Indirect Approach to Ultrasonic Superposition in Micro-EDM

2011 ◽  
Author(s):  
Andreas Schubert ◽  
Nicolas Wolf ◽  
Henning Zeidler ◽  
Jo¨rg Schneider
Keyword(s):  
Ultrasonic Vibration ◽  
Large Scale ◽  
Stable Condition ◽  
Resonant Mode ◽  
Discharge Zone ◽  
Micro Edm ◽  
Serial Production ◽  
Electro Discharge Machining ◽  
First Results ◽  
Edm Process

Micro Electro Discharge Machining is a well known process for machining microstructures with highest precision in hard and brittle or tough materials. The deeper the structures and therefore higher the aspect ratio, the more difficult it is to remove the ablated particles from the discharge zone and keep the process in stable condition. Flushing can be aided by vibration of either tool or workpiece. Thus, applying ultrasonic vibration to micro EDM has proven to enhance the process significantly. The vibration is most efficiently induced via the tool or workpiece directly to the discharge zone. However, to achieve an ultrasonic vibration of the tool or workpiece, a complex vibration system that operates in resonant mode is needed. Any crucial change of the vibrating parts results in a demanding and therefore expensive adjustment of the vibrating system. With this setup, the application of ultrasonic vibration is only profitable for large scale serial production. In this work a different approach of ultrasonic superposition to the EDM is proposed. A highly focused ultrasonic vibration is induced into the dielectric in a way to directly influence the discharge zone. This indirect ultrasonic superposition can be easily applied since it is independent of the tool or workpiece geometry. Experiments are carried out to examine the effects of the indirect ultrasonic superposition on the EDM process. First results show the possibility of enhancing micro-EDM by this approach.

Generation of High Aspect Ratio Micro Holes by a Hybrid Micromachining Process

2007 ◽  
Author(s):  
Murali M. Sundaram ◽  
Sridevi Billa ◽  
Kamlakar P. Rajurkar
Keyword(s):  
Aspect Ratio ◽  
Ultrasonic Vibration ◽  
Machining Process ◽  
Hole Drilling ◽  
Micro Edm ◽  
Shape Distortion ◽  
Machining Time ◽  
Machined Surface ◽  
Electro Discharge Machining ◽  
Debris Removal

Drilling a micro hole with an aspect ratio above 10 is a challenging task for any-micromachining process. In micro electro discharge machining (micro EDM), a proven metallic micromachining process, this is due to the problems associated with debris removal. In such cases, where the capabilities of existing macro machining methods are constantly being challenged, innovative micro manufacturing approaches are required to make progress. Hybrid micromachining is one such approach in which the synergy of constituent processes is exploited to achieve desired results. In this paper, the results of ultrasonic vibration assisted micro electro discharge machining process are presented. This hybrid process is capable of deep hole drilling with aspect ratio of 20 in austenitic stainless steel by overcoming the limitations in the debris removal faced in the typical micro EDM process. Other benefits of ultrasonic vibration are the savings in machining time, and less tool wear. It is also noticed that the ultrasonic vibration causes some shape distortion and produces rougher machined surface.

scholarly journals A study of micro-electro discharge machining electrode wear

2007 ◽  
Vol 221 (5) ◽  
pp. 605-612 ◽  
Author(s):  
D T Pham ◽  
A Ivanov ◽  
S Bigot ◽  
K Popov ◽  
S Dimov
Keyword(s):  
Electrode Wear ◽  
Micro Edm ◽  
Volumetric Wear ◽  
Factors Affecting ◽  
Electro Discharge Machining ◽  
Electrode Shape ◽  
Compensation Methods ◽  
Geometrical Information ◽  
Edm Drilling ◽  
Edm Process

This paper studies the influence of factors contributing to electrode wear during the micro-electro discharge machining (EDM) process. The paper proposes a method for calculating the volumetric wear ratio based only on geometrical information obtained from the process. The objective of the work is to investigate the suitability of micro-EDM electrode wear compensation methods. Electrode shape deformation and random variations in the volumetric wear are studied as two main factors affecting the applicability of wear compensation methods as well as indicating the accuracy achievable with micro-EDM. EDM drilling and EDM milling are regarded as separate processes as they require different approaches in investigating and implementing the results of the study.

