Proposal for Abrasive Layer Fabrication on Thin Wire by Electrical Discharge Machining

2010 ◽  
Vol 4 (4) ◽  
pp. 394-398 ◽  
Author(s):  
Katsushi Furutani ◽  
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Green Compact ◽  
Feed Speed ◽  
Thin Wire ◽  
Initial Tension ◽  
Wire Saw ◽  
The Wire ◽  
Abrasive Layer ◽  
Piano Wire

This paper deals with a method of fabricating an abrasive layer on a thin wire by means of electrical discharge machining (EDM). An electrodeposited wire saw is useful for slicing a silicon ingot. However, strong acids are used in the production process and the depositing speed is slow. To overcome these problems, a fabrication process for an abrasive layer on a thin wire by EDM is proposed. The layer deposited by EDM with a green compact electrode is porous under certain electrical conditions so that the layer is composed of abrasive grit, pores and bond. A mixture of WC, Co, and the abrasive was compressed to make the green compact electrode. Two green compact electrodes were placed facing each other and were reciprocally fed during the process. The WC layer was deposited in 1s on an area in a preliminary experiment. The feed rate of 0.12-mm piano wire was set to 50mm/min. Al2O3abrasive powders with a size of 35-50µm were able to be contained in the WC layer on the wire. The deposit containing the abrasive firmly adhered. Because the deposited WC layer was very hard, tight gripping of the grit can be also expected. A copper block was cut with a raw piano wire, with wires with or without the abrasive deposited by EDM, and with electrodeposited or resinoid wire saws available on the market to compare their cutting performance. The initial tension was set to 5N and the cutting load was changed from 5.5 to 9.0N. The average feed speed of the wire was set to 8m/min. After 2000 reciprocating motions, the amounts machined with the deposited wire were larger than those with the wire saw available on the market. The deposited wire endured the same cutting load as the electrodeposited wire saw.

Automatic Stripping of Dielectric-Encased Wire Tool Electrode Used in Electrical Discharge Machining

2007 ◽  
Vol 129 (5) ◽  
pp. 973-978
Author(s):  
Seiji Kumagai ◽  
Naoki Sato ◽  
Koichi Takeda
Keyword(s):  
Control System ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Threshold Value ◽  
Electrode System ◽  
Tool Electrode ◽  
Feed Speed ◽  
Wire Electrode ◽  
Aspect Ratios ◽  
The Wire

A new electrical discharge machining (EDM) system using a wire encased in a dielectric jacket is proposed as an alternative to conventional hole-fabrication EDM systems. The jacket suppresses secondary discharges occurring between the sidewalls of the wire and the fabricated hole, which allows fabrication of holes with higher aspect ratios compared to those formed by a conventional EDM system using naked pipe electrodes. In this new system, the tip of the wire electrode is stripped by displacing the jacket, which produces continuous sparks for workpiece erosion and keeps the bore and shape of the fabricated holes constant. In the present study, we developed a control system to maintain the exposed length of the tip without the need for visual observation and without the assumption that wear is constant over time. The exposed length of the tip of the wire electrode is related to the feed speed (toward the workpiece) of the electrode system. The jacket was displaced when the feed speed of the electrode system exceeded a threshold value, which resulted in slowing of the electrode system feed. The feed speed was kept within the specified range by determining a threshold value, which led to maintenance of a constant exposed length of the tip. This control system was validated in actual drilling tests. Optimizing the threshold feed speed contributed to a higher machining speed.

scholarly journals Influence of Energy Parameters of Micro WEDM on Kerf

2012 ◽  
Vol 576 ◽  
pp. 527-530
Author(s):  
Mohammad Yeakub Ali ◽  
W.Y.H. Liew ◽  
S.A. Gure ◽  
B. Asfana
Keyword(s):  
Experimental Data ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Kerf Width ◽  
Wire Electrical Discharge Machining ◽  
Machining Parameters ◽  
Wire Electrode ◽  
Wire Vibration ◽  
The Wire ◽  
Micro Wedm

This paper presents the estimation of kerf width in micro wire electrical discharge machining (micro WEDM) in terms of machining parameters of capacitance and gap voltage. An empirical model is developed by the analysis of variance (ANOVA) of experimental data. Using a wire electrode of 70 µm diameter, a minimum kerf width is found to be 92 µm for the micro WEDM parameters of 0.01 µF capacitance and 90.25 V gap voltage. Around 30% increament of the kerf is found to be high. The analysis also revealed that the capacitance is more influential parameter than gap voltage on kerf width produced by micro WEDM. As the gap voltage determines the breakdown distance and affects the wire vibration, the wire vibration factor is to be considered in the analysis and in formulation of model in future study.

scholarly journals Wire Electrical Discharge Machining—A Review

Machines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 69
Author(s):  
Laurenţiu Slătineanu ◽  
Oana Dodun ◽  
Margareta Coteaţă ◽  
Gheorghe Nagîţ ◽  
Irina Beşliu Băncescu ◽  
...  
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Machining Process ◽  
Wire Electrical Discharge Machining ◽  
Wire Electrode ◽  
Machining Processes ◽  
Scientific Papers ◽  
The Wire ◽  
Machining Productivity ◽  
Machined Surfaces

Wire electrical discharge machining has appeared mainly in response to the need for detachment with sufficiently high accuracy of parts of plate-type workpieces. The improvements introduced later allowed the extension of this machining technology to obtain more complex ruled surfaces with increasingly high requirements regarding the quality of the machined surfaces and the productivity of the wire electrical discharge machining process. Therefore, it was normal for researchers to be interested in developing more and more in-depth investigations into the various aspects of wire electrical discharge machining. These studies focused first on improving the machining equipment, wire electrodes, and the devices used to position the clamping of a wire electrode and workpiece. A second objective pursued was determining the most suitable conditions for developing the machining process for certain proper situations. As output parameters, the machining productivity, the accuracy, and roughness of the machined surfaces, the wear of the wire electrode, and the changes generated in the surface layer obtained by machining were taken into account. There is a large number of scientific papers that have addressed issues related to wire electrical discharge machining. The authors aimed to reveal the aspects that characterize the process, phenomena, performances, and evolution trends specific to the wire electrical discharge machining processes, as they result from scientific works published mainly in the last two decades.

