Preparation method of high-temperature-resistant aluminum oxide-silicon oxide aerogel composite material

Abstract

The invention discloses a preparation method of a high-temperature-resistant aluminum oxide-silicon oxide aerogel composite material, wherein the preparation method comprises the following steps: (1) sufficiently dispersing and mixing nano aluminum oxide powder, micron aluminum oxide powder, an infrared opacifying agent and short fibers to obtain a mixture A; (2) performing compression molding on the mixture A to obtain an aluminum oxide composite material; (3) uniformly mixing a silicon source, ethanol and water to obtain silicon dioxide sol; (4) dipping the aluminum oxide composite material by adopting silicon dioxide sol; and (5) performing drying treatment to obtain the high-temperature-resistant aluminum oxide-silicon oxide aerogel composite material. According to the preparation method disclosed by the invention, compounding of aluminum oxide and silicon oxide aerogel is realized through impregnation, a complex preparation process is avoided, the preparation period is shortened, the silicon oxide aerogel is fixed in the aluminum oxide composite material, the compactness of the aluminum oxide composite material is further increased, the composite material has relatively good mechanical properties, and great shrinkage of the aluminum oxide composite material at high temperature is avoided.

Description

technical field [0001] The invention belongs to the field of thermal insulation materials, and in particular relates to a preparation method of a high-temperature-resistant alumina-silica airgel composite material. Background technique [0002] As the flight speed of the aircraft is getting faster and the surface temperature is getting higher and higher, the thermal insulation effect and mechanical properties of conventional aluminum silicate or mullite fibers can no longer meet the thermal protection requirements of aerospace vehicles in the high temperature section. The use of nano-airgel thermal insulation composites has become the leading direction for efficient thermal insulation. [0003] Airgel is currently the most ideal lightweight thermal insulation material. It is a lightweight, amorphous and porous solid material composed of nano colloidal particles or polymer molecules. It has extremely low density, high specific surface area and high porosity. . The pore size...

AI Technical Summary

Problems solved by technology

However, the inherent low strength, high brittleness, poor ability to block infrared radiation, and difficulty in forming of alumina-silica airgel materials limit the application of alumina-silica airgel in industry.