• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.12-12
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• 1997

• Journal of the KSME
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• v.46 no.1 s.302
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• pp.40-45
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• 2006

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.499-500
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• 2006

The electrode wear in micro-EDM significantly deteriorates the machining accuracy. In this regard, electrode wear needs to be compensated in-process to improve the product quality. Therefore, there are substantial amount of research about electrode wear. In this study a control method for micro-EDM using discharge pulse counting is proposed. The method is based on the assumption that the removed workpiece volume is proportional to the number of discharge pulses, which is verified from experimental results analyzing geometrically machined volume according to various number of discharges. Especially, the method has an advantage that electrode wear does not need to be concerned. The proposed method is implemented to an actual micro-EDM system using high speed data acquisition board, simple counting algorithm with 3 axis motion system. As a result, it is demonstrated that the volume of hole machined by EDM drilling can be accurately estimated using the number of discharge pulses. In EDM milling process a micro groove without depth variation caused by electrode wear could be machined using the developed control method. Consequently, it is shown that machining accuracy in drilling and milling processes can be improved by using process control based on the number of discharge pulses.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.546-549
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• 2005

Micro EDM milling using deionized water as dielectric fluid was investigated. After machining micro grooves using deionized water with different voltage. capacitance. and resistivity of deionized water, machining characteristics were investigated. The wear of a tool electrode and the machining time can be reduced by using deionized water instead of kerosene. Micro hemispheres were machined in deionized water and kerosene and their machining characteristics were compared.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.10
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• pp.108-115
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• 2009

Although nanosecond pulsed laser drilling and milling are rapid and non-wear processes in micromachining, the quality cannot meet the precision standard due to the recast layer and heat affected zone. On the other hand, electrical discharge machining (EDM) is a well-known high precision machining process in micro scale; however, the low material removal rate (MRR) and tool wear remain as drawbacks. In this paper, hybrid process of laser beam machining (LBM) using nanosecond pulsed laser and micro EDM was studied for micro drilling and milling. While the quality of the micro structure fabricated by this hybrid process remains as high as direct EDM, the machining time and tool wear can be reduced. In addition, variable depth of layer was introduced as an effective method improving efficiency of hybrid milling.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.3 s.180
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• pp.69-75
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• 2006

In this paper, micro electrical discharge milling using deionized water as dielectric fluid was investigated. In EDM, dielectric fluid is an important factor which affects machining characteristics. When deionized water was used as dielectric fluid, machining characteristics were investigated according to voltage, capacitance, and resistivity of deionized water. Machining gap increased with increasing voltage and capacitance. As the resistivity of deionized water decreased, the machining gap increased. The wear of a tool electrode and machining time can be reduced by using deionized water instead of EDM oil. Surface roughness was also improved when deionized water was used.

• 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.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.189-190
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• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.105-106
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• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.949-950
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• 2008