Wetting behavior in aluminum-alumina-salt systems

Abstract

Wetting characteristics and interfacial properties of metal, oxide, and salt play an important role during the remelting of aluminum scrap. The contact angle between aluminum and alumina immersed in molten salt, and interfacial tensions between aluminum/alumina, aluminum/salt, and alumina/salt are important properties in this regard. In this work, the contact angle between aluminum and alumina immersed in molten salt, based on equimolar NaCl-KCl composition, was measured using the sessile drop method. The interfacial tension between alumina and salt was calculated from the measured value of the contact angle. The calculated change in free energy due to oxide film removal shows that the oxide film removal is not spontaneous.