Enhanced dielectric and electromagnetic interference shielding properties of FeSiAl/Al2O3 ceramics by plasma spraying

FeSiAl/Al2O3 ceramics with flaky metallic FeSiAl were fabricated by low power plasma spraying. High complex permittivity of the flaky FeSiAl/Al2O3 ceramics can be obtained in the X-band due to the larger internal boundary layer capacitance and conductive network. The reflection loss (RL) values less than −7 dB (larger than 80% absorption) can be obtained in the whole X-band for the FeSiAl/Al2O3 ceramics with 20 wt% FeSiAl and a thickness of 1.18 mm. The total electromagnetic interference (EMI) shielding effectiveness is over 36 dB in the whole X-band for the FeSiAl/Al2O3 ceramics with 40 wt% FeSiAl and a thickness of 2 mm. These results indicated that such ceramics with conductive networks and high complex permittivity can be used to produce effective shielding materials for EM application.