Boosting high‐temperature heat transfer of ceramic insulation tile with ordered‐conformation boron nitride

Abstract Boosting heat transfer of ceramics has been an increasing challenge for spacecraft insulation tile. The concurrent superiorities of higher heat stability and comparative thermal conductivity on par with graphene make boron nitride (h‐BN) an ideal reinforcement. Yet, its characteristic of Kapitza thermal resistance inevitably aggravates heat transfer deterioration in aerodynamic in‐service environment. Here, we proposed a multiscale optimal approach to boost the heat transfer of Al 2 O 3 /h‐BN composites with nanoscale interfacial thermal conductance and mesoscale h‐BN ordered conformation. Interfacial thermal conductivity induced by a strong 5% Al‐N bonding configuration in the densification process is improved from 248 MW·m −2 ·K −1 at 300 K to 340 MW·m −2 ·K −1 at 1500 K, which depicts a priority of h‐BN than graphene in composites. Massive delocalized lower‐frequency phonons, an indicator of thermal flutter, are decomposed from localized high‐frequency phonon at high temperature. Mesoscale thermal conductivity of composites is increased from 15 W·m −1 ·K −1 of random distribution to 19 W·m −1 ·K −1 of ordered conformation at 1500 K. This optimal design of ordered conformation induced by external field in fabrication process constructs a rapid path of anisotropic thermal converge, and ameliorates heat transfer deterioration of random dispersion. This work provides an effective strategy for designing a novel ceramic insulation tile to extend the remaining life of next‐generation spacecraft.