• Title, Summary, Keyword: carbon fiber

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Optimum mixture of high performance hybrid fiber reinforced concrete using fractional experimental design by orthogonal array (일부실시 직교배열 실험설계에 의한 고성능 하이브리드 섬유보강 콘크리트 배합 최적화)

  • Park, Tae-Hyo;Noh, Myung-Hyun;Park, Choon-Keun
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.341-344
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    • 2004
  • In the present research, slump, modulus of rupture (MOR) and flexural toughness $(I_{30})$ of high performance hybrid fiber reinforced concrete (HPHFRC) mixed with micro-fiber (carbon fiber) and macro-fiber (steel fiber) and replaced with silica fume were assessed with the analysis of variance (ANOVA). Steel fiber was a considerable significant factor in aspect of the response values of MOR and boo Based on the significance of factors related to response values from ANOVA, following assessments were available; Slump decrease: carbon fiber >> steel fiber > silica fume; MOR: steel fiber > silica fume > carbon fiber; $I_{30}$: steel fiber > carbon fiber > silica fume. Steel fiber $1.0\%$, carbon fiber $0.25\%$ and silica fume $5.0\%$, and Steel fiber $1.0\%$, carbon fiber $0.25\%$ and silica fume $2.5\%$ were obtained as the most optimum mixture.

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Characteristics Correlations Between Fiber-Reinforced and Interfacial Adhesion in Carbon fiber reinforced Cement composite Prepared by Slurry Method. (슬러리법에 의한 탄소섬유보강 시멘트복합체의 제조에서 보강섬유와 계면결착제와의 상관특성)

  • Choi, Eung-Kyoo
    • Journal of the Korea Institute of Building Construction
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    • v.2 no.3
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    • pp.131-138
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    • 2002
  • The objective of the study is to examine the characteristic correlations between reinforcing carbon fiber and interfacial adhesion agent since the interfacial adhesion strength between reinforcing carbon fiber and matrices is believed to be an essential element influencing the physical properties in carbon fiber reinforced cement composite using slurry method. The integrity of interfacial adhesion between reinforcing fiber and cement not only affects the quality of fiber reinforced cement composite but also influences to a large degree the physical properties of the cement composite when producing carbon fiber reinforced cement composite using slurry method. Having analyzed the physical properties 1.e., water content, tensile strength, flexural strength and flexural toughness of carbon fiber reinforced cement composite specimens, C-PAM(cation polyacrylamide) was determined to be an optimum interfacial adhesion agent. The study has also demonstrated that interfacial adhesion strength varies largely on the content and type of the reinforcing fiber. Judging from magnified view of the tensile shear cross-section using VMS(video microscope system), interfacial adhesion strength between reinforcing fiber and matrices is affected by the type of interfacial adhesion agent. According to the result of the experiments, C-PAM was determined to be an ideal interfacial adhesion agent when using carbon fiber in producing carbon fiber reinforced cement composite with the optimum content of carbon fiber being established.

Preparation and Erosion Properties of Reaction-Bonded SiC Reinforced by Carbon Fiber (탄소섬유로 강화된 반응소결 SiC 제조 및 Erosion 특성)

  • 송진웅;임대순;김형욱
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • pp.258-264
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    • 1998
  • Three kinds of reation-bonded SiC that reaction-bonded SiC(RBSC), RBSC reinforced by carbon fiber and RBSC reinforced by activated carbon fiber were prepared for investigating the change of erosion properties. The characteristics of microstructures and the phases have been investigated by using scanning electron microscope and XRD analysis. The hardness test, toughness test and erosion test were camed out. In the cases with no carbon fiber, those kind of specimens had the highest result of hardness test and the lowest result of toughness test. With the increase of carbon fiber content, The hardness and the weight loss were decreased but the toughness was increased in the cases with carbon fiber In the cases with activated carbon fiber those specimens had the highest result of toughness test and the lowest result of hardness test with 30% contents of activated carbon fiber.