Effects of Machining Fluid on Electric Discharge Machining of SiC Ingot

2014 ◽  
Vol 778-780 ◽  
pp. 767-770 ◽  
Author(s):  
Norimasa Yamamoto ◽  
Satarou Yamaguchi ◽  
Tomohisa Kato
Keyword(s):  
Surface Roughness ◽  
Silicon Carbide ◽  
Ion Exchange ◽  
Electric Discharge ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Electric Discharge Machining ◽  
The Wire ◽  
Characteristic Features ◽  
First Time

Recently, ingots of silicon carbide have been adapted to be sliced by the wire-cut electrical discharge machining. Fast slicing, and the reduction in the loss are important for slicing of the wafer. In this paper, characteristic features of the electric discharge machining in the ion-exchange water and the fluorine-based fluid were compared for these improvement. The discharge was caused by a pulse voltage applied to a ingot of silicon carbide and the wire in machining fluid, and the slicing was proceeded. As a result, improvement of surface roughness and kerf loss was confirmed, for the first time. In addition, the improving methods for fast slicing were considered.

Fabrication of Micropins Using Micro Turning Tools

2012 ◽  
Vol 523-524 ◽  
pp. 76-80 ◽  
Author(s):  
Takuya Furukawa ◽  
Yosuke Nomura ◽  
Kazuyuki Harada ◽  
Kai Egashira
Keyword(s):  
Tungsten Carbide ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Cutting Tools ◽  
Depth Of Cut ◽  
Feed Speed ◽  
Tool Breakage ◽  
Micro Cutting ◽  
Hard Materials ◽  
Micro Turning

The turning of straight micropins with a diameter smaller than 10 µm, which has not been reported so far, was carried out using micro turning tools made of cemented tungsten carbide. Tools of 50 µm diameter were fabricated by electrical discharge machining, which is suitable for fabricating micro cutting tools because it can deal with hard materials and carry out micromachining. A turning machine designed especially for micro turning tools was used in the experiments. A brass workpiece was turned using a tool with a length of cut of 100 µm at a feed speed of 3.0 µm/s, feed per revolution of 0.06 µm and depth of cut of 10–11 µm. As a result, a straight micropin of 7.5 µm diameter and 80 µm length was successfully turned. Furthermore, turning was also performed using a tool with a length of cut of 50 µm at a feed speed of 3.0 µm/s, feed per revolution of 0.06 µm and depth of cut of 8.5–20 µm to fabricate a straight micropin of 3 µm diameter and 30 µm length. This micropin is the pin with the smallest ever diameter fabricated by turning, to the best of our knowledge, indicating the possibility of further minimization of the machinable size in turning. Turning properties were also investigated to determine the maximum depth of cut and feed speed that can be employed without tool breakage.

Electrical Discharge Machining of Submicron-Diameter Micropins

2010 ◽  
Vol 447-448 ◽  
pp. 238-241 ◽  
Author(s):  
Hiromitsu Ueno ◽  
Yuki Kono ◽  
Kai Egashira
Keyword(s):  
Electrical Discharge ◽  
Tungsten Wire ◽  
Open Circuit Voltage ◽  
Pulse Generator ◽  
Electrical Discharge Machining ◽  
Open Circuit ◽  
Tool Electrode ◽  
Stray Capacitance ◽  
Finish Machining ◽  
The Wire

The wire electrodischarge grinding (WEDG), which is one of the electrical discharge machining (EDM) methods, of submicron-diameter zinc micropins was attempted using a relaxation-type pulse generator. Tungsten wire of 30 µm diameter was employed as the tool electrode. The open-circuit voltage was set at lower than or equal to 15 V in the finish machining step. The electrostatic capacitance of the pulse generator was its stray capacitance only. As a result, a micropin of 0.3 µm diameter was processed. They are the smallest-diameter micropins fabricated by EDM, to the best of our knowledge.

Study on Modeling and Simulation of Wire Vibration in WEDM

2012 ◽  
Vol 472-475 ◽  
pp. 2013-2017
Author(s):  
Chao Jiang Li ◽  
Yong Feng Guo ◽  
Ji Cheng Bai ◽  
Ze Sheng Lu ◽  
Chuan Chen
Keyword(s):  
Electrical Discharge ◽  
Pulse Width ◽  
Metal Cutting ◽  
Electrical Discharge Machining ◽  
Orthogonal Design ◽  
Pulse Interval ◽  
Machining Accuracy ◽  
Wire Tension ◽  
Wire Vibration ◽  
The Wire

The wire electrical discharge machining (WEDM) has been widely used in the field of metal cutting, mold industry, aerospace and so on. However, in the discharge machining, it is very important to restrain the wire-tool vibration for the improvement of machining accuracy. In this paper, it is created a model of the wire vibration with double-ended fixed, established the differential equation of vibration, and derived its full theoretical solution to analysis the vibration factors. Simulations of the wire vibration with ANSYS Transient dynamics analysis were given. An orthogonal design of the wire vibration using L9 orthogonal table was made, and the experiment found that minimize the servo voltage, reduce the pulse width, and select the appropriate wire tension and pulse interval, which can reduce the wire vibration.

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