H. Jamgotchian et al., Localized microstructures induced by fluid flow in directional solidification - art. no. 166105, PHYS REV L, 8716(16), 2001, pp. 6105
The dynamical process of microstructure localization by multiscale interact
ion between instabilities is uncovered in directional solidification of tra
nsparent alloy. As predicted by Chen and Davis, morphological instability o
f the interface is observed at inward flow-stagnation regions of the cellul
ar convective field. Depending on the driving force of fluid flow, focus-ty
pe and honeycomb-type localized patterns form in the initial transient of s
olidification, that then evolves with time. In the case of solute-driven fl
ow, the analysis of the onset of thermosolutal convection in initial transi
ent of solidification enables a complete understanding of the dynamics and
of the localization of morphological instability.