Wettability of solids by liquid metals plays an important role in numerous technological processes. In this work, the effect of a steady magnetic field (SMF) on the wettability of copper and silica substrates by a Ga−In−Sn liquid alloy was investigated using the sessile drop technique. It was found that the contact angles on both substrates increased with increasing SMF intensity. The reduced wettability can be attributed to a change in liquid surface tension under the action of an SMF. In combination with the equations of state, the increase of the contact angle with the SMF intensity is predicted, which is in reasonable agreement with experimental results.

No abstract

Melting of a single-phase polycrystalline material is known to start by the formation of liquid films at the surface and at grain boundaries. The internal liquid films are not necessarily quiescent, but can migrate to avoid/reduce supersaturation in the solid phase. The migration is discussed in the literature to be governed by coherency strains of the solid/liquid interface, by concentration gradients in the liquid or by concentration gradients in the solid phase. A phase transformation model for diffusional phase transformations considering interface thermodynamics (possible deviations from local deviations) has been put up to describe the migration of the solid/liquid (trailing) and the liquid/solid (leading) interfaces of the liquid film. New experimental results on melting in a temperature gradient in combination with simulation calculations reveal that concentration fluctuations in the liquid phase trigger the liquid film migration and determine the migration direction, until after a short time in the order of microseconds the process is governed by diffusion in the solid phase.