以正硅酸四乙酯(TEOS)和仲丁醇铝(ASB)为前驱体,硝酸为催化剂,复合莫来石纤维为增强支撑骨架,在不使用螯合剂情况下,采用溶胶-凝胶技术,超临界干燥制备了块体硅-铝纤维复合气凝胶。制备的样品分别进行600,800和1000℃热处理。利用扫描电镜、红外分光光度计、X射线衍射仪、Hotdesk热导率分析仪等仪器对复合气凝胶的微观形貌、结构及热性能进行表征。硅铝复合气凝胶在室温下热导率为0.035W/m·K,复合气凝胶的热导率随着温度的升高而升高。硅铝纤维复合气凝胶室温下的热导率为0.046W/m·K,高温处理后的收缩率相比硅铝复合气凝胶有所降低。 Tetraethoxysilane (TEOS) and aluminum sec-butoxide (ASB) as precursors, nitric acid as catalyst, composite mullite fiber reinforced support skeleton, without the use of chelating agent, the use of sol-gel technology , Supercritical drying prepared bulk silicon - aluminum fiber composite airgel. The prepared samples were respectively heat-treated at 600, 800 and 1000 ° C. The morphology, structure and thermal properties of the composite aerogels were characterized by scanning electron microscopy, infrared spectrophotometer, X-ray diffraction and Hotdesk thermal conductivity analyzer. The thermal conductivity of Si-Al composite airgel at room temperature is 0.035W / m · K, the thermal conductivity of the composite airgel increases with the increase of temperature. The thermal conductivity of silica-alumina fiber composite airgel at room temperature is 0.046W / m · K, and the shrinkage after heat treatment is lower than that of silicon-aluminum composite airgel.