For electromagnetic wave (EMW) absorption materials, combining microstructure design with macrostructure design is considered as an effective means to adjust EMW absorption performance. Undoubtedly, the great advantages of three-dimensional (3D) printing technology in structural design and accurate molding provide a convenient and feasible research scheme for the adjustment of EMW absorption performance. In this study, a method combined 3D printing technology with direct chemical vapor infiltration (CVI) has been adopted to fabricate Al₂O₃/SiC whisker (SiCw) honeycomb composites. The porous oblique honeycomb structures with well-designed angle (30°, 45°, 60° and 75°) and micron-scale SiCw effectively improved impedance match, inner scattering and dielectric loss, which resulted in the realization of the optimized wave absorbing composites. Specially, Al₂O₃/SiCw composite with the angle of 30° shows a minimum reflection coefficient (RC_min) value of −63.65 dB (99.9999%) absorption at 9.8 GHz with a thickness of 3.5 mm while the effective absorption bandwidth (EAB) ranges from 8.2 to 12.4 GHz, covering the whole X band. Besides, the EMW absorption mechanism for 3D printed Al₂O₃/SiCw composite is also discussed. As a proof of concept, this strategy provides a novel and effective avenue to fabricate structural composites with broader and higher microwave absorption performance.

对于电磁波（EMW）吸收材料，将微结构设计与宏观结构设计相结合被认为是调整EMW吸收性能的有效手段。毫无疑问，三维（3D）打印技术在结构设计和精确成型方面的巨大优势为调节EMW吸收性能提供了方便可行的研究方案。在这项研究中，采用了结合3D打印技术和直接化学气相渗透（CVI）的方法来制造Al ₂ O ₃/ SiC晶须（SiCw）蜂窝状复合材料。设计良好的角度（30°，45°，60°和75°）和微米级SiCw的多孔斜蜂窝结构有效地改善了阻抗匹配，内部散射和介电损耗，从而实现了优化的吸波复合材料。特别是，角度为30°的Al ₂ O ₃ / SiCw复合材料在9.8 GHz，厚度为3.5 mm的情况下显示的最小反射系数（RC _min）值为-63.65 dB（99.9999％），而有效吸收带宽（EAB） ）范围从8.2到12.4 GHz，覆盖了整个X频段。此外，3D打印Al ₂ O ₃的EMW吸收机理还讨论了/ SiCw复合材料。作为概念的证明，该策略提供了新颖有效的途径来制造具有更广泛和更高的微波吸收性能的结构复合材料。