Wetting and interfacial bonding in ionocovalent oxide-liquid metal systems

Abstract

The nature of the metal-ionocovalent oxide interfacial bond is discussed on the basis of different models. Predictions of these models compared to experimental results as regards the wettability of monocrystalline oxides by pure metals lead to the conclusion that interfacial bond is chemical even in non reactive systems. The influence of oxygen and of metallic additions to the metal on the wettability of the oxide is then discussed. Oxygen has two effects : a damage of the wettability at low temperatures when the oxide film covering the liquid metal is stable and an improvement of the wettability at higher temperatures when it is dissolved in the liquid metal. Metallic solutes can also greatly improve the wetting and the thermodynamic adhesion either by adsorption or reaction processes at the metal-oxide interface