Fabrication and electromagnetic interference shielding effectiveness of Ti3Si(Al)C2 modified Al2O3/SiC composites

A dense alumina fiber reinforced silicon carbide matrix composites (Al2O3/SiC) modified with Ti3Si(Al)C2 were prepared by a joint process of chemical vapor infiltration, slurry infiltration and reactive melt infiltration. The conductive Ti3Si(Al)C2 phase introduced into the matrix modified the microstructure of Al2O3/SiC. The refined microstructure was composed of conductive phase, semiconductive phase and insulating phase, which led to admirable electromagnetic shielding properties. Electromagnetic interference shielding effectiveness (EMI SE) of Al2O3/SiC and Ti3Si(Al)C2 modified Al2O3/SiC were investigated over the frequency range of 8.2–12.4 GHz. The EMI SE of Al2O3/SiC-Ti3Si(Al)C2 exhibited a significant increase from 27.6 to 42.1 dB compared with that of Al2O3/SiC. The reflection and absorption shielding effectiveness increased simultaneously with the increase of the electrical conductivity.