• 한국정밀공학회지
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• 제19권3호
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• pp.114-122
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• 2002

Electric conductivities, mechanical properties and friction properties were investigated far graphite-nylon composites impregnated with oil. Specific resistivity of composites containing oil from 2% to 6% were in the range of $10^7 ~10^6 \ohm$ cm, which were applicable for anti-static purpose of composites improved by the impregnation of graphite with 2%. Improvement in the impact strength and friction properties of graphite/nylon composites was achieved by the impregnation of oil. The coefficient of friction of the composites containing graphite from 2% to 4% and oil with 2 - 4% showed much loller than that of virgin nylon. Also the abrasive wear of the oil impregnated graphite composites were decreased about 1/3 - 1/10.

• Carbon letters
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• 제13권4호
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• pp.221-225
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• 2012

Graphite oxide (GO) was produced using the modified Hummer's method. Poly(p-phenylene sulfide) (PPS)/reduced graphite oxide (RGO) composites were prepared by in situ polymerization method. The electrical conductivity of the PPS/RGO composites was no more than 82 S/m. It was found that as GO content increased in the PPS/RGO composites, the crystallization temperature and electrical conductivity of the composites increased and the percolation threshold value was at 5-8 wt% of GO content.

• Carbon letters
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• 제10권2호
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• pp.94-96
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• 2009

[ $C_f/C-Cu$ ]composites were fabricated by infiltrating molten Cu into different $C_f/C$ preforms prepared by chemical vapor infiltration, resin impregnation and carbonization. The microstructure and properties of the composites were investigated. The results show that Cu in the composites filled the pores and showed network-like distribution. Compared with homemade J204 brush material and certain grade pantograph slider from abroad, the composites have higher flexural strength and better electrical conductivity. The friction and wear properties of the composites are better than that of J204, and closed to that of the abroad material.

• 한국가구학회지
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• 제17권3호
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• pp.87-94
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• 2006

The purpose of this study was to evaluate the relationships between the mixing ratio and water vapor sorption property of charcoal-based loess composites for furniture & building materials with environmental friendly. Charcoal-based loess composite can be easily made by blending method with water. But the composites had much brittle fracture pattern with the increase of charcoal content. That is due to the lack of loess that takes linkage role of composites. In water vapor sorption properties, adsorption ability of charcoal was about six times higher than that of loess. Therefore, vapor sorption ability was maximum at the mixture ratio of charcoal 80% and loess 20%. It is considered that wood charcoal based inorganic composite materials can be used for various purposes as a building interior & exterior and furniture members.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1997년도 추계학술대회논문집
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• pp.216-219
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• 1997

Hot workability of SiCp/AA2024 composites reinforced with different vol. % of SiCp reinforcements (0, 5, 10, 15, 20, and 30 vol. %) was investigated by hot torsion tests. Hot restoration of the composites was studied from the flow curves and deformed microstructures. Dynamic recrystallization (DRX) was occurred in all the composites during the hot deformation at 370-43$0^{\circ}C$ under a strain rate of 1.0/sec. Also, the flow stress of the composites increased with increasing the SiCp reinforcement vol. % and the difference of flow stress between the composites decreased with increasing the deformation temperature.

• The Korean Journal of Ceramics
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• 제4권4호
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• pp.363-367
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• 1998

Alumina/mica and spinel/mica composites were fabricated by sintering of compacts containing 20 mass% fluoromica ($KMg_3AlSi_3O-{10}F_2$) glass and alumina or spinel. In both composites, mica precipitated as plate-like crystals at temperatures lower than $1300^{\circ}C$ and melted at $1300^{\circ}C$ to $1400^{\circ}C$. In alumina/mica composites, alumina and glass reacted to produce spinel, and the densification progressed by the solution-precipitation of alumina. Consequently, the glass composition changed and the mica did not precipitate at temperatures higher than $1400^{\circ}C$. However, mica precipitated after a reheating process. In spinel/mica composites, the glass composition did not change. After the mica phase melted, it recrystallized during slow cooling. The relative density reached the maximum at $1500^{\circ}C$ for alumina/mica and at $1300^{\circ}C$ spinel/mica composites, and decreased at further high temperatures.

• Transactions on Electrical and Electronic Materials
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• 제11권2호
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• pp.89-91
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• 2010

Partial discharge (PD) resistances were investigated for three types of samples: original epoxy resins, epoxy micro composites with and without the silane processing, and mixture composites with micro and nano particles. The PD was applied to these materials using rod, gap, and plane electrodes. The partial discharge resistance found in the micro composites was better than that found in the original epoxy resin. Moreover, the mixture composites of $SiO_2$ nano and micro particles had much larger resistances than the original epoxy resin or microcomposites. It can be regarded that this excellent property was due to the fact that the nano particles have a dense structure between the micro particles.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 C
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• pp.1336-1338
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• 1997

Relations between the composites of SiC-$ZrB_2$ electro-conductive ceramic composites and their electrical resistivity, as well as their temperature, were investigated. The electrical resistivity of hot-pressed composites was measured by the Pauw method in the temperature of RT to $100^{\circ}C$. The electrical resistivity of the composites follow the electrical conduction model for a homogenous mixture of two kinds of particles with different conductivity. Also the electrical resistivity versus temperature curves indicate the formation of local chains of $ZrB_2$ particles. In the case of SiC-$ZrB_2$ composites containing above 30Vol.% $ZrB_2$ showed PTCR, whereas the electrical resistivity of SiC-15Vol.% $ZrB_2$ showed NTCR.

• Carbon letters
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• 제11권4호
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• pp.347-356
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• 2010

Recently, the use of thermal conductive polymeric composites is growing up, where the polymers filled with the thermally conductive fillers effectively dissipate heat generated from electronic components. Therefore, the management of heat is directly related to the lifetime of electronic devices. For the purpose of the improvement of thermal conductivity of composites, fillers with excellent thermally conductive behavior are commonly used. Thermally conductive particles filled polymer composites have advantages due to their easy processibility, low cost, and durability to the corrosion. Especially, carbon-based 1-dimensional nanomaterials such as carbon nanotube (CNT) and carbon nanofiber (CNF) have gained much attention for their excellent thermal conductivity, corrosion resistance and low thermal expansion coefficient than the metals. This paper aims to review the research trends in the improvement of thermal conductivity of the carbon-based materials filled polymer composites.

• Elastomers and Composites
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• 제51권2호
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• pp.106-112
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• 2016

Maleimidopropyltriethoxysilane grafted natural rubber (MISNR) was prepared by reaction of maleic anhydride grafted natural rubber and 3-aminopropyl triethoxysilane. MISNR was used as the compatibilizer of natural rubber/silica composites. The composites were prepared by two-step mixing procedures. The final mixtures were cured with optimum cure condition, which was established by a rheometer. Effects of the amounts of compatibilizer in the composites on the cure characteristics, morphology, thermal stability, and physical and mechanical behaviors were investigated. The composites having MISNR had shown cure characteristics and physical and mechanical properties superior to those without MISNR. Silica particles in the former appeared to be more uniform and reduced in size compared with the latter. The effects of the types of silica were also evaluated.