Multiscale, elastic, and low-density carbon fibre / siliconoxycarbide-phenolic interpenetrating aerogel nanocomposite for ablative thermal protection

Lightweight ablators are considered to be the most potential materials for ablative thermal protection. Herein, a novel needle carbon fibre enhanced siliconoxycarbide-phenolic interpenetrating aerogel (SiCF/PR) nanocomposite with a hierarchical multiscale structure was fabricated by a robust multistage constitutive method. The as-designed multiscale lightweight (0.30–0.35 g/cm3) nanocomposite perfectly inherited its porous nanostructure and captivating properties, including notable high compressive strength (4.57–5.83 MPa), great elasticity and heat-insulation (0.068 W/(m·K)). According to its outstanding oxidation and ablation resistance, the nanocomposite resisted flame blowing of 1000 °C by butane torch for 30 min without structural disintegration, Furthermore, the linear ablation rates show a great improvement from 0.0282 to 0.0109 mm/s with the increase of siliconoxycarbide contents under the oxyacetylene flame ablation of 1.5 MW/m2 for 300 s. These properties suggest that the SiCF/PR nanocomposite is a competitive candidate for the thermal protection of reentry spacecraft and hypersonic vehicles. •The lightweight SiCF/PR was developed by a robust multistage constitutive strategy.•The multiscale structure brings an excellent synergy of mechanical and thermal insulation.•The SiCF/PR aerogel composites possess high compressive strength and good resilience.•The SiCF/PR material shows superior thermal insulating performance at around 1000 °C.•The nanocomposites exhibit outstanding antioxidant ablation properties over 1800 °C.