A kind of silica-based lightweight ceramic thermal protection material and its preparation method and application

Abstract

The invention relates to a silicon dioxide based light ceramic heat protection material and a preparation method and an application of the material. The heat protection material takes a rigid heat insulation tile as a matrix, and is compounded with Si-O-C aerogel; and the surface of the material is coated with a reinforced coating. The preparation method comprises the steps of preparing the rigid heat insulation tile matrix and an Si-O-C collosol precursor, dipping the rigid heat insulation tile matrix in the Si-O-C collosol precursor, performing aging, solvent replacement and supercritical drying sequentially to form a rigid heat insulation tile based Si-O-C aerogel composite, and applying the surface reinforcement coating on the external surface of the rigid heat insulation tile based Si-O-C aerogel composite to prepare the silicon dioxide based light ceramic heat protection material. The prepared material is low in density and high in compressive strength, further has the characteristics of low ablation velocity, low heat conductivity, high emissivity, good heat insulation effect and excellent air flow scouring resistance and can be used as a heat protection material of the external surface of an outer space exploration vehicle.

Description

technical field [0001] The invention relates to the technical field of functional composite materials, in particular to a silica-based lightweight ceramic thermal protection ablation material and its preparation method and application. Background technique [0002] When an interplanetary vehicle such as a Mars probe enters the atmosphere of an extraterrestrial planet at high speed and re-enters the Earth's atmosphere from outer space, it will generate severe aerodynamic heating due to its extremely fast speed. Therefore, thermal protection measures must be implemented on the outer surface of the vehicle. The weight of the aircraft determines the thrust requirements of the required launch vehicle, which in turn determines the feasibility of the project. Therefore, reducing the weight of the thermal protection system on the outer surface of the interplanetary exploration vehicle is very critical to the realization of the project. [0003] Early high-density ablative thermal p...

AI Technical Summary

Problems solved by technology

U.S. Patent No. 5536562 discloses a class of density between 0.15 ~ 0.4g / cm 3 A range of quartz fibers impregnated with organic resins, but the density of the lightweight ceramic-based ablation heat protection material SIRCA prepared as a matrix is ​​0.27-0.82g / cm 3 , and the anti-airflow erosion performance is not excellent enough

Huo Yangyang used vacuum impregnation and mechanical dispersion to uniformly disperse chopped quartz fibers into Si-O-C aerogels to obtain thermal insulation composites, but the preparation of Si-O-C aerogels requires alkoxysilane in acidic Hydrolysis under conditions, followed by polycondensation under alkaline conditions, the preparation process is complicated. In addition, the content of quartz fibers in this material only accounts for 5wt%, and the density has reached 0.126-0.382g / cm 3 , and the low content of quartz fiber will lead to low strength of the material, and the compressive strength is as low as 0.135MPa~0.316MPa

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