PREPARATION AND MICROWAVE ATTENUATION PROPERTY IN THE X BAND OF SiC-C COMPOSITES

SiC-C composites with different additions of graphite grains were fabricated by solid phase sintering and liquid phase sintering. The microwave attenuation and the relative electrical properties of the composites in the X band were measured. The results showed that both methods are cost-effective and easily controllable processes but solid phase sintering was more suitable for obtaining SiC-C attenuation composites. The composite with 3 wt% C prepared by solid phase sintering exhibited the best microwave attenuation, the biggest attenuation was -40.5 dB and most attenuations were above -30 dB in the whole X band. Furthermore, the microwave attenuation of the composites depended on the C content and matching of the interface of wave impedance and high wave consumption are both necessary for microwave attenuation materials.