• 전기화학회지
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• 제5권3호
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• pp.125-130
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• 2002

다공성 그물구조 금속을 반도체 칩 방열재료로써 활용하기 위한 실험을 실시하였다. 이를 위해 다공성 그물구조 구리와 반도체 칩 사이의 열팽창 차이를 최소화하기 위한 시도로써 다공성 구리에 대한 Fe/Ni 합금전착을 수행하였다. Fe/Ni 합금전착 실험으로 표준 Hull Cell을 구성하고 전류밀도 분포에 따른 Fe/Ni 합금층 내의 조성변화를 관찰하였으며, 실험결과 합금전착시 이상공석현상으로 인하여 전해액의 교반정도에 따라 합금층 조성이 크게 영향을 받는 것으로 나타났다. 본 실험에서는 paddle type 교반기를 사용하여 전해질의 확산을 제어하는 방법으로 원하는 조성의 Fe/Ni 합금층을 얻을 수 있었으며, 얻어진 Fe/Ni 후막을 대상으로 TMA 열분석을 실시한 결과 구리에 비해 훨씬 낮은 열팽창율을 보이는 것으로 나타났다. 또한, 본 실험에서 Fe/Ni 합금전착을 통하여 제작한 다공성 그물구조 금속을 대상으로 방열성능을 측정한 결과 구리 평판 대비 최대 2배 이상의 방열성능을 보여 반도체 칩 방열재료로의 활용 가능성을 높여 주었다.

• 한국분말재료학회지
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• 제8권3호
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• pp.157-162
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• 2001

An optimum route to fabricate the ferrous alloy dispersed $Al_2O_3$ nanocomposites such as $Al_2O_3$/Fe-Ni and $Al_2O_3$/Fe-Co with sound microstructure and desired properties was investigated. The composites were fabricated by the sintering of powder mixtures of $Al_2O_3$ and nano-sized ferrous alloy, in which the alloy was prepared by solution-chemistry routes using metal nitrates powders and a subsequent hydorgen reduction process. Microstructural observation of reduced powder mixture revealed that the Fe-Ni or Fe-Co alloy particles of about 20 nm in size homogeneously surrounded $Al_2O_3$, forming nanocomposite powder. The sintered $Al_2O_3$/Fe-Ni composite showed the formation of Fe$Al_2O_4$ phase, while the reaction phases were not observed in $Al_2O_3$/Fe-Co composite. Hot-pressed $Al_2O_3$/Fe-Ni composite showed improved mechanical properties and magnetic response. The properties are discussed in terms of microstructural characteristics such as the distribution and size of alloy particles.

• 대한화학회지
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• 제56권4호
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• pp.448-458
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• 2012

In order to develop alloy resistance in aggressive sulphat ion, the corrosion behavior of metallic glasses $Ni_{92{\cdot}3}Si_{4.5}B_{32}$, $Ni_{82,3}Cr_7Fe_3Si_{4.5}B_{3.2}$ and $Ni_{75.5}Cr_{13}Fe_{4.2}Si_{4.5}B_{2.8}$ (at %) at different concentrations of $H_2SO_4$ solutions was examined by electrochemical methods and Scanning Electron Microscope (SEM) and X-ray Photoelectron Microscopy (XPS) analyses. The corrosion kinetics and passivation behavior was studied. A direct proportion was observed between the corrosion rate and acid concentration in the case of $Ni_{92{\cdot}3}Si_{4.5}B_{32}$ and $Ni_{75.5}Cr_{13}Fe_{4.2}Si_{4.5}B_{2.8}$ alloys. Critical concentration was observed in the case of $Ni_{82,3}Cr_7Fe_3Si_{4.5}B_{3.2}$ alloy. The influence of the alloying element is reflected in the increasing resistance of the protective film. XPS analysis confirms that the protection film on the $Ni_{92{\cdot}3}Si_{4.5}B_{32}$ alloy was NiS which is less protective than that formed on Cr containing alloys. The corrosion rate of $Ni_{82,3}Cr_7Fe_3Si_{4.5}B_{3.2}$ and $Ni_{75.5}Cr_{13}Fe_{4.2}Si_{4.5}B_{2.8}$. alloys containing 7% and 13% Cr are $7.90-26.1{\times}10^{-3}$ mm/y which is lower about 43-54 times of the alloy $Ni_{92{\cdot}3}Si_{4.5}B_{32}$ (free of Cr). The high resistance of $Ni_{75.5}Cr_{13}Fe_{4.2}Si_{4.5}B_{2.8}$ alloy at the very aggressive media may due to thicker passive film of $Cr_2O_3$ which hydrated to hydrated chromium oxyhydroxide.

• 한국수소및신에너지학회논문집
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• 제27권6호
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• pp.636-641
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• 2016

Alkaline water electrolysis is commercial hydrogen production technology. It is possible to operate MW scale plant. Because It used non-precious metal for electrode. But It has relatively low current density and low efficiency. In this study, research objective is development of anode for alkaline water electrolysis with low cost, high corrosion resistance and high efficiency. Stainless steel 316L (SUS 316L) was selected for a substrate of electrode. To improve corrosion resistance of substrate, Nickel (Ni) layer was electrodeposited on SUS 316L. Ni-Fe alloy was electrodeposited on the passivated Ni layer as active catalyst for oxygen evolution reaction(OER). We optimized preparation condition of Ni-Fe alloy electrodeposition by changing current density, electrodeposition time and composition ratio of Ni-Fe electrodeposition bath. This electrodes were electrochemically evaluated by using Linear sweep voltammetry (LSV) and Cyclic voltammetry (CV). The Ni-Fe alloy (Ni : Fe = 1 : 1) showed best activity of OER. The optimized electrode decreased overpotential about 40% at $100mA/cm^2$ compared with Ni anode.

