EFFECTS OF A CaO ADDITIVE ON THE STRUCTURE AND PROPERTIES OF ALUMINIUM TITANATE CERAMICS

Al₂TiO₅ based ceramics with high mechanical strength and good thermal shock resistance were successfully prepared by adding 1 % -7 % CaO to the alumina titanium dioxide mixtures at 1280-1380 °C for 0.5 h, and the effects of the CaO additive and firing temperature on the phase composition and thermo-mechanical properties of the Al₂TiO₅ ceramics were investigated in the present work. The results show that CaO could promote the formation of the Al₂TiO₅ solid solution, showed a significant impact on the development of the phase composition. The aluminium titanate ceramics sintered with 3% CaO at 1350 °C for 30 min gave an average thermal expansion coefficient of (20-600 °C) 0.83×10-6 K-1, and a bending strength before and after three thermal shock cycles in water from 600 °C to room temperature of 40.59 MPa and 42.23 MPa, respectively.