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Preparation and Erosion Properties of Reaction-Bonded SiC Reinforced by Carbon Fiber (탄소섬유로 강화된 반응소결 SiC 제조 및 Erosion 특성)

  • 송진웅;임대순;김형욱
    • Tribology and Lubricants
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    • v.15 no.1
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    • pp.59-67
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    • 1999
  • Three kinds of reation-bonded SiC that reaction-bonded SiC(RBSC), RBSC reinforced by carbon fiber and RBSC reinforced by activated carbon fiber were prepared for investigating the change of erosion properties. The characteristics of microstructures and the phases have been investigated by using scanning electron microscope and XRD analysis. The hardness test toughness test and erosion test was carried out. In the cases with no carbon fiber, those kind of specimens had the highest value of hardness and the lowest value of toughness. With the increase of carbon fiber content the hardness and the weight loss were decreased, but the toughness was increased in the cases with carbon fiber. In the cases with activated carbon fiber specimens had the highest value of toughness and the lowest value of hardness with 30% contents of activated carbon fiber.

Role of Interface on the Development of Microstructure in Carbon-Carbon Composites

  • Dhakate, S.R.;Mathur, R.B.;Dhami, T.L.;Chauhan, S.K.
    • Carbon letters
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    • v.3 no.4
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    • pp.192-197
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    • 2002
  • Microstructure plays an important role in controlling the fracture behaviour of carbon-carbon composites and hence their mechanical properties. In the present study effort was made to understand how the different interfaces (fiber/matrix interactions) influence the development of microstructure of the matrix as well as that of carbon fibers as the heat treatment temperature of the carbon-carbon composites is raised. Three different grades of PAN based carbon fibres were selected to offer different surface characteristics. It is observed that in case of high-strength carbon fiber based carbon-carbon composites, not only the matrix microstructure is different but the texture of carbon fiber changes from isotropic to anisotropic after HTT to $2600^{\circ}C$. However, in case of intermediate and high modulus carbon fiber based carbon-carbon composites, the carbon fiber texture remains nearly isotropic at $2600^{\circ}C$ because of relatively weak fiber-matrix interactions.

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A Structural Study of the Oxidized High Modulus Pitch Based Carbon Fibers by Oxidation in Carbon Dioxide

  • Roh, Jae-Seung
    • Carbon letters
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    • v.5 no.1
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    • pp.27-33
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    • 2004
  • Structural changes of high modulus carbon fiber by oxidation in carbon dioxide gas using SEM, TEM, and XRD have been observed. It was shown that the originally high modulus carbon fiber is composed of highly ordered graphitic crystalline area and non-crystalline area. It was observed that the La increases during the whole oxidation process. It was shown that the oxidation of high modulus carbon fiber initiates at the non-crystalline area and at the ends of fiber. The large pores developed in fiber by direction of fiber length at high temperature ($1,100^{\circ}C$), and the small pores developed on the fiber surface at low temperature ($900^{\circ}C$). In conclusion, it is found that the oxidation of the carbon fiber was progressed through the imperfection.

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Variation of Mechanical Properties by Carbon Fiber Volume Percent of Carbon Fiber Reinforced Reaction Bonded SiC (탄소섬유 강화 반응소결 탄화규소의 탄소섬유 첨가량에 따른 기계적 특성 변화)

  • Yun, Sung-Ho;Yang, Jin-Oh;Cho, Young-Chul;Park, Sang-Whan
    • Journal of the Korean Ceramic Society
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    • v.48 no.5
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    • pp.373-378
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    • 2011
  • The composite added with surface-coated chopped carbon fiber showed the microstructure of a 3 dimensional discretional arrangements. The fiber reinforced reaction bonded silicon carbide composite, containing the 50 vol% carbon fiber, showed the porosity of < 1 vol%, 3-point bending strength value of 250MPa and fracture toughness of 4.5 $MPa{\cdot}m^{1/2}$. As the content of carbon fiber was increased from 0 vol% to 50 vol% in the composite, fracture strength was decreased due to the increase of carbon fiber, which has a less strength than SiC and molten Si. On the other hand, the fracture toughness was increased with increasing the amount of carbon fiber. According to the polished microstructure, carbon fiber was shown to have a random 3 dimensional arrangement. Moreover, the fiber pull-out phenomenon was observed with the fractured surface, which can explain the increased fracture toughness of the composite containing high content of carbon fiber.

