Relationship between the Fine Discharge Parameters and Craters EDMed of the NAK80 Steel

2010 ◽  
Vol 426-427 ◽  
pp. 85-88
Author(s):  
Hong Jun Wang ◽  
Dun Wen Zuo ◽  
X.M. Wu ◽  
M. Wang

The crater diameter and depth of the surface machined by electrical discharge machining (EDM) were used to evaluate indexes for EDMed surface. The influence of discharge parameters selected on the crater diameter and depth in mirror-like surface EDM process was investigated, and the optimization scheme was obtained. An L16 (44×23) Taguchi standard orthogonal array was chosen for the design of experiments. Experimental results indicate that peak current and open discharge voltage have more influence on the crater diameter and depth in comparison with pulse off-time and pulse duration. Also the results confirm that the crater depth is about 10 to 20 percent of its diameter while the near-mirror EDM conducted in the NAK80 steel with fine discharge parameters.

2010 ◽  
Vol 431-432 ◽  
pp. 438-441
Author(s):  
Hong Jun Wang ◽  
Dun Wen Zuo ◽  
Hong Miao ◽  
Hong Feng Wang ◽  
Min Wang

The effects of discharge parameters on micro-surface topography in mirror-like surface electrical discharge machining (EDM) process were investigated, and the optimization scheme was obtained. The realization of the process parameters and their effects were analyzed by the Taguchi method. The surface roughness amd 2D micro-surface topography were measured. An L16 (44×23) Taguchi standard orthogonal array was chosen for the design of experiments. The level of importance of the parameters parameters on surface roughness was determined by using analysis of variance (ANOVA). The experimental results confirmed that peak current and open discharge voltage have more influence on the surface roughness on mirror-like surface EDMed workpiece in comparison with pulse duration and pulse off-time.


Machines ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 36 ◽  
Author(s):  
Thi-Hong Tran ◽  
Manh-Cuong Nguyen ◽  
Anh-Tung Luu ◽  
The-Vinh Do ◽  
Thu-Quy Le ◽  
...  

As a successful solution applied to electrical discharge machining (EDM), powder-mixed electrical discharge machining (PMEDM) has been proposed as an upgrade of the EDM process. The optimization of the process parameters of PMEDM is essential and pressing. In this study, Taguchi methods and analysis of variance (ANOVA) were used to find the main parameters affecting surface roughness in the EDM process with SiC powder-mixed-dielectric of hardened 90CrSi steel. The PMEDM parameters selected were the powder concentration, the pulse-on-time, the pulse-off-time, the pulse current, and the server voltage. It was found that SiC powder exhibits positive effects on reducing surface roughness. The roughness obtained with the optimum powder concentration of 4 g/L was reduced by 30.02% compared to that when processed by conventional EDM. Furthermore, the pulse-off-time was found to be the most influential factor that gave an important effect on surface roughness followed by the powder concentration. The EDM condition including a powder concentration of 4 g/L, a pulse-on-time of 6 µs, a pulse-off-time of 21 µs, a pulse current of 8 A, and a server voltage of 4 V resulted in the best surface roughness.


2017 ◽  
Vol 14 (1) ◽  
pp. 47-64 ◽  
Author(s):  
Pouyan Sadr ◽  
Amin Kolahdooz ◽  
Seyyed Ali Eftekhari

Electrical Discharge Machining (EDM) process is one of the most widely used methods for machining. This method is used to form parts that conduct electricity. This method of machining has used for hard materials and therefore select the correct values of parameters are so effective on the quality machining of parts. D3 steel has a high abrasion resistance at low temperatures therefore can be a good candidate for this method of machining. Also because of high hardness and low distortion during heat treatment, using this method is economical for this alloy. The purpose of this paper is to investigate the influence of the main parameters such as voltage, current, pulse duration and pulse off time and the interaction of them to determine the optimal condition for the D3 steel alloy (alloy with DIN 1.2080). Chip removal rate (MRR) and surface quality of parts were evaluated as the output characteristic of the study. The optimum conditions were achieved when the MRR is in the highest value and surface roughness is in the lowest one. For investigation of interaction, two kinds of DOE methods (Taguchi and determinant of optimal experimental design) are used. Then the optimal parameters are investigated with the help of the analysis signal to noise (S/N) and mathematical modeling. The optimize results were tested again and compared. Also the results showed that regression modeling has better accuracy than the S/N analysis. This is because of a greater number of experiments that done in this part and taking into account the interaction parameters in the regression model.


