Wetting Behavior of Al₂O₃ Substrate by Calcium Ferrite Series Melts

Abstract

Calcium ferrite (CF) is the adhesive phase formed in high-basicity sinter. The wettability of CF with other solid phases plays an important role in assimilation process. In this study, an improved sessile drop technique was used to explore the wettability of a CF series slag, in which constant contents of Al2O3, MgO, SiO2, and TiO2 were added, with solid Al2O3 substrate at 1 250°C. The interfacial structure and spreading mechanisms were also discussed. The dissolution of Al2O3 into the slag was found to be the driving force of the wetting process. The CF series slag could rapidly spread after melting until a low apparent contact angle of approximately 10°-20° was attained. The spreading time positively correlated with the dissolution amount. The addition of MgO, SiO2, and TiO2 improved the wettability of CF on Al2O3 and decreased the surface tension of CF melt. After cooling, a three-layer structure was formed in the slag phase.

Flow and penetration behaviours of liquid phase on iron ore substrate and their effects on bonding strength of sinter

“…A possible reason is that as the wettability of the liquid phase increases, the liquid phase can continuously penetrate into the substrate. Combining the research of Yu et al [24], it can be inferred that the wetting and penetration of the liquid phase on the substrate promote each other.…”

“…During the flow and penetration process of the liquid phase on iron ore substrate, the viscosity and wettability of the primary liquid phase play important roles [23,24]. The relevant angles α and θ are shown in Figure 6.…”

“…θ is the angle between σ l/g and σ s/l . It is the contact angle of the system, and indicates the wettability of the liquid phase [24,25].…”

Wetting Behavior of Calcium Ferrite Melts on Sintered MgO

“…10, and Tables 2 and 4, decreasing the surface tension of the liquid did not decrease the equilibrium contact angle. In addition, no positive or negative correlation relationship exists between the surface tension and spreading rate, in contrast to the wetting behavior of alumina 16) or hematite 28) by CF-based slag. Wetting behavior driven by chemical reaction was far complex than that driven by dissolution because the reaction rate was affected by plenty of factors, such as reactant activity, porosity at the contact area, roughness, temperature, and even regional concentration.…”

Andradite titanium: Preparation, characterization and metallurgical performance

“…Temperatures at the tested sample with 3/4, 1/2, and 1/4 of the initial height in melting stages are defined as softening, melting, and flowing temperature, respectively. The equipment used for this test was a high-temperature vacuum furnace 38 . The AT sample, after melting, cooling, and solidification, was ground to a cuboid of 10 × 5 × 5 mm for the melting performance test, and the results are shown in Figure 8.…”