Nano- and micrometre additions of SiO2, ZrO2 and TiO2 in fine grained alumina refractory ceramics for improved thermal shock performance

The present contribution investigates the influence of micro-metre- as well as nano-metre-additions of zirconia (ZrO2), titania (TiO2), silica (SiO2) and magnesia (MgO) into alumina-rich fine grained ceramic materials for refractory applications. Slip casted samples in the system alumina–zirconia–titania (AZT), alumina–zirconia–titania–silica (AZTS) and alumina–zirconia–titania–magnesia (AZTM) were sintered and the physical as well as mechanical properties were investigated as fired and after thermal shock treatments. The generation of a micro-crack network after sintering due to the formation of phases with different thermal expansion coefficients and the formation and decomposition of aluminium titanate (Al2TiO5) before and after thermal shock exposure leads to higher strengths after thermal shock attack.