• 한국표면공학회지
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• 제13권4호
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• pp.211-220
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• 1980

Internal stress of electrodeposited metals affect physical and mechanical characteristics of deposits. Internal stress of nickel deposits was reviewed intensively. Important outcomes are as follows. Substrate have an important effect on internal stress of electrodeposit. Origin of its internal stress could be explained mismatch of crystal lattice and coalescence of crystallites. When surface cleaning is not satisfying, instantaneous stress is low but the electrodeposited layer being thickened increasingly stress become to high and peeling phenomenon occurs. Effect of current density and temperature on internal stress is variable. Internal stress increases rapidly at pH 5 and above because of codepositing colloidal materials caused hydrolysis. Concentrations of nickel ion and $H_3BO_3$ ion affect little on internal stress and solution which contains impurities tend to increase stress. Especially impurities of $H_2O_2$ and iron ion have a great effect on internal stress. Additives are divided in two kind. One is increasing tensile stress another is increasing compressive stress. Concentrations of additives have a great effect on internal stress.

• 식물조직배양학회지
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• 제22권5호
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• pp.277-281
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• 1995

칼슘이온의 농도가 Arabidopsis thaliana의 원형질체배양에 미치는 영향을 조사하기 위해 Arabidopsis thaliana의 원형질체를 분리하여 서로 다른 농도의 CaCl$_2$를 첨가한 IMH 배지에서 배양하면서 나타나는 현상을 관찰하였다. 대조군과 12.5 mM 이하의 농도에서는 배양세포들이 심하게 액포화되었으며 세포분열은 관찰되지 않았다. 0-50 mM 범위의 농도에서는 농도의 증가와 비례하여 세포의 액포화가 적었으며 이에 반하여 plasma rich cell의 비율은 높아졌다. 세포분열의 유도는 25 mM 이상의 농도에서 관찰되었고 50mM에서 가장 높은 평판효율(5-6%)을 나타내었다. 그러나 100 mM 이상의 농도에서는 뚜렷한 저해효과를 나타내었다. 칼슘이온의 투여 시기가 세포분열과 콜로니 형성과정에 미치는 영향을 조사하기 위하여 서로 다른 농도의 칼슘이온을 각각 원형질체 분리용액과 배양액에 투여하고 배양한 결과, 투여 시기에 따른 영향은 콜로니의 형성과정에 다소 차이를 보였다. 이처럼 높은 칼슘 농도가 원형질체 배양시 요구되는 것은 원형질체가 배지로부터 생장조절물질을 흡수하여 재분화하는 과정에서 칼슘이온이 중요한 조절작용을 하기 때문인 것으로 추측된다.

• Journal of Advanced Marine Engineering and Technology
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• 제20권5호
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• pp.103-113
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• 1996

The properties of the deposited film depend on the deposition condition and these, in turn depend critically on the morphology and crystal orientation of the films. Therefore, it is important to clarify the nucleation occurrence and growth stage of the morphology and orientation of the film affected by deposition parameters, e.g. the gas pressure and bias voltage etc. In this work, magnesium thin flims were prepared on cold-rolled steel substrates by a thermo-eletron activation ion plating technique. The influence of nitrogen gas pressure and substrate bias voltage on their crystal orientation and morphology of the coated films were investigated by scanning electron microscopy (SEM) and X-ray diffraction, respectively. The diffraction peaks of magnesium film became less sharp and broadened with the increase of nitrogen gas pressure. With an increase in nitrogen gas pressure, flim morphology changed from colum nar to granular structure, and surface crystal grain-size decreased. The morphology of films depended not only on gas pressure but also on bias voltage, i.e., the effect of increasing bias voltage was similar to that of decreasing gas pressure. The effect of crystal orientation and morphology of magnesium films on corrosion behaviors was estimated by measuring anodic polarization curves in deaerated 3%NaCl solution. Magnesium, in general, has not a good corrosion resistance in all environments. However, these magnesium films prepared by changing nitrogen gas pressure showed good corrosion resistance. Among the films, magnesium films which exhibited granular structure had the highest corrosion resistance. The above phenomena can be explained by applying the effects of adsorption, occlusion and ion sputter of nitrogen gas.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.357-360
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• 2000

Biosorption process is an economic and potential process for metal sequestering from the water. The oxidized Undaria pinnatifida by nitric acid had high uptake capacity for heavy metals of 4 - 6 meq / g dry mass. For the application of oxidized Undaria pinnatifida, recovery of metal in plating wastewater was studied. The uptake capacity of the oxidized Undaria pinnatifida was high compared to the ion exchanger IR-120 plus. The treatment efficiency of chromium and copper in the wastewater was 85% In batch. Activated carbon was used to assist the recovery of water by removing organic matters of the wastewater.

• 한국정밀공학회지
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• 제18권8호
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• pp.11-17
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• 2001

Industrial use of physical vapor deposition(PVD) has been widely expanded during last two decades, and in the mean time plasma assistance in PVD has become an essential tool in preparing compound films with dense microstructure. The principles of electron beam-based plating, balanced and unbalanced magnetron sputtering and cathodic arc deposition. consisting three basic configuration of plasma assisted PVD(PAPVD)process, were reviewed. Recent technical development in PVD coating process were discussed. This paper tries to show tendency for developing new coating film on cutting tools.

