High-Temperature Wettability Investigations on Laboratory-Developed CaO-CaF<inf>2</inf>-SiO<inf>2</inf> -Al<inf>2</inf>O<inf>3</inf> Flux System-Based Welding Electrode Coatings for Power Plant Applications

This article is an attempt to examines high-temperature wettability properties of laboratory-developed electrode coatings for power plant applications. The properties include contact angle between the solid/liquid interfaces, spreading area, surface tension, and work of adhesion. Coatings were prepared using CaO-CaF2-SiO2 -Al2O3 basic flux system. The sessile drop method was used to estimate the contact angle at the liquid/solid interface while surface tension was calculated using Young’s and Boni’s equations based on the measured contact angle. The interaction effect of individual minerals and their binary mixtures (CaO.CaF2, CaO.SiO2, CaO.Al2O3, CaF2.SiO2, CaF2.Al2O3, and SiO2.Al2O3) on the wettability properties were studied using the regression analysis. Optimum flux compositions were estimated using Multi-response optimization. The contact angle decreases when basic oxides (CaO, CaF2) were added in a higher proportion than the acidic oxides. With the decrease in the contact angle spreading area increased and CaF2 comes out to be the significant constituent causes the increase in the spreading area. Binary mixtures CaO.CaF2, CaO.SiO2, and CaF2.SiO2 has an increasing effect on the work of adhesion.