超低导热系数多层复合材料低气压环境隔热性能

Ultra-low Thermal Conductivity Multilayer Composites for Insulation in LowPressure Environments

本文以氧化锆纤维、碳纤维和石墨纸为主要原料,利用磷酸二氢铝作为粘结剂,采用真空抽滤和逐层铺设工艺制备成氧化锆纤维/碳纤维/石墨纸多层复合隔热材料。测试了制备材料的体积密度,抗压强度和导热系数,并通过XRD分析了制备材料的物相组成,SEM观察了制备材料的微观结构和低气压下隔热测试后的微观结构变化。采用低气压隔热性能测试装置测试了材料在低气压下的绝热性能。探究了低气压条件下对制备材料绝热性能的影响规律。材料的体积密度为0.755g/cm^(3),最大压缩应变量高达70%,1200℃的导热系数只有0.103W/(mK)。在气压2kPa、热面温度1200℃时,冷面温度仅为331.1℃。研究结果表明:低气压下制备材料的隔热性能有显著提高。

Multilayer composite insulation is prepared using a vacuum extraction and layer-by-layer lay-up process.Using zirconium oxide fibers,carbon fibers and graphite paper as the main raw materials and aluminium dihydrogen phosphate as the binder.The bulk density,compressive strength and thermal conductivity of the prepared materials were tested.The physical phase composition of the prepared materials was analyzed by XRD and the microstructure was observed by SEM.The thermal insulation performance of the materials under low air pressure was tested using a low air pressure thermal insulation performance test device.The effect of low air pressure on the adiabatic properties of the prepared materials was investigated.the prepared materials had a low bulk density of 0.755 g/cm^(3),a high compression strain of 70%and ultra-low thermal conductivity of 0.103 W/(m·K)at 1200℃;The cold side temperature is only 331.1℃ when the air pressure is 2 kPa and the hot side temperature is 1200℃.The results indicated that the thermal insulation properties of the materials prepared at low air pressure are significantly improved.