Optimization and modeling of Electrical Discharge
parameters on Machining of Stavax Steel

This work focuses on the use of the Taguchi method in order to find out the optimized parameters of the process like discharge current, pulse on time and pulse off time on the machining features such as material removal rate(MRR), surface roughness(SR) & tool wear rate(TWR) on Stavax Steel by means of Electrical Discharge Machining(EDM). It is also intended to study the individual influence of parameters on the performance characteristics. The dielectric fluid circulating system is modified to conduct the experiments. The analysis of variance (ANOVA) is made to recognise the importance of parameters on the response. By using non-linear regression analysis the empirical models are developed in order to predict these performance characteristics and the confirmation test was conducted at the optimal parameters settings to check the optimum expected values of performance features. Detailed analysis by using ANOVA is done and came out with the findings as a pulse on time is the most significant process parameter, next is the discharge current and the insignificant parameter is the pulse off time. Machining surface morphology was studied and observed that crater size is large and deeper due to a large amount of metal is melted and vaporized at the optimum condition of MRR.

Download Full-text

Analysis of the electrical discharge machining (EDM) performance on Ramor 550 armor steel

Materials Testing ◽

10.1515/mt-2020-620508 ◽

2020 ◽

Vol 62 (5) ◽

pp. 481-491

Author(s):

Engin Nas

Keyword(s):

Discharge Current ◽

Electrical Discharge ◽

Electrical Discharge Machining ◽

Removal Rate ◽

Processing Parameters ◽

Depth Of Cut ◽

Armor Steel ◽

Pulse On Time ◽

Pulse Off Time ◽

Off Time

Abstract This study investigated the electrical discharge machining (EDM) performance of Ramor 500 Armor steel, a material used in the defense industry for armor production. In addition, the surface quality and amount of material wear of the treated surfaces were determined using different electrical discharge processing parameters for a copper electrode including pulse on-time (99, 150, 225, 300, 351 μs), pulse off-time (10, 15, 23, 30, 35 μs), and discharge current (3, 4, 6, 8, 9 A), at a constant pressure of 1 mm depth of cut. As a result of the experiments, the values related to the material removal rate (MRR) and the surface roughness (Ra) were obtained and the findings analyzed via response surface methodology (RSM). The increase in amperage and pulse on time resulted in an increase in Ra and MRR values. The minimum and maximum Ra and MRR values emerged at currents of 3 and 9 A, respectively. In the experiments performed applying currents of between 3 and 9 A, the white layer widths were measured as 0.0474 mm and 0.0915 mm, respectively. The statistical test results showed that the most effective processing parameters for the MRR were the discharge current amperage (49.01 %) and the pulse off-time (16.51 %), whereas the most effective parameter for the Ra value was the discharge current amperage (79.07 %).

Download Full-text

Parametric Optimization of Wire Cut Electrical Discharge Machining on Al-9% PAC Composites using Desirability Approach

International Journal of Vehicle Structures and Systems ◽

10.4273/ijvss.10.6.16 ◽

2018 ◽

Vol 10 (6) ◽

Cited By ~ 1

Author(s):

G. Ramanan ◽

R. Elangovan

Keyword(s):

Surface Roughness ◽

Material Removal Rate ◽

Discharge Current ◽

Electrical Discharge ◽

Material Removal ◽

Electrical Discharge Machining ◽

Removal Rate ◽

Pulse On Time ◽

Pulse Off Time ◽

Off Time

In aerospace and automobile industries manufacturing complex structures using un-conventional machining is increased due to their precision and accuracy. This research investigates the influence of input parameters such as discharge current, pulse on time, pulse off time and servo speed rate of wire cut electrical discharge machining (WEDM) on material removal rate and surface roughness using Box Behnken design supported with response surface methodology. Aluminium alloy 7075 reinforced with 9 % wt. of activated carbon composite is used to carry out the machining process. Most influencing parameters are subjected as the conductive and non-conductive parameters in WEDM process. To find out the significant influence of each factor, analysis of variance was performed. The mathematical model is established using desirability technique and then the optimal machining parameters are determined. The best achieved WEDM performances - material removal rate and surface roughness are 10.46 mm3/min and 3.32μm respectively, by using optimum machining conditions - discharge current 2000mA, pulse on time 8.9µs, pulse off time 25µs and servo speed rate 150rpm at 0.8597 desirability value.

