• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.11a
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• pp.226-227
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• 2015

인쇄회로기판에 솔더 페이스트를 인쇄하기 위하여 스테인리스 스틸 (Stainless steel, (i.e., SUS)) 재질의 솔더 페이스트 인쇄용 스텐실 마스크가 사용되고 있다. 하지만, 솔더 페이스트가 스텐실 마스크에 쉽게 달라붙기 때문에 솔더 페이스트에 의한 오염으로 인하여 생산성이 떨어지며, 스텐실 마스크 수명이 짧아지는 문제점이 발생되고 있다. 이를 해결하기 위하여 본 연구에서는 스텐실 마스크 표면에 소수성을 가진 고분자 코팅을 함으로써 솔더 페이스트가 쉽게 붙는 것을 억제하고자 하였다. 더욱 중요하게 스텐실 마스크에 전해연마 및 플라즈마 처리를 통한 표면 개질을 부여함으로써 고분자 코팅의 내구성을 향상시키고자 하였다.

• Proceedings of the Membrane Society of Korea Conference
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• 2003.07a
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• pp.25-28
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• 2003

Low cost composite metallic membranes for the hydrogen separation and production have been prepared by using thin Pd-Ag foils reinforced by metallic (stainless steel and nickel) structures. Especially, “supported membranes” have been obtained by a diffusion welding procedure in which Pd-Ag thin foils have been joined with perforated metals (nickel) and expanded metals (stainless steel): in these membranes the thin palladium foil assures both the high hydrogen permeability and the perm-selectivity while the metallic support provides the mechanical strength. A second studied method of producing "laminated membranes" consists of coating non-noble metal sheets with very thin palladium layers by diffusion welding and cold-rolling. Palladium thin coatings over these metals reduce the activation energy of the hydrogen adsorption process and make them permeable to the hydrogen. In this case, the dense non-noble metal has been used as a support structure of the thin Pd-Ag layers coated over its surfaces: a proper thickness of the metal assures the mechanical strength, the absence of defects (cracks, micro-holes) and the complete hydrogen selectivity of the membrane. membrane.

• Nuclear Engineering and Technology
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• v.55 no.11
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• pp.4032-4038
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• 2023

Cu, which exhibits excellent corrosion resistance in underground environments, has been investigated as a canister material for use in the deep geological disposal of spent nuclear fuels. In this study, the technical viability of atmospheric plasma spraying for producing Cu-coated canisters was investigated. A high-purity Cu film (millimeter scale) was deposited onto a stainless-steel substrate using a plasma gun with a shroud structure. Potentiodynamic polarization studies revealed that the Cu film exhibited a sufficiently low corrosion rate in the groundwater electrolyte. In addition, no pitting corrosion was observed on the Cu film surface after accelerated corrosion studies. A prototype cylindrical Cu film was fabricated on a 1/20 scale on a stainless-steel tube to demonstrate the scalability of atmospheric plasma spraying in producing Cu-coated canisters.

• Journal of Ocean Engineering and Technology
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• v.25 no.6
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• pp.60-65
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• 2011

A low temperature plasma carburizing process was performed on AISI 316L austenitic stainless steel to achieve an enhancement of the surface hardness without degradation of its corrosion resistance. Attempts were made to investigate the influence of the processing temperatures on the surface hardened layer during low temperature plasma carburizing in order to obtain the optimum processing conditions. The expanded austenite (${\gamma}_c$) phase, which contains a high saturation of carbon (S phase), was formed on all of the treated surfaces. Precipitates of chromium carbides were detected in the hardened layer (C-enriched layer) only for the specimen treated at $550^{\circ}C$. The hardened layer thickness of ${\gamma}_c$ increased up to about $65{\mu}m$ with increasing treatment temperature. The surface hardness reached about 900 $HK_{0.05}$, which is about 4 times higher than that of the untreated sample (250 $HK_{0.05}$). A minor loss in corrosion resistance was observed for the specimens treated at temperatures of $300^{\circ}C{\sim}450^{\circ}C$ compared with untreated austenitic stainless steel. In particular, the precipitation of chromium carbides at $550^{\circ}C$ led to a significant decrease in the corrosion resistance. A diamond-like carbon (DLC) film coating was applied to improve the wear and friction properties of the S phase layer. The DLC film showed a low and stable friction coefficient value of about 0.1 compared with that of the carburized surface (about 0.45). The hardness and corrosion resistance of the S phase layer were further improved by the application of such a DLC film.

