• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.3
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• pp.100-106
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• 1999

Owing to the complexity of electrical discharge machining (EDM) phenomenon, it is very difficult to determine optimal machining parameters fer improving machining performance. This paper proposes a methodology for determining optimal electrical discharge machining parameters, which is maintaining suitable current density for increasing productivity or improving surface roughness. Machining area is closely related on optimal machining parameters in electrical discharge machining process, so calculation of machining area is needed in order to determine optimal machining parameters. In this study machining area, which is corresponding to the machining position, is calculated from intersection curves between the tool surface and a horizontal plane.

• Korean Journal of Computational Design and Engineering
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• v.4 no.4
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• pp.355-359
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• 1999

This paper presents a method for determining machining parameters in electrical discharge machining process (EDM) based on discharge area. The parameters are the peak value of currents, the pulse-on time, and the pulse-off time, on which the EDM performance depends chiefly. The optimal machining parameters are closely related on discharge area, which can be calculated from a tool electrode and a discharge height. In the paper the discharge area is obtained from NC code for machining the tool electrode instead of its geometric model. The method consists of following three steps. First a Z-Map model is constructed from the NC code. Secondly, the discharge area is obtained from the Z-Map model and a Z-height. Finally, the machining parameters are calculated from the discharge area. An introduced example shows that the machining parameters are calculated by the using a Z-map model obtained from the machining data for a tool electrode.

• Journal of Electrochemical Science and Technology
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• v.6 no.4
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• pp.131-138
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• 2015

Electrical discharge machining is an unconventional machining process in which successive sparks applied to machine the electrically conductive materials. Any changes in electrical discharge machining parameters lead to the pieces with distinct surface roughness. The electrical discharge machining process is well applied for high hardness materials or when it is difficult to use traditional techniques to do material removing. Furthermore, this method is widely applied in industries such as aerospace, automobile, molding, and tool making. CK45 is one of the important steels in industrial and electrical discharge machining can be considered as a proper way for its machining because of high hardness of CK45 after thermal operation of the electrical discharge machining process. Optimization of surface roughness as an output parameters as well as electrical discharge machining parameters including current, voltage and frequency for electrical discharge machining of CK45 has been studied using copper tools and kerosene as the dielectric. For such a purpose and to achieve the precise statistical analysis of the experiment results design of experiment was applied while non linear regression method was chosen to assess the response of surface roughness. Then, the results were analyzed by means of ANOVA method and machining parameters with more effects on the desired outputs were determined. Finally, mathematical model obtained for 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.

• Transactions of Materials Processing
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• v.14 no.3 s.75
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• pp.251-256
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• 2005

3-D micro structures and micro tools were fabricated using Micro Electrical Discharge Machining (MEDM). To make micro structures, micro electrical discharge milling process was applied. During micro electrical discharge milling, electrode (tool) worn in the both axial and radial direction. To compensate tool wear which has significant influence on machining accuracy, machining path overlapping was proposed. Machining characteristics of micro electrical discharge milling was investigated in considering of depth of cut and capacitance of discharge circuit. Micro complex shaped tools were also fabricated using REDM (reverse electrical discharge machining). Sacrificial electrodes were machined through electrical discharge milling process and were used as electrode to make micro tools. Using this process several micro tools shape of 'ㄷ', 'ㅁ' and 'o' were fabricated. With these complex shaped tools, micro machining was successfully applied repeatedly.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.05a
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• pp.105-110
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• 1999

Wire electrical discharge machining (WEDM) is one of the unconventional machining processes, which is utilizing electrical energy to remove work-piece. In recent years WEDM used widely in die-sinking industry because WEDM can machine any hard materials if only it has conductivity and can machine accurately to the complex geometry, for fine wire is used in WEDM for the tool electrode. However WEDM is non-contact machining process, which is utilizing discharge phenomena occurring between two electrodes, the size of the machined part is larger than that of the tool electrode size. It is called discharge gap or clearance the difference size between the tool electrode and the machined part in WEDM. By the experiment clearances according to the machining condition was investigated.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.604-607
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• 2005

In the electro-discharge machining the machining performance is closely related to the characteristics of discharge which can be identified from electrical behavior in gap between workpiece and electrode. Therefore, the accurate prediction of electrical behavior in electro-discharge machining (EDM) is useful to process control and optimization. However, any simulation model fur prediction of electrical behavior in EDM process has never been reported until now. In this study, a simulation model is developed to analyze the electrical behavior of electro-discharge plasma which significantly influences electrical behavior in EDM process. For the purpose of this the fundamentals of electro-discharge mechanism such as inception, propagation, formation of plasma channel and termination are investigated to accurately predict the cycle of discharge plasma in EDM. As a result, a mathematical model of electro-discharge plasma is constructed with considering the fundamentals of electro-discharge plasma. Consequently, it is demonstrated that the developed model can predict the electrical behavior of plasma such as electron density in various conditions.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1865-1868
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• 2003

This paper provides a new method for hybrid machining, particularly suited to micro fabrication applications such as micro point, micro line, micro structure, micro partition and so on. Developed micro fabrication process by electrical discharge machining (EDM) and electrical discharge deposition (EDD) with metal powder (Ti, Fe) has been studied to build TiC or FeC structure. Titanium powder or iron powder is supplied from working fluid (kerosene or de-ionized water with powder) and adheres on a workpiece by the heat and electric power caused by the electrical discharge. The use of a tool electrode is expected to keep powder concentration high in the gap between a workpiece and a tool electrode and to accrete powder material on the workpiece. The deposition is tried under various electrical conditions (workpiece. tool electrode, working fluid, discharge current, voltage and powder etc.). On the other hand. using electrical discharge machining (EDM) with the same tool electrode, it can be used as a removal process (cutting) by electro erosion at the same time. Therefore. this new method can do a hybrid machining to build up and down a structure with the workpiece.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.1
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• pp.27-33
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• 2000

This paper presents a method for determining machining parameters in 3-dimentional electrical discharge machining(EDM). The parameters are the peak value of currents, the pulse-on time, and the pulse-off time. It is known that they influence the performance of EDM more than the other else. The parameters are determined from the discharge area between a tool electrode and a work piece. The discharge area is directly influenced by the geometry of a tool surface and the tool discharge position. The discharge area on a tool discharge position is calculated from intersection curves between the tool surface and a horizontal plane. The grid search method is applied to determine the intersection curves. An example is introduced to show that the machining parameters are obtained from the surface geometry of a tool electrode.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.5
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• pp.101-106
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• 2008

In the wire cut electrical discharge machining, the optimal machining parameters setting satisfying the requirements of both high efficiency and good quality is very difficult because its process involves a series of complex physical phenomena and the machining parameters are numerous over diverse range. In this paper, the experimental investigation has been performed to find out the influence of the machining parameters on the machining performance such as cutting speed and surface roughness. The selected experimental parameters are no load voltage, discharge peak current and pulse-off time. The experimental results give the guideline for selecting suitable machining parameters.