Thermal Conductivity and Thermal Expansion Behavior of Pseudo-Unidirectional and 2-Directional Quasi-Carbon Fiber/Phenolic Composites

  • Cho, Donghwan;Choi, Yusong;Park, Jong Kyoo;Lee, Jinyong;Yoon, Byung Il;Lim, Yun Soo
    • Fibers and Polymers
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    • v.5 no.1
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    • pp.31-38
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    • 2004
  • In the present paper, a variety of fiber reinforcements, for instance, stabilized OXI-PAN fibers, quasi-carbon fibers, commercial carbon fibers, and their woven fabric forms, have been utilized to fabricate pseudo-unidirectional (pseudo-UD) and 2-directional (2D) phenolic matrix composites using a compression molding method. Prior to fabricating quasi-carbon fiber/phenolic (QC/P) composites, stabilized OXI-PAN fibers and fabrics were heat-treated under low temperature carbonization processes to prepare quasi-carbon fibers and fabrics. The thermal conductivity and thermal expansion/contraction behavior of QC/P composites have been investigated and compared with those of carbon fiber/phenolic (C/P) and stabilized fiber/phenolic composites. Also, the chemical compositions of the fibers used have been characterized. The results suggest that use of proper quasi-carbonization process may control effectively not only the chemical compositions of resulting quasi-carbon fibers but also the thermal conductivity and thermal expansion behavior of quasi-carbon fibers/phenolic composites in the intermediate range between stabilized PAN fiber- and carbon fiber-reinforced phenolic composites.

Conversion of Carbon Fiber into Silicon Carbide Fiber by Pack-Cementation

  • Joo, Hyeok-Jong;Kim, Jung-Il;Lee, Jum-Kyun
    • Carbon letters
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    • v.1 no.1
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    • pp.12-16
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    • 2000
  • Carbon fiber was reacted with gaseous silicon monoxide which is produced from pack-powder mixture at elevated temperature. As a result of the reaction, two kinds of SiC fiber were obtained. The first one was SiC fibers which were converted from carbon fiber. The fiber is constituted with polycrystal like fine grains or monolithic crystals that have a size from sub-micron to $10\;{\mu}m$. Their size depends on the temperature during the conversion reaction. The second one was ultra-fine SiC fibers that were found on the surface of the converted SiC fibers. The ultra-fine fibers have diameters from 0.08 to $0.2\;{\mu}m$ and their aspect ratio were larger than 100. The chemical composit ion of the ultra-fine fibers was analyzed using an Auger electron spectroscopy. In result, the fibers consist of 51% silicon, 38% carbon and 11% oxygen by weight.

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Improvement of CF/ABS Composite Properties by Anodic Oxidation of Pitch based C-type Carbon Fiber

  • Yang, Xiao Ping;Wang, Cheng Zhong;Yu, Yun Hua;Ryu, Seung-Kon
    • Carbon letters
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    • v.3 no.2
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    • pp.80-84
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    • 2002
  • The surface treatment of C-type isotropic pitch-based carbon fiber was carried out by anodic oxidation in 5 wt% $NH_4NO_3$ electrolyte. The changes of fiber surface and carbon fiber/ABS resin composites were characterized by SEM, XPS and mechanical properties test. The oxygen functional groups on the surface, such as hydroxyl (-C-OH), carboxyl (-COOH) groups etc., increased after oxidation. Tensile strength, flexural strength and modulus of carbon fiber/ABS composites were also enhanced. However, the impact strength decreased with the improvement of the surface adhesion between CF and matrix.

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