• Composites Research
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• 제24권5호
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• pp.34-38
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• 2011

탄소나노튜브가 발견된 이후로, 고분자 수지의 기계적, 전기적 물성을 증대시키는 보강재로서 많은 연구가 수행되어 왔다. 더 나아가, 탄소나뉴튜브를 탄소섬유복합재 (CFRP)의 기지가 되는 수지를 보강시키는 데 이용하는 연구도 최근 활발해지고 있는 추세이다. 단일벽탄소나노튜브가 각각 0.2 %, 0.5 %의 중량비로 에폭시 수지에 먼저 분산, 혼합되었다. 이 혼합액을 CFRP를 제작하는데 주로 쓰이는 방법 중 하나인 진공 수지 충전 공정법 (vacuum assisted resin transfer molding, VARTM)으로 탄소섬유 프리폼에 주입하는 방법과 습식 현장 적층법 (wet lay-up)의 두가지 다른 방법으로 복합재를 제작 하였다. 각각의 제작된 시편에 대하여, 층간전단강도 (interlaminar shear strength, ILSS)를 측정하여, 층간전단강도와 공정의 상관관계, 탄소나노튜브의 보강효과에 대하여 조사했다. 탄소나노튜브/에폭시 복합재의 경우 기계적 물성의 향상을 가져왔으나 이를 기지재로 사용한 탄소섬유복합재의 층간전단강도는 특히 VARTM 공정의 경우, 탄소나노튜브의 첨가에 따른 수지의 점도 증가로 인한 공정상의 문제로 기대만큼의 물성향상을 가져오지는 못한 것을 확인하였다.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2005년도 춘계학술발표대회 논문집
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• pp.121-124
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• 2005

This paper was about experimental test properties by mechnical joint of CF1263/Epoxy Al honeycomb panels. In case of mechanical joint using screw, nut shall be secured over than minimize third screw pitch. In case of insert backsheet for increase of joint force, increase weight for assemble by screw pitch. In case of insert backsheet with CF1263/Epoxy, predominant save weight and minimazer of displacement by tensile weight moreover predominant strength. In case of mechanical joint by rivet, rivet of Monobolt has over-hole in hole of CF1263/Epoxy but rivet of PROTRUDING has predominant of mechanical joint.

• Composites Research
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• 제28권4호
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• pp.168-175
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• 2015

탄소섬유 강화 복합재료는 높은 비강도 및 비강성을 가지기 때문에 자동차 산업, 선박, 우주 항공 산업과 같은 다양한 산업 분야에 적용되어 왔으며, 수요가 점차 증가하고 있다. 탄소섬유 강화 복합재료에는 기지재로 주로 에폭시(Epoxy)와 같이 점도가 낮고 젖음 특성이 우수하며 강도가 양호한 열경화성(Thermosetting) 수지가 사용된다. 열경화성 수지는 우수한 물리적 특성을 나타내지만 재사용이 어렵다. 이러한 문제를 해결하기 위하여 재사용이 가능한 탄소섬유 강화 열가소성 수지(Thermoplastic) 복합재료 개발 및 탄소섬유 재사용에 관한 많은 연구들이 진행되고 있다. 본 연구에서는 열분해 방법을 사용하여 탄소섬유/에폭시 복합재료로부터 탄소섬유와 수지를 분리하여 탄소섬유를 재활용하였다. 에폭시의 분해도(Degree of decomposition)는 열중량분석기(TGA)와 시차 주사현미경(SEM)을 통해 확인하였다. 수지로부터 분리해낸 탄소섬유는 절단(Cutting)과 그라인딩(Grinding) 방법을 거쳐 탄소섬유 복합재료 시트(Sheet)를 제조하였다. 재활용 탄소 섬유로 제조된 탄소섬유 시트는 각각 다른 냉각조건에서 결정화 엔탈피(Crystallization enthalpy)와 기계적 특성, 표면과 단면의 형태를 분석하였다.

• International Journal of Ocean System Engineering
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• 제3권3호
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• pp.142-146
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• 2013

In this study, the effect of Carbon/PEEK composites on the tribological properties has been investigated. Also, its validity has been tested in the capacity of alternative materials of the Ti-based materials used for artificial hip joint. Moreover, this work evaluated the mechanical properties according to the fiber ply orientation, along with the fractured surfaces of the carbon/PEEK composites. The composites with a unidirectional orientation had higher tribological properties than those with a multidirectional orientation. This was caused by the debonding between the carbon fiber and the PEEK, which was proportional to the contact area between the sliding surface and the carbon fiber. The friction test results showed that there were no significant differences in relation to the fiber ply orientation. However, the friction properties of the carbon/PEEK composites were higher than those of the carbon/epoxy composites. In addition, the results showed that a composite that slid in a direction normal to the prepreg lay-up direction had a smaller friction coefficient than one that slid in a direction parallel to the prepreg lay-up direction.

