Stabilization Of Aluminum Titanate And Preparation Of Aluminum Titanate-Mullite Kiln Furniture

Aluminum titanate is a new ceramic material with high melting point and low thermal expansion coefficient. Its high temperature performance is the best in materials with low thermal expansion. But the material has two fatal defects: one was that the crystal was very large anisotropy which made its mechanical strength very low because there was much crack in the material when it cooled. Another was that it would be very easy to decompose into rutile and corundum between 750~1300℃, which made it lose the excellent properties. So its application was restricted.The phases of the material was analyzed by XRD, the decomposition rate of Al2TiO5 was determined, the lattice constants of Al2TiO5 was calculated, the microstructure of the samples were observed, the effects of sintering temperature and amount of mullite on the properties of aluminum titanate-mullite composite were studied before and after ferric oxide added, the thermal stability of aluminum titanate was studied through adding additive and compositing, the mechanism of restraining the decomposition of Al2TiO5 was found out. The preparation of the aluminum titanate-mullite kiln furniture using aluminum titanate-mullite composite was studied.Aluminum titanate is well stabilized by introducing ferric oxide and compositing with mullite. Aluminum titanate received a thermal stress from mullite around it because their differences of structure and property. The aberration of aluminum titanate was not easy to happen, so the thermal stability of aluminum titanate was promoted. The best adding amount of mullite was 30%~50%. After ferric oxide was added, the lattice constant c increased because that Fe3+ and Si4+ replaced Al3+ and Ti4+, the aberrance extent of aluminum titanate decreased, crystal lattice of aluminum titanate was made to be stable, and the thermal stability was promoted. The thermal expansion coefficient of aluminum titanate-mullite composite containing 30% mullite sintered at 1600℃ is 2.03 x 10-6/℃ 20~1300℃Aluminum titanate kiln furniture was prepared using aluminum titanate-mullite composite. The influence of the component and sintering temperature on the properties of the kiln furniture was studied. The effects of heat treatment on the strength of the aluminum titanate-mullite kiln furniture product was discussed, the aluminum titanate-mullite kiln furniture product with good thermal shock resistance behavior was prepared.