Enhancement of the microwave absorption properties of PyC-SiCf/SiC composites by electrophoretic deposition of SiC nanowires on SiC fibers

摘要

The employment of coating technique on the silicon carbide fibers plays a pivotal role in preparing SiC fiberreinforced SiC composites (SiCf/SiC) toward electromagnetic wave absorption applications. In this work, SiC nanowires (SiCNWs) are successfully deposited onto the pyrolytic carbon (PyC) coated SiC fibers by an electrophoretic deposition method, and subsequently densified by chemical vapor infiltration to obtain SiCNWs/PyC-SiCf/SiC composites. The results reveal that the introduction of SiCNWs could markedly enhance the microwave absorption properties of PyC-SiCf/SiC composites. Owing to the increasing of SiCNWs loading, the minimum reflection loss of composites raises up to -58.5 dB in the SiCNWs/PyC-SiCf/SiC composites with an effective absorption bandwidth (reflection loss <= -10 dB) of 6.13 GHz. The remarkable enhancement of electromagnetic wave absorption performances is mainly attributed to the improved dielectric loss ability, impedance matching and multiple reflections. This work provides a novel strategy in preparing SiCf/SiC composites with excellent electromagnetic wave absorption properties.