超高温刚性隔热材料的制备及性能

针对新型航天飞行器高温隔热(约1 500℃)的迫切需求,开展了超高温刚性隔热材料的制备和性能研究。采用陶瓷纤维和无机粘结剂,经过湿法抽滤成型、高温热处理等工艺制备了刚性隔热材料。对材料的微观结构、热物理和力学性能进行了表征、测试。结果表明:纤维有效粘结在一起;通过改变纤维和粘结剂的比例,可以调节材料性能;热导率、力学性能与密度近似呈直线关系。材料在1 500℃经1 h处理后线收缩率<2%,密度为0.3～0.5 g/cm3,热导率为0.06～0.09 W/(m.K),压缩强度为0.6～1.2 MPa。

Fabrication and Properties of Ultra-High Temperature RigidThermal Insulation Materials

To meet the need of thermal protection(~1 500℃) for novel aerospace vehicles,ultra-high temperature rigid thermal insulation materials had been fabricated and investigated.Using a high-resisting fiber and inorganic binder,the insulation was produced through the process of vacuum-molding and firing the dried billet.The microstructure,thermophysical and mechanical properties of the materials were characterized and measured.The results showed that the fibers were bonded effectively;the properties could be tailored by adjusting the ratio of fiber to binder;the thermal conductivity at room temperature and mechanical properties varied linearly with density.The insulation materials had a shrinkage of less than 2% after heating at 1 500℃ for 1 h,a low density in the range of 0.3 to 0.5 g/cm3,thermal conductivity of 0.06 to 0.09 W/(m·K),and compressive strength of 0.6 to 1.2 MPa.