scholarly journals Recent Advances and Perceptive Insights into Powder-Mixed Dielectric Fluid of EDM

Micromachines ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 754 ◽  
Author(s):  
Asarudheen Abdudeen ◽  
Jaber E. Abu Qudeiri ◽  
Ansar Kareem ◽  
Thanveer Ahammed ◽  
Aiman Ziout

Electrical discharge machining (EDM) is an advanced machining method which removes metal by a series of recurring electrical discharges between an electrode and a conductive workpiece, submerged in a dielectric fluid. Even though EDM techniques are widely used to cut hard materials, low efficiency and high tool wear remain remarkable challenges in this process. Various studies, such as mixing different powders to dielectric fluids, are progressing to improve their efficiency. This paper reviews advances in the powder-mixed EDM process. Furthermore, studies about various powders used for the process and its comparison are carried out. This review looks at the objectives of achieving a more efficient metal removal rate, reduction in tool wear, and improved surface quality of the powder-mixed EDM process. Moreover, this paper helps researchers select suitable powders which are exhibiting better results and identifying different aspects of powder-mixed dielectric fluid of EDM.

2020 ◽  
Vol 38 (9A) ◽  
pp. 1406-1413
Author(s):  
Yousif Q. Laibia ◽  
Saad K. Shather

Electrical discharge machining (EDM) is one of the most common non-traditional processes for the manufacture of high precision parts and complex shapes. The EDM process depends on the heat energy between the work material and the tool electrode. This study focused on the material removal rate (MRR), the surface roughness, and tool wear in a 304 stainless steel EDM. The composite electrode consisted of copper (Cu) and silicon carbide (SiC). The current effects imposed on the working material, as well as the pulses that change over time during the experiment. When the current used is (8, 5, 3, 2, 1.5) A, the pulse time used is (12, 25) μs and the size of the space used is (1) mm. Optimum surface roughness under a current of 1.5 A and the pulse time of 25 μs with a maximum MRR of 8 A and the pulse duration of 25 μs.


2021 ◽  
Author(s):  
Dragan Rodic ◽  
Marin Gostimirovic ◽  
Milenko Sekulic ◽  
Borislav Savkovic ◽  
Branko Strbac

Abstract It is well known that electrical discharge machining can be used in the processing of nonconductive materials. In order to improve the efficiency of machining modern engineering materials, existing electrical discharge machines are constantly being researched and improved or developed. The current machining of non-conductive materials is limited due to the relatively low material removal rate and high surface roughness. A possible technological improvement of electrical discharge machining can be achieved by innovations of existing processes. In this paper, a new approach for machining zirconium oxide is presented. It combines electrical discharge machining with assisting electrode and powder-mixed dielectric. The assisting electrode is used to enable electrical discharge machining of nonconductive material, while the powder-mixed dielectric is used to increase the material removal rate, reduce surface roughness, and decrease relative tool wear. The response surface method was used to generate classical mathematical models, analyzing the output performances of surface roughness, material removal rate and relative tool wear. Verification of the obtained models was performed based on a set of new experimental data. By combining these latest techniques, positive effects on machining performances are obtained. It was found that the surface roughness was reduced by 18%, the metal removal rate was increased by about 12% and the relative tool wear was reduced by up to 6% compared to electrical discharge machining with supported electrode without powder.


2013 ◽  
Vol 675 ◽  
pp. 365-369 ◽  
Author(s):  
Yan Cherng Lin ◽  
Han Ming Chow ◽  
Hai Ping Tsui ◽  
Yuan Feng Chen

The aim of this study is to investigate the machining characteristics of ultrasonic vibration assisted electrical discharge machining (EDM) process using gas media as the dielectric fluids. The process parameters were designed based on Taguchi method to conduct the experimental works. The main process parameters such as machining polarity, peak current, pulse duration, air pressure, working time, and servo reference voltage were chosen to determine their effects on machining performance in terms of material removal rate and surface roughness for SKD 61 tool steels. The experimental response values were transferred to signal-to-noise (S/N) ratios, and then the significant machining parameters associated with the machining performance were examined by analysis of variance (ANOVA). Therefore, the technique of ultrasonic vibration assisted EDM process in gas media was established with the concerning features related to environmentally friendly, high efficiency, and high machining quality to fit the demands of modern manufacturing applications.


