• Korean Journal of Materials Research
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• v.3 no.3
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• pp.292-299
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• 1993

In this paper the effects of the length of carbon fiber on the wear properties of carboni carbon composites were investigated. Carbon/carbon composites were fabricated by the liquid impregnation method using the resol-type phenolic resin as a matrix precursor and PAN-based, non-surface treated carbon fiber as a reinforcement. The measured values of the friction coefficient of carbon/carbon composites against AlSl 304 stainless steel ranged from 0.2 to 0.3 under the operating condition used in this study. The effect of the length of carbon fiber on the friction coefficient of carbon/carbon composites were not found. But, it was realized that the wear rate of carbon/carbon composites tends to increase, as the length of carbon fiber increases.

• Composites Research
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• v.25 no.3
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• pp.82-89
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• 2012

This paper investigated the composite materials application examples and trends in the future to the solid rocket motor cases. The motor case must be stiff and tolerate at the high pressures, and light weight. In accordance to these kind of requirements, the composite materials showed the adaptable efficiency, and glass fibers, aramid, carbon fibers are applied to orderly. The comparison of the motor case efficiencies of the D6AC steel alloy, aramid, carbon fibers results in the carbon fibers best. Also the capacity of the payload will be increased more than 20% by using the high strength ones.

• Proceedings of the Korean Fiber Society Conference
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• 1998.10a
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• pp.422-425
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• 1998

섬유강화 복합재료는 고성능 섬유와 고분자 수지를 조합하여 재료의 물성 향상 및 고기능화를 목적으로 만들어지는 재료이며, 사용되는 고분자 매트릭스의 종류에 따라 열가소성 복합재료와 열경화성 복합재료로 나뉘어진다. 이 중 열경화성 복합재료에 관한 연구 및 그의 실용화는 오래 전부터 활발히 진행되어 산업재료 및 군사, 우주용 재료로 각광을 받아 왔으나 최근 지구 환경문제가 심각해지면서 사용 후 분해 및 재활용이 가능한 열가소성 복합재료에 관한 연구에 관심을 가지게 되었다. (중략)

• Composites Research
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• v.28 no.5
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• pp.254-259
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• 2015

Carbon fiber/aluminum (CF/Al) composites were successfully fabricated without pressure casting using wettability modification of carbon fiber. The wettability of liquid aluminum on carbon fibers was enhanced through electroless plating of copper on carbon fibers. Liquid aluminum was well infiltrated into carbon fiber bundles with Cu coating layer due to low wetting angle, and a lot of pores that existed in CF/Al composite without Cu coating on CF were greatly removed. However, a few tiny pores existed in carbon fiber bundles, which is due to not bad wettability between CF and Al but shrinkage cavity that was generated during cooling of CF/Al composite. The tiny pores could be effectively removed by a subsequent rolling.

• Applied Chemistry for Engineering
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• v.27 no.2
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• pp.179-184
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• 2016

In this work, the influence of milled carbon fiber direction on mechanical properties of milled carbon fibers/carbon blacks/natural rubber compounds was investigated. The compounds were prepared by adding the 6 phr milled carbon fibers (MCFs) and 40 phr carbon blacks (CBs) into the natural rubber. The MCFs were aligned in a parallel and orthogonal direction in the compounds using two-roll-mill machine. Mechanical properties of compounds were studied by tensile characteristics and tearing strength. As a result, the compounds showed higher tensile strength, 100%~300% modulus, and tearing strength than those of using any other compounds due to the aligning MCFs in parallel. Mechanical properties of the compounds reinforced with non-aligned MCFs were inferior to those of others. Consequently, the parallel aligned MCFs in the compounds led to an increase of tensile properties and improvement of tearing strength, resulted from MCFs with the high elastic modulus.

