, the secondary dendrite arms are more developed, and the dendrite tip is obvious oriented. For the multiple dendrite growth, the dendrites present the morphology from the tip splitting to the dendrite tip oriented. The multi dendritic branching and remelting states of Al – Si alloy were obtained and the directional solidification remelting and solute segregation were obtained under different anisotropic index conditions. And numerical simulations were conducted to investigate the growth of single and multiple dendrites under coupled conditions of phase field, solute field, and flow field.

Keywords

• Al – Si alloy
• solidification
• dendritic
• segregation
• PFM