Characteristic boundary layer evolution in globulitic solidification of alloys with interface curvature and attachment kinetics

Abstract

The characteristic boundary layer evolution in globulitic solidification of alloys was investigated by using the Landau transformation method that takes into account attachment kinetics and interface curvature. The accuracy of the numerical solution was verified by comparing numerical results with an analytical solution without curvature and kinetic effects. Numerical results show that the increase of the kinetic coefficient results in the decrease of the value of the equilibrium interface liquid concentration, and the normal velocity of the interface was negatively correlated with the kinetic coefficient. We found that the thickness of the quasi-steady characteristic boundary layer is close to that of the unsteady one during globulitic solidification when the supersaturation is small. With the supersaturation increasing, it deviates from the unsteady one. This indicates that the kinetic effect cannot be ignored in the numerical simulations of rapid solidification. It is of practical significance to study the rapid solidification process and predict the microstructure.