• Title/Summary/Keyword: fiber materials

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High Temperature Fiber Fragmentation Characteristics of SiC Single-Fiber Composite With Titanium Matrices

  • Matikas, Theodore E.
    • Advanced Composite Materials
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    • v.17 no.1
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    • pp.75-87
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    • 2008

  • Aerospace structural applications, along with high performance marine and automotive applications, require high-strength efficiency, which can be achieved using metal matrix composites (MMCs). Rotating components, such as jet-engine blades and gas turbine parts, require materials that maximize strength efficiency and metallurgical stability at elevated temperatures. Titanium matrix composites (TMCs) are well suited in such applications, since they offer an enhanced resistance to temperature effects as well as corrosion resistance, in addition to optimum strength efficiency. The overall behavior of the composite system largly depends on the properties of the interface between fiber and matrix. Characterization of the fiber.matrix interface at operating temperatures is therefore essential for the developemt of these materials. The fiber fragmentation test shows good reproducibility of results in determining interface properties. This paper deals with the evaluation of fiber fragmentation characteristics in TMCs at elevated temperature and the results are compared with tests at ambient temperature. It was observed that tensile testing at $650^{\circ}C$ of single-fiber TMCs led to limited fiber fragmentation behavior. This indicates that the load transfer from the matrix to the fiber occurs due to interfacial friction, arising predominantly from mechanical clamping of the fiber by radial compressive residual and Poisson stresses. The present work also demonstrates that composite processing conditions can significantly affect the nature of the fiber.matrix interface and the resulting fragmentation of the fiber.

  • https://doi.org/10.1163/156855108X295663 인용 PDF KSCI

Confocal Microscopy Measurement of the Fiber Orientation in Short Fiber Reinforced Plastics

  • Lee, Kwang Seok;Lee, Seok Won;Youn, Jae Ryoun;Kang, Tae Jin;Chung, Kwansoo
    • Fibers and Polymers
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    • v.2 no.1
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    • pp.163-172
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    • 2001

  • To determine three-dimensional fiber orientation states in injection-molded short fiber composites a CLSM (Confocal Laser Scanning Microscope) is used. Since the CLSM optically sections the composites, more than two cross-sections either on or below the surface of the composite can be obtained. Three dimensional fiber orientation states can be determined with geometric parameters of fibers on two parallel cross-sections. For experiment, carbon fiber reinforced polystyrene is examined by the CLSM. Geometric parameters of fibers are measured by image analysis. In order to compactly describe fiber orientation states, orientation tensors are used. Orientation tensors are determined at different positions of the prepared specimen. Three dimensional orientation states are obtained without the difficulty in determining the out-of-plane angles by utilizing images on two parallel planes acquired by the CLSM. Orientation states are different at different positions and show the shell-core structure along the thickness of the specimen.

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Properties of Silicon Carbide-Carbon Fiber Composites Prepared by Infiltrating Porous Carbon Fiber Composites with Liquid Silicon

  • Lee, Jae-Chun;Park, Min-Jin;Shin, Kyung-Sook;Lee, Jun-Seok;Kim, Byung-Gyun
    • The Korean Journal of Ceramics
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    • v.3 no.4
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    • pp.229-234
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    • 1997

  • Silicon carbide-carbon fiber composites have been prepared by partially Infiltrating porous carbon fiber composites with liquid silicon at a reaction temperature of $1670^{\circ}C$. Reaction between molten silicon and the fiber preform yielded silicon carbide-carbon fiber composites composed of aggregates of loosely bonded SiC crystallites of about 10$\mu\textrm{m}$ in size and preserved the appearance of a fiber. In addition, the SiC/C fiber composites had carbon fibers coated with a dense layer consisted of SiC particles of sizes smaller than 1$\mu\textrm{m}$. The physical and mechanical properties of SiC/C fiber composites were discussed in terms of infiltrated pore volume fraction of carbon preform occupied by liquid silicon at the beginning of reaction. Lower bending strength of the SiC/C fiber composites which had a heterogeneous structure in nature, was attributed to the disruption of geometric configuration of the original carbon fiber preform and the formation of the fibrous aggregates of the loosely bonded coarse SiC particles produced by solution-precipitation mechanism.

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