关键词: 非水解溶胶-凝胶法, 水解溶胶-凝胶法, 钛酸铝, 粉体

Abstract: 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—O—Ti network. As a result, only rutile and corundum are separated from the hydrolytic gel, the Al₂TiO5 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℃ as aluminum titanate. The particle size and specific surface area of Al₂TiO₅ powders prepared by hydrolytic sol-gel method are 1－2μm and 3.2m²/g. It is dropped to 0.1－0.3μm 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.

Key words: nonhydrolytic sol-gel, hydrolytic sol-gel, aluminum titanate, powders