Multiphase synergistic strategy enabling flexible ceramic fibers with electromagnetic stealth capability for thermal protection up to 2000 °C

In situ ZrC nanoparticles at SiC grain boundaries suppress grain coarsening and preserve mechanical flexibility. • The fibers combine ultrahigh-temperature stability and strong electromagnetic wave absorption. • Large-area fiber membranes fabricated continuously confirm scalable production. Next-generation aerospace vehicles demand thermal protection materials that can withstand aerodynamic heating achieving 2000 °C, while concurrently maintaining structural flexibility and electromagnetic stealth capabilities—a synergistic performance portfolio that remains largely unattainable with conventional ceramic materials. To address this exigent requirement, flexible multiphase SiC-ZrC-C fibers are designed and fabricated in this work. In situ-formed ZrC nanoparticles preferentially nucleate at SiC grain boundaries and act as pinning phases, suppressing SiC grain coarsening at ultrahigh temperature, while the continuous porous carbon scaffold accommodates mechanical deformation. The resultant fibers demonstrate exceptional thermal stability, characterized by phase stability following exposure at 1600 °C for 50 h, as well as retained flexibility even after annealing at 2000 °C for 1 h in an Ar atmosphere. Concurrently, the fibers exhibit potent electromagnetic wave absorption capabilities, achieving a minimum reflection loss of −52.60 dB and an effective absorption bandwidth of 5.56 GHz. Besides, continuous fabrication yields large-area fibrous membranes, highlighting the feasibility of large-scale production. The results of this work provide new insights into the design and development of structure-function-integrated thermal protection materials for extreme environments. In brief Flexible multiphase SiC-ZrC-C fibers were designed as multifunctional thermal protection materials for next-generation aerospace vehicles, exhibiting exceptional thermal stability up to 2000 °C, as well as strong electromagnetic wave absorption performance. Download: Download high-res image (244KB) Download: Download full-size image