• 한국세라믹학회지
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• 제45권9호
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• pp.561-566
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• 2008

Carbon fiber fabric-silicon carbide composites were fabricated by liquid silicon infiltration (LSI) process. The porous two-dimensional carbon fiber fabric performs were prepared by 13 plies of 2D-plain-weave fabric in a three laminating method, [0/90], [${\pm}45$], [$0/90/{\pm}45$] lay-up, respectively. Before laminating, a thin pyrolytic carbon (PyC) layer deposited on the surface of 2D-plain weave fabric sheets as interfacial layer with $C_3H_8$ and $N_2$ gas at $900^{\circ}C$. A densification of the preforms for $C_f-Si-SiC$ matrix composite was achieved according to the LSI process at $1650^{\circ}C$ for 30 min. in vacuum atmosphere. The bending strength of the each composite were measured and the microstructural consideration was performed by a FE-SEM.

• 한국정밀공학회지
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• 제33권6호
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• pp.447-452
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• 2016

The simulation of Carbon fiber reinforced polymer (CFRP) machining facilitates the selection of optimal cutting parameter for high machining efficiency and better surface quality. In this study, This paper proposes a dual-dexel model to represent the fiber laminate with computational geometry method to calculate the fiber length removed per revolution and fiber cutting angles. A flat end milling simulation software is developed in C# to simulate and display the CFRP milling process. During simulation, fiber lengths, fiber cutting angle and engaged cutting angle can be displayed in real-time. A CFRP plate with different angles in different layer is used to compare the simulation results.

• Composites Research
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• 제27권3호
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• pp.109-114
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• 2014

나노입자에 대한 복합재료 수요가 증가되면서 효과적인 나노입자 보강재를 이용한 나노복합재료 제조공정 단순화를 추구하고 있다. 본 연구에서는 나노입자를 활용하여 전도성과 계면 강도를 향상시킨 나노입자 강화유리섬유 소재에 대한 연구를 진행하였다. 탄소계 나노입자의 형상에 따른 유리섬유 표면에 흡착된 나노입자 상태를 FE-SEM으로 분석하였다. 나노입자 코팅층의 내구성을 평가하기 위한 방법으로 초음파 세척과정에 따른 나노입자의 세척 정도를 분석하여 탄소계 나노입자의 형상에 따른 나노입자 코팅층의 내구성을 분석하였다. 동적피로 실험을 통하여 나노입자 강화 유리섬유/에폭시의 계면강도를 나노입자 형상에 따른 차이에 따라 비교하였다. 나노입자 코팅층의 내구성은 단섬유 강화 복합재료시편을 이용하여 분석하였다. 겉보기 강성도 결과와 나노입자코팅층의 전도성 변화를 분석하여 코팅층의 다기능성을 분석할 수 있었다. 판상형의 나노입자 보다는 섬유 형태의 나노입자가 유리섬유 표면에 흡착성이 용이하였다. 계면 내구성 및 안정성에 효과가 있음을 확인하였다.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 1995년도 춘계연구발표회 논문개요집
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• pp.36-37
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• 1995

• 한국세라믹학회지
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• 제46권3호
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• pp.301-305
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• 2009

The novel carbon coating process for interlayer of fiber reinforced ceramic composites between fiber and matrix was performed by carbonizing phenolic resin solution that coated on fiber surface in $N_2$ atmosphere at $600^{\circ}C$ to improve the strength and fracture toughness of CMC(ceramic matrix composite). 160 nm carbon layer was coated on fiber surface with 5 vol% of phenolic resin solution. Since the process temperature ($600^{\circ}C$) is lower than chemical vapor deposition($900{\sim}1000^{\circ}C$), the strength and toughness could be preserved. Furthermore the coating thickness uniformity was improved to 8% of deviation along the stacking sequence. Therefore, prevention from fiber degradation during coating process and controlling coating thickness uniformity along the preform depth were achieved by coating with phenolic resin carbonizing method.

• Composites Research
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• 제28권5호
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• pp.254-259
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• 2015

탄소섬유에 대한 액상 알루미늄의 젖음성이 매우 좋지 않기 때문에 통상적인 주조방법으로는 기공이 없는 건전한 탄소섬유/알루미늄 복합재료 제조가 어려워 이를 극복하기 위해서는 복합재료 주조 시 고온, 고압이 요구된다. 본 연구에서는 탄소섬유 표면에 무전해 도금에 의해 구리를 코팅함으로써 탄소섬유에 대한 알루미늄의 젖음성을 향상시켜 고온, 고압을 가하지 않고 액상의 알루미늄이 탄소섬유들 사이를 자발적으로 침투하여 내부기공이 매우 적은 건전한 탄소섬유/알루미늄 복합재료를 제조할 수 있었다. 제조된 탄소섬유/알루미늄 복합재료내 일부 탄소섬유 다발 안에서 미세기공이 발생하였으나 이 미세기공은 압연과 같은 후 가공에 의해 탄소섬유와 알루미늄 사이의 계면분리나 탄소섬유의 파괴 없이 효과적으로 제거될 수 있었다. 복합재료 제조 시 발생한 미세기공은 탄소섬유와 알루미늄의 젖음성 문제는 아니며 탄소섬유들 사이 공간을 효과적으로 채웠던 액상 알루미늄이 냉각되는 동안 수축으로 인해 일부 탄소섬유들 사이로부터 빠져 나가 수축공 형태의 기공이 발생한 것으로 판단된다.

