Aluminum titanate formation by sold-state reaction of alumina and titania

In this work, the formation of A(2)TiO(5) from equimolar mixtures of high purity and fine grained (d(50)< 50 mu m) Al2O3 and TiO2 powders and the influence of the microstructure of the obtained compacts on the milling efficiency have been studied. Different thermal treatments with maximum temperatures between 1350 and 1650 degrees C have been considered and their influence in the degree of reaction and the cell size of Al2TiO5 have been established. Green compacts have been obtained by isostatic pressing. Some compacts have been thermally treated between 1350 and 1650 degrees C using a single thermal cycle. The other com pacts have been thermally treated in two stages using 1600 degrees C as maximum temperature, with an intermediate process of grinding, milling and pressing after the initial low temperature (1350-1500 degrees C) treatment. The evolution of the reaction has been studied by X-ray diffraction, optical microscopy and scanning electron microscopy. The efficiency of the milling processes has been followed using the evolution of the particle size distribution. The results showed that the degree of reaction changes from practically no reaction at 1350 degrees C to the complete reaction at 1650 degrees C, except for the presence of some isolated alumina particles. The thermal treatment conditions used to obtain the materials determine the obtained microstructures of Al2TiO5 and hence affect the grinding conditions.