Microstructure of SiC Fiber Fabricated by Three-stage Chemical Vapor Deposition

doi:10.3724/SP.J.1077.2010.01281

Abstract

Abstract: Continuous silicon carbide (SiC) fiber with carbon coating was fabricated by three-stage chemical vapor deposition (CVD) on tungsten filament heated by direct current (DC), using CH₃SiCl₃ +H₂ as gaseous reactant for SiC sheath and C₂H₂ for the outmost carbon coating, respectively. Microstructure of the SiC fiber was examined by X-ray diffraction (XRD), scanning electron microscope (SEM), Raman spectroscope and transmission electron microscope (TEM). The results show that the SiC fiber consists of tungsten core, a W/SiC interfacial reaction zone, two layers of SiC with total thickness of 41μm and an outermost carbon coating of about 2 μm in thick. The deposited SiC is mainly composed of beta-SiC, and exhibits strong <111> fiber texture with abundant growth defects, such as co-deposit of free silicon and stacking faults, leading to the lattice imperfection of the SiC sheath. Raman spectrum indicates that the outmost carbon coating decomposed from C₂H₂ involves a mixture of amorphous carbon and graphite crystallite.

Key words: SiC fiber, chemical vapor deposition, microstructure, defects, Raman spectra

CLC Number:

TQ343

ZHANG Rong-Jun, YANG Yan-Qing, WANG Chen, SHEN Wen-Tao, LUO Xian. Microstructure of SiC Fiber Fabricated by Three-stage Chemical Vapor Deposition[J]. Journal of Inorganic Materials, 2010, 25(12): 1281-1285.

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