Studies on fabrication of continuous freestanding SiC films from polycarbosilane precursor

Under the technique of the melt spinning of precursor, the uniform and dense continuous freestanding SiC films were successfully fabricated. A special spinneret was designed and manufactured for melt spinning. Polycarbosilane (PCS) was melt spun, cured and pyrolysis treated in the inert gas at high temperature, the initial amorphous PCS green films transformed to polycrystalline β-SiC. The continuous freestanding SiC films were studied for the first time. The microscopic surface and cross-section of resulting freestanding SiC films were investigated by SEM (scanning electron microscope), and their composition and microstructure were characterized by Raman spectrometer, FTIR (fourier transform infrared spectrometer), HRTEM (high resolution transmission electron microscope) and XRD (X-ray diffractometer). The results showed that continuous freestanding SiC films contained amorphous SiO_xC_y, β-SiC nano-crystals and free carbon. And they could be obtained at thickness from 10-30 μm through adjusting the spout size of spinneret and spinning speed.