非压力浸渍成型技术制备夹层结构气凝胶外防热材料  

Preparation of Outside Aerogel Heat Shields with Sandwich Structure by Using Non-pressure Impregnating Process

作　　者：苏力军[1] 张丽娟[1] 宋寒[1] 郭慧[1] 郭建业 李文静[1] 杨洁颖[1] 裴雨辰[1] SU Lijun;ZHANG Lijuan;SONG Han;GUO Hui;GUO Jianye;LI Wenjing;YANG Jieying;PEI Yuchen(Research Institute of Aerospace Special Materials and Processing Technology,Beijing 100074)

机构地区：[1]航天特种材料及工艺技术研究所

出　　处：《材料导报》2019年第A01期206-210,共5页Materials Reports

摘　　要：夹层结构气凝胶外防热材料兼具中间层气凝胶材料高效隔热、陶瓷面板材料抗冲刷特点,在未来新型航天飞行器大面积外防隔热领域具有广阔的应用前景。常规的基于压力浸渍成型技术制备的夹层结构气凝胶外防热材料易于出现中间层气凝胶材料渗胶、塌陷、分层问题,从而失去了气凝胶材料高效隔热的特性。本工作提出了非压力浸渍成型技术,即将压力浸渍改为真空浸渍,解决了气凝胶易于渗胶、塌陷问题,通过调节面板陶瓷前驱体浓度、分子链团聚粒径大小、浸渍次数将面板材料力学强度稳固提高,夹层结构材料隔热性能和应变协调性能优异,中心点挠曲位移达8.89mm,在1200℃电弧风洞考核试验中,1000s时背面温升只有55℃。该技术在未来航天飞行器大面积热防护领域具有潜在的应用价值。Outside aerogel heat shields with sandwich structure have the characteristics with extremely efficient insulation of aerogel,and with excellent anti-washout for severe aerodynamic thermal flow,just like ceramic plate.It will have a promising prospect in the outside heat shielding area for the future aerospace vehicles.However,something wrong occurred when it was produced by using conventional pressure impregnating process,the aerogel was soaked by the plate ceramic precursor,broken down,and collapsed.Finally,the inherent insulative feature was lost.Non-pressure impregnating process was proposed,and the pressure impregnation was changed to non-pressure impregnation.The problems of soaked by the plate ceramic precursor and broken down were solved.When the concentration of plate ceramic precursor was adjusted,agglomerated particle size of molecular chain was transformed,and number of times for impregnation was changed,the mechanical property of the plate was enhanced.It is excellent in the heat-insulating property and strain capacity,with deflection of 8.89 mm,and with back temperature of 55℃when heated by 1 200℃in the wind tunnel for 1 000 s.This process has the potential applied value in the outside heat shielding area for the future aerospace vehicles.

关 键 词：三明治夹层结构 外防热材料 气凝胶 

分 类 号：V45[一般工业技术—材料科学与工程]