·新材料新工艺：
氧化铝气凝胶复合高温隔热瓦的制备及性能
孙晶晶
李俊宁
胡子君吴文军周洁洁
（航天材料及工艺研究所，先进功能复合材料技术重点实验室，北京100076）
文摘以陶瓷纤维制成的高温隔热瓦为骨架，真空漫渍氧化铝溶胶，再经过凝胶、老化和超临界干燥制备出氧化铝气凝胶复合高温隔热瓦，研究了其在不同温度处理后（最高温度1400℃）的微观结构、隔热和力学性能。结果表明：气凝胶复合高温隔热瓦在1400℃保温30min后线收缩率仅为2%；随着热处理温度升高，气凝胶颗粒发生熔并、长大，气凝胶从填充纤维空隙到不断收缩，但对纤维骨架没有明显影响；隔热瓦的室温、高温热导率均显著降低；在热面1400℃的背温测试中，复合后材料的背温从945℃降到870℃；复合后隔热瓦的力学性能略有增加；但是1200~1400℃的压缩强度下降较大。可见，气凝胶复合高温隔热瓦可改善其隔热性能，但在高温下力学性能下降。
关键词气凝胶，隔热瓦，隔热性能，力学性能
中图分类号：TB3
D0I:10.12044/j.issn.10072330.2017.03.008
Fabrication and Properties of Aerogels Impregrated
High-TemperatureInsulatingTiles
SUNJingjing
HUZijun
WUWenjun
LIJunning
ZHOUJiejie
(Science and Technology on Advance Functional Composites Laboratory, Aerospace Research Institute of
Materials & Processing Technology, Beijing 100076)
AbstractUsing ceramic fibrous insulating tiles as skeleton, the alumina sols via sol-gel process were infiltrated into the tiles via vacuum infiltration, followed by gelation, aging and supercirtical drying to fabricate the aerogels im pregnated high-temperature insulating tiles. The aerogel/tile composites' microstructure, thermal and mechanical properties at high-temperatures (up to 1400C) were investigated. The results showed the composites exhibited a small linear shrinkage of 2% after hating at 1400C for 30 min.With increasing heating temperature, the aerogels' particles grew and condensed; the aerogels changed from flling the fibers' pores to being condensed, and to being mainly atta-ched to the fibers' surface, but such evolution did not obviously affect the fibrous skeleton. After the aerogel impreg-nation, the specimen's room-temperature and high-temperature thermal conductivities decreased significantly, and the cold-face temperature dropped from 945°C to 870°C in the back-temperature tests. In addition, although the compos ites' room-temperature mechanical properties increased slightly, the high-temperature compressive strength drastically degraded at 1200℃ and 1400°℃.
Key wordsAerogel,Insulating tiles，Thermal properties，Mechanical properties
0引言
以石英纤维为主要成分的隔热瓦，最早作为美国航收稿日期：2016-0725；修回日期：2017-02-10
基金项目：国家自然科学基金面上项目（No.51576058）
天飞机大面积热防护材料，长时使用温度为1200℃["]；后发展出FRCI、AETB、BRI等系列隔热瓦，在X-43A、X
第一作者简介：孙晶晶，1977年出生，博士，高级工程师，主要从事高效隔热材料方面的研究。E-mail:jisun6@hotmail.com
宇航材料工艺万方数据
http://www.yhclgy.com
2017年第3期
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