Electromagnetic Absorption Properties of 3D Printed Fiber-Oriented Composites Under Different Paths (2024-02)¶

Electromagnetic wave (EMW) pollution poses a tremendous effect on information security and human health. However, ordinary concrete structure incorporated by ferrite fiber lacks EMW absorption flexibility to form electromagnetic superstructures. 3D printing technology paves an effective way to facilitate the anisotropy of electromagnetic absorption capacity by generating directional effects on ferrite fiber. This research evaluates the influence of 3D-printed fiber-oriented superstructure on EMW absorption performance with an equivalent waveguide attenuator model. The microwave-absorbing cementitious composite (10% magnetite and 25% copper slag) was prepared to incorporate 0.5 wt% copper fibers (CF) and steel fibers (SF), respectively. Absorption elements in each group are prepared by laminar parallel printing, cross-printing, and zigzag printing. In addition, the EMW absorption capability (ranging from 2 GHz to 18 GHz) was investigated by the Naval Research Laboratory (NRL) equipment. The overall EMW absorption performance of the SF samples is superior to CF samples. The optimized order of the EMW absorption performance of CF-reinforced samples is determined as zigzag, parallel, and cross printing, while SF is parallel, cross, and zigzag printing methodology. Overall, the laminar parallel printed steel fiber element gave the best shot with a peak reflectivity of − 16.34 dB and an absorption bandwidth of 13.15 GHz. Meanwhile, SF-reinforced specimens all demonstrated absorption peaks around 8 GHz, while CF-incorporated samples’ absorption peaks appeared at both 8 GHz and 12 GHz, offering multiple design and application choices according to engineering requirements. Finally, an equivalent attenuator model is suggested for illustrating the superimposed reinforcement, spatial impedance matching, and multiple scattering of dielectric properties.