Multi-Response Optimization of Machining Process Parameters for Wire Electrical Discharge Machining of Lead-Induced Ti-6Al-4V Alloy Using AHP–TOPSIS Method

2019 ◽  
Vol 18 (02) ◽  
pp. 213-236 ◽  
Author(s):  
A. V. S. Ram Prasad ◽  
Koona Ramji ◽  
Murahari Kolli ◽  
G. Vamsi Krishna

In this study, the effects of the process parameters on their performance characteristics of lead-induced Ti-6Al-4V alloy were investigated. Taguchi’s [Formula: see text] orthogonal array (OA) has been used to conduct the experiments. Four process parameters were considered each at three levels. Peak current, pulse-on-time, servo voltage and pulse-off-time were selected as process parameters on performance characteristics, namely, material removal rate (MRR), surface roughness (SR) and dimensional deviation (DD). A multi-attribute decision-making (MADM) technique, namely, analytic hierarchy process (AHP) and technique for order of preference by similarity to ideal solution (TOPSIS), has been used to investigate the multiple response characteristics. The weights for performance characteristics are determined by AHP. Finally, analysis of variance method has been employed effectively to bring out the influence of the process parameters associated with each performance characteristic, namely, maximization of MRR and minimization of SR and DD.

Author(s):  
Balbir Singh ◽  
Jatinder Kumar ◽  
Sudhir Kumar

This paper presents the experimental investigation on the electro-discharge machining of aluminum alloy 6061 reinforced with SiC particles using sintered Cu–W electrode. Experiments have been designed as per central composite rotatable design, using response surface methodology. Machining characteristics such as material removal rate (MRR), electrode wear ratio (EWR), and surface roughness (SR) have been investigated under the influence of four electrical process parameters; namely peak current, pulse on time, pulse off time, and gap voltage. The process parameters have been optimized to obtain optimal combination of MRR, EWR, and SR. Further, the influence of sintered Cu–W electrode on surface characteristics has been analyzed with scanning electron microscopy, energy dispersive spectroscopy, and Vicker microhardness tests. The results revealed that all the process parameters significantly affect MRR, EWR, and SR. The machined surface properties are modified as a result of material transfer from the electrode. The recast layer thickness is increased at higher setting of electrical parameters. The hardness across the machined surface is also increased by the use of sintered Cu–W electrode.


2021 ◽  
Vol 71 (1) ◽  
pp. 1-18
Author(s):  
Basha Shaik Khadar ◽  
Raju M. V. Jagannadha ◽  
Kolli Murahari

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).


2020 ◽  
Vol 17 (3) ◽  
pp. 389-397
Author(s):  
Harvinder Singh ◽  
Vinod Kumar ◽  
Jatinder Kapoor

Purpose This study aims to investigate the influence of process parameters of wire electrical discharge machining (WEDM) of Nimonic75. Nimonic75 is a Nickel-based alloy mostly used in the aerospace industry for its strength at high temperature. Design/methodology/approach One factor at a time (OFAT) approach has been used to perform the experiments. Pulse on time, pulse off time, peak current and servo voltage were chosen as input process parameters. Cutting speed, material removal rate and surface roughness (Ra) were selected as output performance characteristics. Findings Through experimental work, the effect of process parameters on the response characteristics has been found. Results identified the most important parameters to maximize the cutting speed and material removal rate and minimize Ra. Originality/value Very limited research work has been done on WEDM of Nickel-based alloy Nimonic75. Therefore, the aim of this paper to conduct preliminary experimentation for identifying the parameters, which influence the response characteristics such as material removal rate, cutting speed, Ra, etc. during WEDM of Nickel-based alloy (Nimonic75) using OFAT approach and found the machinability of Nimonic75 for further exhaustive experimentation work.


2018 ◽  
Vol 63 (1) ◽  
pp. 16-25 ◽  
Author(s):  
Partha Protim Das ◽  
Sunny Diyaley ◽  
Shankar Chakraborty ◽  
Ranjan Kumar Ghadai

Wire electro discharge machining (WEDM) is a versatile non-traditional machining process that is extensively in use to machine the components having intricate profiles and shapes. In WEDM, it is very important to select the optimal process parameters so as to enhance the machine performance. This paper emphasizes the selection of optimal parametric combination of WEDM process while machining on EN31 steel, using grey-fuzzy logic technique. Process parameters such as servo voltage, wire tension, pulse-on-time and pulse-off-time were considered while taking into account several multi-responses such as material removal rate (MRR) and surface roughness (SR). It was found that pulse-on-time of 115 µs, pulse-off-time of 35 µs, servo voltage of 40 V and wire tension of 5 kgf results in a larger value of grey fuzzy reasoning grade (GFRG) which tends to maximize MRR and improve SR. Finally, analysis of variance (ANOVA) is applied to check the influence of each process parameters in the estimation of GFRG.


