Thermal behaviour of aluminium titanate combustion powders with MgO additions

Abstract

Submicron Al2TiO5 powders produced by combustion synthesis might provide a possible solution to the known material's fabrication difficulties (microcracking and decomposition). The synthesis technique is very straightforward and the peculiar morphological characteristics of these powders suggest the possibility of producing an in-situ reinforced microstructure with improved mechanical properties. In this work, a systematic sintering/densification study carried out with pure and MgO doped Al2TiO5 powders, prepared by combustion from the corresponding metal precursor-urea mixtures, is described (MgO is a common additive used in reaction-sintered titanate ceramics to counteract the compound thermal instability). The MgO was introduced in the synthesis step and incorporated as a solid solution. The results obtained show the effects of heating rate, sintering temperature and added MgO on the thermal instability, sintering behaviour and microstructure development.