Regulating the phase composition and microstructure of Fe₃Si/SiC nanofiber composites to enhance electromagnetic wave absorption

The rational introduction of multi-components to fabricate electromagnetic wave absorbing (EMA) materials with synergistic conductive/dielectric/magnetic losses promises lightweighting and excellent EMA performance, but it remains a challenge. In this work, multicomponent Fe₃Si/SiC nanofibre composites with network structure were constructed by electrostatic spinning method and in-situ carbothermal reduction strategy. Design of microstructures and multicomponent modulation by controlling the carbothermal reduction temperature. As a result, the presence of a large number of non-homogeneous interfaces, three-dimensional (3D) conductive network structures and defect structures in Fe₃Si/SiC nanofibre composites induces a combination of multiple loss mechanisms that significantly improve the EMA performance. When the filling amount of Fe₃Si/SiC in the paraffin transmission matrix is 20 wt%, the maximum effective absorption bandwidth (EAB_max) of the fabricated material reaches 5.84 GHz with a thin thickness of 2.02 mm. Moreover, the minimum reflection loss (RL_min) value at 10.96 GHz is as low as −67.57 dB. Meanwhile, the radar cross-section (RCS) simulation verifies that the F-4 peak RCS is reduced to −30.37 dB in the range of −60°<θ < 60°. It indicates that the Fe₃Si/SiC nanofiber composites have a good radar-wave dissipation capability in practical applications. In summary, the comprehensive performance of lightweight multicomponent Fe₃Si/SiC nanofiber composites can meet the new application requirements and is expected to become an emerging multifunctional wave-absorbing material suitable for harsh environments.