2012 ◽  
Vol 622-623 ◽  
pp. 19-24
Author(s):  
P. Balasubramanian ◽  
Thiyagarajan Senthilvelan

In this study, input parameters of Electrical Discharge machining (EDM) process have been optimised for two different materials EN-8 and Die steel-D3 were machined by using sintered copper electrode. Analysis of variance (ANOVA) was applied to study the influences of process parameters viz: - peak current, pulse on time, di-electric pressure and diameter of electrode on material removal rate (MRR), tool wear rate (TWR) and surface roughness (SR) for both materials. Response surface methodology (RSM) has been applied to optimise the multi responses in order to get maximum MRR, minimum TWR and minimum SR. Furthermore, mathematical model has been formulated to estimate the corresponding output responses for both work pieces. It has been observed that compared to EN 8 material, the MRR value is low and TWR is high for D3 material. However the SR value is marginally lower than obtained in EN8.R2 value is above 0.90 for both work pieces.


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.


Author(s):  
Uvaraja Ragavendran ◽  
Ranjan Kumar Ghadai ◽  
Akash Kumar Bhoi ◽  
Manickam Ramachandran ◽  
Kanak Kalita

Electrical discharge machining (EDM) is a broadly used nonconventional material removal process for the machining of conductive work material irrespective of their hardness. In this article, empirical models for material removal rate (MRR) and surface roughness (Ra) of the workpiece are developed based on the extensive experiments performed on a special steel (WP7V) workpiece using a copper electrode. To account for the various parameters, an experimental design based on response surface methodology (RSM) is conducted considering three different factors namely — current, pulse-on-time, and pulse-off-time, each having three different levels. Analysis of variance (ANOVA) is conducted to test the statistical significance of the proposed empirical models. It is essential to determine the relationship and significance of input–output variation. Thus a sensitivity analysis is conducted. The interaction effect of input variables is also studied. Two different state-of-art optimization techniques, namely genetic algorithm (GA) and particle swarm optimization (PSO), are applied to predict the optimal combination of process parameters. Finally, multi-objective optimization is also carried out to simultaneously maximize MRR while minimizing Ra.


2013 ◽  
Vol 43 (1) ◽  
pp. 33-40
Author(s):  
Md. Ashikur Rahman Khan

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


2018 ◽  
Vol 7 (3.34) ◽  
pp. 256
Author(s):  
S Rajamanickam ◽  
R Palani ◽  
V Sathyamoorthy ◽  
Muppala Jagadeesh Varma ◽  
Shaik Shaik Mahammad Althaf ◽  
...  

As on today, Electrical Discharge Machining (EDM) is world famous unconventional machining process for electrically conductive materials. In this project work, Ti-6Al-4V is performed in electrical discharge machining using differently shaped (circular and convex) copper electrode. The machining parameters considered are the pulse on- time, pulse off-time, voltage and current to investigate machining characteristics like material removal rate and tool wear rate. Taguchi method is applied to frame experimental design. Ti-6Al-4V finds wide usage in industrial applications such as marine, aerospace, bio-medical and so on. 


2014 ◽  
Vol 68 (1) ◽  
Author(s):  
Md. Ashikur Rahman Khan ◽  
M. M. Rahman

Electrical discharge machining (EDM) produces complex shapes and permits high-precision machining of any hard or difficult-to-cut materials. The performance characteristics such as surface roughness and microstructure of the machined face are influenced by numerous parameters. The selection of parameters becomes complicated. Thus, the surface roughness (Ra) and microstructure of the machined surface in EDM on Grade 6 titanium alloy are studied is this study. The experimental work is performed using copper as electrode material. The polarity of the electrode is maintained as negative. The process parameters taken into account in this study are peak current (Ip), pulse-on time (Ton), pulse-off time (Toff), and servo-voltage (Sv). A smooth surface finish is found at low pulse current, small on-time and high off-time. The servo-voltage affects the roughness diversely however, a finish surface is found at 80 V Sv. Craters, cracks and globules of debris are appeared in the microstructure of the machined part. The size and degree of craters as well as cracks increase with increasing in energy level. Low discharge energy yields an even surface. This approach helps in selecting proper process parameters resulting in economic EDM machining. 


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