Bioinspired C/C composites with long-duration ablation resistance for thermal protection up to 2400 °C

The development of ultrahigh-temperature thermal protection materials (TPMs) with long-term ablation resistance is crucial for high-speed aircraft, where surface heat accumulation and protective layer instability remain key limiting factors for service lifetime. Ultrahigh-temperature TPMs face a critical challenge in balancing active cooling and passive protection during long-term servicing. Inspired by human skin’s thermoregulation and tree rings’ functional partitioning, we present a dual-biomimetic structural design strategy for carbon/carbon (C/C) composites that overcomes this limitation. Through a novel selective-area reactive melt infiltration method and design of thermal conductive rods, we engineered bioinspired C/C composites featuring: (1) high-thermal-conductivity Cu channels mimicking hair shafts for enhanced heat dissipation, (2) a functional partitioning architecture effectively mitigating thermal stress with an ablation-resistant ZrC-Cu core and sweat-cooling SiC-Cu-Cu_xSi_y periphery, and (3) highly stable oxide protective film at ablation surface. This dual-biomimetic structure design synergistically reduces surface heat accumulation and surface temperature (active cooling via heat conduction and dissipation), and promotes a formation of La-stabilized oxide films (relying on regulating the phase transition), enabling the bioinspired C/C composites to achieve thermal protection for 720 s with negligible ablation damage at a high heat flux of 4.18 MW/m²and a temperature exceeding 2400 °C, which surpass most reported C/C-based TPMs. Our work establishes a new paradigm for designing long-duration TPMs through bioinspired multifunctional integration, with broad implications for aerospace applications and extreme environment materials.