2003 Volume 44 Issue 11 Pages 2298-2302
An experimental study was undertaken to determine how wettability affect the volume and formation of gas bubble at nozzles in liquid aluminum. X-ray fluoroscope was used to carry out in-situ observation in the melt. The nozzles were made of steel, silica and alumina to establish different wettability by liquid aluminum. The frequency of bubble formation and the bubbles volume were investigated for low gas flow rate from 0.43 to 12 cm3/s and for various diameters of the nozzle. It was shown that bubble volume increased with wettability worsening both for aqueous and metallic systems. A further insight into the mechanism of the bubble formation was obtained by comparison of the bubble behavior at the tip of the injection devices in liquid aluminum and water.