Ablation behavior and mechanism of TaSi₂-modified carbon fabric-reinforced phenolic composite

The increasingly serious service condition in aerospace industry has posed a higher requirement to the ablation resistance of hypersonic vehicle structural carbon fabric-reinforced phenolic composites. To further enhance the ablation resistance of the composite, different contents of TaSi₂-modified carbon fabric-reinforced phenolic composites were successfully prepared. The ablation behavior and mechanism of these composite were investigated. Results showed that the ablation resistance of the modified composite was significantly improved due to the addition of the TaSi₂. When the mass fraction of TaSi₂ on the matrix resin was 50 wt%, the mass and liner ablation rate of the modified composites were 30% and 12% lower than those of the unmodified composites, respectively. The formed double-layer structural residue acted as an insulating layer and effectively obstructed the flame flow and oxygen to the inner material. Moreover, the occurrence of the endothermic reactions and the evaporation of the reaction gases further dissipated the heat energy. The multi-effect synergy mechanism effectively reduced the thermal oxidative ablation degree of the modified composites. All these results confirmed that the TaSi₂-modified composite exhibits excellent oxidative ablation resistance, which provided a basis for the application of composite to more serious service environments.