A REVIEW ON VIBRATION-ASSISTED EDM, MICRO-EDM AND WEDM

2019 ◽  
Vol 26 (05) ◽  
pp. 1830008 ◽  
Author(s):  
K. P. MAITY ◽  
M. CHOUBEY

Electrical discharge machining (EDM) is an unconventional machining process used for machining of hard-to-cut materials. Both EDM and micro-EDM processes are extensively used for producing dies and molds, complex cavities, and 3D structures. In recent years, researchers have intensively focused on improving the performance of both micro-EDM and EDM processes. This paper reviews the research work carried out by the researchers on vibration-assisted EDM, micro-EDM, and wire EDM. The consolidated review of this research work enables better understanding of the vibration-assisted EDM process. This study also discusses the influence of vibration parameters such as vibration frequency and amplitude on the material removal rate (MRR), electrode wear rate (EWR), and surface roughness (SR). The important issues and research gaps in the respective area of research are also presented in this paper.

2014 ◽  
Vol 941-944 ◽  
pp. 2127-2133 ◽  
Author(s):  
Nirdesh Ojha ◽  
Florian Zeller ◽  
Claas Mueller ◽  
Holger Reinecke

The ability to machine advanced ceramic materials such as ZrO2, SiC, and AlN is of high interest for various industries because of the extraordinary material properties that these ceramics possess. Once sintered, these ceramics are characterized with high mechanical strength, high thermal stability and high chemical inertness. Therefore it is extremely difficult to machine these ceramics with dimensions in few microns using traditional techniques. Electrical discharge machining (EDM) is an electro-thermal machining process used to structure conductive materials. By applying a conductive layer on top of the non-conductive material, the EDM process can also be used to machine the non-conductive material. This paper presents a study on the effect of tool polarity and tool rotation on the material removal rate and electrode wear ratio during the EDM process of non-conductive SiC, ZrO2 and AlN ceramics. The reasons for the variation in the material removal rates among the different ceramics are examined by comparing the material properties. Relatively lower value of flexural strength, fracture toughness and melting temperature is the reason for AlN ceramic to have the higher MRR than SiC and ZrO2 ceramics.


2014 ◽  
Vol 903 ◽  
pp. 51-55 ◽  
Author(s):  
Alexis Mouangue Nanimina ◽  
Ahmad Majdi Abdul Rani ◽  
Mohd Amri Lajis ◽  
Turnad Lenggo Ginta ◽  
T.V.V.L.N. Rao

Shape of workpiece, electrode orientation and flushing system play important role in electrical discharge machining (EDM) process. Low material removal rate and relatively high electrode wear ratio are some of the disadvantages of EDM process. This can be due to the flushing modes. Workpiece shape has a significant effect in effectiveness of dielectric flushing flow and orientation during EDM process. This research work is conducted to analyze the influence of various workpiece shapes. Square cavity, L shape, flat shape and U shape were machined with same cross-section electrode material. Test parameters are material removal rate (MRR) and electrode wear ratio (EWR). Experiment results show slight difference in MRR and EWR values for different shapes. U shape presents the highest MRR and the lowest EWR occurs in flat shape compared to cavity and L shapes. It can be concluded that flat and U shapes result in good EDM machining quality due to good dielectric flow and flushing conditions in the area of EDM machining.


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.


Author(s):  
Shivraj Yeole ◽  
Nagabhushana Ramesh Nunna ◽  
Balu Naik Banoth

Electrical Discharge Micro Drilling (EDMD) is considered as one of the most effective method for machining difficult to cut and hard materials like titanium alloy. However, selection of process parameters for achieving superior surface finish, higher machining rate and accuracy is a challenging task in drilling micro-holes. In this paper, an attempt is made to optimize micro-EDM process parameters for drilling micro holes on titanium grade 19 alloy. In order to verify the optimal micro-EDM process parameters settings, material removal rate (MRR), electrode wear rate (EWR) and over cut (OC) were chosen as the responses to be observed. Pulse on time, pulse off time, electrode diameter and current were selected as the governing process parameters for evaluation by Taguchi method. Nine micro holes of 300 μm, 400 μm and 500 μm were drilled using L9 orthogonal array (OA) design. Optimal combination of machining parameters were obtained through Signal-to-Noise (S/N) ratio analysis. It is seen that machining performances like material removal rate and overcut are affected by the peak current whereas electrode wear is affected by peak current and electrode diameter. Morphology of the micro holes has been studied through SEM micrographs of machined micro-hole.


2012 ◽  
Vol 622-623 ◽  
pp. 380-384 ◽  
Author(s):  
T. Muthuramalingam ◽  
B. Mohan

In automobile and aeronautical industries, complex moulds and dies is produced by Electrical Discharge Machining process. The surface finish is determined by the crater volume in EDM process. The amount of crater volume is influenced by the amount and distribution of discharge energy. The discharge energy is directly proportional to the average discharge current. This amount of current is determined by the duration of discharging effect. This study deals about evaluating the performance of iso current pulse generator on machining characteristics in EDM. Due to its ability of reducing stochastic nature in EDM process, iso pulse generator could produce better surface finish than conventional transistor pulse train generator with higher material removal rate.