2019 ◽  
Vol 8 (3) ◽  
pp. 5844-5848

Metal matrix composites (MMC’s) have evolved an extreme attention in current era for their superior applications in aerospace, defence and automobile industries. Metal matrix composites are found as current materials, possessing the characteristics of light in weight, greater wear resistance & superior specific strength. Due to presents of high hardened reinforcement strength, composite materials are very difficult to do machining by traditional techniques. Therefore unconventional machining like Electrical Discharge Machining becomes feasible method to these kinds of composite materials. EDM process does not require any mechanical energy because there is no direct contact between tool and workpiece. So there no influence of superior material properties like hardness, strength, toughness etc in machining hybrid metal matrix composite. In the present paper , an analysis is carried out to evaluate the influence of input parameters such as peak current (I), tool lift (TL), pulse off time (T off) and pulse on time (Ton) on the machining of 90%-Al(6061)-3 weight % silicon carbide (SiC)-7 weight % boron carbide (B4C) hybrid metal matrix composite through electrical discharge machining. The individual parameters were analyzed with an objective to minimize tool wear ratio (TWR) and to maximize the material removal rate (MRR). The grey relation grade (GRG) for Electric discharge machining is obtained by using taghuchi based grey relation analysis (GRA) method with multiple response parameters like MRR and TWR. The ANOVA based GRA method is employed to find the significance of process parameters like Peak Current, Pulse on time, and Pulse off time and Tool lif


AISI 1020 Steel is hard while machining because of its nature of harness and brittleness. Electrical Discharge Machining (EDM) is a significant technique to machine such materials. Current research examines the pulse current effect (A), discharge voltage (B), pulse on time (C), pulse off time (D),Oil pressure (E)and spark gap(F) on Metal Removal Rate (MRR) and Surface Roughness on EDM of AISI 1020 Steel. Experiments have been carried out in a methodical type taking up nearly 54 successive trails utilizing an EDM machine and a copper electrode of 10mm diameter. Three factors, three levels, Box Bekhen through response surface methodology design was utilized to analyze the outcomes. Gray relational analysis techniques are adopted for finding parameter influencing range for MRR and SR. A multi regression mathematical model was brought up in launching the association between parameters of machining and artificial neural network techniques are used for predicting the optimized parameters.


2012 ◽  
Vol 488-489 ◽  
pp. 871-875
Author(s):  
V. Anandakrishnan ◽  
V. Senthilkumar

Copper based metal matrix composite reinforced with Boron Carbide is a newly developed Electrical Discharge Machining (EDM) electrode showing better performance than the conventional copper based electrode. Right selection of machining parameters such as current, pulse on time and pulse off time is one of the most important aspects in EDM. In this paper an attempt has been made to develop mathematical models for relating the Material Removal Rate (MRR), Tool Removal Rate (TRR) and Surface roughness (Ra) to machining parameters (current, pulse-on time and pulse-off time). Furthermore, a study was carried out to analyze thSubscript texte effects of machining parameters on various performance parameters such as, MRR, TRR and Ra. The results of Analysis of Variance (ANOVA) indicate that the proposed mathematical models, can adequately describe the performance within the limits of the factors being studied. Response surface modeling is used to develop surface and contour graphs to analyze the effects of EDM input parameters on outer parameters.


Author(s):  
Debal Pramanik ◽  
Dipankar Bose

An important electro-thermal process known as wire electrical discharge machining (WEDM) is applied for machining of conductive materials to generate most precisely. All cutting inaccuracies of WEDM arise out of the major cause of wire bending. At the time of cutting a sharp corner or cut profile, bending of the wire leads to a geometrical error on the workpiece. Though this type of error may be of a few hundred microns, it is not suitable for micro applications. In this research study, an experimental investigation based on response surface methodology (RSM) has been done on wire EDM of Aluminium 6061 t6 alloy. This chapter studies the outcome of input process variables (i.e., wire feed rate, pulse on time, pulse off time, and gap voltage) on machining output responses (i.e., corner inaccuracy) extensively. Experimental validation of the proposed model shows that corner inaccuracy value may be reduced by modification of input parameters.