• 한국진공학회지
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• 제6권S1호
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• pp.133-136
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• 1997

In this paper multi-arc plasma plating film equipment Bulat-6 and its technical characteristics were analyzed in detail. This machine is the first of its kind in China. Influential factors and reducing methods on microdroplets of titanium were investigated. By method of electromagnetic field control and ion beam enhanced deposition excellent titanium nitride film could be obtained. Bicrohardness and adhesion were 250Mpa and 6.5Kg respectively.

• 한국재료학회지
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• 제11권4호
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• pp.324-328
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• 2001

아크이온 플레이팅 장치를 이용하여 STD61강 기판 위에 이온질화 전처리를 행하거나 하지 않은 후, CrN 박막을 증착하고, 대기중 $700~900^{\circ}C$의 온도에서 40시간동안 이들에 대한 산화거동을 연구하였다. 산화거동은 열중량분석기, X선회절기, EDS, SEM을 이용하여 조사하였다. 증착된 CrN박막은 CrN과 $Cr_2$N의 두 상으로 구성되어 있었다. CrN박막은 보호적 $Cr_2$O$_3$층을 형성하여 기판을 산화로부터 보호하였다. 이온질화처리는 CrN박막의 내산화성에 영향을 주지 않았다.

• 청정기술
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• 제17권2호
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• pp.103-109
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• 2011

전기도금의 seed layer를 형성하는 무전해 동도금 공정의 throwing power (TP)와 두께 편차를 개선하기 위한 공정 최적화 방법을 제시하였다. 실험계획법 (DOE)을 이용하여 가능한 모든 공정 인자들 가운데 TP와 두께 편차에 가장 큰 영향을 미치는 주요 인자를 파악해 보았다. 균일성을 가진 via filling을 위해서는 도금액 내의 Cu 이온의 농도를 높여주고 도금 온도를 낮추어 주는 것이 바람직한 것으로 판단되었으며 이는 표면 반응성의 측면에서 설명되었다. Kinetic Monte Carlo (MC) 모사가 이를 시각화하기 위해 도입되었으며 실험에서 관찰된 현상을 정성적으로 무리 없이 설명할 수 있었다. 실험계획법을 이용한 체계적인 실험과 이를 뒷받침하는 이론적인 모사가 결합된 본 연구의 접근법은 관련 공정에서 유용하게 활용될 수 있을 것이다.

• 한국표면공학회지
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• 제49권6호
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• pp.580-586
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• 2016

Cr-Si-Al-N coating with different Si content were deposited by hybrid physical vapor deposition (PVD) method consisting of unbalanced magnetron (UBM) sputtering and arc ion plating (AIP). The deposition temperature was $300^{\circ}C$, and the gas ratio of $Ar/N_2$ were 9:1. The CrSi alloy and aluminum targets used for arc ion plating and sputtering process, respectively. Si content of the CrSi alloy targets were varied with 1 at%, 5 at%, and 10 at%. The phase analysis, composition and microstructural analysis performed using x-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) including energy dispersive spectroscopy (EDS), respectively. All of the coatings grown with textured CrN phase (200) plane. The thickness of the Cr-Si-Al-N films were measured about $2{\mu}m$. The friction coefficient and removal rate of films were measured by a ball-on-disk test under 20N load. The friction coefficient of all samples were 0.6 ~ 0.8. Among all of the samples, the removal rate of CrSiAlN (10 at% Si) film shows the lowest values, $4.827{\times}10^{-12}mm^3/Nm$. As increasing of Si contents of the CrSiAlN coatings, the hardness and elastic modulus of CrSiAlN coatings were increased. The morphology and composition of wear track of the films was examined by scanning electron microscopy (SEM) and energy dispersive spectroscopy, respectively. The surface energy of the films were obtained by measuring of contact angle of water drop. Among all of the samples, the CrSiAlN (10 at% Si) films shows the highest value of the surface energy, 41 N/m.

• 전기화학회지
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• 제25권3호
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• pp.113-118
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• 2022

본 연구에서는 polyethylene glycol (PEG)이 구리전해도금에 미치는 영향을 cyclic voltammetry를 이용해 분석해보았다. PEG의 흡착은 함께 존재하는 음이온의 특이흡착에 따라 변화되었다. 가장 일반적인 도금액 성분인 sulfate 이온(SO₄^2-)이 존재하는 경우, PEG의 흡착이 억제되었으며 그로 인해 미약한 억제 효과가 관찰되었다. 실제로 도금액이 SO₄^2- 없이 특이흡착하지 않는 perchlorate 이온(ClO₄^-)으로만 이뤄진 경우, PEG는 도금 반응을 강하게 억제하였으며 억제 효과는 PEG의 분자량에 비례하여 나타났다. 반면, 염소 이온(Cl^-)의 특이흡착이 존재하는 경우 오히려 PEG의 억제 효과는 강화되었다. RDE 분석을 통해 강한 억제 효과는 PEG와 Cl^-간의 흡착구조체 형성에 의한 것임을 확인하였으며, 이러한 흡착 구조체 형성은 용액 조성에 따라 달라지는 특성을 나타내었다. 특히, 소수성 특성이 증가된 PEG 유도체의 경우 억제 효과가 더욱 강화되는 것으로 미루어, PEG와 Cl^-간의 흡착 구조체 형성에 PEG의 소수성 특성이 중요함을 확인하였다.