• 한국가스학회지
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• 제5권4호
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• pp.33-39
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• 2001

흡수식냉동기의 작동매체로 사용되고 있는 LiBr수용액 중에서 각 구성재료인 일반구조용 압연강재, 동 및 동합금재인 Ai-Ni bronze의 부식거동에 관한 연구를 하기 위하여, 여러 가지 농도의 LiBr 수용액 중에서 각 재료에 대한 분극실험을 실시하여 부식거동을 고찰한 결과 다음과 같은 결론을 얻었다. 1) 수용액의 LiBr 농도가 증가할수록 각 재료의 분극저항은 낮아지고, 개로전위는 비전 위화되면서 부식전류밀도는 높게 배류된다. 2) 일반구조용 압연강재의 개로전위는 동 및 Al-Ni bronze의 개로전위보다 비전위화되면서 부식전류밀도는 더 높게 배류된다. 3) 동 및 Al-Ni bronze에 대한 $62\%$ LiBr 수용액 중에서의 양극분극은 활성태로 지속되지만, 천연해수 중에서의 양극분극은 활성태가 지속되다가 부동태화전류가 나타난다.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2002년도 춘계학술대회논문집
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• pp.147-152
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• 2002

This paper was studied on corrosion of heat exchanger tube for absorption refrigeration machine. In the 62 % lithium bromide solution at $60^{\circ}C$, polarization test of Cu, Al-brass, 10 % cupro nickel(90-10 % Cu-Ni) and 30 % cupronickel(70-30 % Cu-Ni) tube was carried out. And polarization behavior, polarization resistance characteristics, open circuit potential, anodic polarization of heat exchanger tube for absorption refrigeration machine were considered. The main results are as following: The open circuit potential of Al-brass tube becomes less noble than that of Cu tube, corrosion current density of that becomes lower than Cu tube. The open circuit potential of cupronickel tube is more noble than that of Cu tube, corrosion current density of that is controlled than Cu tube. The passivation critical current of 30 % Cu-Ni tube is lower than that of 10 % Cu-Ni tube, potential of passive region of that is more wide than 10 % Cu-Ni tube.

• Current Photovoltaic Research
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• 제5권4호
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• pp.105-108
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• 2017

The reactive ion etching (RIE) technology which enables nano-texturatization of surface is applied on monocrystalline silicon solar cell. The additional RIE process on alkalized textured surface further improves the blue response and short circuit current. Such parameter is characterized by surface reflectance and quantum efficiency measurement. By varying the RIE process time and matching the subsequent processes, the absolute efficiency gain of 0.13% is achieved. However, the result indicates potential efficiency gain could be higher due to process integration. The critical etch process time is discussed which minimizes both front surface reflectance and etching damage, considering the challenges of required system throughput in industry.

• 한국가스학회지
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• 제6권1호
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• pp.92-97
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• 2002

가스흡수식 냉온수기의 작동매체로 사용되고 있는 LiBr 수용액 중에서 열교환기 세관용 재료인 동 세관 및 동합금재인 큐프로니켈 세관의 부식특성에 관한 연두를 하기 위하여 $62\%$ LiBr 수용액 중에서 각 재료에 대한 전기화학적 분극실험을 실시하여 부식특성을 고찰한 결과 다음과 같은 결론을 얻었다 1) 열교환기 세관재의 분극저항은 $30\%$ 큐프로니켈 세관 > $10\%$ 큐프로니켈 세관 > 동 세관의 순으로 높게 나타난다 2) 큐프로니켈 세관의 개로전위는 동 세관보다 귀전위화되면서 부식전류밑도는 더 억제된다 3) $30\%$ 큐프로니켈 세관의 부동태 영역은 $10\%$ 큐프로니켈 세관보다 전위구간이 더 크게. 나타나면서 부동태유지 전류밀도는 더 낮아진다.

• Corrosion Science and Technology
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• 제23권4호
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• pp.310-314
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• 2024

The corrosion behavior of high chromium white cast iron was studied in 0.5 mol dm^-3 H₂SO₄ + 0.01 mol dm^-3 HCl solution over time through electrochemical and immersion experiments. Potentiodynamic and potentiostatic polarizations revealed active-passivation transition behavior, with critical current densities observed at -0.27 V_SSE and 0.00 V_SSE, repectively. The former potential showed preferential dissolution of primary γ phases, while the latter one showed preferential dissolution of eutectic γ phases. Immersion tests showed an exponential increase in corrosion rate, with significant acceleration observed around 1000 seconds due to the onset of eutectic γ phase dissolution. Over a 24-hour immersion period, both γ phases exhibited extensive corrosion, leaving carbides largely intact. These findings elucidate distinct corrosion behaviors of high chromium white cast iron in acidic environments, providing critical insights into material performance evaluation. Understanding these mechanisms is essential for predicting the longevity and durability of materials in corrosive conditions, thereby informing better material design and application strategies.

