Chemical interaction between Ba-celsian (BaAl2Si2O8) and molten aluminum

Wetting and corrosion experiments by molten aluminum were performed on mullite and Ba-celsian (BaAl2Si2O8) substrates. The BaAl2Si2O8 was synthesized from a mixture of alumina, silica and barium carbonate at 1450 °C for 10 h. The formation of pure BaAl2Si2O8 was corroborated by X-Ray Diffraction analysis. Corrosion tests were performed by an immersion test of samples in molten pure aluminum or 319.0 alloy at 900 °C for 24 h. The wetting angles were measured using the sessile droop test at 900 °C for 2 h using the same Al alloys. The mullite sample showed a severe corrosion after the test, while the BaAl2Si2O8 sample showed a corrosion layer of about 100 μm. The wetting angles were 109° and 127° for mullite in contact with pure Al and 319.0 alloy, respectively, while for BaAl2Si2O8 were 153° and 149°, showing a no wetting behavior.