Dissolutive Wetting and Spreading Phenomena Between Al₂O₃ Substrate and CaO-Al₂O₃ Liquid Slags

The wetting and spreading behavior are influenced by the dissolution reaction. The wetting and spreading behavior between CaO-Al₂O₃ slag and Al₂O₃ substrate were investigated using the dispensed drop technique and a high speed camera (1000 frame/s) at 1823 K (1550 °C) using saturated slag and non-saturated slag on Al₂O₃. The contact angle of the saturated slag and the non-saturated slag was not substantially different. The apparent height of the spreading droplet for the non-saturated slag was lower than that of the saturated slag due to the formation of a crater generated by the dissolution reaction. A spherical cap model is associated with crater formation was suggested by analyzing the spread droplet and a quenched sample. The spreading rate of the non-saturated slag was faster than that of the saturated slag due to convection. For the saturated slag, the experimental values are in good agreement with the De Gennes’s theoretical model. (Non-reactive viscous model) In contrast, the non-saturated slag curve shifts the experimental curve to correspond with the saturated slag curve.