• 대한전자공학회논문지
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• 제21권6호
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• pp.64-69
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• 1984

Al-MIS(p-Si)태양전지의 최대 효율은 Al 박막을 0.6A/sec 이하의 속도로 증착시켜 80Å인 두께가 되었을 때임을 알았다. ZnS와 SiO로 AR coating을 했는데, 단층 피막일때는 각각 570Å과 690Å인 박막 두께에서 최대 Isc를 나타냈다. 이는 quarter-coating 조건인 n1d1=λ/4를 만족함을 알았다. 이중층 피막일 때는 한 층을 단층 피막때의 최적 두께를 유지하면서 다른 한 층을 조절했다. 이때의 최대 Isc는 단층피막일 때와 비슷한 값이었으나 넓은 범위의 두께에서 그 값이 그대로 유지되었다. 한편 dzns/ds10=1.9/2.3=570/690인 관계를 유지하면서 총 두께를 각각의 단층피막때의 최적 두께 합에 대해서 70∼90%로 얇게 했을 때 앞에서 논의한 어떤 경우보다도 20%이상의 더 높은 Isc를 얻을 수 있었다 따라서 높은 효율을 얻으면서 정밀한 두께 조절이 불필요한 새로운 AR coating방법을 얻었다.

• 한국표면공학회지
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• 제35권1호
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• pp.17-32
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• 2002

Electroplating methods by molten salts and non-aqueous melts were employed for aluminium coating on STS 316L stainless steel. After coated with Ni or non-coated surface on stainless steel, Al pulse plating was carried out in two different types of electrolytes at room temperature. The Al layer from $AlCl_3$-TMPAC melts could not obtain appreciable thickness for engineering application due to chemical reactions between deposits and moisture of air. However, The Al coating by pulse plating in the Ethylbenzene-Toluene-$AlBr_3$ systems was found to be solid coating layer with a few $\mu\textrm{m}$ scale. The conductivity of Ethylbenzene-Toluene-$AlBr_3$ electrolyte was as functions of time and agitation. By seven days exposure after mixing of the electrolyte, Al-deposited layer shows uniform and near by pore-free with high current density (higher than 30mA/$\textrm{cm}^2$). The roughness and imperfection of coating layer were decreased with a increasing agitation speed. It was found that the optimum condition for the Al pulse plating on the 316L stainless steel was a 400mA peak current, duty cycle, $t_{on}$ $t_{ off}$=3ms/1ms, and a current density of 30mA/$\textrm{cm}^2$.

• 한국세라믹학회지
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• 제29권8호
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• pp.667-673
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• 1992

The alumina-zirconia composite powders of core particle ZrO2 coated with Al2O3 were prepared by the hydrolysis-deposition of the mixed aluminum salt solution of Al2(SO4)3-Al(NO3)3-Urea. The effects of hydrolysis reaction and coating parameters on characteristics of coated powders and composites were also investigated. The degree of coating could be estimated from the ratio of tetra-/mono-ZrO2 present at the room temperature after heat-treating coated powders at 120$0^{\circ}C$ and the result of TEM observations. When the content of ZrO2 in the dispersed coating system, the coating time, and the volume ratio of water/solution were 50 mg/g, 180 min, and 5, respectively the coating efficiency was maximum (the ratio of tetra-/mono-ZrO2 was 87/13). The relative densities of coated Al2O3-ZrO2 composites sintered at 1$650^{\circ}C$ for 4 hrs were about 91~98% and the maximum ratio of tetra-/mono-ZrO2 in Al2O3-20wt% ZrO2 composites was 62/38.

• Corrosion Science and Technology
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• 제23권2호
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• pp.113-120
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• 2024

An attempt was made to apply digital image correlation (DIC) strain analysis to in-situ scanning electron microscopy (SEM) observations of bending deformation to quantify local strain distribution inside a ZnMgAl-alloy coating in deformation. Interstitial-free steel sheets were hot-dipped in a Zn-3Mg-6Al (mass%) alloy melt at 400 ℃ for 2 s. The specimens were deformed using a miniature-sized 4-point bending test machine inside the SEM chamber. The observed in situ SEM images were used for DIC strain analysis. The hot-dip ZnMgAl-alloy coating exhibited a solidification microstructure composed of a three-phase eutectic of fine Al (fcc), Zn (hcp), and Zn2Mg phases surrounding the primary solidified Al phases. The relatively coarsened Zn₂Mg phases were locally observed inside the ZnMgAl-alloy coating. The DIC strain analysis revealed that the strain was localized in the primary solidified Al phases and fine eutectic microstructure around the Zn₂Mg phase. The results indicated high deformability of the multi-phase microstructure of the ZnMgAl-alloy coating.

