The Mechanism of Ultrasonic Vibration Improving MRR in UEDM in Gas

2004 ◽  
Vol 471-472 ◽  
pp. 741-745 ◽  
Author(s):  
Qin He Zhang ◽  
Ru Du ◽  
Jian Hua Zhang ◽  
J.Y. Yang ◽  
Sheng Feng Ren

A new machining method, ultrasonic vibration aided electrical discharge machining (UEDM) in gas, is proposed in this paper. It is shown that electrical discharge machining with ultrasonic vibration aid can be achieved well in gas medium. In the process of UEDM in gas, the tool electrode is formed to be thin-walled pipe, high pressure gas medium is supplied from inside, and ultrasonic vibration is applied to workpiece. The property of ultrasonic is introduced. The same to other sound waves, ultrasonic have the characteristics of reflecting, refracting, intervening and resonance. The mechanism of elastic pole keeping in resonance with ultrasonic transferring from one end to the other end is explained with characteristics of ultrasonic. During the process of UEDM in gas, ultrasonic vibration of workpiece can improve the machining process. The theories of ultrasonic vibration increasing materials removal rate (MRR) are introduced. One theory is that the adhere strength between the metallic liquid drops and workpiece is not enough for the accelerative vibration, so metallic liquid drops will be ejected off easily. Another theory is that ultrasonic vibration increases the number of the effective discharge.

Author(s):  
Gurpreet Singh ◽  
DR Prajapati ◽  
PS Satsangi

The micro-electrical discharge machining process is hindered by low material removal rate and low surface quality, which bound its capability. The assistance of ultrasonic vibration and magnetic pulling force in micro-electrical discharge machining helps to overcome this limitation and increase the stability of the machining process. In the present research, an attempt has been made on Taguchi based GRA optimization for µEDM assisted with ultrasonic vibration and magnetic pulling force while µEDM of SKD-5 die steel with the tubular copper electrode. The process parameters such as ultrasonic vibration, magnetic pulling force, tool rotation, energy and feed rate have been chosen as process variables. Material removal rate and taper of the feature have been selected as response measures. From the experimental study, it has been found that response output measures have been significantly improved by 18% as compared to non assisted µEDM. The best optimal combination of input parameters for improved performance measures were recorded as machining with ultrasonic vibration (U1), 0.25 kgf of magnetic pulling force (M1), 600 rpm of tool rotation (R2), 3.38 mJ of energy (E3) and 1.5 mm/min of Tool feed rate (F3). The confirmation trail was also carried out for the validation of the results attained by Grey Relational Analysis and confirmed that there is a substantial improvement with both assistance applied simultaneously.


2006 ◽  
Vol 315-316 ◽  
pp. 81-84 ◽  
Author(s):  
Qin He Zhang ◽  
Jian Hua Zhang ◽  
Q.B. Zhang ◽  
Shu Peng Su

Ultrasonic vibration aided electrical discharge machining (UEDM) in gas is an electrical discharge machining (EDM) technology, in which gases such as air and oxygen are used as dielectrics and ultrasonic vibration is applied. 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 possesses virtues of wide applications, high machining efficiency and simple tool electrodes and so on. The principle of UEDM in gas is introduced in this paper. Experiments have been carried out to study the effects of machining parameters on material removal rate (MRR), surface roughness of the workpiece and tool electrode wear ratio (TWR), and the experiments results have also been analyzed.


2012 ◽  
Vol 433-440 ◽  
pp. 655-659
Author(s):  
S. Thiyagarajan ◽  
S.P. Sivapirakasam ◽  
Jose Mathew ◽  
M. Surianarayanan

This paper presents a study on the influence of process parameters on the manufacturing and environmental aspects of die sinking electrical discharge machining process using graphite as the tool electrode. This investigation included peak current, pulse duration, dielectric level and flushing pressure as the input parameters and aerosol emission rate, material removal rate and tool wear rate as the output parameters. The experiments were planned according to the Taguchi L9 orthogonal array. The effects of process parameters on the output responses were analyzed using main effect plots. Peak current was the most significant process parameter. A discussion on the optimization of process parameters is also presented in this paper.


2013 ◽  
Vol 845 ◽  
pp. 730-734 ◽  
Author(s):  
M.A. Moudood ◽  
A. Sabur ◽  
Mohammad Yeakub Ali ◽  
I.H. Jaafar

Electrical discharge machining (EDM) is a non-conventional machining process where materials are removed by the thermal energy exerted from series of electrical sparks. This process is applied for machining of non-conductive alumina (Al2O3). The workpiece is covered with the adhesive copper foil to initiate the initial spark between the workpiece and the tool electrode. A pyrolytic carbon (PyC) layer is generated on workpiece surface by dissociating kerosene dielectric after the machining of initial copper assisting electrode (AE) layer. In this study, experiments were performed by varying the peak current and keeping other parameters constant in order to investigate the effect of peak current on material removal rate (MRR) in EDM of Al2O3. The results showed that the lowest and the highest values of peak current were 1.1 A and 1.3 A, respectively. Material cannot be removed due to insufficient PyC layer generation for any values of peak current less than 1.1 A or more than 1.3 A. From the results, it is also observed that the MRR is increased when higher peak current values are used. MRR was found to be 0.052 mm3/min at peak current 1.1 A and it was found to be 0.132 mm3/min at peak current 1.3 A.


