Aluminum Titanate

Abstract

This chapter focuses on properties and production of aluminum titanate. Aluminum titanate-based ceramics show an excellent thermal shock resistance. Their refractoriness and nonwetting character in contact with many molten metals have served to establish these ceramics in various fields of application. In commercial materials, aluminum titanate grain sizes in the range of about 1–100 μm are found and these are large enough to initiate the required microcracks. Frequently, a silicate-based second phase is incorporated to improve the mechanical strength. The dispersed second phase may act as a barrier against microcrack coalescence. There is still an evident deficiency in the theoretical understanding of the relationships that exist between the microcrack system and the thermomechanical properties. In industrial practice, powder conditioning and forming follow similar routes to those used for other types of technical ceramics. In a temperature range slightly above 1280°C, the Al 2 TiO 5 nucleation in an Al 2 O 3 –TiO 2 mixture is difficult, and the limited number of activated growth sites results in only a few relatively large Al 2 TiO 5 single crystals. It is found that at higher temperatures, the number of growth sites increases, changing the growth mechanism.