The microstructural features of an alumina–mullite–zirconia refractory material corroded by molten glass

An alumina-mullite-zirconia refractory penetrated by a standard soda-lime-silica glass was statically tested at 1370 °C for 72 h. Microstructural features and EDAX analysis of the compositions in the corroded region were examined by SEM. During penetration, alumina particles started dissolving in the glassy-phase; and thus randomly oriented needle-like alumina crystals were formed and began growing up in the penetrated region. On the other hand, zirconia made an effective barrier in the corroded zone, and therefore the formation of needle-like alumina crystals disappeared steadily towards to the end of the penetration region, with a low solubility rate of SiO2, Na2O and CaO, leading to a high corrosion resistance of the refractory.