Simulation model of debris and bubble movement in consecutive-pulse discharge of electrical discharge machining

Author(s):  
Jin Wang ◽  
Fuzhu Han
Author(s):  
Y. F. Luo ◽  
Jia Tao

A new understanding of the expulsion mechanism in electrical discharge machining (EDM) is discussed in this investigation. The shifting secondary discharge inside a cathodic root is revealed as the major driving force for metal expulsion in EDM. A typical electrode couple of steel for cathode and copper for anode is used in all the experiments and discussions. Micro graphs of discharge craters are taken from the complex surface directly after a continual discharging process while either normal or reversed polarity is applied. The apparent difference in crater morphologies on anode and cathode indicates the unique expulsion mechanism, namely secondary discharges, which only take place inside the cathodic root. The compliance of secondary discharges with long-disputed phenomena, such as the discrepancy between energy distribution and metal removal, is demonstrated through the applications of the mechanism to the phenomena. The applied methods and results are more realistic since single pulse discharge among other process changes is prohibited. Such a more reliable understanding can correlate the complex metal removal mechanisms to better future process developments.


2016 ◽  
Vol 818 ◽  
pp. 112-116
Author(s):  
Fatemeh Karimi Pour ◽  
Mahrokh Bavandi ◽  
Azli Yahya

Electrical discharge machining (EDM) is one of the earliest non-traditional machining processes and controlled process where pulsed electrical discharge is used to erode metal in a workpiece. EDM pulsed power generator applies voltage pulse discharge occurs in a small gap between the work piece and the electrode and removes the unwanted material from the parent metal through melting and vaporization. The essential requirement for EDM system is to obtain the output waveform similar to the ideal EDM waveform. This paper seeks to discuss on the design and simulation based on RC (resistance-capacitance) power generator circuit. Based on the findings of the study, from the equation gained, the simulation is constructed through using electrical model in Matlab Simulink software and circuit analysis in Lapels transform in EDM system process. Also this procedure simulated in Matlab software.


2018 ◽  
Vol 913 ◽  
pp. 536-541
Author(s):  
Yong Fu Zhang ◽  
Wei Wei Chen ◽  
Huan Wu Cheng ◽  
Yu Ping Zhang

A new method was adopted in this study to machine C/SiC composite. The machinability was studied by processing some shapes in the material in this way. Small deep holes were machined firstly to test whether the copper electrode was suitable enough to be adopted in the Electrical Discharge Machining. Then holes of different diameters were processed by two kinds of electrodes to study the more appropriate electrode material by comparing machining efficiency of two electrodes. Then complicated shapes were machined based on these conditions. Finally, a simulation model was built up to study the influence of the fluid on the electrode and the workpiece in the Fluent 6.3. According to the study, Electrical Discharge Machining Technology is suitable enough to machine the hard and brittle materials like C/SiC composite and the accuracy that the error should not exceed 0.5 mm can also be guaranteed well.


2014 ◽  
Vol 1017 ◽  
pp. 764-769
Author(s):  
Tian Feng Zhou ◽  
Li Zheng Ma ◽  
Zhi Qiang Liang ◽  
Xi Bin Wang

This paper aims to quantify the effects of the machining condition on the surface topography in electrical discharge machining (EDM), including pulse current, pulse duration and so on. Firstly, the heat source of a single electrical pulse is defined by Gauss distribution, and the thermal effects of machining parameters on the workpiece material erosion are simulated by Finite Element Method (FEM) package ANSYS. Then, the crater size of a single pulse is numerically simulated based on the thermal model of a single pulse discharge. Furthermore, the superposition of multiply craters created by continuous pulse discharges in a random distribution is calculated by MATLAB software program, so that the evolution of the surface topography can be obtained with the combination of FEM simulation and topology calculation. In this way, the surface roughness is quantitatively calculated from the specified EDM parameters.


2016 ◽  
Vol 818 ◽  
pp. 106-111
Author(s):  
Fatemeh Karimi Pour ◽  
Azli Yahya ◽  
Mahrokh Bavandi ◽  
Ronia Tavakkoli ◽  
Dana Dehghani

One of the latest non-traditional machining processes and controlled process is presented as Electrical Discharge Machining (EDM) that the pulsed electrical discharge is used to erode metal in a work piece. The voltage pulse discharge occurs when EDM pulsed power generator is applied on a workpiece. The discharge happens in a small gap between the work piece and the electrode. The important function of EDM is to obtain the output waveform parallel with the ideal EDM waveform. Additionally, the EDM design is according to the transistor kind pulse power generator circuit. The present paper seeks to discuss on the current modeling and voltage gap waveform intended for the system in EDM process. Based on the derived equation, the simulation is done using electrical model in Matlab Simulink software and circuit analysis in Lapels transform in EDM process.


2012 ◽  
Vol 523-524 ◽  
pp. 951-956
Author(s):  
Yoshiaki Akematsu ◽  
Kazuro Kageyama ◽  
Naotake Mohri ◽  
Hideaki Murayama

This paper describes some experimental results on a fundamental phenomenon of the single pulse discharge. In electrical discharge machining (EDM), processing accuracy was effected by behaviors of fused material. Pressure was important for removing fused material. So, it was needed to clarify that the mechanism of pressure occurrence by electrical discharge. In this study, it was investigated that effect of discharge condition on cavitations behavior by single pulse discharge. Gap region medium viscosity was changed by medium and temperature. Electrical discharge current was changed by applied voltage. The optical fiber vibration sensor is located on an aluminum work-piece (cathode) plate. Pressure was measured by optical fiber sensor during single pulse discharge. As the results, burst acoustic emission (AE) wave was occurred during single pulse discharge. The occurrence of several times burst AE wave was caused by cavitations behavior. The condition on which bubble does not collapse has become apparent. It was found that cavitations behavior was mainly depended on discharge current except for the condition on which bubble does not collapse.


2011 ◽  
Vol 291-294 ◽  
pp. 3069-3072 ◽  
Author(s):  
Lan Chen

This paper presents a new method to fabricate tungsten microelectrode in a single pulse electrical discharge. The electrode material, diameter and polarity affect the shape of probe. The 80μm diameter tungsten wire between 500 and 600μF capacitance can be fabricated in 1μm tungsten electrode probe tip. The experiment use different material such as W, Cu and Mo. Finally, in the condition of “negative pole machining”, only tungsten can be used to make probe. It can greatly shorten the microelectrode fabrication time and effectively improve the reliability of the microelectrode and can fabricate a nanometer level tip in general electrical discharge machining (EDM) machine tool not add any other apparatus. The fabricated microelectrode can be used as a probe for scanner and measurement devices.


2008 ◽  
Vol 375-376 ◽  
pp. 500-504
Author(s):  
Qin He Zhang ◽  
Jian Hua Zhang ◽  
Shu Peng Su ◽  
Qing Gao

Ultrasonic vibration aided electrical discharge machining (UEDM) in gas is a new machining technology developed in recent years. This technology uses air or oxygen as dielectric and ultrasonic vibration is applied to the workpiece during machining. UEDM in gas can avoid environment pollution, the most serious disadvantage of conventional EDM in kerosene-based oil or other dielectric fluids, and it is environmental-friendly. The technology also has virtues of wide applications, high machining efficiency, and simple tool electrodes and so on. In this paper, the formation and transformation of the spark plasma and the mechanism of material removal during a single pulse discharge are introduced.


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