Lightweight, elastic, and thermally insulative aluminum silicate ceramic felt/polysiloxane@resorcinol-furfural aerogel composite for repeatable high-temperature protection

Lightweight and flexible ablative thermal protection materials (TPMs) are critically needed for aerospace vehicles that endure complex dynamic stresses in high-temperature environments. This work presents a lightweight, elastic aluminum silicate fiber/polysiloxane aerogel coated with resorcinol–furfural aerogel (ASF/Si@RFA) composite, fabricated via a facile process involving vacuum impregnation, sol–gel reaction, and atmospheric pressure drying. The composite features a unique multiscale architecture that integrates a macroscopic ceramic ASF felt, a micron-scale flexible and ceramizable SiA, and a nanoporous carbonizable RFA into a highly porous, three-dimensionally interconnected network. This multiscale design yields a low density (∼0.165 g·cm −3 ), superior compressive resilience with full recovery from 60% strain, and excellent thermal insulation (∼34 mW·m −1 ·K −1 ) across both high and cryogenic temperatures, alongside notable hydrophobicity (a water contact angle of 130°). More importantly, exceptional repeatable high-temperature protection performance under a 1300 °C butane flame. A synergistic protective mechanism, arising from the in-situ formation of a silicon oxycarbide barrier, the release of pyrolysis gases for transpiration cooling, the high emissivity of the carbon aerogel, and transverse heat dissipation, results in near-zero surface recession(0.17 μm·s −1 ) and backside temperature below 100 °C throughout 15 heating cycles. This strategy provides a promising pathway for developing advanced lightweight, flexible ablative TPMs.