Absorption properties of carbon black/silicon carbide microwave absorbers

An absorbing medium is prepared using nanosize carbon black (CB) blended with nanosize silicon carbide (SiC). The medium improves the wave absorption properties and the wave band of the single CB absorbent. The microstructure, conductivity, dielectric property, and microwave absorption of the material are studied by means of field emission scanning electron microscopy, trielectrode method, and vector network analyzer respectively. The results show that SiC can reduce the percolation threshold of CB/epoxide resin composite. Addition of certain mass of SiC can improve the microwave absorption of the composite. When 5 wt.% carbon black is blended with 50 wt.% SiC to fabricate a composite with a 2 mm thickness, the maximum reflection loss becomes −41 dB at 9 GHz, and the −10 dB bandwidth reaches 6 GHz. Thus, the prepared composite has the potential for use in electromagnetic absorption.