Download Full-text

Mathematical Modeling of Machining Parameters in Electrical Discharge Machining with Cu-B4C Composite Electrode

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.488-489.871 ◽

2012 ◽

Vol 488-489 ◽

pp. 871-875

Author(s):

V. Anandakrishnan ◽

V. Senthilkumar

Keyword(s):

Mathematical Models ◽

Current Pulse ◽

Electrical Discharge ◽

Electrical Discharge Machining ◽

Removal Rate ◽

Machining Parameters ◽

Pulse On Time ◽

Pulse Off Time ◽

Off Time ◽

Selection Of

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.

Download Full-text

Influence of Process Parameters on Characteristics of Electrical Discharge Machining of PH17-4 Stainless Steel

Journal of Advanced Manufacturing Systems ◽

10.1142/s0219686715500122 ◽

2015 ◽

Vol 14 (03) ◽

pp. 189-202 ◽

Cited By ~ 6

Author(s):

V. Vikram Reddy ◽

P. Madar Valli ◽

A. Kumar ◽

Ch. Sridhar Reddy

Keyword(s):

Material Removal Rate ◽

Electrical Discharge ◽

Material Removal ◽

Electrical Discharge Machining ◽

Removal Rate ◽

Surface Hardness ◽

Machining Process ◽

Pulse On Time ◽

Pulse Off Time ◽

Off Time

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.

Download Full-text

MODELLING AND OPTIMIZATION OF PERFORMANCE CHARACTERISTICS IN ELECTRICAL DISCHARGE MACHINING ON TITANIUM ALLOY

Journal of Mechanical Engineering ◽

10.3329/jme.v43i1.15778 ◽

2013 ◽

Vol 43 (1) ◽

pp. 33-40

Author(s):

Md. Ashikur Rahman Khan

Keyword(s):

Electrical Discharge ◽

Electrical Discharge Machining ◽

Short Pulse ◽

Removal Rate ◽

Performance Characteristics ◽

Pulse Interval ◽

Hard Material ◽

Set Up ◽

Pulse On Time ◽

Pulse Off Time

Electrical discharge machining (EDM) technique possesses noticeable advantages over othermachining process and can machine any hard material effectively. Proper selection of parameters in EDM isvery much essential to achieve better performance characteristics that are still challenging. This study attemptsto investigate the effects of parameters on EDM performance characteristics on Ti-6Al-4V utilizing coppertungsten as electrode and negative polarity of the electrode. Mathematical model associating the influences ofthese variables and the EDM characteristics such as material removal rate (MRR) and tool wear rate (TWR)are set up in this study. The optimal machining conditioning in favor of MRR and TWR are estimated. Design ofexperiments method and response surface methodology techniques are adopted to attain the objectives. Analysisof variance (ANOVA) has been performed for the validity test of the fit and adequacy of the proposed models.Optimum MRR is found at high discharge ampere, long pulse on time and short pulse off time. 8A peak current,10 ?s pulse on time and 184 ?s pulse interval yields lowest TWR. The result of this investigation guides torequired process outputs and economical industrial machining optimizing the input factors.DOI: http://dx.doi.org/10.3329/jme.v43i1.15778

Download Full-text

Electric Discharge Machining of Cryo-Treated NiTi Alloys

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.787.366 ◽

2015 ◽

Vol 787 ◽

pp. 366-370 ◽

Cited By ~ 1

Author(s):

Vaibhav Gaikwad ◽

Vijaykumar S. Jatti ◽

T.P. Singh

Keyword(s):

Electrical Discharge ◽

Material Removal ◽

Electrical Discharge Machining ◽

Removal Rate ◽

Tool Wear Rate ◽

Workpiece Material ◽

Pulse On Time ◽

Pulse Off Time ◽

Off Time ◽

Conventional Machining

NiTi alloys possess superior material properties such as high specific strength, high corrosion resistance, high wear resistance and high anti-fatigue property. Due to these properties it is difficult to machine these alloys using conventional machining process. Nowadays non-conventional machining processes are widely used for machining such adavanced materials. Electrical Discharge machining (EDM) is one such non-conventional process, which can machine electrically conductive materials of any hardness values. Present study aims at drilling mesoscale 3 mm square holes on NiTi alloy by varying the electrical parameters namely, gap current, pulse on time and pulse off time. Additional, the present work includes finding out the effect of cryogenic treatment of NiTi work material on electrical discharge machining performance measures namely material removal rate (MRR) and tool wear rate (TWR). Based on experiments conducted, it can be concluded that with increase in current both material removal rate and tool wear rate increases. It is also noted that cryo-treatment of workpiece material improves MRR with respect to gap current. Similarly there is an increase in MRR with respect to pulse on time and pulse off time for cryo-treated workpiece material. There is a slight improvement of TWR with respect to gap current, pulse on time and pulse off time for cryo-treated workpiece material.

