Thin-thickness FeSiAl/flake graphite-filled Al₂O₃ ceramics with enhanced microwave absorption

Thin and enhanced microwave absorption FeSiAl/ flake graphite (FG) filled Al₂O₃ ceramics were fabricated by low power plasma spraying. The characteristics of the sprayed ceramics, such as phase composition, microstructure, electromagnetic (EM) properties and reflection loss (RL) were investigated. Suitable values and frequency dependence of the complex permittivity of the FeSiAl/ FG filled Al₂O₃ ceramics can be obtained in the Ku-band due to the larger internal boundary layer capacitance and the combination of the advantages of the FeSiAl and FG. RL values less than −7 dB (larger than 80% absorption) can be obtained in the whole Ku-band for the FeSiAl/FG filled Al₂O₃ ceramics with a sample thickness of 0.8 mm. These results suggest a possible use of these ceramics as effective microwave absorbing materials for EM applications.