• Journal of the Korean institute of surface engineering
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• v.28 no.5
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• pp.300-308
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• 1995

The effect of nitrogen finishing for the control of coating weight in a nitrogen sealing box on the coating surface property in hot dip galvanizing process has been studied. The coated surface is free of oxide marks and edge overcoated. The coating uniformity is excellent ; the standard deviation of the coating thickness along width of the specimen was $1~1.2\mu\textrm{m}$ in the box whereas $2.5~3\mu\textrm{m}$ in the air. Considering surface quality of the coating such as oxide mark, edge overcoated and zinc dust, the oxygen content between 40 and 200 ppm was suggested in the box in addition the oxygen content of at least 40 ppm or the minimum dew point of $-27^{\circ}C$ is required to prevent a zinc vaporization.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.10a
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• pp.313-317
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• 2003

Micro-Channel ultra-precision polishing is a new technology used in magnetic field-assisted relishing. In this paper, an electromagnet or the i18 of test system was designed and manufactured. A size of magnetic abrasive is used on 25~75${\mu}{\textrm}{m}$ and for the polish a micro-channel upper part. A surface of channel which is not even is manufactured using magnetic abrasive finishing at upper surface of micro-channel. As a result, the surface roughness rose by 80％ after upper surface of micro- channel was polished up 8 minutes by polishing.

• Corrosion Science and Technology
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• v.2 no.2
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• pp.102-108
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• 2003

The surface treatments. Chrome/Manganese and Modified Chrome Pickle, that are treated to improve the anti-corrosion property which is needed to increased the probability of prototype product enabled the sand cast Magnesium test specimens to have better corrosion resistance than non-treated one. Sand cast Magnesium specimens which was treated only with chemical conversion coating had same corrosion resistance with the Steel specimens plated by Zinc, and the another one that had the finishing treatment(painting) worked on the chemical surface treatment had the corrosion resistance property to meet to FPO-3 requirement. We also investigated the multiple finishing system(chemical surface treatment + 3 coating) to test the severe condition that magnesium should to endure.

• Korean Journal of Metals and Materials
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• v.49 no.7
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• pp.522-529
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• 2011

Carbon fiber reinforced plastics (CFRP), which have been developed for their high mechanical properties, are insufficient to secure machinery. This paper investigates the use of magnetic abrasive finishing methods and the characteristics of surface roughness for mirror machining of CFRP. The cylindrical surface of CFRP was ground using a diamond paste with sizes of 0.1, 0.5, 1 and 6${\mu}m$. Consequently, an effective surface roughness of 0.03${\mu}m(R_a)$ could be obtained via a paste size of 0.5${\mu}m$. The surface roughness was not improved due to epoxy abrasion between the carbon fiber and the epoxy.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2002.05a
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• pp.39-39
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• 2002

In order to improve wear and fatigue resistance of the structural materials, especially cold work roller for 304 stainless steel, an eco-super-finishing and surface hardening treatment using ultrasonic vibration energy was developed and applied to the SKD-ll roller. The eco-super-finishing machine was designed and fabricated by DesignMecha Co, by its own technology. It was observed that the surface roughness, hardness and residual stress were changed from $Ra{\;}={\;}O.25\mu\textrm{m}$, Hv=710 and ${\sigma}$={\;}+400{\;}MPa{\;}to{\;}Ra{\;}={\;}0.165\mu\textrm{m}$, Hv = 1200 and ${\sigma}=-610$ MPa after 20 KHz micro-cold forging, which means almost equal to the 300 % improvement of life-time.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.280-283
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• 1995

In centrifugal barrel finishing, it is easy to establish the optimum working conditions for different workpieces. As they are adjusted in trial and error practically, production efficiency and quality are some- times low In the present paper, firstly, installation of the barrel finishing machine, finishing purpose and working conditions have been analyzed in order to eliminate the defects of the finished surface. Secondly, on the basis of this result, quantity of the water and selection of the media and the compound, etc. have been investigated. As a result, production efficiency and quality have been improved under the specified optimum working conditions. In addition, durability of the media and the compound has been tested experimentally. As a result, it was found that the expected life of the media is about 85 hrs and that of the compound is about 5 hrs. Besides high quality control has been achieved by newly proposed inspection at regular intervals.

• Textile Coloration and Finishing
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• v.25 no.1
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• pp.70-74
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• 2013

For amine gas detection, we incorporated two well-known isomers, 2-chloro-3,5-dinitro-benzotrifluoride and 4-chloro-3,5-dinitro-benzotrifluoride, in polyurethanes. Nanoweb and thin film were prepared by electrospinning and lamination, respectively, in order to compare their sensing behaviors. Moreover, we studied photophysical property using UV-Vis spectrometer and observed surface area through scanning electron microscope to compare between the Nanoweb and thin film. We found out that nanowebs exhibited high sensitivity specifically to primary amine gas.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.13 no.6
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• pp.74-80
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• 2004

An internal finishing process by the application of magnetic abrasive machining has been developed as a new technology to obtain a fine inner surface of pipe. In this paper, the finishing process of a non-ferromagnetic pipe by a static magnetic field method is introduced and its finishing characteristics is discussed with effective factors by various experiments. From these experimental results, it is found that the magnetic abrasives inserted in the pipe are arranged according to the magnetic force line. Through the experimental, it is possible to estimate the proper supply volume of the abrasive, which in proportional to the diameter of pipe.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.123-124
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• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.237-238
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• 2010