No abstract

The heat insulation ability and thermal stability of thermal protection materials play extremely important role in the thermal protection of aero-engines under high temperature. Herein, we design the carbon-SiO2-Al2O3 (CSA) composite aerogel through thermochemical restructuring from the phenol-formaldehyde resin-SiO2-Al2O3 (PSA) composite aerogel. This thermochemical restructured aerogel not only shows better adhesion property under room temperature but also possesses higher thermal stability and desirable heat insulation ability under high temperature. Taking the PSA-0.5 composite aerogel as an example, the compressive strain–stress test unveils that it can be compressed by 66% without catastrophic collapse, which is beneficial for the adhesion with the metallic matrix. Meanwhile, the transmission electron microscopy and scanning electron microscopy images exhibit the unbroken three-dimensional structure for the CSA-0.5 composite aerogel, which confirmed the structural stability of the composite aerogel after thermochemical restructuring. The thermal cycle test indicates that the weight loss of the CSA-0.5 composite aerogel is only ca. 8%, firmly confirming its thermal stability. Importantly, the thermal conductivity of the CSA-0.5 composite aerogel ranges from 0.024 to 0.083 W m–1 K–1, indicating the superior performance of heat insulation. Moreover, the numerical simulation is carried out to validate the thermal protection effect of the CSA-0.5 composite aerogel as a thermal protection layer. Together with laminated cooling, it could enhance the surface cooling effectiveness of the metallic matrix to above 0.8. Briefly, this work paves a new pathway for efficient thermal protection materials of aero-engines via the rational design of the thermochemical restructured composite aerogel under the guidance of ANSYS numerical simulations.

Insulation materials play an extremely important role in the thermal protection of aerospace vehicles. Here, aluminum carbon aerogels (AlCAs) are designed for the thermal protection of aerospace. Taking AlCA with a carbonization temperature of 800 °C (AlCA–800) as an example, scanning electron microscopy (SEM) images show an integrated three-dimensional porous frame structure in AlCA–800. In addition, the thermogravimetric test (TGA) reveals that the weight loss of AlCA–800 is only ca. 10%, confirming its desirable thermal stability. Moreover, the thermal conductivity of AlCA–800 ranges from 0.018 W m−1 K−1 to 0.041 W m−1 K−1, revealing an enormous potential for heat insulation applications. In addition, ANSYS numerical simulations are carried out on a composite structure to forecast the thermal protection ability of AlCA–800 acting as a thermal protection layer. The results uncover that the thermal protective performance of the AlCA–800 layer is outstanding, causing a 1185 K temperature drop of the structure surface that is exposed to a heat environment for ten minutes. Briefly, this work unveils a rational fabrication of the aluminum carbon composite aerogel and paves a new way for the efficient thermal protection materials of aerospace via the simple and economical design of the aluminum carbon aerogels under the guidance of ANSYS numerical simulation.