• Composites Research
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• v.28 no.5
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• pp.311-315
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• 2015

Measuring fiber volume fraction properly is very important in designing composite materials because the fiber volume fraction mainly determines mechanical and thermal properties. Conventional Ignition methods are effective for ceramic fiber reinforcing composite materials. However, these methods are not proper for applying to carbon fiber reinforcing composites because of the venerable characteristic against oxidation of carbon fiber. In the research, fiber volume fraction of carbon fiber composites was obtained by a thermogravimetric analysis considering oxidation characteristic of the carbon fiber and the method was compared and verified with the results from microscopic cross section images.

• Elastomers and Composites
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• v.45 no.1
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• pp.2-6
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• 2010

The sizing treatments of PAN-based carbon fiber surfaces were carried out in order to improve the interfacial adhesion in the carbon fibers/nylon6 composite system. The parameter to characterize the wetting performance and surface free energy of the sized fibers were determined by a contact angle method. The mechanical interfacial properties of the composites were investigated using critical stress intensity factor ($K_{IC}$). The cross-section morphologies of sized CFs/nylon6composites were observed by SEM. As the experimental results, it was observed that silane-based sizing treated carbon fibers showed higher surface free energies than other sizing treatments. In particular, the KIC of the sizing-treated carbon fibers reinforced composites showed higher values than those of untreated carbon fibers-reinforced composites. This result indicated that the increase in the surface free energy of the fibers leads to the improvement of the mechanical interfacial properties of carbon fibers/nylon6 composites.

• Applied Chemistry for Engineering
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• v.10 no.5
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• pp.778-783
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• 1999

The effect of carbon fiber orientation on the tribological properties of carbon fiber/epoxy composites used as a reflecting material for the electromagnetic wave has been investigated. It was found that the carbon fiber/epoxy composite which slides normal to prepreg lay-up direction had less friction and wear that those slides parallel to prepreg fiber lay-up direction due to the increase of delamination between carbon fiber and epoxy. Composite with unidirectional orientation($0/0^{\circ}$) had higher tribological properties than those with multidirectional orientation($0/45/90/-45^{\circ}$ and $0/90^{\circ}$) when the sliding direction was normal to prepreg lay-up direction. This was caused by the debonding between carbon fiber and epoxy which is proportional to contact area between the sliding surface and carbon fiber. Opposite results have been found when the sliding direction was parallel to prepreg lay-up direction due tot he tensile force applied on carbon fiber. In addition, it was shown that wear factor increased with increasing sliding velocity but the friction coefficient did not depend upon the sliding velocity.

• Applied Chemistry for Engineering
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• v.26 no.3
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• pp.239-246
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• 2015

The hybridization of carbon nano-materials enhances the efficiency of each function of the resulting structure or composites. Also, the addition of non-carbon elements to nanomaterials modifies the electrochemical properties. Electrodes combining porous carbon nanofibers (CNFs) and metal oxides benefit from the combination of the double-layer capacitance of the CNFs and the pseudocapacitive character associated with the surface redox-type reactions. Consequently, they demonstrate superior supercapacitor performance in terms of high capacitance, high energy/power efficiency and high rate capability. This paper presents a comprehensive review of the latest advances made in the development and application of various metal oxide/CNF composites (CNFCs) to supercapacitor electrodes.

• Composites Research
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• v.19 no.2
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• pp.7-12
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• 2006

Graphite particle/carbon fiber hybrid conductive polymer composites were fabricated by the compression molding technique. Graphite particles were mixed with an epoxy resin to impart the electrical conductivity in the composite materials. In this study, graphite reinforced conductive polymer composites with high filler loadings were manufactured to accomplish high electrical conductivity above 100S/cm. Graphite particles were the main filler to increase the electrical conductivity of composites by direct contact between graphite particles. While high filler loadings are needed to attain good electrical conductivity, the composites becomes brittle. So carbon fiber was added to compensate weakened mechanical property. With increasing the carbon fiber loading ratio, the electrical conductivity gradually decreased because non-conducting regions were generated in the carbon fiber cluster among carbon fibers, while the flexural strength increased. In the case of carbon fiber 20wt.% of the total system, the electrical conductivity decreased 27%, whereas the flexural strength increased 12%.