Nonequilibrium molecular dynamics simulation of rapid directional solidification

We present the results of nonequilibrium molecular dynamics simulations for the growth of a solid binary alloy from its liquid phase. The regime of hi gh pulling velocities V, for which there is a progressive transition from s olute segregation to solute trapping, is considered. In the segregation reg ime, we recover the exponential form of the concentration profile within th e liquid phase. Solute trapping is shown to settle in progressively as V is increased and our results are in good agreement with the theoretical predi ctions of Aziz [J. Appl. Phys. 53, 1158 (1981)]. In addition, the fluid adv ection velocity is shown to remain directly proportional to V, even at the highest velocities considered here (V similar or equal to 10 ms(-1)).