A facile in-situ strategy to fabricate lightweight carbon fiber/silicone-phenolic aerogel composites with superior toughness and ablation performance

The development of lightweight carbon fiber/phenolic ablator plays a vital role in advancements of space technology. However, the complex fabrication process and inherent brittleness of ablators impede its further progress. Herein, we fabricated a high-performance carbon fiber/silicone-phenolic aerogel (CFSP) composite through a facile in-situ strategy, which exhibits lightweight nature (0.25–0.28 g/cm³), low thermal conductivity (0.054–0.056 W/(m·K)) and thermal stability. Meanwhile, the as-designed composites effectively addressed the disadvantage of brittleness that exhibited a fracture strain of 34.32% and a flexural modulus of 4.07 MPa, which was a significant improvement compared with the toughness of the unmodified composite (15.60%, 21.44 MPa, respectively). Notably, in the oxyacetylene test, the linear ablation rates show a great decline from 0.381 mm/s to 0.227 mm/s with the increase in silicone contents. Therefore, the CFSP composite is a competitive candidate for the thermal protection material of the next generation of hypersonic vehicles.