Ultra-low thermal conductivity and high strength of aerogels/fibrous ceramic composites
Ultra-low thermal conductivity and high strength of aerogels/fibrous ceramic composites
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DOI：
10.1016/j.jeurceramsoc.2015.11.021
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发表时间：
2016-05-01
影响因子：
5.7
通讯作者：
Wang, XiaoJing
中科院分区：
文献类型：
--
作者：
He, Jian;Li, Xiaolei;Wang, XiaoJing
受自然界燕窝结构的启发，以莫来石纤维为基质，以氧化锆-二氧化硅气凝胶为填料，采用真空浸渍法制备了新型气凝胶/纤维陶瓷复合材料。因此，用气凝胶填充莫来石纤维预制体的大孔，形成类似鸟巢的结构，具有较高的孔隙率(85%)和大量的介孔。所制备的气凝胶/纤维陶瓷复合材料的抗压强度高达1.05 Mpa，约为莫来石纤维预制体的2倍，是纯气凝胶的10倍，并对其压缩破坏机理进行了分析。与传统的纤维材料相比，气凝胶/纤维陶瓷复合材料在室温下的导热系数仅为0.0524W m(-1)K-1，在500℃和1200℃下的导热系数为0.082~0.182 W m(-1)K-1，表明其在较宽的温度范围内具有良好的隔热性能。因此，这种高强度的超低导热系数气凝胶/纤维陶瓷复合材料是一种应用于航空航天领域的优良隔热材料。(C)2015爱思唯尔有限公司。保留所有权利。
Novel aerogels/fibrous ceramic composite, inspired by the bird's nest structure in nature, is synthesized using mullite fibers as matrix and ZrO2-SiO2 aerogels as filler through vacuum impregnation. Thus, the macropore of mullite fiber perform are filled by aerogels to form similar bird's nest structure with high porosity (85%) with a large amount of mesoporous. The as-prepared aerogels/fibrous ceramic composite exhibits high compressive strength of up to 1.05 MPa which is approximately two times as much as that of mullite fiber perform and ten times higher than that of pure aerogels, and the compressive failure mechanism is analyzed. Compared to conventional fibrous materials, the aerogels/fibrous ceramic composite shows a much lower thermal conductivity of 0.0524W m(-1) K-1 at room temperature and 0.082-0.182 W m(-1) K-1 during 500 degrees C and 1200 degrees C indicating its excellent thermal insulation property in a wide temperature range. Therefore, this ultra-low thermal conductivity aerogels/fibrous ceramic composite with high strength is an excellent heat-insulation material applied in the fields of aerospace. (C) 2015 Elsevier Ltd. All rights reserved.