Broadband, wide-angle, and high-temperature microwave absorbers enabled by 3D-printed torsion SiC metamaterials

The design and fabrication of absorbers exhibiting ultra-broadband and wide-angle absorption characteristics represent a viable strategy for enhancing the radar evasion capabilities of hypersonic vehicles. However, traditional microwave absorbing materials are difficult to meet the application requirements of hypersonic vehicles due to their strong angular domain sensitivity, insufficient stealth frequency band, and limited performance under elevated temperature conditions. This study presents a straightforward approach to the development of a 3D-printed ceramic-based microwave absorber. Utilizing powder extrusion printing (PEP) technology, we fabricated a torsion metamaterial absorber composed of silicon carbide (SiC). The structural design integrates the impedance gradient properties of a stepped configuration, the multi-surface attributes of a triply periodic minimal surface structure, and the porous characteristics inherent to a honeycomb structure. The absorber benefits from significant interfacial loss and dipole polarization resulting from the diverse phases within SiC ceramics, in conjunction with the innovative design that merges gradient-variable impedance with a multi-scale loss mechanism of the twisted body. Consequently, the absorber achieves an effective absorption bandwidth (EAB, RL < -10 dB) of 32.87 GHz, a RLmin of -57.15 dB, and demonstrates insensitivity across a wide angular range of 0° to 60°, while also exhibiting remarkable absorption stability at elevated temperatures. These findings offer valuable insights for the advancement of novel high-temperature microwave absorbing materials characterized by extensive absorption frequency ranges and wide-angle performance.