Effect of chemical vapor infiltration of SiC on the mechanical and electromagnetic properties of Si3N4–SiC ceramic

The mechanical and electromagnetic (EM) properties of Si3N4 ceramic were improved by infiltrating SiC into porous Si3N4 ceramic by chemical vapor infiltration (CVI). After CVI of SiC, the Si3N4–SiC ceramic possesses improved mechanical properties, high permittivity and dielectric loss, and excellent EM shielding effectiveness and EM absorbing properties compared to Si3N4 ceramic. The lowest EM reflection loss appears when the thickness of the Si3N4–SiC ceramic equals a quarter-wavelength, and the reflection loss remains unchanged for larger thicknesses.