Modeling of a Single Resistance Capacitance Pulse Discharge in Micro-Electro Discharge Machining

2005 ◽  
Vol 127 (4) ◽  
pp. 759-767 ◽  
Author(s):  
Sandeep Dhanik ◽  
Suhas S. Joshi
Keyword(s):  
Material Removal ◽  
Pulse Generator ◽  
Pulse Discharge ◽  
Plasma Temperature ◽  
Micro Edm ◽  
Variable Source ◽  
Electro Discharge Machining ◽  
Single Discharge ◽  
Edm Process ◽  
Lower Discharge

Micro-EDM (electro discharge machining) is a derived form of EDM process especially evolved for micro-machining. The use of resistance capacitance pulse generator, an advanced controller for machining in smaller interelectrode gaps and with lower discharge energies than in EDM, makes the material removal characteristics of a single discharge in micro-EDM different from that of the EDM. A comprehensive model predicting the material removal in a single discharge in micro-EDM is conceptualized. The model incorporates various phenomena in the prebreakdown period. It considers plasma as a time-variable source of energy to the cathode and anode to evaluate material removal at the electrodes. The plasma temperature and radius of the crater at the cathode (workpiece) predicted using the model were found to agree well with the experimental data in the literature.

Alloy Inconel 718 by 3D Micro-Electro Discharge Machining

2014 ◽  
Vol 590 ◽  
pp. 239-243 ◽  
Author(s):  
Piyapong Kumkoon ◽  
Chana Raksiri ◽  
Chaiyakorn Jansuwan
Keyword(s):  
Inconel 718 ◽  
Micro Edm ◽  
Optimal Parameters ◽  
Electro Discharge Machining ◽  
Debris Removal ◽  
Micro Drilling ◽  
Voltage Frequency ◽  
Off Time ◽  
Edm Drilling ◽  
Edm Process

This article aims to show the effects of the Micro-EDM process that influences the hole taper by comparing the parameters values during micro-drilling hole on the inconel 718 material. The condition of Micro-EDM drilling spark on the surface workpiece was 300 μm of depth and 200 μm of diameter tungsten carbide electrode. The experiment was carried out under the cover of hydrocarbon, using fluid dielectric cooling. The experiment parameters included on-time duty factor, off-time, voltage, frequency, and current, respectively. The experiment, it was found that the hole taper an immense effect on the machinability of drilling the workpieces, cause melting and recasting in the spark area, making a decrease in the ability of debris removal. Moreover, the experiment result, the tapered workpiece showed a minimized is 16.87 s, when using parameters at current 32 mA, frequency 150 Hz, and voltage 110 v, respectively. The optimal parameters to affected minimum hole taper is 0.195 degree, when using parameters at current 32 mA, frequency 130 Hz, and voltage 110 v, respectively.

Finite Element Modeling of Discharge Zone in Micro-EDM Process

2012 ◽  
Author(s):  
Jose Mathew ◽  
Deepak G. Dilip ◽  
Mathew J. Joseph ◽  
Basil Kuriachen
Keyword(s):  
Finite Element ◽  
Titanium Alloy ◽  
Removal Rate ◽  
Discharge Zone ◽  
Dielectric Fluid ◽  
Work Piece ◽  
Uniform Mesh ◽  
Tool Electrode ◽  
Micro Edm ◽  
Edm Process

