• Proceedings of the Materials Research Society of Korea Conference
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• 2009.11a
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• pp.34.2-34.2
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• 2009

The ceramic coatings on metallic materials have attracted by many researchers due to the chemical inertness of ceramic materials. In such aspect, SiOC is a promising material tobe used as protective coating layer on metallic materials due to its outstanding thermal stability and chemical inertness. In this research, SiOC coating was carried out onto SuS-316 substrate using Cl free preceramic polymers such aspolyphenylcarbosilane. 20% of polymethylphenylsilane in cyclohexane solution was coated onto metal surface by dip coating method. Thermal oxidation was carried out at $200^{\circ}C$ for crosslink of the preceramic polymer and the sample was pyrolysized at $800^{\circ}C$ under argon to convert the preceramic polymer to amorphous SiOCx state. The microstructure of the SiOCx film after pyrolysis was investigated using FE-SEM. Corrosion resistance of SiOC coated SuS-316 substrate has been investigated using 5% HCl solution at 25, 40, 60 and $80^{\circ}C$ for 7days. The data revealed that the corrosion resistance increased with SiOC coating on SuS-316 substrate.

• Korean Journal of Materials Research
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• v.29 no.1
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• pp.52-58
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• 2019

The microstructure, hardness, and wear behaviors of a High Velocity Oxygen Fuel(HVOF) sprayed WC-CoFe coating are comparatively investigated before and after laser heat treatments of the coating surface. During the spraying, the binder metal is melted and a small portion of WC is decomposed to $W_2C$. A porous coating is formed by evolution of carbon oxide gases formed by the reaction of the free carbon and the sprayed oxygen gas. The laser heat treatment eliminates the porosity and provides a more densified microstructure. After laser heat treatment, the porosity in the coating layer decreases from 1.7 % to 1.2 and the coating thickness decreases from $150{\mu}m$ to $100{\mu}m$. The surface hardness increases from 1440 Hv to 1117 Hv. In the wear test, the friction coefficient of coating decreases from 0.45 to 0.32 and the wear resistance is improved by the laser heat treatment. The improvement is likely due to the formation of oxide tribofilms.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.4
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• pp.68-75
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• 2018

The introduction of advanced water treatment facilities has increased as the conventional purification method cannot remove the substance clearly. However, the internal waterproofing and Anticorrosion materials of the advanced water treatment facility using ozone deteriorate due to the oxidation power of ozone and affects the concrete, which causes a decrease in durability. This study is to evaluate the ozone resistance according to the type of spray metal and the surface treatment method of the coating, and the bond strength after ozone treatment in order to develope a finishing method to prevent deterioration of concrete structure of water treatment facility using metal spraying method as a way to construct metal panel with excellent ozone resistance and chemical resistance by an easier way than the previous. The Experimental results show that spray metal Ti has superior ozone resistance even after spraying. It is considered to be the most suitable method for ozone resistance and bond performance by finishing using Teflon sealing as surface treatment method.

• Journal of Electrochemical Science and Technology
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• v.14 no.4
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• pp.377-387
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• 2023

Ni-W/Al₂O₃ nano-composites were electrodeposited on mild steel substrate for mechanical and corrosion resistance applications. This study focused on the preparation of Ni-W/Al₂O₃ nano-composite coating with various quantity of Al₂O₃ incorporations. The addition of Al₂O₃ in the electrolytes were varied from 1-10 g/L in electrolytes and the Al₂O₃ incorporation in Ni-W/Al₂O₃ nano-composite coatings were obtained from 1.82 to 13.86 wt.%. The incorporation of Al₂O₃ in Ni-W alloy matrix influenced the grain size, surface morphology and structural properties were observed. The distributions of Al₂O₃ particle in alloy matrix were confirmed using electron microscopy (FESEM and TEM) and EDAX mapping analysis. The crystal structure informations were studied using X-ray diffraction method and it confirms that the deposits having cubic crystal structure. The better corrosion rate (0.87 mpy) and microhardness (965 HV) properties were obtained for the Ni-W/Al₂O₃ nano-composite coating with 13.86 wt.% of Al₂O₃ incorporations.

• Tribology and Lubricants
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• v.18 no.2
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• pp.138-143
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• 2002

Abstract - Tribofilms formed on won surface protect the DLC coating surface and decrease the fiction coefficient. However it is very difficult to evaluate their micromechanical properties due to their small thickness, inhomogeneity and discontinuity. The phase contrast images in tapping mode atomic farce microscopy allow an estimation of inhomogeneity in micromechanical properties of the sample surface. The purpose of this investigation is to demonstrate how the phase contrast images contribute to the characterization of thin tribofilms.

• Journal of the Korean Ceramic Society
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• v.35 no.8
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• pp.791-794
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• 1998

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2001.06a
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• pp.299-304
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• 2001

Tribofilms formed on worn surface protect the DLC coating surface and decrease the friction coefficient. However it is very difficult to evaluate their micromechanical properties due to their small thickness, inhomogeneity and discontinuity. The phase contrast images in tapping mode atomic force microscopy allow an estimation of inhomogeneity in micromechanical properties of the sample surface. The purpose of this investigation is to demonstrate how the phase contrast images contribute to the characterization of thin tribofilms.

• Proceedings of the Korean Magnestics Society Conference
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• 2014.11a
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• pp.126-126
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• 2014

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1356-1359
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• 2007

• Proceedings of the Materials Research Society of Korea Conference
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• 1993.11a
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• pp.48-48
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• 1993