Thermal ablation‐insulation performance, microstructural, and mechanical properties of carbon aerogel based lightweight heat shielding composites

Abstract

AbstractIn this study, carbon aerogel based lightweight composite ablators (CALCAs) with different densities and microstructures were prepared using the vacuum impregnation method. The mechanical strength and morphology of CALCAs were investigated. Ablation‐insulation performance of the samples was also evaluated by an oxyacetylene flame test with a constant heating rate of 2.5 MW/m2. Moreover, the structural evolution during the ablation was studied and the ablation mechanism of CALCAs was proposed. The porous insulators showed good compressive strength (3.2–9 MPa) and low thermal conductivity (lower than 0.35 W/mK). Besides the tunable density, the low recession rate (as low as 0.117 mm/s), and good ablation‐insulation performance (175°C at 25 mm and 125 at 35 mm in‐depth), these lightweight porous heat shielding composites are promising candidates to use as the thermal protection systems for aerospace applications.