Absorbing performance of MoSi₂/BC composites using bamboo charcoal template

Abstract

Using the bamboo charcoal(BC) material as the template, the metallic chemical compound MoSi2 as the absorption catalyst, the MoSi2/BC porous composite materials were fabricated by the embedded solid reaction sintering method. The components, microstructure and dielectric constant of the MoSi2/BC composite material were detected by XRD, SEM and vector network analyzer respectively. The results show that in the argon protective atmosphere(Ar), at the sintering temperature of 1450℃, the phase composition of MoSi2/BC composite material primarily consists of MoSi2, SiC and amorphous carbon. In the pores of the bamboo charcoal, the SiC whiskers(SiCW) are distributed in an irregular way with different size and length, furthermore to form an intersecting network except MoSi2 particles. The existence of SiCW can significantly improve the wave absorption ability. At the range of 8.2-12.4GHz, after mixed with epoxy resin, the reflection losses of the composites of MoSi2/BC are gradually decreased with the increase of MoSi2/BC content. With the increase of sample thickness at the MoSi2/BC 50%(mass fraction) content, the minimum absorption peak of reflection loss is moving to the low frequency. The composites' lowest reflection loss is -13dB at 11.87GHz, and the reflection bandwidth value below -10dB is around 1.0GHz.This ind-icates that the MoSi2/BC composites possess perfect microwave absorbing performance.

Keywords

• composites
• bamboo charcoal/MoSi₂ microwave absorbing materials
• template mould method
• dielectric property