• Journal of the Korean Electrochemical Society
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• v.3 no.3
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• pp.136-140
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• 2000

A stainless steel separator for a molten carbonate fuel cell is usually coated with aluminum diffusive layer to protect its surface against corrosion by the molten carbonate at high temperatures. In this study, a relatively simple method was devised to form the aluminum diffusive layer on a stainless steel substrate. Slurry coating of aluminum on the substrate followed by heat treatment under reducing atmosphere at $650\~800^{\circ}C$ produced the aluminum diffusive layer of $25\~80{\mu}m$ thickness. The thickness of aluminum diffusive layer increased with increasing the temperature or duration of the heat-treatment. The corrosion resistance against molten carbonate under oxidizing atmosphere was significantly improved by aluminum diffusive layer formed by the sluny painting and heat treatment method. Moreover, the sample prepared in this study showed corrosion behavior similar to the sample with aluminum diffusive layer prepared by ion vapor deposition and heat treatment.

• Laser Solutions
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• v.10 no.4
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• pp.7-12
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• 2007

The aluminized steel sheet exhibits excellent resistance to oxidation and corrosion, and can substitute for stainless steel or heat-resisting steel in some situations. Furthermore it has wide applications, owing to its low cost and excellent performance, in the petrochemical industry, electric power, other energy conversion system, etc. and has attracted the attention of many investigators. Laser welding is a remarkably advantageous method for welding of thin sheets and surface-treated steel sheets since the method requires less heat input, and it is suitable for high-speed welding. In this study, thus, the laser weldability of aluminized steel sheet was investigated. As the result from the study, there is an Al-rich zone in a welded part which has decreased the welding strength due to the intermetallic compounds in the Al-rich zone.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2018.06a
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• pp.41-41
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• 2018

안정적이고 효율적인 전력 공급을 위해 번화가 대로변 주변에 다수의 지상 변압기 및 개폐기가 설치되고 있으며, 이로 인해 불법 부착물로 인한 도시의 미관 훼손, 변압기 및 개폐기의 오염 등의 문제가 발생하고 있다. 따라서 각 산업체 및 연구 기관에서는 부착 방지용 코팅 도료 및 시트에 대해 다양한 연구개발을 진행하고 있으며, 현장에 적용되고 있는 사례도 있다. 하지만 현재 현장에 적용된 대부분의 제품들은 약 1년 정도의 시간이 지나면 고유의 기능을 상실하며, 도료 및 시트와 기판 사이의 박리가 일어나 우수한 성능을 보이지 않아, 결과적으로 도시에 더욱더 악영향을 주고 있다. 이러한 원인으로는 도료 및 시트의 성능 평가를 위한 다양한 규격들이 존재하지만, 테이프류 탈착 시 영향을 주는 인자(Factor)들이 명확하게 설정되어 있지 않고, 이에 대해 면밀하게 분석한 자료가 없으며, 정량적이고 객관적인 시험 방법이 고려되지 않고 있기 때문에 좋은 제품을 선별하기 어려운 상황이다. 따라서 여러 가지 제품들의 비교평가 및 기술 개발에 활용할 수 있는 가이드라인을 제시하기 위해 일반적으로 사용되고 있는 면테이프(Duct tape)를 이용하여 기판(Substrate)에 대해 다양한 인자를 기준으로 탈착 특성을 측정 및 평가하였다. 현재 지상 배전함 및 개폐기는 분체도장(Powder coating)으로 구성되어져 있으며, 그 모재는 탄소강(Carbon steel)으로 이루어져 있고, 소수의 경우 스테인리스(Stainless steel)를 사용하기 있기 때문에 분체도장(Powder coating), 탄소강(Carbon steel), 스테인리스(Stainless steel)를 기판으로 선정하여 탈착 특성을 평가했다. 탈착 특성에 관여하는 요인으로는 탈착 각도(Peeling angle), 탈착 속도(Peeling speed), 표면 조도(Surface roughness) 등이 있고, 상대 습도(Relative humidity)의 경우 탈착 특성에 영향을 거의 주지 않는 것을 확인했다. 탈착 시 각도가 클수록, 속도가 빠를수록, 조도가 작을수록 부착력(Peel resistance, N/cm)과 탈착 에너지(Energy, J)가 커지며, 탈착 특성에 영향을 주는 인자를 바탕으로 95% 신뢰도 구간을 적용한 탈착특성 모델링을 제시하였다. 이 모델링을 이용하여 실제 현장에서 발생할 수 있는 다양한 각도($90^{\circ}$, $180^{\circ}$)와 속도 범위(100 ~ 1500mm/min)에서의 탈착 특성을 추정하는 것으로, 좋은 성능 및 내구성을 가진 제품을 효과적으로 선별한다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.2
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• pp.81-86
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• 2003

