SiC Nanowire Mesh in High-Porosity Silicon Foam for Enhanced Electromagnetic Wave Absorption

The growth of SiC nanowires (SiCNWs) plays a vital role that determines the microstructure and the dielectric and absorption properties. With SiCNW growth, regulating the growth space and atmosphere of the nanowire is an important method to determine its performance. In this article, we propose a novel approach to control the microstructure of SiCNWs. The SiC precursor prepares the high-porosity foams based on a particle-stablized foaming process. The growth and microstructure of SiCNWs are adjusted by controlling porosity and reaction conditions. Adjusting the foam porosity indirectly coordinates the atmosphere of individual pores and the growth space of the SiCNW mesh. Foam pore structure density and the reactive sintering temperature enable control over SiCNW mesh growth composition. The influence of the microstructure on dielectric and absorption properties of nanowires was studied. The SiCNW mesh composites exhibit a favorable electromagnetic absorption performance, and the minimum reflection loss (RL) is −19.1 dB. The effective bandwidth (RL < −5 dB) of the SiCNW mesh in the thickness range of 2.40–2.58 mm can cover the whole X-band. This provides a potential new direction in the investigation of absorption materials.