Ceramics-Silikáty 55, (1) 8 - 13 (2011)

For developing an effective, low-cost method on preparation of microwave attenuation material, SiC–C composites with different additions of graphite grain were fabricated with solid phase sintering and liquid phase sintering, respectively. The microwave attenuation and the relative electrical properties of composites in the X band were measured. The results show that both methods are cost-effective and easily controllable processes and Solid phase sintering was more suitable to obtain SiC-C attenuation composites than the liquid phase sintering. 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 composites depended strongly on the C additions; Match of interface of wave impedance and high wave consumption are both necessary for microwave attenuation materials.