▎ 摘　　要

Siliconboron carbonitride (SiBCN) ceramics, with excellent microwave attenuation properties, are introduced into three-dimensional graphene foam (3D GF) via low-pressure chemical vapor deposition and infiltration (LPCVD/CVI) from the SiCl3CH3-NH3-BCl3-H-2-Ar system. The results show that GF/SiBCN composites exhibit total shielding effectiveness and specific shielding effectiveness of about 19 dB and 29 dB.cm(3)/g, respectively. Owing to the porous 3D foam structure and strong attenuation ability of graphene, the composites are dominated by absorbing and shielding mechanisms. The SiBCN content did not influence the electromagnetic shielding performance of the composites because the conductive network has been formed by the highly conductive graphene. The present work provides novel insights and promising strategy for the development of lightweight, high-efficiency, high-temperature and oxidation-resistant ceramic-based electromagnetic shielding materials.