• 한국군사과학기술학회지
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• 제14권6호
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• pp.1018-1025
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• 2011

The improved properties of corrosion for 90Cu10NiFe alloy in natural seawater were explained by sodium diethyl dithio carbamate(NaDDC), namely organic compound, which is reagent for heavy metal extractions of waste water. The efficiency of NaDDC as corrosion inhibitor for 90Cu10NiFe alloy has been investigated in seawater after immersion in various concentrations of NaDDC solutions for 12~36hrs at pH 8.2 by weight loss test and electrochemical techniques including potentiodynamic polarization and SEM-EDS measurements. The results showed that the corrosion resistance of 90Cu10NiFe alloy improves with the increasing concentration of NaDDC but it did not improves with increasing time any more, so the highest inhibition efficiency was 93% at 100mg/L, 36hrs. The results obtained from weight losses and corrosion rates in polarization curve measurements were in good agreement. Therefore, it showed that NaDDC is a good inhibitor for copper corrosion of 90Cu10NiFe alloy.

• 한국재료학회지
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• 제10권6호
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• pp.392-397
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• 2000

Fe-30Ni-0.35C 합금과 몇가지 저융점 순금속의 상변태에 미치는 압력의 영향에 대하여 PDSC를 이용하여 조사하였다. Fe-30Ni-0.35C 합금의 오스폼트 마르텐사이트 및 마르폼드 마르텐사이트 오스테나이트로 역변태시 압력이 1 기압에서 60기압으로 증가하에 따라. $A_s$점이 약 $2~4^{\circ}C$ 저하하며, 이것은 상전이시의 체적변화가 음의 값이 되기 때문이다. 또한 $A_f$ 점은 압력이 증가함에 따라 변함없이 일정하거나 매우 미소한 상승을 나타내는데, 이것은 압력이 증가할수록 탄화물의 석출이 촉진되기 때문이다. Fe-30Ni-0.35C 합금의 오스폼드 마르텐사이트의 역변태시 엔탈피변화는 압력이 1 기압에서 60기압으로 상승함에 따라 10~14J/g 증가한다. 순금속 Se, Sn, Pb, Zn, Te 등의 용융점은 압력이 1기압에서 60기압으로 증가함에 따라 매우 완만하게 상승하며, 용융시의 엔탈피변화는 압력의 증가에 따라 거의 변화가 없거나 미소 증가를 나타낸다.

• 한국분말재료학회지
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• 제9권3호
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• pp.161-166
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• 2002

Processing and properties of $Al_2O_3$ composites with Ni-Fe content of 10 and 15 wt% were investigated. Homogeneous powder mixtures of $Al_2O_3$/Ni-Fe alloy were prepared by the solution-chemistry route using $Al_2O_3$, $Ni(NO_3)_2{\cdot}6H_2O$ and $Fe(NO_3)_3{\cdot}9H_2O$ powders. Microstructural observation of composite powder revealed that Ni-Fe alloy particles with a size of 20nm were homogeneously dispersed on $Al_2O_3$ powder surfaces. Hot-pressed composites showed enhanced fracture toughness and magnetic response. The properties are discussed based on the observed microstructural characteristics.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 추계학술대회논문집
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• pp.188-191
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• 2004

Electroforming is a process that employs technology similar to that used for electroplating but which is used for manufacturing metallic articles, rather than as a means of producing surface coatings. Electroforming provides a cost-effective means of producing alloys and fully dense nanocrystalline metals as foils, sheets and complex shapes. It was able to make Fe-Ni foil with $5{\mu}m$ thickness by electroforming. Electroformed Fe-Ni alloy was nanocrystalline and the yield strength was in the range $2000{\sim}2800\;MPa$. The magnetic permeability at high frequency of electroformed Fe-Ni foil was higher than that of thicker foils.

• 한국재료학회지
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• 제13권8호
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• pp.491-496
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• 2003

Fe-Ni alloy nanoparticles were prepared by ERC (Evaporation and Rapid Condensation) method, and the crystal structure and the behavior of martensite for the nanosized alloy particles were investigated by X-ray diffraction analysis. The relation between the rate of martensite transformation and the internal strain of austenite was discussed. The lattice spaces of austenite and martensite for the nanoparticles agreed with those of the bulk materials. The rate of martensite transformation from austenite and the internal strain of austenite was reduced with decreasing the average size of Fe-Ni nanoparticles. It was thought that the residual austenite in the Ni content range of 11∼l5at% was caused by the internal strain, and the residual martensite in the Ni content range of 32∼36at% had its origin in the high surface energy of nanoparticles.

• 한국표면공학회지
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• 제36권6호
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• pp.437-443
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• 2003

The effects of additive(grain refiner, GR) on process efficiency of the Ni-Fe-P alloy electrodeposition and the material properties of the deposit were investigated. Electrochemical properties of the deposits were investigated using polarization and electrochemical impedance techniques, and the material properties of the deposits were characterized through inductively coupled plasma(ICP), spiral contractometer, XRD, SEM and TEM. When the additive was added into the electrodeposition bath, current efficiency, Ni content and corrosion resistance of the deposit increased, whereas residual stress, surface roughness and grain size of the deposit decreased.