Silicon carbide (SiC) nanofibers have been synthesized by a solid-vapor reaction (SVR) between carbon nanofibers (CNFs) and SiO vapor, the CNFs being grown using alloys of Ni-Fe, Fe-Al, and Ni-Fe-Al as catalysts by thermal decomposition of C2H4 in the temperature range of 550-650 oC. After removal of the catalysts in the as-synthesized CNFs with 2 mol/l HNO3, the SVR process occurred between the CNFs and the SiO vapor in the temperature range of 1200-1450 oC for a fixed dwell time of 5 h, with a heating rate of 5 oC·minute−1 under an Ar/H2 (160 : 40) flow of 200 cm2 (ml/minute). The SiC nanofibers consisted of β-SiC and α-SiC and have a thicker diameter than that of the mother CNFs. The effects of catalyst composition and synthesis temperature on the microstructural evolution of the SiC nanofibers are discussed based on the quantitative and qualitative results obtained.

Keywords: Carbon nanofiber, Silicon carbide, Nanostructure, Catalyst, Solid-vapor reaction.