A Study on Plasma Channel Expansion in Micro-EDM

Chu, Xia; Zhu, Kai; Wang, Chunmei; Hu, Zhang; Zhang, Yiru

doi:10.1080/10426914.2015.1059445

Cited by 39 publications

(11 citation statements)

References 26 publications

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“…EDM is a nonconventional technology in that material is removed from the workpiece as a result of a series of discharges. During a single electrical discharge, the temperature inside the plasma channel is estimated to be between 6000 and 7000 K [50]. Heat flux causes melting and evaporation of both the workpiece and the working electrode.…”

Section: Resultsmentioning

confidence: 99%

The Effects of Reduced Graphene Oxide Flakes in the Dielectric on Electrical Discharge Machining

Świercz

Oniszczuk-Świercz

2019

Nanomaterials

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Electrical discharge machining (EDM) is a nonconventional technology that is frequently used in manufacturing for difficult-to-cut conductive materials. Drawbacks to using EDM include the resulting surface roughness and integrity. One of the recent innovations for improving surface integrity with EDM is the use of a powder mixed dielectric. The aim of this study is to analyze the influence of having reduced graphene oxide (RGO) in the dielectric on the ionization of the plasma channel and the dispersion of electrical discharges. The main goal is to improve the surface integrity of the tool steel 55NiCrMoV7 during finishing machining. To achieve this goal, an experimental investigation was carried out to establish the smallest possible values of discharge current and pulse time at which it is possible to initiate an electric discharge, which causes material removal. Next, the effect of the direction of the electric discharges (electrode polarity) and the concentration (percentage) of RGO in the dielectric on surface integrity was investigated. The results of this experiment indicate that during EDM with RGO, the discharges are dispersed on the RGO flakes. This leads to a multiplication of the discharges during a single pulse, and this strongly affects the surface integrity. The obtained results indicate that it is possible to reduce surface roughness and thickness of the recast layer by approximately 2.5 times compared with conventional EDM.

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Section: Resultsmentioning

confidence: 99%

The Effects of Reduced Graphene Oxide Flakes in the Dielectric on Electrical Discharge Machining

Świercz

Oniszczuk-Świercz

2019

Nanomaterials

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“…Moreover, the machining performance can be improved using graphene nanofluid as the dielectric [ 75 ]. Studies on plasma channel expansion, nano-powder-mixed sinking and milling in micro-EDM were also carried out [ 76 , 77 ].…”

Section: Powder-mixed Edmmentioning

confidence: 99%

Recent Advances and Perceptive Insights into Powder-Mixed Dielectric Fluid of EDM

et al. 2020

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Electrical discharge machining (EDM) is an advanced machining method which removes metal by a series of recurring electrical discharges between an electrode and a conductive workpiece, submerged in a dielectric fluid. Even though EDM techniques are widely used to cut hard materials, low efficiency and high tool wear remain remarkable challenges in this process. Various studies, such as mixing different powders to dielectric fluids, are progressing to improve their efficiency. This paper reviews advances in the powder-mixed EDM process. Furthermore, studies about various powders used for the process and its comparison are carried out. This review looks at the objectives of achieving a more efficient metal removal rate, reduction in tool wear, and improved surface quality of the powder-mixed EDM process. Moreover, this paper helps researchers select suitable powders which are exhibiting better results and identifying different aspects of powder-mixed dielectric fluid of EDM.

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“…where τ nuc is the nucleation time (s). Through Clausius-Clapeyron equation, the bubble pressure of nucleation can be obtained as follows [20]:…”

Section: Formation and Expansion Of Discharge Plasmas Of Micro-edmmentioning

confidence: 99%

“…The initial temperature of plasma T p can be obtained from Equation (11). It has been found that the initial pressure of discharge plasma is as high as 1010 Pa, the initial radius is about 0.18 µm, and the initial temperature is as high as 17,304 K [20]. These are expected to be adopted as initial conditions in the iterative calculation of plasma expansion and heating stages.…”

Section: Formation and Expansion Of Discharge Plasmas Of Micro-edmmentioning

confidence: 99%

Study on the Time-Varying Characteristics of Discharge Plasma in Micro-Electrical Discharge Machining

Liu

Zhang

et al. 2019

Coatings

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Micro electrical discharge machining (micro-EDM) has been widely applied in the field of precision machining, but the machining mechanism is still unclear. In this paper, the relationship between the characteristics of discharge plasma and discharge duration is clarified by analyzing the formation and expansion process of the discharge plasma channel under micro-scale discharge conditions. Based on the experimental results, the effects of discharge duration on the discharge current, discharge voltage and discharge crater size are discussed. The results show that the expansion acceleration, internal pressure, temperature, and electron density of the discharge plasma decrease as the discharge duration increase, while the radius and expansion velocity of the discharge plasma increase, and finally the discharge plasma reaches the state of shape–position equilibrium. The resistance of discharge plasma is estimated to fluctuate in the range of 38–45 Ω by the ratio of discharge maintenance voltage to discharge current. The energy utilization rate of micro-EDM is very high when discharge duration is less than 4 μs, and then decreases gradually as the discharge duration increased. There is a positive linear relationship between discharge crater volume and discharge duration. The discharge duration has no significant effect on the discharge crater depth. This study provides a theoretical basis for further study of discharge plasma characteristics in micro-EDM.

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A Study on Plasma Channel Expansion in Micro-EDM

Cited by 39 publications

References 26 publications

The Effects of Reduced Graphene Oxide Flakes in the Dielectric on Electrical Discharge Machining

The Effects of Reduced Graphene Oxide Flakes in the Dielectric on Electrical Discharge Machining

Recent Advances and Perceptive Insights into Powder-Mixed Dielectric Fluid of EDM

Study on the Time-Varying Characteristics of Discharge Plasma in Micro-Electrical Discharge Machining

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