Micro-EDM (μ-EDM) is a derived form of EDM process especially evolved to perform micro-machining. The μ-EDM process is based on the thermoelectric energy created between a work piece and an electrode submerged in a dielectric fluid. When the work piece and the electrode are separated by a specific small gap, a pulsed discharge occurs which removes material from the work piece through melting and evaporation. A thermo-electrical approach to model the temperature variation in the discharge gap using finite element method has been done so as to predict the temperature distribution in the discharge channel and find out the maximum temperatures acting on the work piece as well as the tool electrode and the subsequent material removal rate on the work piece. The temperature generated on the surface of the work piece depends upon the various properties of the conductor; as a result it varies depending on the conductor. An axi-symmetric two-dimensional model was used for modeling the region between the two electrodes. Tungsten and titanium alloy were the materials used for cathode and anode, respectively. A 60μm by 60μm region was taken for modeling the process. An uniform mesh of equal dimensions was made to carry out the modeling. The finite element results were compared with the results obtained by conducting experiments on titanium alloy using single spark generator device under the same discharge conditions that were given as input for the mathematical model. The MRR obtained agrees very well with the predicted MRR thus validating the model.

Materials for the history of the gospel-Baptist movement in Ukraine

1996 ◽  
pp. 4-15
Author(s):  
S. Golovaschenko ◽  
Petro Kosuha
Keyword(s):  
Large Scale ◽  
Religious Studies ◽  
Theological Seminary ◽  
National Academy Of Sciences ◽  
Evangelical Christians ◽  
Evangelical Christian ◽  
First Results ◽  
History Of ◽  
Fruitful Cooperation ◽  
Academy Of Sciences

The report is based on the first results of the study "The History of the Evangelical Christians-Baptists in Ukraine", carried out in 1994-1996 by the joint efforts of the Department of Religious Studies at the Institute of Philosophy of the National Academy of Sciences of Ukraine and the Odessa Theological Seminary of Evangelical Christian Baptists. A large-scale description and research of archival sources on the history of evangelical movements in our country gave the first experience of fruitful cooperation between secular and church researchers.

Sustainable Production of Honeydew and Muskmelon in Western Mexico

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 495d-495
Author(s):  
J. Farias-Larios ◽  
A. Michel-Rosales
Keyword(s):  
Large Scale ◽  
Management Practices ◽  
Glomus Intraradices ◽  
Cultural Practices ◽  
Bare Soil ◽  
Western Mexico ◽  
First Results ◽  
Legume Cover Crop ◽  
Banana Leaves ◽  
Research Show

In Western Mexico, melon production depends on high-input systems to maximize yield and product quality. Tillage, plasticulture, fumigation with methyl bromide, and fertigation, are the principal management practices in these systems. However, at present several problems has been found: pests as sweetpotato whitefly (Bemisia tabaci Gennadius), aphids (Myzus and Aphis), leafminer (Liryomiza sativae); diseases as Fusarium, Verticilium, and Pseudoperenospora, and weeds demand high pesticide utilization and labor. There is a growing demand for alternative cultural practices, with an emphasis on reducing off-farm input labor and chemicals. Our research is based on use of organic mulches, such as: rice straw, mature maize leaves, banana leaves, sugarcane bagasse, coconut leaves, and living mulches with annual legume cover crop in melons with crop rotation, such as: Canavalia, Stilozobium, Crotalaria, and Clitoria species. Also, inoculations with mycorrhizal arbuscular fungi for honeydew and cantaloupe melon seedlings production are been assayed in greenhouse conditions for a transplant system. The use of life barriers with sorghum, marigold, and other aromatic native plants in conjunction with a colored yellow systems traps for monitoring pests is being studied as well. While that the pest control is based in commercial formulations of Beauveria bassiana for biological control. The first results of this research show that the Glomus intraradices, G. fasciculatum, G. etunicatum, and G. mosseae reached 38.5%, 33.5%, 27.0%, and 31.0% of root infection levels, respectively. Honeydew melons production with rice and corn straw mulches shows an beneficial effect with 113.30 and 111.20 kg/plot of 10 m2 compared with bare soil with 100.20 kg. The proposed system likely also lowers production cost and is applicable to small- and large-scale melon production.

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