Comparative Research on the Synthesis of Aluminum Titanate Powders by a¤Nonhydrolytic and Hydrolytic Sol-Gel Method

Aluminum titanate powder was synthesized by nonhydrolytic and hydrolytic sol-gel method, respectively. The sol-gel process, the phase transformation and the sintering properties of powders were studied by TG-DTA, XRD, FT-IR and SEM analysis. The results show that during the hydrolytic sol-gel process, the Al3+ ions mostly exist in the interspace of Ti aO aTi network. As a result, only rutile and corundum are separated from the hydrolytic gel, the Al2TiOa5 has to be synthesized at 1350 Comparatively, the gel network is formed through the polymerization reaction of Al3+ and Ti4+ ions in nonhydrolytic sol-gel process, these ions occupy the similar position to build the gel network together. Therefore, the armorphous phase is directly crystallized at 750 s aluminum titanate. The particle size and specific surface area of Al2TiO5 powders prepared by hydrolytic sol-gel method are 1￡2| and a 3.2m2/g. It is dropped to a 0.1￡0.3aa| under nonhydrolytic sol-gel method, while the specific surface area of the powders is 35 times of hydrolytic sol-gel sample. The bending strength of the sintered Al2TiO5 ceramic prepared by nonhydrolytic sol-gel method is 2.3 times of hydrolytic sol-gel sample, which is only 7.2MPa. It indicates that the properties of Al2TiO5 powders prepared by nonhydrolytic sol-gel method are better than that of hydrolytic sol-gel sample.a¤