Microwave-absorbing and mechanical properties of carbonyl-iron/epoxy-silicone resin coatings

Coatings with flake carbonyl-iron particles as absorber and epoxy-silicone resins as matrix were prepared. The complex permittivity, complex permeability and microwave-absorbing properties were investigated in the frequency range of 2-18 GHz. Both the real part of permittivity and permeability were increased with carbonyl-iron weight concentration. The minimum reflection loss shifts to the low-frequency region with increase in carbonyl-iron weight concentrations. The minimum reflection loss value of -42.5 dB was obtained at 10.6 GHz for the coatings with 55 wt% carbonyl-iron. The values of adhesive power and impact strength are up to 24 MPa and 50 kg cm, respectively. These results show that the coatings possess good microwave-absorbing and mechanical properties.