• Tribology and Lubricants
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• 제31권3호
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• pp.79-85
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• 2015

RC delay is a critical issue for achieving high performance of ULSI devices. In order to minimize the RC delay time, we uses the CMP process to introduce high-conductivity Cu and low-k materials on the damascene. The low-k materials are generally soft and fragile, resulting in structure collapse during the conventional high-pressure CMP process. One troubleshooting method is electrochemical mechanical polishing (ECMP) which has the advantages of high removal rate, and low polishing pressure, resulting in a well-polished surface because of high removal rate, low polishing pressure, and well-polished surface, due to the electrochemical acceleration of the copper dissolution. This study analyzes an electrochemical state (active, passive, transpassive state) on a potentiodynamic curve using a three-electrode cell consisting of a working electrode (WE), counter electrode (CE), and reference electrode (RE) in a potentiostat to verify an electrochemical removal mechanism. This study also tries to find optimum conditions for ECMP through experimentation. Furthermore, during the low-pressure ECMP process, we investigate the effect of current density on surface roughness and removal rate through anodic oxidation, dissolution, and reaction with a chelating agent. In addition, according to the Faraday’s law, as the current density increases, the amount of oxidized and dissolved copper increases. Finally, we confirm that the surface roughness improves with polishing time, and the current decreases in this process.

• Journal of Advanced Marine Engineering and Technology
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• 제21권5호
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• pp.535-541
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• 1997

The effect of concentration of each solution( HCI, $H_2SO_4$ and $HNO_3$), scan rate and polished surface condition on the corrosion of AISI 304 Stainless Steel were investigated, utilizing the Method ASTM G5 - 87. It can be concluded that: 1) For the same concentration(i.e. 1N) of each solution the corrosion rate is the highest in HCI and lowest in $HNO_3$. Also, the difference of values of $i_{cirt}$ generated for each solution is significant. 2) As the concentration of the solution $H_2SO_4$ is increased (O.5N, 1N, 2N) the values of $E_{cor}$ $i_{crit}$ and $i_{p}$ are increased. 3) In case of existence of SCN ion of O.OlN, the values of iCTIt and ip generated are approximately 100 times and 1.4 times higher respectively, than in the case of non - existence of $SCN^{-}$. However the existence of $SCN^{-}$ doesn't affect the value of $E_{cor}$ and $E_{p}$. 4) The values of $i_{crit}$ and $i_{p}$ are increased due to the increase of scan rate. But the values of $E_{cor}$ and $E_{p}$ do not depend on the scan rate. 5) The $i_{p}$ value depends greatly on oxygen in the solution, but the changes in values of $E_{cor}$ $i_{crit}$ and $E_{b}$ due to the oxygen are insignificant. 6) If a component is polished using #400, #600 and #800 wet polish paper, the effect of surface condition on variations of values of $i_{crit}$ and $i_{p}$ is slightly significant.

• 한국진공학회지
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• 제15권1호
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• pp.89-96
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• 2006

최근 미세전자 소자에서 초고집적, 적층구조 추세는 선폭이 $0.25{\mu}m$ 이하까지 소형화되고 있는 실정이다. 이러한 미세화는 박막배선에서 높은 전류밀도를 초래하게 된다. 높은 전류밀도 하에서는 엘렉트로마이그레이션에 의한 결함발생이 미세전자 소자에서의 치명적인 문제점의 하나로 대두되고 있다. 본 연구는 Ag, Cu, Au, 그리고 Al 박막 등에서 엘렉트로마이그레이션 특성을 조사함으로써 박막배선 재료를 개선하기 위한 것이다. 고전기전도도를 갖고 있는 Ag, Cu, Au, 그리고 Al 박막배선에서 엘렉트로마이그레이션에 대한 저항 특성을 결함발생 시간 분석으로부터 활성화 에너지를 측정함으로써 조사하였다. 광학현미경 그리고 XPS 분석이 박막에서의 결함분석에 사용되었다. Cu 박막이 엘렉트로마이그레이션에 대해 상대적으로 높은 활성화 에너지를 보였다. 따라서 Cu 박막이 높은 전류빌도 하에서 엘렉트로마이그레이션에 대한 높은 저항성이 요구되는 차세대 미세전자 소자에서 적합한 박막배선 재료로서의 가능성을 갖는 것으로 판단된다. 보호막 처리된 Al 박막은 평균수명 증가, 엘렉트로마이그레이션에 대한 저항 특성 향상을 나타내며 이는 보호막 층과 박막배선 재료 계면에서의 유전 보호막 효과에 기인하는 것으로 사료된다.