• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.4
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• pp.547-555
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• 2012

This paper focuses on the research of the anode and cathode in the Ni-MH secondary battery. In this paper, the proposed method employs a continuous wave Nd : YAG laser based on the pure Ni instead of the low carbon steel to improve the conductivity although the conventional secondary battery is based on the resistance spot welded with low carbon steel SS41. It welds a sandwich panel using the pure Ni and the porous thin plate, and the tested optimal conditions for the laser power and irradiation speed were 300 and 350 Watt, and 1.0~1.6m/min, respectively. Finally, we observed a ratio, heat input and cross-section and measured the conductivity of the welding section to test the weldability.

• Journal of the Korean Electrochemical Society
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• v.13 no.4
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• pp.270-276
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• 2010

Nickel-copper foam electrodes with pore gradient micro framework and nano-ramified wall have been prepared by using an electrochemical deposition process. Growth habit of nickel-copper co-deposits was quite different from that of pure nickel deposit. In particular, the ramified structure of the individual particles was getting clear with chloride ion content in the electrolyte. The ratio of nickel to copper in the deposits decreased with the distance away from the substrate and the more chloride ions in the electrolyte led to the more nickel content throughout the deposits. Compositional analysis for the cross section of a ramified branch, together with tactical selective copper etching, proved that the copper content increased with approaching central region of the cross section. Such a composition gradient actually disappeared after heat treatment. It is anticipated that the pore gradient nickel-copper nanostructured foams presented in this work might be a promising option for the high-performance electrode in functional electrochemical devices.

• 한국전기화학회:학술대회논문집
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• 1999.10a
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• pp.49-49
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• 1999

• Analytical Science and Technology
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• v.5 no.1
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• pp.97-101
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• 1992

Potentiodynamic corrosion tests were conducted to know the corrosion characteristics of the NiTi intermetallic compound composed of pure Ni and Ti in artificial saline. Tafel extrapolation and linear polarization technique show similar results. Corrosion current Icorr and corrosion rate was increased in the order of NiTi

• Resources Recycling
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• v.22 no.1
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• pp.11-19
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• 2013

Recovery of pure cobalt and nickel from diverse resources is important due to the increased demand for these metals. In order to get cobalt and nickel with high purity, separation of them from other metal ions is necessary. In this review, several methods to obtain pure cobalt or nickel solution, such as solvent extraction, ion exchange, precipitation were introduced and compared. For solvent extraction, the advantage and disadvantage of the separation process together with detailed process conditions were investigated.

• Journal of the Korean Magnetics Society
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• v.15 no.3
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• pp.198-201
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• 2005

We investigated the effects of organic additives on the properties of nickel-copper thin films prepared by electroplating. Compared with thin films fabricated by pure electrolyte only, the films utilizing organic additives show different crystalline orientations. With no alteration of plating conditions simply adding the organic materials changed the composition of copper and nickel. The concentration of nickel could be varied to $65-95\%$ depending on the species and concentration of the additives. The change of material property has contributed to the increase or decrease of the magnetoresistance.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.05a
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• pp.315-316
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• 2012

전기도금법으로 제조한 $Ni-TiO_2$ 복합체에 교반 속도가 전류효율에 미치는 영향을 연구하였다. 교반은 공기를 불어넣은 공기교반과 자석막대를 회전시킨 자석교반으로 나누어 실시하였다. 교반 속도는 공기교반의 경우에는 0.5, 1.0, 1.5 L/min, 자석교반의 경우에는 100, 200, 300, 400, 500 rpm으로 변화시켜 $Ni-TiO_2$ 복합체의 전류효율과 순수 니켈의 전류효율 변화를 관찰하였다. 순수 니켈의 경우 전류효율이 두 종류의 교반 방식 모두, 속도가 높아질수록 다소 감소하였으나, 그 폭이 크지 않았다. 반면, $Ni-TiO_2$ 복합체의 경우에는 교반 속도가 높아지면, 전류효율이 급격히 감소하였다. 특히, 공기교반의 경우에는 1.0L/min에서 1.5L/min으로 교반속도가 증가하면 전류효율이 크게 감소하였다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.263-264
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• 2013

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2014.11a
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• pp.216-218
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• 2014

자동차용 고광택 크롬 도금 박리액에는 질산과 유가금속인 구리 및 니켈이 다량 함유되어 있는 것으로 알려져 있다. 질산($HNO_3$) 및 유가금속은 고가이며 유독하므로 경제적 및 친환경적으로 반드시 회수하여 재활용하여야 한다. 본 연구에서는 도금박리액으로부터 질산과 구리, 니켈을 용매 추출법을 이용하여 분리하였다. 수상에 존재하는 질산의 농도는 0.01 ~ 1N NaOH를 이용하여 적정하여 분석하고, 금속의 농도는 ICP-MS 및 ICP-AES 등을 이용하여 분석하였다. 도금 박리액을 분석한 결과 Cu(76850mg/L), Ni(51990 mg/L)이 함유되어 있음을 알 수 있었다. 용액 내 질산의 양을 NaOH 용액을 이용하여 적정법으로 측정하였을 때, 질산의 양은 대략 1.02 M 임을 알 수 있었다. 50 % Tributylphosphate (TBP)를 이용하여 3단 추출한 유기층의 용액을 증류수를 이용하여 3회의 역추출을 하였을 때, 원액으로부터 48.1 %의 질산을 회수할 수 있음을 알 수 있었으며, 순도는 99.5% 이상이었다. 질산 회수 후 용액 내에 남은 구리와 니켈은 ISE-106로 구리를 추출하여 니켈을 분리한 후 황산을 이용해 역추출 하였다. 회수된 구리는 NaOH를 이용하여 pH를 조절하고 수산화구리 형태로 침전시킨 후 $N_2H_4$를 이용하여 환원시켰고, 온도와 pH 및 환원제를 이용하여 다양한 조건 하에 구리 분말을 제조하였다. 구리를 추출하여 라피네이트 용액으로 분리된 니켈은 $NaBH_4$를 이용하여 환원시켰고, 다양한 조건 하에서 니켈 분말을 제조하였다. 환원 된 분말은 분석결과 99%의 순수한 분말임을 알 수 있었다.

• Journal of the Microelectronics and Packaging Society
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• v.28 no.1
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• pp.67-71
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• 2021

In this study, graphene layer was grown on metal microwire using chemical vapor deposition. The difference of carbon solubility between copper and nickel resulted in the formation of mono-layer and multi-layer graphene were formed on the surfaces of copper and nickel microwires, respectively. During the growth of graphene at high temperature, copper and nickel were recrytallized and the grain size increased. The ampacity of graphene/copper microwire was improved by approximately 27%, 1.91×105 A/㎠, compared to pristine copper microwire. Similar to this behavior, the ampacity of multilayer graphene/nickel microwire was 4.41×104 A/㎠ which is about about 36% improved compared to the pure nickel microwire. The excellent electrical properties of graphene/metal composites are beneficial for supplying the electrical energy to the high-power electronic devices and equipment.