Preparation and electromagnetic wave absorption properties of SiC_NW-C_f/LAS composites

Abstract

SiCNW were prepared with different molar ratio of silicon to carbon on carbon fiber cloth by thermal evaporation method using acetylene black as carbon source. SiCNW-Cf/LAS(Li2O-Al2O3-SiO2) were prepared by using slurry-impregnation and vacuum sintering process with SiCNW-Cf as intermediate interlayer. The results show that as the molar ratio of silicon to carbon decreasing, the diameter of SiCNW decreases continuously, and the yield first increases and then decreases and reaches the highest when the molar ratio of silicon to carbon is 1:3. The SiCNW-Cf/LAS prepared with a molar ratio of silicon to carbon of 1:1 has a minimum reflection loss of -40.9 dB (7 GHz, 3 mm) for electromagnetic wave. The SiCNW-Cf/LAS prepared at a molar ratio of silicon to carbon of 1:3 has a maximum effective bandwidth for absorbing electromagnetic wave of 4.61 GHz (Ku band, 1.5 mm). The excellent absorbing properties of SiCNW-Cf/LAS composites can be attributed to their higher dielectric loss and scattering loss for electromagnetic wave and adjustment of LAS to material and space impedance matching.

Keywords

• sic_nw-c_f/las
• different molar ratio of silicon to carbon
• absorbing property
• electromag-netic wave loss mechanism