以九水硝酸铝和正硅酸乙酯为原料,用溶胶-凝胶方法在pH=0.5~5.5的条件下制备莫来石前驱体凝胶,当pH=0.5时,热处理到1 100℃,保温4 h,开始出现莫来石晶相,1 150℃保温4 h,已完全莫来石化,当pH=5.5时,热处理到1 250℃才能完全莫来石化。采用XRDI、R对其莫来石化行为进行了表征,研究表明:莫来石化经历了Al-Si尖晶石的形成及与无定形SiO2的反应生成莫来石的过程。 A mullite precursor gel was prepared by sol-gel method under the condition of pH = 0.5-5.5 using aluminum nitrate nonahydrate and tetraethyl orthosilicate as raw materials. When pH = 0.5, heat treatment was carried out to 1100 ℃, After 4 h, the mullite phase began to appear, and at 1 150 ℃ for 4 h, it had completely mullitized. When the pH value was 5.5, it could be completely mullitized by heat treatment at 1 250 ℃. X-ray diffraction (XRD) and X-ray diffraction (XRD) were used to characterize the mullitization behavior. The results show that mullitization undergoes the formation of Al-Si spinel and the reaction with amorphous SiO2 to form mullite.