Electromagnetic interference shielding effectiveness of carbon fiber reinforced multilayered (PyC–SiC)_n matrix composites

Carbon fiber reinforced multilayered (PyC–SiC)_n matrix (C/(PyC–SiC)_n) composites were fabricated by alternately depositing PyC and SiC inside preforms via isothermal chemical vapor infiltration. A four-layer structure consisting of alternate PyC and SiC was formed compactly on the surface of carbon fibers. The electromagnetic interference shielding effectiveness (SE) in the frequency range of 8.2–12.4 GHz of the composites was investigated. The composites showed a high SE value of about 40 dB in the whole frequency band due to the repeated reflection and dissipation of electromagnetic wave between the interfaces of SiC layers and PyC layers, PyC layers and carbon fibers. Therefore, C/(PyC–SiC)_n composites exhibited great potential as functional materials.