Thermal-insulation and ablation-resistance of Ti-Si binary modified carbon/phenolic nanocomposites for high-temperature thermal protection

Ablative thermal protection systems are considered to be one of the most promising means of protection for spacecraft re-entry, but challenges remain. Herein, efficient Ti-Si binary modified carbon fiber reinforced phenolic aerogel nanocomposites (Cf/TS-PR) were originally designed based on a multi-stage construction strategy. The Cf/TS-PR exhibited desirable mechanical strength, good thermal insulation with a minimum thermal conductivity of 0.0756 W/(m·K), remarkable thermal stability and outstanding ablation resistance, benefiting from the features of TiO2 and the special structure of TiO2-SiO2 coating. The linear ablation rates are as low as 0.004 and 0.003 mm/s at the heat flow of 1.0 and 1.5 MW/m2, respectively. The mass loss rates are as low as 0.006 and 0.009 g/s at the heat flow of 1.0 and 1.5 MW/m2, respectively. These results indicate that the Cf/TS-PR nanocomposites can be a reliable thermal protection material for the future high-temperature service environment of ultra-high-speed vehicles and neutral rockets.