scholarly journals Discharge Energy as a Key Contributing Factor Determining Microgeometry of Aluminum Samples Created by Electrical Discharge Machining

Crystals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1371
Author(s):  
Katarzyna Peta ◽  
Michał Mendak ◽  
Tomasz Bartkowiak
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Multiscale Methods ◽  
Discharge Energy ◽  
Regression Analyses ◽  
Electrical Discharges ◽  
Exponential Regression ◽  
Geometrical Features ◽  
Surface Microgeometry ◽  
Focus Variation

The aim of this study is first to determine the effect of the discharge energy on the surface microgeometry of aluminum samples created by electrical discharge machining (EDM). Secondly, an additional purpose is to demonstrate the differences between the geometric multiscale methods: length-, area-scale, and curvature. Eleven samples were manufactured using discharge energies ranging from 0.486 mJ to 1389.18 mJ and, subsequently, measured with focus variation microscopy. Standard ISO and multiscale parameters were calculated and used for surface discrimination and regression analysis. The results of linear, logarithmic, and exponential regression analyses revealed a strong correlation (R2 > 0.9) between the geometrical features of the surface topography and the discharge energy. The approach presented in this paper shows that it is possible to shape surface microgeometry by changing the energy of electrical discharges, and these dependencies are visible in various scales of observation. The similarities of the results produced by curvature and length-scale methods were observed, despite the significant differences in the essence of those methods.

Small Diameter External Cylindrical Surfaces Obtained by Ram Electrical Discharge Machining

2014 ◽  
Vol 611-612 ◽  
pp. 650-655 ◽  
Author(s):  
Laurenţiu Slătineanu ◽  
Margareta Coteaţă ◽  
Hans Peter Schulze ◽  
Oana Dodun ◽  
Irina Besliu ◽  
...  
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Process Analysis ◽  
Electrical Discharge Machine ◽  
Small Diameter ◽  
Machining Process ◽  
Dielectric Fluid ◽  
Tool Electrode ◽  
Electrical Discharges ◽  
Pulse On Time

Electrical discharge machining uses the pulse electrical discharges generated between the closest asperities existing on the workpiece surface and the active surface of the tool electrode in dielectric fluid. Essentially, some distinct electrical discharge machining schemas could be used in order to obtain cylindrical external surfaces; within this research, one preferred a machining schema based on the use of a cooper plate in which there were small diameter holes, by taking into consideration the existence of a ram electrical discharge machine. The results of the machining process analysis were presented. A thin copper was considered to be used as tool electrode, in order to diminish the spurious electrical discharges, able to generate shape errors of the machined surface. Some experimental researches were developed by changing the sizes of the process input parameters. As output factors, the test piece and tool electrode masses decreases were considered. Power type empirical mathematical models were determined, in order to highlight the influence exerted by the pulse on time, off time and machining process duration on the output parameters values.

Effects of Electrical Discharge Energy on Machining Performance of Sintered NdFeB Magnet

2009 ◽  
Vol 620-622 ◽  
pp. 711-714 ◽  
Author(s):  
Li Li ◽  
Guang Ming Yuan ◽  
Zong Wei Niu ◽  
Rong Guo Hou
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Machining Parameters ◽  
Discharge Energy ◽  
Machining Performance ◽  
Ndfeb Magnet ◽  
Machined Surface ◽  
Micro Cracks ◽  
Ndfeb Permanent Magnet

Sintered NdFeB permanent magnet is widely used in many areas because of its excellent magnet property. In this study, the machining parameters of electrical discharge machining (EDM) are varied to study the effects of electrical discharge energy on material removal rate and surface roughness of NdFeB magnet. Moreover, the micro-cracks on the machined surface induced by EDM are also examined. The experimental results reveal that the MRR increases with the electrical discharge energy. The number of surface cracks on the machined surface increases with the enhancement of discharge energy Thus, using EDM process to machine sintered NdFeB magnet depends on setting the machining parameters to prevent surface crack.

Evolution of White Layer and Residual Stress in Electrical Discharge Machining

2021 ◽  
Author(s):  
Guisen Wang ◽  
Fuzhu Han ◽  
Liang Zhu
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Fatigue Life ◽  
Layer Thickness ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
White Layer ◽  
Machining Parameters ◽  
Discharge Energy ◽  
White Layer Thickness

Abstract White layer and residual stress are the main reasons for the decrease in fatigue life of electrical discharge machined samples. Therefore, it is important to research the evolution of the white layer and residual stress in electrical discharge machining and explain the influence mechanism of machining parameters on them. In this study, the surface topography, white layer thickness, and residual stress of electrical discharge machined samples under different processing parameters were evaluated. The results indicated that surface roughness, white layer thickness, and residual stress increased as the discharge current (I) and pulse-on time (ton) increased. However, when the ton was short, the effect of I (≤ 9.8 A) on surface roughness is not very obvious. When the discharge energy is similar, surface roughness is high under high I conditions. When the discharge energy is similar and low, the average thickness of the white layer is thin under the low I. The effect of I on surface residual stress was greater than that of the ton. The I and ton affect the white layer and residual stress by affecting the amount of melting and removal of the materials. These results were demonstrated that the input process of discharge energy has an important influence on residual stress and the white layer. Therefore, under the premise of ensuring the processing requirements, they can be controlled by selecting the appropriate combination of the ton and I to improve the fatigue life of the workpiece.

