【摘要】 分别采用非水解和水解溶胶-凝胶法合成钛酸铝粉体,利用FT-IR、DTA-TG、XRD、SEM等方法研究了溶胶-凝胶转变和合成相变化过程及粉体烧结性能.结果发现:水解凝胶过程中A l3+以网络外离子形式富集于Ti-O-Ti凝胶网络之间,凝胶依次晶化成金红石和刚玉,再通过固相扩散在1350℃时合成钛酸铝,粉体粒径为1~2μm,比表面积仅3.2m2/g,1400℃烧结后抗弯强度为7.2MPa.非水解凝胶化过程中A l3+和Ti4+通过聚合共同形成凝胶网络,其在网络结构中地位趋同,凝胶在750℃已直接由无定型晶化为钛酸铝,粉体粒径为0.1~0.3μm,比表面积与抗弯强度分别为水解法样品的35倍和2.3倍,性能较好.更多还原

【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 Al2TiO5 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 0.1-0.3μm 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.更多还原