Author(s):  
Jayakumar Narasimhan ◽  
Kamlakar P. Rajurkar

Now-a-days, many sophisticated systems are available to monitor the process in real time that drastically reduce the cost and lead time to manufacture a part because it takes away the offline sampling. For Electrical Discharge Machining (EDM), current signal monitors are very useful to predict the material removal rate and determine the arcing that can damage the surface. This paper discusses the design and development of an online monitoring for micro-EDM using correlation developed via experimentation. Surface roughness is predicted based on online monitoring.


Author(s):  
Hardik Beravala ◽  
Pulak M Pandey

In the present research work, an attempt has been made to develop the mathematical model to predict the material removal rate in the electrical discharge machining process when the assistance of air and magnetic field is provided together. The proposed model incorporates the physical phenomenon occurred during electrical discharge machining such as the plasma column expansion and reduction in the mean free path of electron in the plasma column due to magnetic field. In addition, the model incorporates the effect of air on the material removal rate. The developed model correlates the material removal rate with the process parameters such as the peak current, pulse duration, duty cycle, air pressure and magnetic flux density. The experimental data were used to evaluate the constants for district processing conditions. The relation between air pressure and breakdown voltage in the liquid-air mixed dielectric has been established experimentally. The obtained expression of material removal rate has been validated for the experimental conditions other than that used for obtaining constants. The results show less than 10% error in the prediction by the model over the respective experimental values.


ROTASI ◽  
2019 ◽  
Vol 21 (1) ◽  
pp. 1
Author(s):  
Petrus Londa

Electrical Discharge Machining (EDM) adalah non-conventional machining process. EDM dapat memotong semua jenis benda kerja yang bersifat penghantar listrik, terutama digunakan pada benda kerja yang sangat keras dan memiliki bentuk yang rumit, yang tidak dapat dipotong oleh mesin konvensional. Penelitian ini menggunakan metode Taguchi untuk menentukan variabel pemesinan yang secara signifikan mempengaruhi proses pemotongan pada beberapa material elektroda (tembaga, kuningan, alumunium) dan benda kerja dari bahan K460 (amutit S). Taguchi L25 Orthogonal standard arrays dan analysis of variance (ANOVA) dapat menentukan performa variabel pemotongan (PON, POFF, GAP, QDON, SERVO dan LT) dengan variabel yang diteliti adalah Electrode Wear Rate (EWR), Material Removal Rate (MRR) dan Diameter Overcut (DOC). Hasil dari penelitian ini ditampilkan dalam bentuk tabel-tabel dan grafik yang menunjukan variabel pemesinan yang signifikan mempengaruhi proses pemotongan sesuai dengan jenis material elektroda yang digunakan.


Author(s):  
Sanjeev Verma ◽  
PS Satsangi ◽  
KD Chattopadhyay

The application of nonconductive ceramic materials is growing in engineering and manufacturing field due to their properties such as high hardness, low thermal conductivity, and resistance to oxidation. But fabricating structures from such materials are difficult and most of the traditional machining techniques are not appropriate. The electrical discharge machining has become a popular machining process for machining nonconducting oxide and nonoxide ceramics such as alumina, silicon nitrides, SiAlON, and zirconium. In the present study, a technique to machine the nonconductive SiAlON ceramic, having resistivity of the order of 100000 Ω-cm is developed. An assistive electrode technique along with graphite powder mixed specially made dielectric mixture of hydrocarbon fluids was used for the electrical discharge machining process. The experiments were conducted according to the Taguchi design and analysis of variance using signal-to-noise ratios showcasing significant parameters and their optimal values for material removal, electrode wear, and size overcut achieved after electrical discharge machining. For multiparameter optimization, the grey relational analysis was carried out for response parameters with suitable weights. Analysis of variance on the grey relational grade showed discharge current, duty factor, and additive percentage as most significant parameters. As the central aim of this research is material removal, the significant parameters found for material removal rate were further used for response surface methodology and their optimum values as central design values for experimentation. A second-order response model was formulated to estimate the machining performance. To validate the study, confirmation experiments were carried out and predicted results have been found to be in good agreement with experimental findings. Based on the experimental investigations, it can be said that a novel and efficient technique has been developed to machine the high resistivity ceramics. The scanning electron microscopic images confirmed that material is removed mostly by spalling and no significant cracks are visible.


Author(s):  
Shrihar Pandey ◽  
Pankaj K Shrivastava

To shape advanced engineering materials, many unconventional machining processes have been developed. Electrical discharge machining is such an unconventional machining process which is very popular nowadays but it is limited by poor material removal efficiency. Electrical arc machining is another unconventional machining process which is quite similar to electrical discharge machining and is now gaining attention from research fraternity due to its high material removal efficiency. In the present research, an innovative unconventional machining process known as vibration-assisted electrical arc machining has been developed. The performance of vibration-assisted electrical arc machining has been evaluated during machining of Al–B4C metal matrix composite by considering peak current, flushing velocity of dielectric and tool vibrations as input control factors. The quality characteristics considered were material removal rate, tool wear rate, relative electrode wear rate and surface roughness. It has been observed that vibration-assisted electrical arc machining results in approximately 3000% more material removal rate as compared to conventional electrical discharge machining during machining of Al–B4C metal matrix composite. The effects of various input control factors on output parameters have also been discussed. Further modelling and optimization of the process parameters has also been done by artificial intelligence approach.


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