Electrode Tool Wear at Electrical Discharge Machining

2012 ◽  
Vol 504-506 ◽  
pp. 1189-1194 ◽  
Author(s):  
Laurenţiu Slătineanu ◽  
Hans Peter Schulze ◽  
Oana Dodun ◽  
Margareta Coteaţă ◽  
Lorelei Gherman ◽  
...  
Keyword(s):  
Cross Section ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Experimental Tests ◽  
Machining Process ◽  
Electrode Wear ◽  
Electrical Discharges ◽  
Workpiece Material ◽  
Electrode Tool ◽  
Theoretical Considerations

As consequence of the development of electrical discharge machining process, the electrode is affected by wear; knowing the evolution of the electrode wear, a better estimation of its service life is possible. It is expected that the electrode wear depends on the energy of the electrical discharges and the mass of the electrode. It is known also that the nature of the workpiece material exerts influence on the evolution of the electrode wearing process. In the paper, some theoretical considerations are used to highlight the above mentioned aspects. A set of experimental tests was designed and developed in order to highlight the influence exerted by the nature of the workpiece material and by the size of the cross section of the electrode, respectively, on the electrode wear. Empirical mathematical models corresponding to the evolution of the electrode wear were established.

Electrical Discharge Machining (EDM): Selection of Dielectric in Machining ASSAB 718HH

2012 ◽  
Vol 622-623 ◽  
pp. 520-524
Author(s):  
Norliana Mohd Abbas ◽  
Darius Gnanaraj Solomon
Keyword(s):  
Electrical Discharge ◽  
Material Removal ◽  
Electrical Discharge Machining ◽  
Plasma Channel ◽  
Removal Rate ◽  
Dielectric Strength ◽  
Work Piece ◽  
Electrical Discharges ◽  
Tool Wear Ratio ◽  
Selection Of

Electrical Discharge Machining (EDM) in Malaysia is widely used in mould making industries. Parts for automotive, defence and telecommunication industries are also other examples of the products produced. The process is based on removing material from a part by a series of repeated electrical discharges between a tool called electrode and the work piece with the presence of dielectric. The dielectric serves as transportation of removed particles, remains electrically non-conducting until the breakdown voltage is reached, reconditions the dielectric strength, increases the energy density in plasma channel and cools the electrode. This paper presents the machining of ASSAB 718HH work pieces with copper tool using EDM die sinking method. Three commercial EDM dielectrics; Kerosene, Novis and Amoil were tested and comparison between material removal rate (MRR), tool wear ratio (TWR) and surface finish (SF) are given. Through Pugh Method, result shows that ASSAB 718HH is best machined with Novis.

Measurement of Polycrystalline Diamond Craters in Electrical Discharge Machining

2014 ◽  
Vol 664 ◽  
pp. 304-309 ◽  
Author(s):  
Bo Hu ◽  
Song Lin Ding ◽  
Christopher Lim ◽  
Milan Brandt ◽  
John Mo
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Polycrystalline Diamond ◽  
Discharge Process ◽  
Grinding Method ◽  
3D Microscopy ◽  
Crater Morphology ◽  
Focus Variation ◽  
The Individual ◽  
Variation Technique

The electrical discharge grinding method is widely used to machine polycrystalline diamond tools because diamond is the hardest material and the traditional abrasive grinding method leads to high tool wear rate. The aim of this study was to find a method to precisely measure the individual diamond crate morphology during the electrical discharge process. A 3D microscopy with the focus-variation technique was chosen to obtain the stereolithography file of the polycrystalline diamond craters. The measurements were shown that the polycrystalline diamond crater morphology is more complex than that of normal tungsten carbide material. This finding can help build more accurate model of polycrystalline crater formation during electrical discharge process.

Investigation of RC Type Electrical Discharge Machining on ASSAB 618 Steel Using Copper Electrode

2013 ◽  
Vol 315 ◽  
pp. 30-34
Author(s):  
Muhammad Zulhisham Ahmed Zaki ◽  
M. Azuddin
Keyword(s):  
Surface Finish ◽  
Electrical Discharge ◽  
Pulse Generator ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Copper Electrode ◽  
Energy Output ◽  
Electrode Wear ◽  
Discharge Energy ◽  
Rc Circuit

This paper presents the investigation on Electrical Discharge Machining (EDM) on ASSAB 618 steel using copper electrode. The sparking power was generated using Resistor Capacitor (RC) Circuit and not usual Transistor Pulse Generator Circuit. The performance of the electrodes in the EDM RC circuit was evaluated based on the achieved surface roughness with respect to material removal rate (MRR) and electrode wear ratio (EWR). In this study, investigations have been conducted with surface finish at different discharge energy output. It was found that the surface characteristics are dependent mostly on the discharge energy during machining. The fine finish electrical discharge machining requires minimization of the discharge energy supplied into the gap. In addition, the surface finish was found to be influenced greatly by the electrical and thermal properties of the electrode material.

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