【摘要】 SiO₂-Al₂O₃复合气凝胶（SAA）耐高温性能明显优于纯SiO₂、Al₂O₃气凝胶，可用于1 000℃以上高温环境，对高温窑炉、设备隔热保温具有重要意义。本文综述了SAA及纤维增强复合材料的制备技术研究进展，在阐明硅铝复合溶胶水解、聚合机理的基础上，讨论了前驱体种类、干燥方式、水、添加剂等对溶胶胶凝过程及气凝胶微观结构与物化性能的影响，简要介绍了SAA微观结构、高温烧结行为特点及硅铝物质的量比对孔结构及耐高温性能的影响，介绍了基于粉煤灰、煤矸石、高岭土等廉价原料的SAA制备方法，以及基于纳米颗粒组装、冰模板、壳聚糖模板的制备新方法。在纤维增强复合材料方面，介绍了以纤维为分散相、纤维预制体为主体骨架两类复合材料的制备方法及纤维种类（石英、莫来石、碳纤维、纳米SiO₂、碳纳米管、氧化锆等）对复合材料力学及耐高温性能的影响。最后梳理了目前复合气凝胶研究中存在的问题，展望了其发展趋势。更多还原

【Abstract】 SiO₂-Al₂O₃ aerogel（SAA） is distinguished by its superior stability in high-temperature applications, especially higher than 1 000 ℃ compared with the pure SiO₂ and Al₂O₃ aerogel, which guarantees its vast applications in many industrial ovens and facilities. Herein, we review the recent advances in the preparation techniques of SAA and the corresponding fiber reinforced composites. The hydrolysis and condensation mechanism of SiO₂-Al₂O₃ hybrid sol is introduced first, followed by the effects of the precursor type, the drying mode, and the water content and the admixtures. The microstructure and the sintering features at high temperature of SAA are presented, combined with the effects of the Si/Al molar ratio. A special series of low-cost materials based on fly-ash, coal gangue and kaolin earth are emphasized, followed by some novel preparation techniques involving the assembly of nanoparticles, the ice template and the chitosan template. Two types of fiber reinforced composites are described: the composite with the fiber as the dispersive phase and the composite with the fiber preform as the skeleton, covering varied fiber types including quartz, mullite, carbon fiber, nano SiO₂, carbon nanotube and zirconia. The review is ended by an in-depth analysis of the problems existing in the current research of SAA and an outlook of its possible trends in the near future.更多还原