• 방사선산업학회지
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• 제4권3호
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• pp.259-263
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• 2010

Carbon fibers are used as a reinforcement material in an epoxy matrix in advanced composites due to their high mechanical strength, rigidity and low specific density. An important aspect of the mechanical properties of composites is associated to the adhesion between the surface of the carbon fiber and the epoxy matrix. This paper aimed to evaluate the effects of electron beam irradiation on the physicochemical properties of carbon fibers to obtain better adhesion properties in resultant composite. Chemical structure and surface elements of carbon fiber were determined by FT-IR, elemental analysis and X-ray photoelectron spectroscopy, which indicated that the oxygen content increased significantly with increasing the radiation dose. Thermal stability of the carbon fibers was studied via the thermalgravimetric analysis. Surface morphology of carbon fiber was analyzed by scanning electron microscope. It was found that the degree of surface roughness was increased by electron beam irradiation.

• 대한금속재료학회지
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• 제49권7호
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• pp.522-529
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• 2011

Carbon fiber reinforced plastics (CFRP), which have been developed for their high mechanical properties, are insufficient to secure machinery. This paper investigates the use of magnetic abrasive finishing methods and the characteristics of surface roughness for mirror machining of CFRP. The cylindrical surface of CFRP was ground using a diamond paste with sizes of 0.1, 0.5, 1 and 6${\mu}m$. Consequently, an effective surface roughness of 0.03${\mu}m(R_a)$ could be obtained via a paste size of 0.5${\mu}m$. The surface roughness was not improved due to epoxy abrasion between the carbon fiber and the epoxy.

• Macromolecular Research
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• 제17권6호
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• pp.430-435
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• 2009

The effect of oxyfluorination temperature on the surface properties of carbon fibers and their reinforced epoxy composites was investigated. Infrared (IR) spectroscopy results for the oxyfluorinated carbon fibers revealed carboxyl/ester (C=O) and hydroxyl (O-H) groups at 1632 and 3450 $cm^{-1}$, respectively, and that the oxyfluorinated carbon fibers had a higher O-H peak intensity than that of the fluorinated ones. X-ray photoelectron spectroscopy (XPS) results indicated that after oxyfluorination, graphitic carbon was the major carbon functional component on the carbon fiber surfaces, while other functional groups present were C-O, C=O, HO-C=O, and $C-F_x$. These components improved the impact properties of oxyfluorinated carbon fibers-reinforced epoxy composites by improving the interfacial adhesion between the carbon fibers and the epoxy matrix resins.

• Composites Research
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• 제33권6호
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• pp.341-345
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• 2020

열중량분석기를 적용하여 탄소섬유/에폭시 복합재의 구성재 함유량을 평가하기 위한 측정기법을 제시하였다. 시험에 사용된 시료는 탄소섬유/에폭시 토우 프리프레그로 제작된 스트랜드 시편에서 채취하였으며 시간에 따른 시료의 무게 변화를 실시간으로 측정하였다. 또한 전자현미경을 이용하여 수지 제거 여부와 탄소섬유의 열손상 상태를 관찰하였다. 연구결과에 따르면 열중량분석기를 적용하면 기존의 머플로를 적용한 경우에 비해 소량의 시료에 대해서도 시험이 가능하며, 설정 온도와 노출 시간을 제어함으로써 구성재의 함유량을 효율적이고 정량적으로 평가할 수 있음을 알 수 있었다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 1996년도 재료학회 추계학술발표회
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• pp.119-119
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• 1996

• 한국정밀공학회지
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• 제14권4호
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• pp.119-125
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• 1997

The drilling experiment of carbon fiber epoxy composite material with WC-drill has been done under the various cutting conditions in order to minimize the problems occurred in the material while being drilled. It has been confirmed by a frequency analysis of the cutting force signals that the variation of cutting force resulted from the periodic variation of the angle between the ortating drill and the stacking angle of the carbon fiber. By the drilling experiment with several drills having different point angles, the drilling char- acteristics, which show the relations between the change in the point angle and cutting force or external surface condition, were analyzed.