• Advances in nano research
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• 제14권5호
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• pp.443-450
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• 2023

Carbon nanotubes (CNTs) have received increased interest in reinforcing research for polymer matrix composites due to their exceptional mechanical characteristics. Its high surface area/volume ratio and aspect ratio enable polymer-based composites to make the most of its features. This study focuses on the experimental tensile testing and fabrication of carbon nanotube reinforced composite (CNTRC) beams, exploring various micromechanical models. By examining the performance of these models alongside experimental results, the research aims to better understand and optimize the mechanical properties of CNTRC materials. Tensile properties of neat epoxy and 0.3%; 0.4% and 0.5% by CNT reinforced laminated single layer (0°/90°) carbon fiber composite beams were investigated. The composite plates were produced in accordance with ASTM D7264 standard. The tensile test was performed in order to see the mechanical properties of the composite beams. The results showed that the optimum amount of CNT was 0.3% based on the tensile capacity. The capacity was significantly reduced when 0.4% CNT was utilized. Moreover, the experimental results are compared with Finite Element Models using ABAQUS. Hashin Failure Criteria was utilized to predict the tensile capacity. Good conformance was observed between experimental and numerical models. More importantly is that Young' Moduli of the specimens is compared with the prediction Halpin-Tsai and Mixture-Rule. Although Halpin-Tsai can accurately predict the Young's Moduli of the specimens, the accuracy of Mixture-Rule was significantly low.

• 한국안전학회지
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• 제19권4호
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• pp.31-35
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• 2004

The A17075/CFRP multi-layered hybrid laminate material consists of the alternating A17075-T6 sheets and carbon/epoxy prepregs of M40 fade. The influence of volume fraction and fiber orientation of A17075/CFRP layer on flexural properties of A17075/CFRP laminate alternating A17075-T6 and carbon/epoxy prepreg was investigated. The results obtained from the experimental analysis are as follows: 1. In the $0^{\circ}$ fiber orientation, the mont of increase of the flexural rigidity was $20.5\%$ at the $26.5\%$ volume fraction and $38.0\%\;at\;the\;35.7\%$ volume fraction compared with the flexural rigidity level(20.0GPa) of the $10\%$ volume fraction of CFRP. 2. In the $\pm45^{\circ}$ fiber orientation the amount of decrease of the flexural rigidity was $23.5\%\;at\;the\;20.0\%$ volume fraction and $31.5\%\;at\;the\;33.3\%$ volume fraction compared with the flexural rigidity level of the $10\%$ volume fraction of CFRP. 3. In the $0^{\circ}$ fiber orientation, the flexural strength was 481.5MPa at the $10\%$ volume fraction of CFRP and 583.8MPa at the $26.5\%$ volume fraction and 653.7MPa at the $35.7\%$ volume faction. 4. In the $\pm45^{\circ}$ fiber orientation, the flexural strength was 354.0MPa at the $20.0\%$ volume fraction of CFRP and 340.5MPa at the $33.3\%$ volume fraction.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2003년도 봄 학술발표회 논문집
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• pp.98-100
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• 2003

The efficiency of the adsorption of adsorbents depends on both pore size and shape. In other to adsorb hydrated ion in application of electric double layer capacitor (EDLC), mesopore is necessary[1,2]. Tamai et al.[3] reported that an increased portion of mesopore was introduced through addition of metal or organometallic compound in the precursor and following activation of the carbon fibers with steam. (omitted)

• Carbon letters
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• 제2권1호
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• pp.27-36
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• 2001

The pack-cementation process is the method which is formed SiC coating layer to improve weak oxidation properties of CFRCs (carbon fiber-reinforced carbons). This method develops the anti-oxidation coating layer having no dimensional changes and good wetting properties. In this study to improve the oxidative resistance of the prepared 4D CFRCs, the surface of CFRCs is coated by SiC using pack cementation method. The mechanical properties of SiC-coated 4D CFRCs are measured by the 3-point bending test, and their ablation properties are investigated by the arc torch plasma test. From the results, it is found that both mechanical and ablation properties of SiC-coated 4D CFRCs are much better than bare CFRCs.