Hierarchical porous SiCnws/SiC composites with one-dimensional oriented assemblies for high-temperature broadband wave absorption

• Hierarchical porous SiC nws /SiC composites are fabricated by in-situ growth of SiC interface on one-dimensional oriented SiC nws skeleton, which provides broadband impedance matching and strong wave attenuation capability, resulting in excellent absorption performance and thermal stability. • The SiC nws /SiC composites present a RL min of −41.4 dB and an EAB of 5.9 GHz (ranging from 12.1 GHz to 18 GHz), which can be attributed to the presence of numerous interfaces and uniform micropores. • The RL min of −30.4 dB and EAB of 4.9 GHz of the SiC nws /SiC composites after annealing at 1100 °C prove the high-temperature resistance and absorbing stability, indicating an application potential in aero-engines applications and extreme environments. The research on high-performance electromagnetic wave absorption materials with high-temperature and oxidative stability in extreme environments is gaining popularity. Herein, the lightweight silicon carbide nanowires (SiC nws )/SiC composites are fabricated with in-situ SiC interface on one-dimensional oriented SiC nws skeleton, which collaborative configuration by 3D printing and freeze casting assembly. The constructed porous structure optimizes the impedance matching degree and scattering intensity, the maximum effective absorption bandwidth (EAB max ) of 5.9 GHz and the minimum reflection loss (RL min ) of −41.4 dB can be realized. Considering the inherent oxidation resistance of SiC, the composites present well-maintained absorption performance at 600 °C. Even at 1100 °C, the EAB max of 4.9 GHz and RL min of −30.4 dB also demonstrate the high-temperature absorption stability of the composites, indicating exceptional wave absorption properties and thermal stability. The slight attenuation can be attributed to the decrease in impedance matching capability accompanying the elevated dielectric constant. This work clarifies the impact of structure and component synergy on wave absorption behavior, and offers a novel approach to producing high-performance and high-temperature resistance ceramic-based electromagnetic wave absorption materials suitable for extreme environments.