FeNi-modified carbon nanotube arrays on silicon carbide fibers for electromagnetic wave absorption

The implementation of in situ carbon nanotube growth on fibers is regarded as a proficient strategy for enhancing the electromagnetic wave (EMW) absorption capabilities of the fibers. However, the introduction of magnetic properties to the fibers and the adjustment of their impedance matching still present significant challenges. In this study, the deposition of uniform arrays of carbon nanotubes (CNTs) onto SiC fibers was successfully achieved through chemical vapor deposition. Subsequently, a FeNi coating was applied to the CNT arrays using the magnetron sputtering technique, as confirmed by SEM and TEM analyses. Furthermore, the SiCf/CNT@FeNi composites exhibited improved EMW absorption characteristics. With a thickness of 2.5 mm, the reflection loss was optimized, attaining an impressive value of −63.4 dB at 16.03 GHz, while the effective frequency bandwidth spanned 6.26 GHz (ranging from 11.74 to 18 GHz). Notably, the radar cross-section (RCS) was reduced by 21.64 dB m2. The enhanced EMW absorption performance of the SiCf/CNT@FeNi composites can be attributed to the incorporation of FeNi-modified CNT arrays, which effectively amplify Debye dipole polarization and optimize the impedance matching of the SiC fiber. This approach paves the way for the fabrication of EMW absorption materials exhibiting superior performance.