The influence on a stability analysis involving a prototype solidification problem of including an interfacial surface entropy effect in the heat balance relationship at the interface

Abstract A reexamination of the conservation of heat boundary condition usually imposed at the solid-liquid interface during controlled solidification by means of a careful application, to energy conservation at that interface, of a general balance equation from continuum mechanics for surfaces of discontinuity yields a new conservation of heat condition containing an extra term involving interfacial curvature and surface entropy. A standard linear stability analysis by a normal mode technique of the uniform growth of a planar interface of a pure solid into a thermally undercooled liquid shows that the consideration of this extra term has a destabilizing effect on a model which does not include it for this prototype priblem if surface entropy is negative and a stabilizing influence if it is positive.