• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1997.10a
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• pp.190-195
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• 1997

The requirement of precision products about difficult-to-cut materials such as Cu and Aluminum alloy is becoming more and more. Because of soft materials, the exist narrow groves on surface are difficult to gotten off even on the polishing stage. It has been proved that Magnetic-Electrolytic-Abrasive Polishing (MEAP) is a efficient method to resolve this problem by using the nonwoven-abrasive pads together [1, 2]. In this study, through the experiments, their machining properties of newly developer polishing material of SiC, Al2O3 and diamond nonwoven abrasive pads have been proved. Through the experiments, the optimal machining conditions on larger cylinder shape workpiece of Cu and Aluminium alloy have been found, through the Taguchi[3] method the optimal machining conditions can be selected.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.1 s.178
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• pp.97-104
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• 2006

ELID(Electrolytic In-process Dressing) grinding is an excellent technique for mirror grinding of various advanced metallic or nonmetallic materials. A polishing process is also required for elimination of scratches present on ELID grinded surfaces. MAP(Magnetic Assisted Polishing) has been used as polishing method due to its high polishing efficiency and to its resulting in a superior surface quality. This study is describing an effective fabrication method combining ELID and MAP of nano-precision mirror grinding for glass-lens molding mould. It also presents some techniques for achieving the nanometer roughness of the hard metals, such as WC-Co, which are extensively used in precision tooling material.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.12
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• pp.2962-2969
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• 1993

Recently, a study on the mirror-like surface grinding of brittle materials is active and as branch of these study, new dressing method for superabrasive wheel, electrolytic inprocess dressing(Elid) was developed. Using Elid, the mirror-like surface of brittle material can be generated without polishing or lapping process. In the future, Elid grinding will take important place in industry. But so far the analysis on Elid grinding was not quantitative but qualitative. In this study, The purpose is the quantitative analysis on Elid grinding by computer simulation, For computer simulation, the mean and the variance of the abrasive distribution were measured by tracing of the grinding wheel with stylus in transverse direction in the case of respective dressing current condition. This measurement result in a density distribution of abrasive by mathematical formulation using statistical method. The prediction of the surface roughness in Elid grinding was based on this density distribution.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.65-68
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• 1995

A slicing method by thin diamond blade is widely usd slicing of hard and brittle materials such as ceramics,glass and ferrite etc.. In this study, a new slicing system which realizes highly efficient and mirror surface slicing was developed by applying ELID-grinding with metallic bond diamond blades and its performance was evaluated. Hard and brittle materials such as ceramics,glass and ferrite were used as workpiece. Metallic bond diamond blades with grit sizes #325 and #2000 were used. Experimental results show that highly efficient slicing and good mirror surface can be successfully obtained using the developed slicing system with ELID features.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.2 no.4
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• pp.25-32
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• 2003

In this study, the grinding characteristics of CBN wheels, such as grinding force and surface roughness, have been compared and analyzed from various working conditions of spindle speed and depth of cut. To actualize high efficient grinding at ceramic and silicon nitride material, electrolytic in-process dressing (ELID) method has been applied at metal bonded diamond and CBN wheels. Super precision grinding using ductile mode at difficult-ta-cut materials could be performed.

• Journal of the Korean institute of surface engineering
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• v.28 no.1
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• pp.46-54
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• 1995

An electrochromic(EC) cell was constructed using $WO_3$ as a electrochromic material and NiO as a counter electrode, deposited onto ITO-coated glass by the implementation of electron beam evaporation. The electrolytic media were both lithium and proton conducting polymers such as poly-acrylonitrile(PAN)-$LiClO_4$, poly-ethylene oxide(PEO)-$LiClO_4$, poly-vinyl butyral(PVB)-LiCl and PVB-H$_3$$PO_4$. Potentiodynamic cycling of the cells using PAN-$LiClO_4$, or PVB-$H_3$$PO_4$ electrolyte yielded a transmission variation of more than 40% at the wavelength of 632.8 nm within less than 10 sec response time at room temperature. These results indicate that these electrolytes, transparent in gel type, are premising for the application in large area electrochromic windows.

