• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.1075-1079
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• 1995

It is difficult to machine microparts, such as microshaft and microholes, by conventional machining. Such micropart can be easily machined by EDM because it's machining force is very low. In micro-EDM, the precise electrode movement and discharge energy control are important. Therefore, high precision motion stage and EDM device with high performance is necessary. In this research, a new EDM machine was developed and microshaft and microhole, with various shape and size, was machined.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.4
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• pp.24-31
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• 2004

The objective of this work is to suggest a mastless pattern fabrication technique using the combination of machining by Nanoindenter(equation omitted) XP and HF wet etching. Sample line patterns were machined on a borosilicate surface by constant load scratch (CLS) of the Nanoindenter(equation omitted) XP with a Berkovich diamond tip, and they were etched in HF solution to investigate chemical characteristics of the machined borosilicate surface. All morphological data of scratch traces were scanned using atomic force microscope (AFM).

• Tribology and Lubricants
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• v.16 no.4
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• pp.253-258
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• 2000

Frictional behavior of wire electric discharge machined surfaces of spheroidized annealed STDll steel was investigated. The surfaces were produced with a various series of finish cuts where pulse energy was reduced with increase in the number of finish cuts. Roughness and micro-hardness of the surfaces were also measured. It is observed that the increase in the number of finish cuts produces the surface exhibiting lower frictional resistance followed by higher resistance after considerable wear. Effects of finish cuts on the friction characteristics are discussed with the aid of roughness and micro-hardness of the surfaces.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.953-956
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• 1997

Micro drilling characteristics by EDM method was investigated. In detail, Micro tool electrode for EDM drilling was machined by use of WEDG method and micro hole was drilled using the machined tool electrode in SUS plate. The machining accuracy and time was compared in a different dielectric fluid. As a result, it was convinced that this method could be utilized as a fabrication technology of micro mold or micro 3 dimensional parts.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.80-84
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• 1996

The effects of guide pads on burnishing action and accuracy of machined hole are investigated in drilling with burnishing drill using a speciaaly designed tool experimentally. The cutting forces are balanced at the small forward regions of guide pads. The burnishing action takes place under a high contact pressure between the bore wall and those regions. The over size mechanism of machined hole by the guide pads is discussed.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1997.03a
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• pp.171-174
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• 1997

In this study, a computer program was developed which generates automatically a drawing of the forging design in axisymmetric hot-forging of steel. The program designs a forging envelope from a machined part geometry according to forging design rules: parting line, draft angles, fillet and corner radii, minimum web and rib thicknesses. For the purpose of verification, the program was applied to a machined part from a factory. It was found that the generate forging design agreed well with the actual one used in the factory.

• Tribology and Lubricants
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• v.11 no.5
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• pp.156-161
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• 1995

The subsurface damaged layer in ultraprecisison machined single crystal Ge was examined by ion channeling. Single crystal Ge surfaces were prepared by chemo-mechanical polishing, mechanical polishing with 1/4 gm diamond abrasive, single point diamond turning and ultraprecision orthogonal flycutting. The extent of subsurface lattice disorder was compared to the crystal's orginal surface quality. Ion channeling is seen to be useful for quantitative measure of lattice disorder in finely finished surfaces.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.10a
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• pp.468-473
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• 2002

This paper presents the methodology for measuring eccentricity of the cylindricaliy machined part using CCS(Cylindrical Capacity Spindle Sensor) signal in the CNC turning process. In order to investigate the relationships between CCS orbits and eccentricities, the initial conditions for various eccentricity state and machining process is applied to the experimental strategy. AS a result, it is considered the linearities of CCS signal and magnitude of eccentricity of machined cylindrical surfaces based on the possibility as a automatic detection apparatus for the CNC lathe.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.209-215
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• 2005

The dimensions and forms of precise machined parts are different to kinds of machine. It will be variant according to machine wear, tool form, cutting method and cutting condition at the same machine. At that time, the most important things are controlled and measured by appropriate measuring instruments. This paper aims to contribute to improving measurement accuracy through evaluation and consideration about various roundness in the machining company.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.6
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• pp.175-180
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• 2007

In this paper, an aberration free aspherical lens is designed and machined by new design method and the spherical aberration measuring system is developed. It confirmed the propriety of new design method by measuring optical characteristics of machined lens with the new measuring system. The system could measure a spherical aberration quantitatively by using CCD camera, laser, collimator and so on.