• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 춘계학술대회 논문집
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• pp.37-40
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• 2005

Light reflectance and arc resistance of PTFE composites were investigated. PTFE composites have been used widely as a material for circuit breaker nozzle. Arc energy is transported to the nozzle material by radiation. It is needed to add some fillers to PTFE to avoid energy penetration into the nozzle material. In this paper, some fillers that have endurance in the high temperature arc environment were added into PTFE. The light reflectance and arc resistance of PTFE composites according to the kinds and content of fillers were investigated.

• 한국해양공학회지
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• 제14권4호
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• pp.49-55
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• 2000

This study has been investigated to apply fiber reinforced composites instead of asbestos as a friction material. the reinforced used was E-glass fiber and binder resin was phenol having good mechanical properties and heat resistance. And it has been also investigated the effect of molding conditions and some additives such and carbon black, alumina and rubber powder in E-glass fiber/phenol resin composite on the friction on the friction and wear characteristics. As a result, it was found that the molding conditions of E-glass fiber/phenol resin composites for friction materials had to be different from those of phenol resin and was found that the wear rate of E-glass fiber/phenol resin composites added alumina powder was higher than of composites added carbon black in the same wear distance. And it was found that friction coefficient of E-glass/phenol resin composites added carbon black was decreased and that of the composites added the powder of natural rubber and ABS rubber were increased compared to the composites.

• 한국구조물진단유지관리공학회 논문집
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• 제14권6호
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• pp.85-92
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• 2010

최근 국내에서도 지진의 발생 가능성이 증가하는 추세이며 교량 및 터널 등의 시설물에 대한 지진과 같은 예상하지 못한 작용하중에 대한 안전성을 강화하고 있다. 특히, 1988년 이전 건설된 도시철도 시설물의 대부분은 내진설계가 반영되지 않아 지진하중에 대해 취약할 수 있으므로, 내진안전성에 대한 검토와 보강이 요구되고 있다. 이 연구에서는 도시철도 개착식 터널의 내진성능 향상을 도모하고자, 구조적 취약부분인 내측 기둥에 내진보강을 위한 새로운 FRP-연성재 적층복합체를 제안하였다. 적층조건에 따른 FRP-연성재 적층복합체에 대한 실험을 통해 재료물성치를 산출하여, 이를 근간으로 수치모델을 작성하였다. 수치해석을 통해 제안된 보강재로 보강된 RC기둥의 내진성능이 증대됨을 알 수 있었다. 또한 섬유보강재의 적층조건 (연성재의 종류, FRP 적층수, 섬유배향각)에 따라 성능 향상의 차이가 있는 것을 확인할 수 있었다.

• 한국응용과학기술학회지
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• 제24권4호
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• pp.416-426
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• 2007

Polypropylene (PP) composites with wood flour/wax/coupling agent were manufactured by melt compounding and injection molding. The influence of wood flour(WF), wax, and coupling agent on the mechanical and thermal properties of the composites was investigated. The addition of wood flour to neat PP has the higher tensile modulus and strength compared with neat PP. The presence of wax also improved the tensile modulus. At the same loading of PP and WF, the addition of coupling agent highly decreased the tensile modulus, and increased the tensile strength. From thermogravimetric analysis (TGA), the addition of wax improved the thermal stability of the composites in the later stages of degradation. The presence of MAPP and wood flour in turn decreased thermal stabilities of composites. From differential scanning calorimetry analysis (DSC), neither the loading of wax. nor the presence of MAPP has shown significant effect on the thermal transition of composites.

• 한국전기전자재료학회논문지
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• 제29권12호
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• pp.796-802
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• 2016

In order to develop an electrical insulation material for gas GIS (insulation switch gear) spacer, 4 types of epoxy/micro-alumina (40, 50, 60, 70 wt%) composites and 9 types of epoxy/nano-alumina (1, 3, 5 g)/micro-alumina (40, 50, 60, 70 wt%) composites were prepared and tensile test was carried out. In here, nano-alumina was previously surface-treated with GDE (glycerol diglycidyl ether). As micro-alumina and GDE-treated nano-alumina contents increased, tensile strength increased and the highest value was shown in the system with 3 g GDE-treated nano-alumina.

• 한국세라믹학회지
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• 제55권6호
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• pp.556-561
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• 2018

In this study, we performed a microwave sintering (MWS) of $Al_2O_3$ ceramic and $Al_2O_3$-based composites with nominal contents of graphene nanoplatelets (GPLs) of 0.2, 0.4, 0.6, and 0.8 vol%. The GPL dispersion in N-methyl pyrroleketone was optimized to deagglomerate the GPLs without damaging their structure. Dense composites were then obtained by MWS at $1500^{\circ}C$ for 30 min. The effects of different GPL contents on the phase compositions, microstructures, and mechanical properties of the composites were investigated. The microstructures of the composites became finer with the incorporation of the GPLs. The well-dispersed GPL fillers led to higher sintered densities in the composites. The optimal mechanical properties were achieved with 0.4 vol% GPLs. For this sample, the hardness, fracture toughness, and bending strength were $2000kgf/mm^2$, $6.19MPa{\cdot}m^{1/2}$, and 365.10 MPa, respectively. The addition of GPL could improve the microstructure of the $Al_2O_3$ ceramic and has potential to improve the fracture toughness of the ceramics.

• 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.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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• pp.317-320
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• 1999

In this study, the piezoelectric ceramics PZT powder was synthesized by Wet-Dry combination method. And the flexible 1-3-0 type composites were fabricated with piezoceramic PZT and Eccogel polymer matrix embedded 3rd phase. Dielectric constant of 1-3-0 type composites was lower than that of single phase PZT ceramics. Thickness mode coupling factor k/sub t/ which was comparable with single phase PZT ceramics and mechanical quality factor Qm were about 0.65 and 6, respectively. These composites are considered as a good candidates for broad-band type transducer applications. The acoustic impedance of 1-3-0 type composites was lower than that of single phase PZT ceramics. Therefore, these composites would be better used for hydrophone applications.

• 반도체디스플레이기술학회지
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• 제17권1호
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• pp.1-5
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• 2018

Wood Polymer Composites(WPC) have attracted significant attention because of ecological and environmental concerns. However, the structure of Wood Flour containing many hydroxyl groups(-OH) reduces the interface adhesion to Phenol-formaldehyde(PF) and it decreases the mechanical properties of the PF/Wood Flour Composites. The present work involves the modification of Wood Flour using silanes reinforced with Phenol-formaldehyde to enhance the mechanical properties of the composites. The spectroscopic properties of the composites were analyzed using FT-IR, XPS(X-ray Photoelectron Spectroscopy) and the mechanical properties i.e., tensile strength, flexural strength and impact strength were studied. We confirmed the modification effect of silanes by spectroscopic analysis, and the mechanical properties of the composites using wood flour modified by silanes were significantly improved.

• 한국전기전자재료학회논문지
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• 제34권4호
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• pp.229-241
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• 2021

Since 2010, polymer-based magnetoelectric (ME) composites have been developed with detailed investigations of multiferroic properties such as piezoelectric, magnetostrictive, and magnetoelectric, etc. In particular, as a piezoelectric polymer, poly(vinylidene fluoride) and its co-polymers have been widely used in ME composites for energy harvesting, health monitoring, environment treatment, and bio-medical applications. In this study, main research trend and selected experimental results of polymer-based ME composites are briefly reviewed with respect to composite structure as well as application field. A conclusion was drawn that the polymer-based ME composites would be feasible as flexible devices or functional membranes in the near future.