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

Abstract

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 (SiCnws)/SiC composites are fabricated with in-situ SiC interface on one-dimensional oriented SiCnws 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 (EABmax) of 5.9 GHz and the minimum reflection loss (RLmin) 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 EABmax of 4.9 GHz and RLmin 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.