2015 ◽  
Vol 14 (03) ◽  
pp. 189-202 ◽  
Author(s):  
V. Vikram Reddy ◽  
P. Madar Valli ◽  
A. Kumar ◽  
Ch. Sridhar Reddy

In the present work, an investigation has been made into the electrical discharge machining process during machining of precipitation hardening stainless steel PH17-4. Taguchi method is used to formulate the experimental layout, to analyze the effect of each process parameter on machining characteristics and to predict the optimal choice for each electrical discharge machining process parameters namely, peak current, pulse on time and pulse off time that give up optimal process performance characteristics such as material removal rate, surface roughness, tool wear rate and surface hardness. To identify the significance of parameters on measured response, the analysis of variance has been done. It is found that parameters peak current and pulse on time have the significant affect on material removal rate, surface roughness, tool wear rate and surface hardness. However, parameter pulse off time has significant affect on material removal rate. Confirmation tests are conducted at their respective optimum parametric settings to verify the predicted optimal values of performance characteristics.


2015 ◽  
Vol 766-767 ◽  
pp. 902-907
Author(s):  
Bibin K. Tharian ◽  
B. Kuriachen ◽  
Josephkunju Paul ◽  
Paul V. Elson

Wire electrical discharge machining is one of the important non-traditional machining processes for machining difficult to machine materials. It involves the removal of material by the discrete electric discharges produced between the inter electrode gap of continuously moving wire electrode and the work piece. The ability to produce intricate profiles on materials irrespective of the mechanical properties made this process to be widely used in industries. The present study investigates the relationship of various process parameters in WEDM of AISI 202 stainless steel with brass electrode.The experiments were planned according to Taguchi’s L18 orthogonal array and experimental models were developed. The important process parameters identified for the present study were pulse on time, peak current, pulse off time, wire feed, wire tension, dielectric flushing pressure, servo feed and gap voltage. The surface roughness of the machined surface was measured as the process performance measure. Analysis of variance test has also been carried out to check the adequacy of the developed models and to identify the level of significance of each process parameters. In addition to the developed models, ABC optimization has been performed to identify the optimum parameter combination for minimum surface roughness and the obtained optimal process parameters are peak current 11 A, pulse on time 100 μs, pulse off time 49 μs, wire feed 4 m/min, wire tension 10 N, flushing pressure 12 kg/cm2, servo feed 2100 mm/min and set gap voltage 30 V. Finally the results were verified with the experimental results and found that they are in good agreement.


2018 ◽  
Vol 14 (4) ◽  
pp. 115-124 ◽  
Author(s):  
Shukry H. Aghdeab ◽  
Nareen Hafidh Obaeed ◽  
Marwa Qasim Ibraheem

Electrical Discharge Machining (EDM) is a non-traditional cutting technique for metals removing which is relied upon the basic fact that negligible tool force is produced during the machining process. Also, electrical discharge machining is used in manufacturing very hard materials that are electrically conductive. Regarding the electrical discharge machining procedure, the most significant factor of the cutting parameter is the surface roughness (Ra). Conventional try and error method is time consuming as well as high cost. The purpose of the present research is to develop a mathematical model using response graph modeling (RGM). The impact of various parameters such as (current, pulsation on time and pulsation off time) are studied on the surface roughness in the present research. 27 samples were run by using CNC-EDM machine which used for cutting steel 304 with dielectric solution of gas oil by supplied DC current values (10, 20, and 30A). Voltage of (140V) uses to cut 1.7mm thickness of the steel and use the copper electrode. The result from this work is useful to be implemented in industry to reduce the time and cost of Ra prediction. It is observed from response table and response graph that the applied current and pulse on time have the most influence parameters of surface roughness while pulse off time has less influence parameter on it. The supreme and least surface roughness, which is achieved from all the 27 experiments is (4.02 and 2.12µm), respectively. The qualitative assessment reveals that the surface roughness increases as the applied current and pulse on time increases


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