• 제목/요약/키워드: Cathodic

검색결과 754건 처리시간 0.025초

Crack free 경질 크롬 도금욕 개발에 관한 연구 (A study on the development of solution for the Crack Free Hard Chromium Deposits)

  • 추현식;이홍로
    • 한국표면공학회지
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    • 제25권4호
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    • pp.181-186
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    • 1992
  • To investigate how to produce the crack free and chromium deposits, bath compositions, additives, electrolysis conditions and other electroplating parameters, such as cathodic current efficiency, surface hard-ness, crack density and corrosion rate of deposits were examined carefully. The crack free chrome deposits were well obtained using both wetting agents and two kind of additives. At 60 A/d$\m^2$, $60^{\circ}C$ electrolysis condition, crack free bright hard chromium deposits were well obtained to a thickness $300\mu\textrm{m}$ in Additive-I and Additive-II added solution.

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염화인-아세트산-숙신산 염 용액에서 납의 전해석출 (Electrodeposition of lead from $PbCl_2$-Acetate-Succinate Solutions)

  • 강탁
    • 한국표면공학회지
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    • 제19권2호
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    • pp.44-50
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    • 1986
  • Effects of cathodic overvoltages on the electrodeposition of lead from electrolyte containing lead chloride, ammonium acetate and sodium succinate was investigated at 20$^{\circ}C$. The use of organic additives, phenol and gelatin was found effective to inhibit the growth of dendritic crystals. At the carthodic overvoltages higher than 0.2V, the lead deposit becames less compact even in the presence of organic additives. The applications of agitation and pulse current promoted compact and shiny deposits.

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콘크리트 중의 철근부식 방지를 위한 외부전원법의 적용 (The Application of Impressed Current System for the Corrosion Control of Reinforcing Steel in Concrete)

  • 문한영;김성수;김홍삼
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1997년도 봄 학술발표회 논문집
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    • pp.197-202
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    • 1997
  • Recently the interest in the reinforcing steel corrosion due to the use of sea-sand and deicing salt, marine environment, and carbonation in RC structures is increasing, therefore the studies on the corrosion control of reinforcing steel in concrete are vigorously proceeding. In this study, from the viewpoint of electrochemical process of steel corrosion in concrete we applied the impressed current system among the cathodic protections to reinforcing steel in concrete and ascertained the protection effect by half-cell potential, corrosion rate, and depolarization.

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리기다소나무의 수용추출액이 무 종자의 발아과정에서 단백질과 동위효소 패턴에 미치는 영향 (Effects of Aqueous Extracts of Pinus rigida on Protein and Isozyme patterns during Radish Germination)

  • 김용옥;이호준
    • The Korean Journal of Ecology
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    • 제21권6호
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    • pp.771-777
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    • 1998
  • Aqueous extracts of Pinus rigida changed the electrophoretic patterns of total proteins and of hydrolytic enzymes such as peroxidase, esterase and amylase during the germination of radish (Raphanus sativus var. hortensis for. acanthiformis). When the extract treatment was finished, at the late stage of radish germination, aqueous extracts of P. rigida had suppressed the expression of 24 KD and 60 KD proteins. the extract induced new isozyme bands, indicating concomitant activity of peroxidases, esterase activities were stimulated in the cathodic region. The activity of amylase was enhanced by the extract.

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Deposition and high temperature oxidation characterization of CrAlSiN thin films

  • Kim, Sun-Kyu;Lee, Dong-Bok
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2007년도 추계학술대회 논문집
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    • pp.7-9
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    • 2007
  • Thin films of CrAlSiN were deposited on SKD11 tool steel substrate using Cr and AlSi cathodes by a cathodic arc plasma deposition system. The influence of process parameters on the deposited film properties were investigated. The oxidation characteristics of the films were studied at temperatures ranging from 800 and 1000+C up to 50 h in air. The films showed superhardness and good oxidation resistance..

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크롬도금의 틈부식 거동에 관한 연구 (A Study on the Crevice Corrosion Behavior of Chromium Plating)

  • 곽남인;임우조
    • 한국표면공학회지
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    • 제36권4호
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    • pp.324-328
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    • 2003
  • This study was made on the crevice corrosion behavior of chromium plating in fresh water. Under the various crevice, the electrochemical polarization test of chromium plating was carried out. Results are discussed In terms of corrosion potential, polarization resistance, corrosion current density and cathodic control of chromium plating.

