In-situ growth of SiC nanowire arrays on carbon fibers and their microwave absorption properties

Large-scale SiC nanowire arrays have been directly grown on the surface of carbon fibers via a molten salt -assisted chemical vapor deposition process at relatively low temperature (1200 degrees C). The morphology, microstructure, and phase composition of the as-grown products were characterized by field-emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD). The characterization results indicate that the as-grown nanowires were of single-crystalline beta-SiC phase with the growth direction along [111], lengths up to several tens of micrometers and diameters of 50-100 nm. The growth of the nanowires was governed by the molten mediated vapor-liquid-solid (VLS) mechanism. The microwave absorption properties of the as fabricated SiC nanowires/carbon fibers (SiCnw/C-f) composites were investigated over 2-12 GHz and a minimum reflection loss of -21.5 dB at 7.7 GHz could be achieved with 30 wt% SiCnw/C-f as fillers in the silicone matrix. (C) 2016 Published by Elsevier B.V.