Abstract In this study, a 3D printing technology, selective laser sintering (SLS), and infiltration techniques were used to prepare a complex three-dimensional metamaterial absorber with high performance. The raw carbonyl iron (CI) powders were coated by polyamide12 (PA12), where the dissolution-precipitation method was used to improve their uniformity. The coated powders were then printed by SLS. The influence of laser power on the relative density of the composites was studied, where 18W was thought as the optimal laser power. And the SLS samples were infiltrated by thermosetting epoxy resin (EP, E−44) to increase their relative densities and strength. Mechanical tests showed that the infiltrated composites have an ultimate tensile strength of 41.98 MPa, almost 15 times higher than those without infiltration. The final metamaterial absorber (MMA) exhibited the reflection loss below −10 dB in 2.7–18 GHz. The above results indicate that the fabricated processes proposed in this paper have great potential for the preparation of three-dimensional metamaterial absorbers.

中文翻译：

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基于选择性激光烧结和渗透技术的超材料吸收体力学性能增强

摘要 在本研究中，采用 3D 打印技术、选择性激光烧结 (SLS) 和渗透技术制备了一种复杂的高性能三维超材料吸收体。原始羰基铁 (CI) 粉末涂有聚酰胺12 (PA12)，其中使用溶解-沉淀法来提高其均匀性。然后通过 SLS 印刷涂覆的粉末。研究了激光功率对复合材料相对密度的影响，其中18W被认为是最佳激光功率。并且 SLS 样品被热固性环氧树脂（EP，E-44）渗透以增加它们的相对密度和强度。力学测试表明，渗透后的复合材料的极限拉伸强度为 41.98 MPa，几乎是未渗透的复合材料的 15 倍。最终的超材料吸收器 (MMA) 在 2.7-18 GHz 中表现出低于 -10 dB 的反射损耗。上述结果表明，本文提出的制造工艺在制备三维超材料吸收体方面具有巨大潜力。