Hybrid carbon‑silicon carbide fibers produced from stabilized pitch filaments and carbon fibers

Abstract

Carbon fibers and their intermediates, oxidative-stabilized filaments, were used as carbon sources in the chemical vapor reaction method to produce carbon‑silicon carbide fibers. A comprehensive analysis of the microstructure and composition of the fibers was achieved using a combination of microscopic detectors, including Secondary Electron (SE), Backscattered Electron (BSE), and Energy Dispersive X-ray Spectroscopy (EDS). This analysis revealed a dense carbide layer and SiC deposits within the fibers, positioned near their core, in samples derived from both precursors. The reaction conditions and precursors allowed the diffusion of SiO gas through the fiber structure. This method, when applied to stabilized filaments, demonstrated the feasibility of simultaneously forming carbide during fiber carbonization. SiC nanowires were observed exclusively in products derived from carbon fibers. Through X-ray diffraction (XRD) and Raman spectroscopy, crystallinity and defects of the raw materials and hybrids were assessed. The small differences did not justify the absence of the nanostructures in hybrids produced from stabilized filaments. Instead, the lack of SiC whiskers were associated with the emission of volatile compounds at the high temperature treatment.