2010 ◽  
Vol 97-101 ◽  
pp. 4178-4181 ◽  
Author(s):  
Albert Wen Jeng Hsue ◽  
Chih Hung Chung

Owing to its low removal rate and debris ejection nature, EDM is a very slow machining process. A novel jump motion control for electrode in electrical discharge machining (EDM) equipped with dual linear motors (LmEDM) was proposed to release this debris efficiency point. The direct drive EDM and a novel pulse discriminator were developed. By introducing the discriminator to count effective discharge pulses, an EDM jump control was proposed. Experiments for verification of the EDM efficiency were conducted for 35 mm deep and thin EDM processes with 2 mm thin platelet. EDM efficiency of proposed jump control is verified to be four times over the traditional EDM.


2007 ◽  
Vol 359-360 ◽  
pp. 374-378
Author(s):  
Ming Rang Cao ◽  
Shi Chun Yang ◽  
Wen Hui Li ◽  
Sheng Qiang Yang

The EDM can machined some superhard conducting material that cannot be handled by the traditional method, such as carbide alloy, tool steel and engineering materials etc., however, it is also accompanied with slow material removal rate(MRR) and poor surface quality (surface roughness). For some fine machining having rigorous criterion on size and surface roughness, the EDM cannot meet the demand. Some researches indicate that the MRR of small hole by electrical discharge machining combined with ultrasonic vibration (UEDM) can increase in certain range, but the surface quality is still poor. Although there are lots of the researches on the UEDM, some debates on machining mechanism and applied scope existed, and technology of UEDM needs the further study. After small hole machined by the UEDM, it is polished by ultrasonic vibrating. Two steps are includes in this technology. In the first place, on a high velocity electro discharge small hole machine with high-pressure dielectric liquid and hollow electrode, a transducer and horn are attached between the spindle and the electrode. The ultrasonic vibration of the tool electrode is implemented by connecting the horn and the tool electrode together with a chucking appliance. The second, after the small hole is complete, with the same machine tool and tool electrode the process of polishing the inwall of the small hole is carried out by accompanying the ultrasonic vibration, revolution and feed of the tool electrode with the abrasive material. In the experiments, the reference point for UEDM is found and the new theory is proposed to explain the increase of the MRR and the decrease of the surface roughness value .The polish with the ultrasonic vibration can improve further the surface roughness. The ultrasonic vibrating polish after the hole by UEDM is an economical and effective technology, which realizes machining of two procedures in one machine tool. So the process for changing machine tool and tool is not needed any more and the efficiency is further improved.


2021 ◽  
Author(s):  
Xiang Gao ◽  
Jucai Li ◽  
Qixuan Xing ◽  
Qinhe Zhang

Abstract In this paper, ultrasonic-vibration assisted electrical discharge machining (UEDM) is used to process SiCp/Al composite materials in order to achieve a higher material removal rate (MRR) and lower surface roughness, width overcut, and relative tool wear rate (RTWR). FLUENT software was used to simulate the gap flow field. The simulation results of the gap flow field show that the ultrasonic vibration of the tool electrode is conducive to the removal of chips, which makes the discharge more stable and improves the machining efficiency. Based on the single factor experiment, the effects of peak current, reference voltage, pulse width, and pulse interval on MRR, surface roughness, width overcut, and RTWR of the workpiece are studied. Then, based on the orthogonal experiment, the grey relational analysis method was used to optimize the process parameters, and the order of the influence of the 4 process indicators on the comprehensive performance and the optimal processing parameter combination was obtained. The reliability of the process optimization was verified with experiments.


Author(s):  
Sagil James ◽  
Sharadkumar Kakadiya

Shape Memory Alloys are smart materials that tend to remember and return to its original shape when subjected to deformation. These materials find numerous applications in robotics, automotive and biomedical industries. Micromachining of SMAs is often a considerable challenge using conventional machining processes. Micro-Electrical Discharge Machining is a combination of thermal and electrical processes, which can machine any electrically conductive material at micron scale independent of its hardness. It employs dielectric medium such as hydrocarbon oils, deionized water, and kerosene. Using liquid dielectrics has adverse effects on the machined surface causing cracking, white layer deposition, and irregular surface finish. These limitations can be minimized by using a dry dielectric medium such as air or nitrogen gas. This research involves the experimental study of micromachining of Shape Memory Alloys using dry Micro-Electrical Discharge Machining process. The study considers the effect of critical process parameters including discharge voltage and discharge current on the material removal rate and the tool wear rate. A comparison study is performed between the Micro-Electrical Discharge Machining process with using the liquid as well as air as the dielectric medium. In this study, microcavities are successfully machined on shape memory alloys using dry Micro-Electrical Discharge Machining process. The study found that the dry Micro-Electrical Discharge Machining produces a comparatively better surface finish, has lower tool wear and lesser material removal rate compared to the process using the liquid as the dielectric medium. The results of this research could extend the industrial applications of Micro Electrical Discharge Machining processes.


Author(s):  
Omer Eyercioglu ◽  
Kursad Gov

This study presents an experimental investigation of small hole electrical discharge machining of Al-Mg-Ti alloys. A series of drilling operations were carried out for exploring the effect of magnesium content. Holes of 2 mm diameter and 15 mm depth were drilled using tubular single-hole rotary brass electrodes. The rates of material removal and electrode wear, surface roughness, overcut, average recast layer thickness, taper height and angle were studied for Al-Mg-Ti alloys contain 2%, 4%, 6%, 8%, 10%, 12%, and 14% Mg. The results show that the material removal rate is increasing with increasing Mg content while the rate of electrode wear is almost unchanged. Due to decreasing the melting temperature of the Al-Mg-Ti alloy with increasing Mg content, more metal melts and vaporizes during electrical discharge machining drilling. Therefore, more overcut and taper, thicker white layer, and rougher surfaces were measured for higher Mg content.


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