Rapid preparation of SiC fibers by spark plasma assisted vapor silicon infiltration

Abstract

SiC fibers were rapidly prepared by spark plasma-assisted chemical vapor siliconizing approach using Si powders in the pretreated silicon slurry waste as silicon source and coir fibers as biocarbon template. X-ray diffraction studies show that the starting and ending temperatures of the Si powder gasification were 1100 °C and 1350 °C, respectively. Scanning electron micrographs reveal that the prepared product fibers reproduce the biomorphic cellular structure of the coir fibers with high precision. The gaseous Si atoms which diffused to the surface and into the interior of the carbonized fiber through stomas, holes, and micropores reacted with the carbon atoms on the surface and interior wall of the carbonized fiber to form β-SiC. SiC fibers with biomorphic cellular structure and surface morphology of the coir fiber have been prepared at optimization temperature of 1500 °C. The intrinsic structures of the fibers were gradually collapsed and damaged from surface to interior at temperatures above 1500 °C. Moreover, the SiC shows considerable electromagnetic wave absorption with a minimum reflection loss of −21.88 dB and the bandwidth < −5 dB is about 1 GHz.