Material–structure–function integrated additive manufacturing of SiC/mullite metamaterial with low-frequency compatible ultra-broadband electromagnetic absorption

Advanced radar systems require electromagnetic wave (EMW) absorbers that can function reliably under extreme conditions. SiC-based absorbers exhibit excellent high-temperature resistance and chemical stability; however, achieving low-frequency-compatible ultra-broadband electromagnetic absorption remains a significant challenge. Herein, we propose a material-structure-function integrated strategy to design and fabricate a biomimetic SiC/mullite metamaterial with low-frequency-compatible ultra-broadband EMW absorption using laser powder bed fusion (LPBF) technology. Specifically, by employing a microscopic non-magnetic hetero-interfacial polarization strategy, a tunable effective absorption bandwidth (EAB) covering the entire 2-18 GHz range can be achieved by adjusting the matching thickness within 6 mm. The incorporation of macroscopic hybrid 2D/3D honeycomb metamaterial designs greatly expanded the EAB to 3.11-40 GHz (RL < -10 dB). This strategy results in the fabricated metamaterial with high oxidation resistance at high temperatures, enabling it to retain stable absorption performance even after oxidation at 1 200 °C, which indicates its readiness for use in extreme thermal applications. This work extends the additive manufacturing of high-performance EMW-absorbing metamaterials through a material-structure-function integrated strategy while also significantly advancing the development of environmentally adaptive absorbers.