• Journal of the Korean institute of surface engineering
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• v.50 no.6
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• pp.432-438
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• 2017

AZ91D casting alloy requires an advanced plasma anodizing processing because large amount of defects are liable to generate during anodization. In this study, plasma electrolytic oxidation (PEO) of AZ91D Mg alloy was conducted by the application of either constant voltage or current using a pulse mode and its effects on pore formation, surface roughness and corrosion resistance were investigated. The PEO films showed a three-layer structure. The PEO film thickness was found to increase linearly with voltage. The surface roughness, Ra, ranged between $0.2{\mu}m$ and $0.3{\mu}m$. The corrosion resistance increased from RN 3.5 to 9.5 by the PEO treatment when evaluated according to the 72 hour salt spray test. The PEO-treated surface exhibited higher pitting potential than the raw material.

• Journal of the Korean Electrochemical Society
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• v.18 no.4
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• pp.156-160
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• 2015

Experiments using a metal oxide of a non-nuclear material as a fuel are very useful to develop a new electrolytic reducer for pyroprocessing. In this study, the titanium oxides (TiO and $TiO_2$) were selected and investigated as the non-nuclear fuel for the electrolytic reduction. The immersion tests of TiO and $TiO_2$ in a molten 1.0 wt.% $Li_2O$-LiCl salt revealed that they have solubility of 156 and 2100 ppm, respectively. Then, the Ti metals were successfully produced after the separate electrolytic reduction of TiO and $TiO_2$ in a molten 1.0 wt.% $Li_2O$-LiCl salt. However, Ti was detected on the platinum anode used for the electrolytic reduction of $TiO_2$ unlike TiO due to the dissolution of $TiO_2$ into the salt.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.6
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• pp.684-688
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• 2007

The results of potentiostatic electrolysis of aqueous solution containing fluoride by bipolar packed bed electrolytic cell filled with granular aluminium were summarized. Removal efficiency of fluoride ion which it analyzed with ion chromatograph were 53, 73, 90% in applied voltage. Control the concentration of supporting electrolyte were 10, 30, 50, 70 mg/L and volume of packing material were 0, 25, 50, 75%, respectively, the quantity of electricity was $2.58A{\cdot}hr$ when the concentration of supporting electrolyte was 50 mg/L and the volume of packing material was 75%. As the results of electrolytsis of fluoride aqueous solution containing fluoride 10, 30, 50, 70 mg/L for 3 hours at 10 V, the removal efficiency of fluoride were 93.3, 80, 68.6%. Then the quantity of electricity were 2.58, 3.89, $5.43A{\cdot}hr$ and the fluoride removal amounts per quantity of electricity were 4.0, 3.5, $2.0mg/A{\cdot}hr$.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.38 no.1
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• pp.79-88
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• 2002

13%Cr martensitic stainless steel has been used mainly with a material for fish pre-processing machinery. However, it has not very nice cutting section because of little of the carbon content. Therefore, SUS420J2 steel that contents 0.3%C with high-strength in spite of the rust is used with a material for fish pre-processing machinery. However, studies on the corrosion characteristics of SUS420J2 steel are relatively rare. Especially, the corrosion phenomenon may cause serious degradation because the fish pre-processing machinery is exposed always to seawater environment. In this paper, the immersion corrosion test was carried out at seawater environment (pH=7.52) on SUS420J2 steel specimens that have various post-treatment conditions and its corrosion characteristics were evaluated. From test results, the specimens such as base metal, vacuum heat treatment, electrolytic polishing and tempering after quenching tend somewhat sensitive from the corrosion. In the case of vacuum heat treatment specimen of continuous immersion during 360 days, the weight loss ratio was high about seven times when compared with the different specimens. On the contrary, SUS420J2 steel specimen that has the heat treatment of tempering after quenching and the electrolytic polishing was less sensitive from the corrosion, and the weight loss ratio was very low.