Phase-Field Simulation for Non-isothermal Solidification of Al-Cu Binary Alloy

Abstract

Based on the principle of dilute solution approximation, a phase field model for dendritic growth during the non-isothermal solidification process was proposed by coupling the phase field, concentration field and temperature field, and was adopted to investigate the dendritic growth of Al-Cu binary alloy during the non-isothermal solidification process. Also, the simulations of free dendritic growth in an undercooled melt of Al-4.5%Cu binary alloy with different perturbation intensity and anisotropy were carried out by the present phase field model. The results show that during the non-isothermal solidification process of Al-4.5%Cu binary alloy, the dendrite grow into undercooled melt with the solute rejection and latent heat release at the front of solid/liquid interface, and the solute enriches at the dendrite root and high temperature appears at the dendritic growth front. With the increase of perturbation intensity, the dendritic growth becomes more developed and more branches appear. Moreover, the anisotropy coefficient also has a great effect on the dendritic growth, and the growth speed of dendrite increases with the increase of anisotropy coefficient.