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

Abstract A dense alumina fiber reinforced silicon carbide matrix composites (Al 2 O 3 /SiC) modified with Ti 3 Si(Al)C 2 were prepared by a joint process of chemical vapor infiltration, slurry infiltration and reactive melt infiltration. The conductive Ti 3 Si(Al)C 2 phase introduced into the matrix modified the microstructure of Al 2 O 3 /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 Al 2 O 3 /SiC and Ti 3 Si(Al)C 2 modified Al 2 O 3 /SiC were investigated over the frequency range of 8.2–12.4 GHz. The EMI SE of Al 2 O 3 /SiC-Ti 3 Si(Al)C 2 exhibited a significant increase from 27.6 to 42.1 dB compared with that of Al 2 O 3 /SiC. The reflection and absorption shielding effectiveness increased simultaneously with the increase of the electrical conductivity.