High-Temperature Strength and Form Stability of Compact and Cellular Carbon-Bonded Alumina

To prove the applicability of carbon-bonded refractories on basis of Al2O3-C for the filtration of metal melts, their mechanical properties such as compression and bending strength were investigated at elevated temperatures up to 1500 °C. The tests have been carried out on compact specimens and on real filter structures without and with functional coatings. Fracture mechanical tests were performed at room temperature and 1400 °C. In a further approach, the residual strength after contact of the filters with molten steel was determined at elevated temperatures. In addition, a new environmentally friendly binder system based on tannin and lactose has been evaluated.