To measure the pressure using semiconductor type pressure sensor in water or chemical solution, the sensor must be protected from the solution using proper packaging materials. stainless steel isolated type pressure sensor packaged with SUS316 can be widely used to measure the pressure in water or chemical due to its high corrosion-resistance and good performance in tensility and welding. Even if the surface of SUS316 has a plenty of nickel and chromium, the SUS316 is highly corrosive in acidic or alkaline solution. We coated parylene and adhesion promoting copper layer are 5${\mu}{\textrm}{m}$ and 200nm, respectively. The parylene coated stainless steel pressure sensor showed good anti-corosive characteristics in various strong acids. The accuracy of pressure sensor wasn't varied after parylene coating with 0.5%FSO.

• Corrosion Science and Technology
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• v.7 no.6
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• pp.301-306
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• 2008

Surface composite layers of 1.9~2.9 mm in thickness were fabricated by depositing metamorphic powders on a carbon steel substrate and by irradiating with a high-energy electron beam. In the surface composite layers, 48~64 vol.% of $Cr_{2}B$ or $Cr_{1.65}Fe_{0.35}B_{0.96}$ borides were densely precipitated in the austenite or martensite matrix. These hard borides improved the hardness of the surface composite layer. According to the otentiodynamic polarization test results of the surface composites, coatings, STS304 stainless steel, and carbon steel substrate, the corrosion potential of the surface composite fabricated with 'C+' powders was highest, and its corrosion current density was lowest, while its pitting potential was similar to that of the STS304 steel. This indicated that the overall corrosion resistance of the surface composite fabricated with 'C+' powders was the best among the tested materials. Austenite and martensite phases of the surface composites and coatings was selectively corroded, while borides were retained inside pits. In the coating fabricated with 'C+' powders, the localized corrosion additionally occurred along splat boundaries, and thus the corrosion resistance of the coating was worse than that of the surface composite.

• Korean Journal of Materials Research
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• v.11 no.8
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• pp.666-670
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• 2001

To improve the corrosion resistance of separator wet-seal area which is the barrier of commercialization of molten carbonate fuel cell(MCFC), Ni/Y/Al coating layer was fabricated by Ni electroplating and Y, Al e-beam PVD on AISI 316L stainless steel. NiAlY alloy coating layer was formed by heat treatment in reduction atmosphere at $800^{\circ}C$ for 5hr. Immersion test in molten carbonate salt at $650^{\circ}C$ was performed on as- received AISI 316L stainless steel and NiAlY coated specimen. According to cross sectional SEM/EDS observations, corrosion resistance of separator wet-seal area was improved by formation of dense oxide layers of Al and Y.