In situ analysis of phase transformation in sol-gel cogelified nanopowder mixture of Al_2O_3 and TiO_2 using synchrotron X-ray radiation diffraction experiments

摘要

Aluminium titanate (Al_2TiO_5) has been selected for study due to its high melting point and thermal shock resistance. In situ analysis of phase transformation and of transformation kinetics of sol-gel powder mixture of alumina and ti-tania cogelified samples was performed using high-temperature synchrotron radiation X-ray diffraction experiments. The high reactivity and molecular mixing of sol-gel cogelified precursor powders contributed to the evolution of the reaction. The stability of the TiO_2-tetragonal structure (anatase) increases due to Al_2O_3 presence. The temperature of the aluminium titanate endothermic reaction decreases when heating rate increases. The results obtained by in situ analysis have been used to establish the sintering parameters in order to obtain fully transformed, dense aluminium titanate bulk ceramics.