Investigation and improvement of thermal stability properties of aluminum titanate ceramics

Aluminum Titanate (Al2TiO5) is a ceramic material with low thermal conductivity coefficient and high thermal shock resistance. Al2TiO5 is a phase which is stable above about 1300 °C, showing decomposition below this temperature. In addition, the micro cracks formed during the sintering of Al2TiO5 lead to low mechanical strength. Various oxide additives are used to improve mechanical properties and to stabilize the Al2TiO5 phase. In this study, SiO2, MgO and Fe2O3 were used as additives and their effects on porosity, phase composition, bending strength, microstructure, thermal shock resistance were investigated and inferences were made about thermal stability. The samples were shaped by an uniaxial press, sintered at 1450 °C and 1600 °C for 3 hours to obtain different samples of compositions. It was determined that sintering, thermal shock resistance and thermal stability behaviors of the samples produced under same conditions vary depending on the ratio of additives and sintering temperature. As a result, the addition of SiO2, MgO and Fe2O3 has played an active role in improving the thermal stability properties of Al2TiO5 ceramics.