Evidence of Inverted Undercutting of a Solid Metal Substrate by a Liquid Ceramic Sessile Specimen at Elevated Temperatures

Abstract

When a drop of liquid is placed on a solid substrate, a metastable configuration, illustrated in Fig. 1, is often achieved instantaneously. This configuration may be maintained for a very long period of time, if the temperature is substantially below the melting point of the solid. This configuration is only an approximation of the final equilibrium state, because the surface free energy vectors do not balance. However, as θ decreases toward zero the approximation becomes closer. As the magnitude of the vector G_lv decreases relative to G_ls and G_sv, once again, the approximation becomes closer. As we approach the melting point of the solid, mass transport in it becomes measureable, and the rate of achieving equilibrium becomes much greater.