• Journal of the Korean institute of surface engineering
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• v.53 no.6
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• pp.306-311
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• 2020

In this work, diamond-like carbon (DLC) films are coated onto plasma nitrided AISI 4140 steel by DC-pulsed PECVD. One problem of DLC films is their very poor adhesion on steel substrates. The purpose of the nitriding was to enhance adhesion between the substrate and the DLC films. The white layer formation is avoided. Plasma nitriding increased adhesion from 8 N for DLC coating to 25 N for duplex coating. Duplex plasma nitriding/DLC coating was proven to be more effective in improving the adhesion. The purpose of the bond layer was to enhance adhesion between the substrate and the DLC films.

• Journal of the Korean institute of surface engineering
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• v.53 no.6
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• pp.343-350
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• 2020

The degradation of mechanical properties of nitride coatings to steel substrates is one of the main challenges for industrial applications. In this study, plasma nitriding treatment was used in order to increase the mechanical properties of Mo-Cu-N coating to the H13 tool steel. The nanostructured Mo-Cu-N coating was deposited using pulsed DC magnetron sputtering method with a single alloy Mo-Cu target. Mechanical properties of MoN-Cu coated samples after nitriding were found to be relatively better than non-nitrided MoN-Cu coating.

• Korea-Australia Rheology Journal
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• v.18 no.4
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• pp.209-215
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• 2006

Recent research results on viscocapillary models of various pre-metered coating flows such as curtain, slide, and slot coatings have been reviewed in this paper. Such one-dimensional models have been simplified from two-dimensional Navier-Stokes equations for viscous coating flows with free surfaces, using integral momentum balances and lubrication approximation. It has been found that these viscocapillary models is capable of predicting flow dynamics in various coating systems, providing the good agreement with results by 2-D models.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.2
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• pp.117-123
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• 2011

The purpose of this study is to show the friction and wear characteristics on the vapor deposited coating layers on the SCM415 steel. In this research, frictional wear characteristic of coating materials such as Ti-series, Cr-series & WC/C and TiAlN+WC/C multilayer coating was investigated under room temperature, normal air pressure and no lubricating condition. Therefore, this study carried out research on the friction coefficient, micro hardness(Hv), surface roughness and wear quantity on the vapor deposited coating layers on the SCM415 steel. As the wear experimental result, the excellence of TiAlN+WC/C multilayer coating has been proven by high micro-hardness, low friction coefficient and wear quantity.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.581-582
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• 2013

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.881-882
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• 2010

• Proceedings of the Korean Magnestics Society Conference
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• 1999.10a
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• pp.82-83
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• 1999

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.287.2-287.2
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• 2014

PV (photovoltaic) has becoming an important industry to invest due to its high robustness and require very little maintenance which goes a long time. Solar cell fabrication involves a few critical processes such as doping to make the N-type and P-type silicon, contact metallization, surface texturization, and anti-reflection coatings. Anti-reflection coating is a kind of surface passivation which ensures the stability, and efficiency of the solar cell. Thus, I will focus on the changes happen to the solar cell due to the reflectance and anti-reflection coating by PC1D. By using the PC1D (solar cell simulation program), I would analysis the effect of reflectance on the N-type cell. At last I will conclude the result regarding what I learned throughout this experiment.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.187-188
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• 2023

In this study, the analysis of concrete cracks was conducted with a total of three variables: coating thickness, oxygen diffusion rate, and reinforced diameter of reinforced concrete structures. Cracks occurred after about 3, 4, and 6 years at the coating thickness of 30, 40, and 50mm when the coating thickness was used as a variable, and cracks occurred after about 4, 5, and 10 years at oxygen diffusivity of 2e-9, 2e-11, and 2e-12 (m²/s) when the oxygen diffusion rate was used as a variable. In the case of reinforcing bar diameters, cracks occurred after about 4, 3, and 2 years on the reinforcing bar diameters of D10, D19, and D25.

• Korean Chemical Engineering Research
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• v.49 no.3
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• pp.314-319
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• 2011

In this study, the flow behavior of Newtonian and non-Newtonian coating liquids inside slot die has been scrutinized for the purpose of optimal internal die design in slot coating system from three-dimensional computations by CFD Fluent solver. A hybrid slot die could be optimally designed by changing the chamber or manifold structure to guarantee the uniform velocity distribution of coating liquids at die exit. Especially, for the non-Newtonian coating liquids, the length of coat-hanger for the uniform coating has been properly chosen, according to the degree of their shearthinning properties.