Electromagnetic Interference Shielding Effectiveness of Pure SiC–Ti3SiC2 Composites Fabricated by Reactive Melt Infiltration

Silicon carbide-based titanium silicon carbide (SiC–Ti3SiC2) composites with low free alloy content and varying Ti3SiC2 contents are fabricated by two-step reactive melt infiltration (RMI) thorough complete reactions between carbon and TiSi2 alloy in SiC-C preforms obtained. The densities of SiC-C preform are tailored by the carbon morphology and volumetric shrinkage of slurry during the gel-casting process, and pure composites with variable Ti3SiC2 volume contents are successfully fabricated with different carbon contents of the preforms. Due to the increased Ti3SiC2 content in the obtained composites, both electrical conductivity and electromagnetic interference (EMI) shielding effectiveness improved progressively, while skin depth exhibited decreased consistently. The improvement in the EMI shielding effectiveness of the composite is due to the free electrons being bound to move in the conductive network formed by the Ti3SiC2 phase, converting electrical energy into thermal energy and reducing the energy of electromagnetic waves. Notably, at a Ti3SiC2 content of 31 vol.%, the EMI shielding effectiveness of the SiC–Ti3SiC2 composites in the X-band reached an impressive 62.1 dB, confirming that SiC–Ti3SiC2 composites can be treated as high-performance EMI shielding materials with extensive application prospects.