上海科技大学知识管理系统

Silicon carbide nanowires (SiCNWs) possess excellent electromagnetic absorption performance and a three-dimensional (3D) network structure is beneficial to the multiple reflection and absorption of electromagnetic waves (EMWs). The 3D staggered SiCNWs network preforms with a volume fraction of 20% was realized by vacuum filtration method. And then the PyC interphase and SiC matrix were prepared through chemical vapor infiltration (CVI) process, and the densified SiCNWs/SiC ceramic matrix composites were obtained through CVI and precursor impregnation pyrolysis (PIP) process. Methane (CH4) and trichloromethylsilane (MTS) were selected as gaseous precursor of the PyC and SiC, respectively. With increase of deposited PyC from 0 to 29.5%, the electromagnetic interference (EMI) shielding efficiency (SE) of the porous SiCNWs increases from 9.2 dB to 64.1 dB in 8-12 GHz (X-band). The densified SiCNWs/SiC ceramic matrix composites with a mass gain of about 13% of PyC interphase present an average EMI SE of 37.8 dB in X-band. The achieved EMI shielding properties suggested that the potential application of the SiCNWs/SiC ceramic matrix composites may be a promising new-generation EMI shielding material.