Preparation, Mechanical and Microwave Absorption Properties of Resin-Based Coating with Bionic Helical Structures

To optimize the electromagnetic and mechanical properties, a resin-based coating with a bionic helical structure made by carbonyl iron fibers (CIF) was prepared by alternating spray and brushing with 0°/45°/90°. The morphologies of CIP and CIF were characterized by a scanning electron microscope (SEM). The electromagnetic parameters of CIP were measured in the frequency range of 2–18 GHz by the coaxial ring method, and microwave absorption properties of the coating were evaluated by reflection loss (RL). The mechanical properties of the coating with the bionic helical structure were investigated by the pull-off method. The effects of the CIP ratio, CIF content, and thickness on the microwave absorption were discussed, respectively. The results show that 6.5:3.5 is the optimal CIP-to-paraffin ratio with superior electromagnetic performance and RL. The coating with the triple helical structure, fiber content of 3 wt% and free of CIP (C4) exhibits optimal electromagnetic wave absorption performance with a minimum RL value of −10.66 dB and wide effective absorbing bandwidth (EAB) of 10.58 GHz at a thickness of 0.6 mm. Moreover, the adhesion strength of C4 reaches 13.52 MPa. The excellent absorption performance and mechanical properties of the resin-based coating with the bionic helical structure indicate that it has potential application value in the field of stealth materials.