Melt synthesis of Al2TiO5 containing composites and reinvestigation of the phase diagram Al2O3-TiO2 by powder X-ray diffraction

Recently the fabrication of ceramics starting from the appropriate melts of the educts has attracted increasing attention due to the easy shaping of work pieces and other advantages compared to powder sintering methods. We focused our interest on aluminum titanate (beta-Al2TiO5) based ceramics which are interesting for high temperature applications due to the low thermal expansion coefficient. For this purpose we have investigated the titania-rich side of the Al2O3-TiO2 system (up to 50 mol% titania) under rapid cooling conditions with respect to the phase formation. By powder X-ray diffraction we could prove the solely formation of the known phases rutile and beta-Al2TiO5 in agreement with the equilibrium phase diagram. Furthermore, powder pattern fitting has revealed the formation of solid solutions for both compounds