Yttrium Silicate‐Coated Carbon Fiber Reinforced Phenolic Aerogel‐like Composites with Low Density and Low Ablation

Abstract The evolution of hypersonic vehicles has raised higher requirements for thermal protection materials, which have become the focus of research on how to meet the lightweight and less ablative. Herein, a yttrium silicate‐coated carbon fiber felts (YS‐CFs) reinforced phenolic aerogel‐like (PR) composites were prepared. The YS‐CFs/PR with the addition of 12 % hexamethylenetetramine exhibited low density (0.540 g/cm 3 ), low thermal conductivity (0.145 W/(m⋅K)), and good thermal stability. Specifically, under an oxyacetylene flame examination with 2.44 MW/m 2 heated for 120 s, its mass ablation rates (9.833 mg/s) and line ablation rates (5 μm/s) were decreased by 40.8 % and 32.6 %, respectively, compared to others. The results show that the composites with these combined properties can meet the requirements for thermal protection materials in the field of hypersonic vehicles.