The influence of different additives on microstructure and mechanical properties of aluminum titanate ceramics

The aluminum titanate (AT: Al2TiO5) ceramics with different additives, including SiO2, MgO, Fe2O3 and their mixture, were prepared by reaction sintering at 1500 degrees C in air for 2 h. The influence of additives on the microstructure and flexibility of AT ceramics is studied. Research illustrates that additives, MgO, Fe2O3 and their mixture, can be dissolved in AT ceramics to promote the formation of elongated grains and grain boundary microcracks. The elongated grains can interlock together and restrain crack propagation while microcracks can provide gaps for grains to move, leading to obvious flexibility of sample. Especially, the AT ceramics doped with MgO and Fe2O3 (ATFM) show the optimum flexibility with a deflection about 0.55 mm and strength up to 13.85 MPa. While the additive of SiO2 can reduce the size of grains and microcracks, resulting in high mechanical strength but poor flexibility. The successful fabrication of such AT flexible ceramics will provide potential opportunity for anti-vibration and refractory application.