Abstract: Aluminium titanate is an excellent inorganic non-metal material due to its high melting point
and low expansion. In order to improve its strength and to suppress its thermal decomposition, additives are frequently introduced into
it. In this paper, the effect of a single additive or compound additives on the thermal expansion coefficient of Al₂TiO₅ was investigated.
The results show that the addition of some rare-earth oxide can greatly reduce the thermal expansion coefficient of Al₂TiO₅. For example, the
addition of 1～4mol% CeO₂ or 2mol% La₂O₃ makes its expansion coefficient come near zero. That gives a new approach in the development of materials with no thermal expansion. It is
indicated that there is no change in the expansion coefficient of Al₂TiO₅ by adding 1～4mol% Fe₂O₃ in it. The addition of SiO₂
in Al₂TiO₅ containing 4mol% Fe₂O₃ increases its expansion coefficient while the addition of another rare-earth oxide decreases
the expansion coefficient. Proper batching of three additives can adjust the expansion coefficient of Al₂TiO₅ to minimum. The addition
of the compound additives may be very significant for improving the properties of Al₂TiO₅.

Key words: aluminium titanate, thermal expansion coefficient, additives