Multi-mechanism cooperative optimization of electromagnetic shielding and mechanical properties in Cf/PyC/SiC-SiCN(Fe) ceramic-based composites

Abstract

Heterogeneous interfaces greatly impact material electromagnetics, but combining structural design, interface regulation, and magnetic enhancement remains challenging. This study synthesizes a carbon fiber-reinforced metal-containing silicon carbonitride (Cf/PyC/SiC-SiCN(Fe)) composite by incorporating multilayer interfaces and magnetic particles. The research reveals that the existence of multiphase heterogeneous interfaces produces a plethora of lattice defects and amplifies polarization effects, thereby enhancing electromagnetic shielding performance. The addition of carbon fibers augments conductive loss, while magnetic particles contribute to magnetic loss. Their combined effect results in an impressive shielding effectiveness of 62.1 dB in the 8–12 GHz band and 38.6 dB in the 12–18 GHz band. Furthermore, the carbon fiber and double-layer interface structure provide robust mechanical support for the composite, with a strength reaching 444.8 ± 20.9 MPa. These findings illustrate that through meticulous interface design and structural optimization, the composite achieves excellent electromagnetic shielding and mechanical properties at low density, indicating wide potential applications.