Bias voltgae에 따른 TiCrAlSiN 코팅막의 미세구조 분석 (Microstructural Characterization of TiCrAlSiN Thin Films Deposited with Various Bias Voltages)

  • 이재욱;이정용;;김선규
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2007년도 춘계학술발표회 초록집
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    • pp.122-123
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    • 2007
  • Bias voltage를 달리하여 cathodic arc plasma 방법으로 Si 기판 위에 성장시킨 TiCrAlSiN 코팅막의 미세구조를 투과전자현미경으로 관찰하였다. -200 V에서 0 V로 bias voltage가 변화함에 따라 'nano-multilayered' 구조가 무너지면서 '주상형(columnar)'구조로 코팅막의 미세구조가 변함을 알 수 있었고, EDS line scan을 통해 multilayer의 화학적 조성 변화를 확인하였다.

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음극 아크법으로 증착한 ZrO2/Al2O3 박막의 고온특성 (High temperature characteristic of cathodic arc deposited ZrO2/Al2O3 thin films)

  • 이동복;;김선규
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2012년도 춘계학술발표회 논문집
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    • pp.174-175
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    • 2012
  • 음극 아크법으로 증착한 $ZrO_2/Al_2O_3$ 박막의 고온특성을 대기중 $600-900^{\circ}C$에서 50시간동안 노출시킨후 XRD, XPS, AES. SEM, TEM을 이용하여 분석하였다. 증착된 박막은 비정질이었고, 고온에서 가열함에 따라 점차 결정질로 바뀌었다.

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알루미늄으로 제작된 심해 장비의 부식 저항 능력 향상 방법 및 측정 방법 조사 (Study on Methods of Enhancement and Measurement of Corrosion Resistance for Subsea Equipment made of Aluminum)

  • 서영균;정정열
    • 플랜트 저널
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    • 제16권3호
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    • pp.47-52
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    • 2020
  • 본 연구에서는 알루미늄으로 제작된 심해 장비의 부식 저항 능력 향상시키기 위해 알루미늄 부식 방지 방법과 측정방법을 조사하였다. 조사된 부식 방지 방법은 Cathodic Protection(음극화 보호), Conversion Coating, Anodizing, 및 Organic Coating이었다. 그리고 간단하게 조사된 측정 방법은 Scanning Electron Microscope (SEM), Electrochemical Impedance Spectroscopy (EIS), Glow discharge optical emission spectrum spectroscopy (GD-OES), Fourier Transform Infrared Spectroscopy (FT-IR), Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS), Scanning Vibrating Electrode Technique (SVET), Contact Angle(접촉각), Interfacial Tension (경계면 장력)이었다. 알루미늄 부식을 방지하기 위해 널리 사용되는 방법은 Anodizing과 Organic Coating이었으며, 부식 측정을 위해서는 여러 방법들이 골고루 사용되었다. 그 중 많이 사용되는 방법은 표면의 구조를 관찰하 위한 SEM과 부식 저항 능력을 측정하기 위한 접촉각 측정이었다.

귀금속(Au, Rh) 전극계면에서 Langmuir 흡착등온식에 관한 위상이동방법 (The Phase-Shift Method for the Langmuir Adsorption Isotherms at the Noble Metal (Au, Rh) Electrode Interfaces)

  • 천장호;전상규;이재항
    • 전기화학회지
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    • 제6권2호
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    • pp.119-129
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    • 2003
  • The Langmuir adsorption isotherms of the over-potentially deposited hydrogen (OPD H) fur the cathodic $H_2$ evolution reaction (HER) at the poly-Au and $Rh|0.5M\;H_2SO_4$ aqueous electrolyte interfaces have been studied using cyclic voltammetric and ac impedance techniques. The behavior of the phase shift $(0^{\circ}{\leq}{-\phi}{\leq}90^{\circ})$ for the optimum intermediate frequency corresponds well to that of the fractional surface coverage $(1{\geq}{\theta}{\geq}0)$ at the interfaces. The phase-shift profile $({-\phi}\;vs.\;E)$ for the optimum intermediate frequency, i.e., the phase-shift method, can be used as a new electrochemical method to determine the Langmuir adsorption isotherm $({\theta}\;vs.\;E)$ of the OPD H for the cathodic HER at the interfaces. At the poly-Au|0.5M $H_2SO_4$ aqueous electrolyte interface, the equilibrium constant (K) and the standard free energy $({\Delta}G_{ads})$ of the OPD H are $2.3\times10^{-6}$ and 32.2kJ/mol, respectively. At the poly-Rh|0.5M $H_2SO_4$ aqueous electrolyte interface, K and ${\Delta}G_{ads}$ of the OPD H are $4.1\times10^4\;or\;1.2\times10^{-2}$ and 19.3 or 11.0kJ/mol depending on E, respectively. In contrast to the poly-Au electrode interface, the two different Langmuir adsorption isotherms of the OPD H are observed at the poly-Rh electrode interface. The two different Langmuir adsorption isotherms of the OPD H correspond to the two different adsorption sites of the OPD H on the poly-Rh electrode surface.