Insight into microstructural architectures contributing to the tensile strength of continuous W-core SiC fiber. Issue 15 (December 2020)

• Record Type: Journal Article
• Authors: Zhang, Y.; Wen, M.; Sun, G.X.; Huang, H.; Zhang, S.M.; Wang, M.J.; Zhang, K.; Pang, H.P.; Zheng, W.T.
• Is Part Of: Journal of the European Ceramic Society. Volume 40:Issue 15(2020)
• Page Start: 5147
• Page End: 5161
• Publication Date: 2020-12
• Subjects: SiC fibers -- Chemical vapor deposition -- Microstructure -- Tensile strength -- Fracture behavior; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2020.06.063
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: The properties of CVD silicon carbide (SiC) fiber are closely correlated with its complex microstructure; however, the microstructural architectures contributing to its strength are not well understood. Here, two kinds of W-core SiC fibers (SiC-3200 and SiC-3800) coated with same C coating, possessing different tensile strength and discrepant microstructure in SiC portion, were fabricated by controlling deposition temperature during CVD process. The structure discrepancy contributing to the different tensile strength for both SiC fibers were explored by the combined Raman spectra, EPMA, SEM and HRTEM. It is revealed the high-crystallinity β-SiC columnar grains in the inner zone always evolve into a higher disorder character yet involving partial surviving columnar grains toward surface for both SiC fibers. However, as compared with SiC-3800 fiber, the slightly higher C over-stoichiometric composition yields lower-crystallinity SiC columnar grains across the radius for SiC-3200 fiber, further resulting in lower strength via forming smoother stepped fracture morphology.