• 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 Korea Academia-Industrial cooperation Society
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• v.5 no.6
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• pp.511-514
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• 2004

Punch and die plate which are press die parts can be made using machine tool or using both machine tool and W-EDM. When machine tool is used, the die life is 2,000,000 to 230,000 strokes. But with W-EDM, the die life is 700,00 to 800,000 strokes. This can be caused by the process deformation layer after W-EDM. SEM pictures of processed section before and after W-EDM are taken to see if the process deformation layer appeared. Also the elimination method is studied.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1998.03a
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• pp.35-39
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• 1998

Determination of effective EDM parameters is significant to increase productivity. However, With the complexity of EDM phenomena, a universal selection method of EDM parameters has not been established yet. Moreover, No attempt has been tried before to suggest a logical method in determining essential machining parameters for effective electrical discharge machining. Peak current, one of the most significant factors in EDM, is proportional to EDM area. This paper presents a method that can be Z-map modeling from CMM data, and calculate EDM area using Z-map.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.12
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• pp.55-61
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• 1998

Recently, the needs of machining technologies of very small parts have been increasing with advent of micro-revolution. These technologies have mostly used the method applied to semi-conductor production process such as LIGA, etc. But they have serious difficulties to settle down in terms of workpiece materials, machining thickness, 3-dimensional structure. Therefore. mciro-machining technology using EDM(Electrical Discharge Machining) was proposed. It is very difficult to machine the micro-parts (microshaft, microhole) using conventional machining. Micro-machining using BDM can machine the micro-parts easily because it requires little machining force. This MEDM(Micro-EDM) need the capabilities to move a electrode and control a discharge energy precisely, and the gap control strategy to maintain the optimal discharge condition is necessary. Therefore, in this study, the new EDM machine with high precision motion stage and high-performance EDM device was developed. Using this MEDM machine, we have machined microshaft and microhole with various shapes and sizes.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.5-6
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• 2008

• 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 Korean Institute of Industrial Engineers
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• v.39 no.3
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• pp.149-155
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• 2013

Electric discharging machining (EDM) is commonly adopted to machine the precise and tiny part when it is difficult to meet the productivity and the tolerance by the conventional cutting method. The die-sinking EDM method works well to machine the micro-parts and the perpendicular wall of die and mould, whereas EDM drilling, called super drill, is excellent to machine the deep and narrow hole regardless the material hardness and the hole location. However, the electrode wear is rapid compared to the conventional cutting tool and makes it difficult to control the electrode feeding and to machine precisely. This paper presents an efficient method to estimate the electrode wear using hole pass-through experiment while the stochastic method is used to compensate for the estimation model. To validate the proposed method, the commercial EDM drill machine is used. The experiment result shows that the electrode wear amount can be predicted very precisely.

• International Journal of Precision Engineering and Manufacturing
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• v.6 no.2
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• pp.5-11
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• 2005

Among the micro machining techniques, micro EDM is generally used for machining micro holes, pockets, and micro structures on difficult-cut-materials. Micro EDM parameters such as applied voltage, capacitance, peak current, pulse width, duration time are very important to fabricate the tool electrode and produce the micro structures. Developed micro EDM machine is composed of a 3-axis driving system and RC circuit equipped with pulse generator. In this paper, using micro EDM machine, the characteristics of micro EDM process are investigated and it is applied to micro holes, slots, and pockets machining. Through experiments, relations between machined surface and voltages and between MRR and feedrate are investigated. Also the trends of tool wear are investigated in case of hole and slot machining.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1998.10a
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• pp.176-179
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• 1998

In general, machining time by electrical discharge machining (EDM) process is much longer than that of cutting process, so rough-cut has done for the purpose of reducing machining time prior to EDM Nowadays EDM speed is improving due to the advance of EDM capacity. Therefore a new method, machining a raw material directly by EDM without rough-cut, is used widely. EDM area is varies according to the EDM position in three-dimensional EDM process, so EDM parameters should be determined adaptively based on the EDM area to increase productivity. However it is difficult to calculate EDM area corresponding to the EDM position the EDM workers who have experience in shop floor determine machining parameters by experience. This paper proposes a method for determining EDM parameters based on EDM area corresponding to EDM position.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.1
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• pp.1-7
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• 2011

Micromachining is gaining popularity due to recent advancements in MEMS(Micro Electro Mechanical Systems). Using conventional micromachining, it is relatively difficult to produce moving components in the order of microns. Photolithography for silicon material has high accuracy machining, but it has low aspect ratio. X-ray lithography has ultra high accuracy machining, but it has expensive cost. Micro-EDM(electro discharge machining) has been gaining popularity as a new alternative method to fabricate micro-structures. In this study, Micro-EDM machine is developed available for fabricate micro-structures and two processes such as side cut EDM and milling EDM is proposed. Several sets of experiment results have been performed to study the characteristics of the machining process.