• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.1
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• pp.134-139
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• 2005

This paper works on the manufacture and performance evaluation of bi-polar power supplied diesinking electrical discharge machine. The design and implementation of diesinking electrical discharge machine consists of two parts which are a polarity voltage controller design and a servo motor controller design and they are verified and manufactured through simulation. The performance of the implemented machine and conventional one were evaluated by comparing its machining speed and roughness of machined surface. Eventually, the designed machine showed improved performance in the speed and the roughness.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.473-477
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• 2000

The experimental study of die-sinking electrical discharge machining(EDM) was conducted for Cold Die Alloy Steel of SKD-11 with rotary electrode according to the peak current of 11A, 15A and 19A, and the duty factor of 0.24, 0.45. dielectric fluid flow through the electrode inside according to the change of electrode internal diameter during the EDM working. Material removal rate(MRR) was increased with flushing & rotation of electrode at the condition for the peak current of 15A, 19a but the MRR is decreased at the flushing only. The more surface roughness was obtained for the case of the flushing & rotation under the peak current of 19A.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.1
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• pp.71-77
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• 2001

Experimental study if die-sinking electrical discharge machining(EDM) was conducted with rotating electrode system including inside hole for increasing the material removal rate(MRR). With the help of dielectric fluid flow through the inside according to the different internal diameter of the hole, the molten workpiece debris could be removed and flushed out during the EDM, Cold die alloy(SKD-1) was executed for different peak current and duty factor. From this study, the MRR was found to be increased with the peak current. The more MRR was obtained for the case of electrode inside diam-eter of 10 mm, but the MRR was decreased as the diameter near at the 4mm and 6mm. The values of surface roughness and roundness were analyzed under various conditions, and these were affected by the inside diameter change of electrode.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.8
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• pp.9-15
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• 1999

Die-sinking electrical discharge machining(EDM) for conductive ceramic matrix composite(CMC) of Tic/$Al_2O_3$ was experienced with addition of ultrasonic emission, and the results were compared with ones obtained by the EDM only. From this experimental study, the values of material removal rate(MRR) and surface roughness($R_{max}$), scanning electron microscope(SEM) micrographs, and weibull probability distribution of bending strength for the specimens were obtained and compared. The trend of MRR was found to be increased slightly with the current and the duty factor for both EDM only and EDM with ultrasonic emission. The MRR values were found to be increased for EDM with ultrasonic emission. The SEM micrographs of EDMed surface by under various operating conditions showed less micro cracks in various places. Although smaller bending strength value was obtained by EDMed surface with ultrasonic emission by weibull probability distribution analysis of bending strength.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.5
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• pp.73-80
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• 2002

In this study, work materials of the ree form surface shape was machined by ball end mill cutter according to the change of cutting location and depth, and the acquired data of cutting force, tool deflection and shape accuracy were analyzed. Cutting force results were obtained with tool dynamometer and tool deflection values were measured by a couple of eddy-current sensors. Shape accuracy was obtained by roundness tester and surface profile measuring machine. As inclination angle was decreased, cutting force was increased. Cutting force showed large value at $105^{\circ}$ and $150^{\circ}$. Tool deflection was less at down milling than at up milling, decreased at 45$^{\circ}$ and 120$^{\circ}$, and shown large tool deflection at $150^{\circ}$. Roughness values were found to be bad in the inside of surface shape tool deflection. Surface accuracy was obtained better precision in down milling than in up milling.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.05a
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• pp.245-250
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• 1999

The experimental study of die-sinking electrical discharge machining for alloy tool steel of STD-11 with circular electrode was conducted for various conditions of the peak current and duty factor with the change of internal size of electrode for distributing the amount of dielectric flow through the electrode. From this study, the material removal rate(MRR) was found to be increased with the peak current and duty factor. The more MRR was obtained for the case of electrode inside diameter of 10mm. The surface roughness and roundness values were analyzed regularity under various conditions, and these values were not affected by the inside diameter change of electrode.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.1
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• pp.119-124
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• 2010

This paper addresses the design and fabrication of desktop die-sinking dry electrical discharge machining (EDM) system and its experimental performance analysis. The developed desktop dry EDM machine has the horizontal configuration with the size of $300{\times}200{\times}260mm$. The experimental performance analysis is conducted to investigate the effects of EDM conditions and dielectric gas temperature on the surface roughness of EDMed slots and number of EDM sparks. The experimental results demonstrate that low feed rate and large electrode displacement are good for better surface roughness and more number of EDM sparks. In addition, low temperature of dielectric gas results in better surface roughness.

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.3
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• pp.429-436
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• 2003

The electrical discharge machining(EDM) with Si electrode instead of Gr or Cu electrode. made enormous effects on the surface. machining time, anti-caustic workpiece surface and so on In this paper. we experimented on the inter-role distance during discharge the electrical phenomenon of inter-pole, the distribution of discharge point. the distribution of off load time. etc., using Si electrode Cu electrode and Gr electrode under the same machining condition. As a result of a large quantity generated exclusive powders. the performance of the EDM using Si electrode. compared with EDM using others. is improved. We show that the quantities of those make far pole-gap discharge and discharge scatter under stable machining status possible.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.85-86
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• 2008

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.8
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• pp.35-42
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• 2020

In discharge machining, material is removed by electrical discharge between the electrode and the workpiece. An important consideration in EDM is that the wear of the electrodes decreases the final precision of the workpiece. The edge wear of the electrodes proceeds very quickly because sparks occur more frequently at the edges with high local electrical strength. In this study, mold steel was discharged with a wedge-shaped graphite electrode to measure the edge wear of the electrode according to the depth. The electrode edge wear increased with depth during EDM and a wear model was developed. The model predicted that the edge wear can be reduced by approximately 70% using two electrodes instead of a single electrode. The model was supported by the experimental comparison of the dual electrode method and the single electrode method.