Download Full-text

Effects of Side Flushing and Multi-Aperture Inner Flushing on Characteristics of Electrical Discharge Machining Macro Deep Holes

Metals ◽

10.3390/met11010148 ◽

2021 ◽

Vol 11 (1) ◽

pp. 148

Author(s):

Suppawat Chuvaree ◽

Kannachai Kanlayasiri

Keyword(s):

Electrical Discharge ◽

Electrical Discharge Machining ◽

Removal Rate ◽

Electrode Wear ◽

Machining Parameters ◽

Machining Performance ◽

Electrode Rotation ◽

Pulse On Time ◽

Pulse Off Time ◽

Off Time

This research investigates the effect of machining parameters on material removal rate, electrode wear ratio, and gap clearance of macro deep holes with a depth-to-diameter ratio over four. The experiments were carried out using electrical discharge machining with side flushing and multi-aperture flushing to improve the machining performance and surface integrity. The machining parameters were pulse on-time, pulse off-time, current, and electrode rotation. Response surface methodology and the desirability function were used to optimize the electrical discharge machining parameters. The results showed that pulse on-time, current, and electrode rotation were positively correlated with the material removal rate. The electrode wear ratio was inversely correlated with pulse on-time and electrode rotation but positively correlated with current. Gap clearance was positively correlated with pulse on-time but inversely correlated with pulse off-time, current, and electrode rotation. The optimal machining condition of electrical discharge machining with side flushing was 100 µs pulse on-time, 20 µs pulse off-time, 15 A current, and 70 rpm electrode rotation; and that of electrical discharge machining with multi-aperture flushing was 130 µs, 2 µs, 15 A, and 70 rpm. The novelty of this research lies in the use of multi-aperture flushing to improve the machining performance, enable a more uniform GC profile, and minimize the incidence of recast layer.

Download Full-text

Machining of B1914 nickel-based superalloy using wire electrical discharge machining

Proceedings of the Institution of Mechanical Engineers Part E Journal of Process Mechanical Engineering ◽

10.1177/09544089211031746 ◽

2021 ◽

pp. 095440892110317

Author(s):

Katerina Mouralova ◽

Ales Polzer ◽

Libor Benes ◽

Josef Bednar ◽

Radim Zahradnicek ◽

...

Keyword(s):

Surface Topography ◽

Discharge Current ◽

Electrical Discharge ◽

Electrical Discharge Machining ◽

Cutting Speed ◽

Wire Electrical Discharge Machining ◽

Nickel Based Superalloy ◽

Pulse On Time ◽

Pulse Off Time ◽

Off Time

The unconventional technology of wire electrical discharge machining is a key engineering technology, designed primarily for machining of conventionally difficult machine materials. One of them is nickel alloys, which are majorly used in the aerospace and energy industries. The subject of research in this study was specifically the B1914 nickel-based superalloy, which was subjected to many analyses leading to an overall optimization of its machining using wire electrical discharge machining. In order to determine the effect of machine parameters setup (pulse off time, gap voltage, discharge current, pulse on time and wire feed) on cutting speed, topography, morphology, surface and subsurface layer quality, an extensive Box–Behnken design experiment consisting of 46 rounds was carried out. The analyses of the condition of the surface and subsurface layers were performed, including their chemical composition and changes caused by wire electrical discharge machining. It was found out that the factors like pulse off time, discharge current and pulse on time have the greatest effect on the cutting speed, although from the point of view of surface topography the parameter pulse off time is not significant. The remaining two parameters cause the cutting speed to act against the surface topography i.e. with the increasing cutting speed, the surface topography gets worse and vice versa.

Download Full-text

Sustainable processing of Inconel 718 super alloy in electrical discharge machining process

World Journal of Engineering ◽

10.1108/wje-03-2020-0077 ◽

2020 ◽

Vol 17 (5) ◽

pp. 687-695

Author(s):

Ruben Phipon ◽

Ishwer Shivakoti ◽

Ashis Sharma

Keyword(s):

