Effect of heat transfer on the growth angles observed in meniscus-defined solidification

Abstract

The interfacial geometry at the triple-phase line is defined by the growth angle, θgr, and the solid angle, θs. θgr is the angle between the melt-gas interface and the plane defined by the solid–gas interface, and θs is the angle between the solid-melt and solid–gas interfaces. A local analysis of the temperature field near the triple-phase line of solidification was used to identify the interfacial configurations that have a nonsingular heat flux. It was shown that there is a nonsingular region in the θs-θgr plane, the bounds of which depend on ratios of thermal conductivities. Results indicate that experimentally observed growth angles seem to fall into the nonsingular regions although experimental data is highly limited. Predictions of growth angles based on interfacial tensions were also examined but it was difficult to determine if either criterion was predictive.