2015 ◽  
Vol 787 ◽  
pp. 371-375
Author(s):  
Rahul R. Jadhav ◽  
Vijaykumar S. Jatti ◽  
T.P. Singh

Monel alloys are pioneering materials which have exceptional engineering properties such as corrosion resistance, high toughness and show good response to cryogenic treatment. It finds uses in ship building, nuclear aerospace, missile and valve industries. These materials shows strain hardening effect which results in tool wear and in some cases tool breakage when machined by conventional methodshence, unconventional machining such as electrical discharge machining (EDM)discoverspurpose for machining of such materials. Researchers have recognized relation between electrical input process parameters of EDM process and output parameters of EDM process. But researchers have not investigated the influence of external magnetic field and cryo-treatment of work piece on EDM performance measures namely material removal rate (MRR) and tool wear rate (TWR). In vision of this the objective of present work was to study the effect of gap current, external magnetic field and cryogenic treatment of work part on MRR and TWR. Experiments were carried out by creating a 3 mm square hole on Monel400 alloys. Based on experimental results it was found that as gap current increases the MRR and TWR increases for untreated work part. For treated work part MRR increases and TWR decreases with increasein gap current. MRR and TWR increases with constant gap current for untreated work part, as magnetic field increases. For treated work part MRR increases and TWR decreases with increase in magnetic field at constant gap current.


Author(s):  
S. Nallusamy

Electrical Discharge Machining is a machining method primarily used for hard metals or those that are impossible to be machined with traditional techniques. The experimental investigation of material removal rate and tool wear rate during machining of oil hardened non-shrinking steel with brass and copper electrodes using EDM machine was carried out in this paper. This investigation presents the analysis and evaluation of heat affected zones and surface finish of the work piece using different tool electrodes and varying the machine parameters. The commercial grade kerosene oil has been used as dielectric fluid. The effect of various important EDM parameters such as discharge current (Ip) 2 to12A, pulse duration (Ton and Toff) and sparking voltage (V) of 80±5% have been used to yield the response in terms of Material Removal Rate (MRR) and Tool Wear Rate (TWR). Further a detailed analysis of the heat affected regions was also been carried out by using scanning electron microscopy.


2011 ◽  
Vol 264-265 ◽  
pp. 956-961 ◽  
Author(s):  
Md. Ashikur Rahman Khan ◽  
M.M. Rahman ◽  
M.M. Noor ◽  
K. Kadirgama ◽  
M.A. Maleque

Electrical discharge machining (EDM) technique has been widely used in modern metal working industry for producing complex cavities in dies and moulds, which are otherwise difficult to create by conventional machining. The process has the advantage of being able to machine hardened tool steels. However, its low machining efficiency and poor surface finish restricted its further applications. To address these problems, one relatively new technique used to improve the efficiency and surface finish is EDM in the presence of powder suspended in the dielectric fluid. Powder mixed electric discharge machining (PMEDM) is one of the recent innovations for the enhancement of capabilities of EDM process. In PMEDM, the electrically conductive powder is mixed in the dielectric fluid of EDM, which reduces the insulating strength of the dielectric fluid and increases the spark gap between the tool and workpiece. As a result, the process becomes more stable, thereby, improving the material removal rate (MRR) and surface finish. Moreover, the surface develops high resistance to corrosion and abrasion. This paper presents the current research trends on dry, near dry EDM and review on research carried out in the area of PMEDM.


2020 ◽  
Vol 27 (12) ◽  
pp. 2030002 ◽  
Author(s):  
AMOLJIT SINGH GILL ◽  
SANJEEV KUMAR ◽  
JUJHAR SINGH ◽  
VIVEK AGGARWAL ◽  
SHUBHAM SHARMA

Electrical discharge machining (EDM) is one of the most explored nonconventional machining processes due to its ability to machine intricate shapes on conductive materials. However, tool wear is one of the major challenges in the EDM process as it directly affects the accuracy of machining, surface roughness, reproduction of geometrical characteristics on the workpiece and cost of the process. Lots of work have been done to minimize the tool wear by improving the discharge conditions by controlling the EDM process parameters, varying the dielectric characteristics, powder-mixed dielectric methods and ultrasonic-assisted methods. However, minimizing the tool wear by the above approaches also constrains the material removal rate from the workpiece and accuracy of the process. This review highlights the efforts done by the researchers to improve tool wear by recently developed techniques or modifications. Researches available in the field of using treated tool electrode, cooled tool electrode, coated tool electrode, noble tool materials and other techniques are highlighted.


Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 989 ◽  
Author(s):  
Manu Goiogana ◽  
Ahmed Elkaseer

This article reports an experimental investigation of the efficacy of self-flushing in the Electrical Discharge Machining (EDM) process in terms of tool wear rate (TWR), hole taper angle and material removal rate (MRR). In addition to a plain cylindrical shape, electrodes of different cross sections (slotted cylindrical, sharp-cornered triangular, round-cornered triangular, sharp-cornered square, round-cornered square, sharp-cornered hexagonal and round-cornered hexagonal) were designed as a means of inducing debris egress and then fabricated in graphite. EDM drilling trials using the rotating shaped electrodes were carried out on a Ti6Al4V workpiece. The results revealed that, although a low TWR and minimum hole taper angle were achieved using a plain cylindrical electrode, the usage of rotating shaped electrodes provided self-flushing of the dielectric fluid during the EDM process, which led to an improvement in MRR compared to that achieved with a plain cylindrical electrode. Besides, in general, the electrodes with rounded corners are associated with a lower TWR, a lower hole taper angle and a higher MRR when compared to the electrodes with sharp corners. Considering these results, it was concluded that different process attributes, i.e., TWR, hole taper angle and MRR, are all greatly affected by the electrode shape, and thus, the proper selection of the electrode shape is a precondition to attain a specific response from the EDM process.


1987 ◽  
Vol 109 (2) ◽  
pp. 117-121 ◽  
Author(s):  
S. M. Pandit ◽  
T. M. Mueller

A new method of computer control of electro-discharge machining based on Data Dependent Systems (DDS) methodology has been recently proposed. The control is based on a parameter which effectively represents the resistance of arc and is isolated by the DDS model from the random current and voltage signals in spite of the large noise. This paper presents an experimental verification to show that this parameter indeed represents the arc resistance which cannot be measured by any other means and that the parameter is quite sensitive to the change from beneficial sparking condition to the harmful arcing condition. Off-line analysis of the EDM process under different conditions is presented with this parameter as the response variable. Development of the control strategy using the results of this analysis is illustrated. Implementation of the strategy by means of a Motorola microcomputer is described. A comparison of metal removal rate (MRR), surface roughness, and tool wear for the computer control and the optimal manual adjustment recommended by the EDM machine manufacturer is presented. It shows that the computer control yields an increase in the MRR of 47 percent and 19 percent, while the ratio of tool wear to MRR reduces by 26 percent and 16 percent, respectively, in finishing and roughing conditions.


2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Shahriar Tanvir Alam ◽  
AKM Nurul Amin ◽  
Md. Ibrahim Hossain ◽  
Maliha Huq ◽  
Shaqauit Hossain Tamim

AbstractTi–6Al–4V is the most commonly used titanium alloy in aerospace, marine, and biomedical applications. Due to the properties of poor machinability in conventional machining, Electrical Discharge Machining (EDM) is considered a prospective alternative for machining this strategic material. This study aims at enhancing the performance of powder mixed EDM (PMEDM) in the machining of Ti–6Al–4V with the application of two different types of powders, namely Graphite (Gr) and Titanium Oxide (TiO2) powders, with different concentrations in dielectric—kerosene. The effect of these powers and their relative quantities are studied in terms of metal removal rate (MRR), tool wear rate, Surface Roughness, and surface integrity. Machining is performed using the copper electrode and kerosene as the dielectric medium. A separate container and a submersible pump are used to limit the quantity of powder and keep the powder in suspension, respectively. Design of experiments guided by Design-Expert software is employed to minimize the number of experimental runs and develop empirical models of response parameters in terms of the variable parameters—peak current, powder type, and powder concentration. Findings indicate that TiO2 powder has a much higher effect on MRR compared to graphite powder, as the maximum MRR in the case of TiO2 powder is recorded 41.01 mm3/min against 11.98 mm3/min for graphite powder, i.e., 3.42 times higher. Similarly, the tool wear ratio for TiO2 powder is 0.0704 against 0.1219 for graphite powder at the maximum MRR, which is 1.73 times lower compared to that of graphite powder. The same ratios at the minimum MRR for TiO2 is 0.0098, and for graphite power is 0.0282, which is again 2.88 times lower compared to that of graphite powder. In terms of average surface roughness, Ra, the performance of TiO2 is far better compared to graphite powder since the maximum surface roughness attained with TiO2 powder is 3.265 μm against 9.936 μm for graphite powder at the highest MRR and the same attained at the lowest MRR are 2.228 μm and 2.411 μm for TiO2 and graphite powders respectively. The mechanism of the effects of PMEDM on surface texture has also been observed using SEM images to study the influence of powder concentration on surface morphology.


Sign in / Sign up

Export Citation Format

Share Document