Competition between kinetic and surface tension anisotropy in dendritic growth

摘要

The combined effect of an anisotropic surface tension and interface kinetics in dendritic crystal growth is studied numerically by a fully dynamical front-tracking method in two dimensions. It is shown how kinetic effects can be incorporated into the algorithm without causing numerical instabilities. The results are compared to the theory of E. A. Brener V. I. Mel'nikov (Adv. Phys. 40, 53 (1991)). A particularly interesting case arises when the directions of minimum surface tension and minimum kinetic effect are different. In this case, when the deviation from local equilibrium is increased, the predicted transition from dendrites growing into the direction of the minimum surface stiffness to the direction of minimum kinetic effect is confirmed. Dendrites near this transition show strong oscillations and correlated side-branching. The transition where the oscillating dendrites change direction shows hysteresis.