Improvement of the electromagnetic shielding properties of C/SiC composites by electrophoretic deposition of carbon nanotube on carbon fibers

The current study reports on the improvement of electromagnetic interference (EMI) shielding properties of carbon fiber-reinforced silicon carbide composites by introduction of carbon nanotubes on carbon fiber cloths through the electrophoretic deposition (EPD) route and subsequent densification by chemical vapor infiltration. Findings demonstrate that the electrical conductivity of the composites increased with EPD durations up to 10 min, while the skin depth remained, in all case, one order on magnitude less than the specimen thickness, hence rendering multiple internal reflection issues negligible. The EMI absorption shielding effectiveness of the specimens was found to increase significantly with EPD duration, while absorption effectiveness reached a maximum of 38.2 dB at an EPD duration of 10 min, an increase of 56.5% over plain C/SiC composites. The achieved indices meet the specifications for effective EMI shielding of materials targeted for commercial and military field applications.