• Tribology and Lubricants
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• 제34권6호
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• pp.284-291
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• 2018

Ball-milling for reactant powders in advance and using an induction heating system for Ni-Al intermetallic coating process are known to enhance the reactivity of combustion synthesis. In this work, the effects of the charging weight ratio of ball to powder in ball-milling for reactant Ni-Al powders and the synthesizing temperature in induction heating on sliding wear behavior of the coating layers are investigated. Sliding wear behavior of the coating layers is examined against a tool steel using a pin-on-disc type sliding wear machine. As results, wear of the coating layer ball-milled without ball was severely worn out at the sliding speed of 2m/s, regardless of the synthesizing temperature in induction heating. However, the wear rate of the coating layers at the sliding speed was remarkably decreased with increasing the charging weight ratio of ball in ball-milling for reactant powders. This can be explained by the fact that the void in the coating layer is disappeared and the coating layer is densified by the ball-milling. The evidence showed that pitting damages were disappeared on the worn surface of ball-milled coating layer. Consequentially, the Ni-Al intermetallic coating layer could have better wear resistance at all sliding speed ranges with the ball-milling for reactant powders in advance.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 추계학술발표강연 및 논문개요집
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• pp.226-226
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• 2003

The Commercial LiCoO$_2$ particles, which were 7.7${\mu}{\textrm}{m}$ in average diameter, were coated with $Al_2$O$_3$ by a gas suspension spray coating method. The coating amount of $Al_2$O$_3$ on the surface of LiCoO$_2$ was varied from 0.1 to 2 wt.% and compared their electrochemical characteristics with those of bare LiCoO$_2$. $Al_2$O$_3$ coating on the surface of LiCoO$_2$ increased surface area and electrical conductivity, and showed the better cycle and thermal stability even at the higher voltage. The observed optimum A1$_2$O$_3$ coating amount that exhibited the highest capacity retention was 0.2 wt.%.

• 한국주조공학회지
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• 제15권4호
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• pp.360-367
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• 1995

Effects of metal coating treatment on SiC particle on wetting behavior and interfacial strength were studied. Experimental variables are included types of coated metallic films such as Cu and Ni-P, and temperatures of heat-treatment under vacuum. The experimental results concerning wetting phenomena of liquid Al on SiC, showed that coating treatment of metallic film on SiC particles remarkably improves the wetting behavior of liquid Al on SiC, especially in the case of Ni-P coating. The interfacial strength of Al/SiC composites made of coated SiC plate was higher than that of the composite with non-coated SiC plate although the coating treatment was not perfect.

• 한국재료학회지
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• 제18권5호
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• pp.241-246
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• 2008

Pure Mg and Mg-6wt.%Al alloy were coated by the plasma electrolytic oxidation with various coating times and the microstructural and mechanical characteristics of the coatings were investigated. The coatings on pure Mg and Mg-6wt.%Al alloy consisted of MgO and $Mg_2SiO_4$. The surface roughness and thickness of the coatings became larger as the coating time increased. The coatings on the Mg-6wt.%Al alloy were more uniform and thicker than those on pure Mg. The microhardness and friction coefficient of the coatings increased progressively as the coating time increased. In addition, the coatings on the Mg-6wt.%Al alloy compared to pure Mg showed improved microhardness and a better friction coefficient.

• 한국양식학회지
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• 제16권2호
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• pp.76-83
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• 2003

본 연구에서는 상향류식 연속 역세여과 연구를 통하여 양어장 순환수 처리 후 박테리아 및 바이러스 등을 효과적으로 처리하는 기술 개발과 여과사에 금속염을 코팅시켜 생물막의 형성을 도모하는 연구를 수행하였다. 여과사를 코팅한 경우 중성 pH에서 zeta potential 양(+)이 됨을 알 수 있었고 zeta potential이 양(+)에 근접할수록 column test에서 바이러스 제거효율이 증가함을 알 수 있었다. 따라서 여과사를 금속염으로 코팅을 하는 경우가 안한 경우 보다 음이온을 띤 부유물 제거에 탁월한 효능이 있음을 보여주었다. pH에 따른 여과재료의 흡착율에서 Al coating과 Al+Fe coating은 반응 시간 30분까지 효과적으로 흡착이 일어나는 것을 볼수 있었고 이 후의 반응시간에서 파과 곡선형태를 보여주었다. 회분식 형태로 운영한 여과재료를 이용한 탈착실험에서 Non, Al, Fe및 Al+Fe coating모두에서 pH 9.95에서 용출(leaching)되는 농도가 가장 높았으며 각각의 농도는 7.47, 4.80, 20.89 및 7.23 mg/L로 각각 나타났다. 이번 연구에서 Al coating의 경우 pH에 따른 영향은 거의 나타나지 않았으며, pH가 증가함에 따라 약간 감소하는 것을 알수 있었고 Fe coating에서는 pH의 영항이 없었으며, Al+Fe coating에서는 pH가 증가함에 따라 탁도도 역시 일정하게 증가하는 것으로 나타났다.

• Journal of Electrochemical Science and Technology
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• 제7권4호
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• pp.263-268
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• 2016

This study describes the effect of coating the $Li[Ni_{0.8}Co_{0.15}Al_{0.05}]O_2$ cathode surface with a homogeneous carbon layer produced by carbonization of polyvinylidene fluoride (PVDF) as a novel organic source. The phase integrity of the above cathode was not affected by the carbon coating, whereas its rate capability and cycling performance were enhanced. Similarly, the cathode thermal stability was also improved after coating, which additionally protected the cathode surface against the reactive electrolyte containing hydrofluoric acid (HF). The results show that coating the $Li[Ni_{0.8}Co_{0.15}Al_{0.05}]O_2$ cathode with carbon using the PVDF precursor is an effective approach to enhance its electrochemical properties.