Discharge Current ◽

Inconel 718 ◽

Electrical Discharge ◽

Electrical Discharge Machining ◽

Deionized Water ◽

Control Parameters ◽

Content Type ◽

Pulse On Time ◽

Pulse Off Time ◽

Off Time

Purpose This paper aims to present the performance of deionized water in electrical discharge machining (EDM) during machining of Inconel 718, copper tool electrode and deionized water as dielectric. Three parameters, namely, pulse-on-time, pulse-off-time and discharge current were taken as control parameters with individual parameter having three levels. Influence of these control parameters on response such as tool wear rate (TWR), material removal rate (MRR) and surface roughness (Ra) is evaluated at various combinations of parametric levels. The results reveal deionized water can be effectively used as a sustainable dielectric and may substitute the hydrocarbon-based dielectric in electrical discharge machining. Also, the control parameters considered show significant impact on the process criteria. Super ranking method was adopted to achieve optimal integration of EDM control factors for obtaining higher MRR, lower TWR and Ra. Further, by applying analysis of variance test, discharge current is established as the dominant parameter during the machining process. Design/methodology/approach The experimentation was performed on Inconel 718 in SPARKONIX MOS, 35 A, ZNC EDM using deionized water as dielectric and copper tool as electrode. The dielectric circulatory system was developed without disturbing the existing dielectric circulation system. Figure 1 shows the EDM with newly developed dielectric system. The existing system consists of hydrocarbon-based dielectric, which has a number of drawbacks during the machining such as carbide deposition on the work material, which reduces removal of material from work material; carbon particle adhesion on tool, which results in inefficient discharge between the electrode; and the work material and production of CO and CH4 during machining, which makes the machining environment toxic. To overcome these drawbacks, a sustainable dielectric was adopted in present work. Trial experiments were conducted to select the ranges of parameters, namely, discharge current, pulse-on-time and pulse-off-time. The process characteristics were evaluated at different parametric combinations and the experimentation was designed as per Taguchi L9 orthogonal array. Table 1 shows the properties of Inconel 718. Table 2 shows the parameters considered with its ranges. Table 3 shows the experimental values. The difference of weight of work piece before and after was taken and divided by the machining time used for calculating the MWR. Similarly, the difference of weight of tool material before and after was taken and divided by machining time and is used for calculating TWR. Measurement of surface roughness was done using Talysurf surface roughness meter. Findings The experimentation was conducted at different parametric combination on Inconel 718 taking copper as electrode and deionized water as dielectric. The performance criteria was evaluated at considered parametric combination. The result shows that the EDM parameters have significant contribution on the performance criteria and deionized water can be effectively used as dielectric medium in EDM. The use of deionized water as dielectric will improve the process and sustainable green machining can be performed. Super ranking method has been implemented to achieve the best combination of control factors and it is obtained that the combination A1B1C3 (i.e. discharge current = 3 A, pulse-on-time = 1 µs and pulse-off-time = 3 µs) is best combination for obtaining the higher MRR and lower TWR and Ra. The contributing factor in the proposed research work is discharge current. Further, ANOVA was implemented to check the adequacy of these result. It was established that discharge current is the most influential factor followed by pulse-on-time and the least contributing factor as pulse-off-time. The findings of this paper may open the guidelines for researcher for performing research in the field of sustainable machining of difficult to cut materials such as Inconel 718 with sustainable dielectrics in engineering applications. Originality/value The paper is original in nature. The findings of this paper may open the guidelines for researcher for performing research in the field of sustainable machining.

Download Full-text

Multi-Objective Optimization of Process Parameters for Powder Mixed Electrical Discharge Machining of Inconel X-750 Alloy Using Taguchi-Topsis Approach

Strojnícky casopis – Journal of Mechanical Engineering ◽

10.2478/scjme-2021-0001 ◽

2021 ◽

Vol 71 (1) ◽

pp. 1-18

Author(s):

Basha Shaik Khadar ◽

Raju M. V. Jagannadha ◽

Kolli Murahari

Keyword(s):

Boron Carbide ◽

Process Parameters ◽

Electrical Discharge Machining ◽

Removal Rate ◽

Optimization Technique ◽

Dielectric Fluid ◽

Carbide Powder ◽

Powder Concentration ◽

Pulse On Time ◽

Pulse Off Time

Abstract The paper investigates the influence of boron carbide powder (B4C) mixed in dielectric fluid on EDM of Inconel X-750 alloy. The process parameters selected as discharge current (Ip), pulse on time(Ton), pulse off time(Toff), boron carbide(B4C) powder concentration to examine their performance responses on Material Removal Rate (MRR), Surface Roughness(Ra) and Recast Layer Thickness (RLT).In this study, o examine the process parameters which influence the EDM process during machining of Inconel X-750 alloy using combined techniques of Taguchi and similarity to ideal solutions (TOPSIS).Analysis of variance (ANOVA) was conducted on multi-optimization technique of Taguchi-TOPSIS. ANOVA results identified the best process parameters and their percentages. It developed the mathematical equation on Taguchi-TOPSIS performance characteristics results. The multi optimization results indicated that Ip and Toff are more significant parameters; V, and Ton parameters are less significant. Finally, surface structures were studied at optimized EDM conditions by using scanning electron microscope (SEM).

Download Full-text