文献类型：期刊文献

中文题名：高强度碳气凝胶复合材料的制备及结构、性能研究

英文题名：Preparation, structure and properties of high strength carbon aerogel composites

作者：沈泽慧[1];曹宇[1];郝晶莹[2];张琪凯[2];牛波[1];张亚运[1];龙东辉[1]

机构：[1]华东理工大学化工学院,上海200237;[2]北京新风航天装备有限公司,北京100854

年份：2024

期号：6

起止页码：5

中文期刊名：复合材料科学与工程

外文期刊名：Composites Science and Engineering

收录：;北大核心:【北大核心2023】；

基金：国家自然科学基金(22078100,52102098);中国博士后科学基金(2022M711140)。

语种：中文

中文关键词：碳气凝胶;复合材料;力学性能;隔热性能;格子玻尔兹曼方法

外文关键词：carbon aerogel;composite;mechanical properties;thermal insulation properties;lattice Boltzmann method

摘要：针对热防护系统的热桥阻断需求,以碳/石英纤维混编针刺预制体为增强体,酚醛树脂为碳前驱体,通过溶胶-凝胶、常压干燥和高温碳化工艺,制备出一种中密度-高强度碳气凝胶复合材料,系统研究了材料的微观结构、力学性能和隔热性能。结果表明:所制复合材料在中密度(约为0.80 g·cm^(-3))下具有较强的力学性能(5%压缩应变时压缩应力约为10 MPa)和优异的隔热性能(室温热导率<0.230 W·m^(-1)·K^(-1))。随着预制体中石英纤维质量分数从0%增加至20%,复合材料在1 000℃下等效热导率从0.224 W·m^(-1)·K^(-1)下降至0.158 W·m^(-1)·K^(-1),具备了高温热桥阻断应用潜力。进一步采用格子玻尔兹曼方法对材料室温至1 600℃下的热导率进行预测,发现了材料结构和环境因素对热导率的影响趋势,即碳气凝胶基体孔隙率的上升会导致热量传递的阻碍增大,从而导致复合材料热导率下降;预制体密度的增大导致热量传递的通道增加,使复合材料热导率增大;石英纤维含量的增加会导致复合材料热导率逐渐下降;当气压较小时,热导率随气压的增大迅速增大,而当气压较大时,热导率几乎不受影响。
Aiming at the thermal bridge blocking demand of thermal protection system,carbon aerogel composites with medium-density and high strength were prepared by sol-gel,atmospheric pressure drying and high temperature carbonization processes using carbon/quartz fiber hybrid needle-punched preforms as reinforcement and phenolic resin as carbon precursor,and the microstructure,mechanical properties and thermal insulation performance of the composites were systematically investigated.The results show that the composites has strong mechanical properties(compressive stress approximately 10 MPa at 5%compressive strain)and excellent thermal insulation properties(room temperature thermal conductivity<0.230 W·m^(-1)·K^(-1))with medium density(approximately 0.80 g·cm^(-3)).As the mass fraction of quartz fibers in the preform increases from 0%to 20%,the equivalent thermal conductivity of the composite decreases from 0.224 W·m^(-1)·K^(-1) to 0.158 W·m^(-1)·K^(-1) at 1000℃,indicating the potential for high-temperature thermal bridge-blocking applications.Further,the lattice Boltzmann method was used to predict the thermal conductivity of the material from room temperature to 1600℃,and the trends of the influence of material structure and environmental factors on the thermal conductivity were found.The increase in the porosity of the carbon aerogel matrix leads to the increase in the resistance of heat transfer,which leads to the decrease in the thermal conductivity of the composite.The increase in the density of the preform leads to the increase in the channels for heat transfer,which makes the thermal conductivity of the composite increase.The increase of quartz fiber content leads to the gradual decrease of thermal conductivity of the composites.When the air pressure is low,the thermal conductivity increases rapidly with the increase of air pressure,while when the air pressure is high,the thermal conductivity is almost unaffected.