Effect in melt of convection motion induced by density change on dendritic solidification

Abstract

An investigation was made of the effect of fluid motion, induced by the change of density during solidification, on the pattern formation of dendritic structure. The results obtained show that the global trapped wave (GTW) instability mechanism, which we previously discovered for dendritic solidification from a pure substance with no density change, still applies for the present system. The effect of density-change on the GTW modes and corresponding eigenvalues is evaluated. The dependence of the selected tip velocity on the relative density change in the solid and liquid phase is derived.