Microstructure of SiC fiber fabricated by two-stage chemical vapor deposition on tungsten filament

✍ Scribed by Rong-Jun Zhang; Yan-Qing Yang; Wen-Tao Shen; Chen Wang; Xian Luo

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 941 KB
• Volume: 313
• Category: Article
• ISSN: 0022-0248
• DOI: 10.1016/j.jcrysgro.2010.10.001

✦ Synopsis

Continuous silicon carbide (SiC) fiber with a diameter of about 100 mm was fabricated by two-stage chemical vapor deposition on tungsten filament. Microstructure of the fiber was investigated by means of scanning electron microscopy, X-ray diffraction, transmission electron microscopy and Raman spectrometry. The results showed that the fiber consists of tungsten core, a W/SiC interfacial reaction zone with the reaction products of W 5 Si 3 and WC, and a predominant b-SiC layer. The W/SiC interface can be described as W/W 5 Si 3 /WC/SiC. The SiC originates at the surface of the WC with a buffer layer, in which b-SiC crystallites nucleate and grow with their preferred (1 1 1) orientation, exhibiting strong /1 1 1S fiber texture. Raman spectra revealed that the SiC in the fiber is stoichiometric, which is composed of b-SiC and amorphous SiC. Furthermore, the formation mechanism of W/SiC interfacial reaction zone and structural evolution of SiC are discussed.