Dr. Shailesh Dewangan | NIT ROURKELA (original) (raw)

Journal Papers by Dr. Shailesh Dewangan

The surface integrity and dimensional accuracy remain critical concern in electrical discharge ma... more The surface integrity and dimensional accuracy remain critical concern in electrical discharge machining (EDM).
The current research work aims at investigating the influence of various EDM process parameters like pulse current
(Ip), pulse-on time (Ton), tool work time (Tw) and tool lift time (Tup) on various aspects of surface integrity like white
layer thickness (WLT), surface crack density (SCD) and surface roughness (SR). The dimensional accuracy,
characterized by over cut (OC), has also been studied in the similar way. A response surface methodology (RSM) -
based design of experiment has been considered for this purpose. The present study also recommends an optimal
setting of EDM process parameters with an aim to improve surface integrity aspects after EDM of AISI P20 tool
steel. This has been achieved by simultaneous optimization of multiple attributes (i.e. WLT, SCD, SR and OC)
using Fuzzy-TOPSIS-based multi-criteria decision making (MCDM) approach. The optimal solution was obtained
based on five decision makers’ preferences on the four responses (i.e. WLT, SCD, SR, and OC). From this analysis,
an optimal condition of process parameters of Ip= 1A, Ton = 10μs, Tw = 0.2s, and Tup = 1.5s has been determined.
Furthermore, sensitivity analysis is also carried out to study the sensitivity or robustness of five decision makers’
preference of optimal machining parameters. Form this study, decision makers’ preference for surface crack density
has been found to be the most sensitive response and therefore should be chosen first and analyzed very carefully.

Inconel 825 belongs to the family of Nickel-based super alloy and is widely used in aerospace and... more Inconel 825 belongs to the family of Nickel-based super alloy and is widely used in aerospace and marine industry. Although most of the research work was concentrated on machinability of Inconel 718, no such work on the current grade of Inconel 825 has been reported so far. The current study investigated the effect of cutting speed and multilayer (TiN/TiCN/Al2O3/ZrCN) coating deposited by chemical vapour deposition (CVD) on machined surface integrity of Inconel 825 during dry turning. Present paper particular emphasis on measurement of sub-surface hardness. Fuzzy logic method is used to find predicted value of microhardness of sub-surface and compare the experimental and predicted value for both uncoated (ISO P 30 grad) and CVD coated tool

The current study aims at investigating the influence of different machining parameters such as c... more The current study aims at investigating the influence of different machining parameters such as cutting speed (Vc), feed (f) and
depth of cut (t) on different performance measures during dry turning of AISI 304 austenitic stainless steel. ISO P30 grade
uncoated cemented carbide inserts was used a cutting tool for the current purpose. L27 orthogonal array design of experiments
was adopted with the following machining parameters: Vc= 25, 35, 45 m/min., f= 0.1, 0.15, 0.2 mm/rev. and t= 1, 1.25, 1.5 mm.
Three important characteristics of machinability such as material removal rate (MRR), cutting force (Fc) and surface roughness
(Ra) were measured. Attempt was further made to simultaneously optimize the machining parameters using grey relational
analysis. The recommended parametric combination based on the studied performance criteria (i.e. MRR, Fc and Ra) was found
to be Vc =45m/min, f=0.1mm/rev, t=1.25mm. A confirmatory test was also carried out to support the analysis and an
improvement of 88.78% in grey relational grade (GRG) was observed.

Electric discharge machining (EDM) has verified to be an alternate approach for machining complex... more Electric discharge machining (EDM) has verified to be an alternate approach for machining complex and critical shapes on
workpiece. In this work described EDM of AISI P20 tool steel in which best process environment (optimal) has been determined
to satisfy efficiency of graphite electrode material. Multi objective optimization of various EDM parameters for obtaining
favorable preference measures in surface integrity (surface crack density, white layer thickness and surface roughness) using
PCA based grey relational analysis has been selected.

Surface integrity in electro discharge machining (EDM) has been proven to be one of the major cha... more Surface integrity in electro discharge machining (EDM) has been proven to be one of the major challenges in recent years. The current study focused on investigating the influence of different tool electrode materials such as copper, brass and graphite and
various process parameters like discharge current (Ip), pulse on time (Ton), duty cycle (τ) and polarity on EDMed surface integrity science formation of white layer, surface cracks and surface roughness predominantly influence surface integrity they have been considered in the current study. The result indicated that maximum white layer thickness (WLT), surface crack density (SCD) and surface roughness (SR) were obtained for graphite tool. Therefore it cannot be recommended to use under the given operating conditions. The brass tool performed based followed by copper tool when different aspect of surface integrity were analysed. Pulse current was found to be the most influential process parameters affecting machine surface integrity of AISI P20 tool steel.

INPRESSCO, Apr 1, 2014

Abrasive Jet Machining (AJM) is a non-conventional machining process that carried a high-pressure... more Abrasive Jet Machining (AJM) is a non-conventional machining process that carried a high-pressure air stream with small abrasive particles to impinge the work surface through a nozzle. In this paper drilling experiment was done on glass as the work piece and aluminum oxide (Al2O3) as abrasive powder on AJM. The effect of Overcut (OC) and Material Removal Rate (MRR) of glass material was finding by using L9 Orthogonal Array (OA) based on Taguchi design. The multi-objective optimization of AJM process using the Taguchi’s quality loss function has been carried out for responses of AJM. The air pressure and stand-off-distance are considering control parameter.

This study presents a new method to determine multi-objective optimal condition using Principal C... more This study presents a new method to determine multi-objective optimal condition using Principal Component Analysis (PCA) based on Grey Relational Analysis (GRA) Method for Characteristics as Material Removal Rate (MRR), Tool Wear Rate (TWR) and Surface Roughness (Ra) on Electrical Discharge Machining (EDM).In this paper, an attempt has been made to machining the AISI P20 tool steel by using cylindrical copper electrode perform on EDM. A well-designed L27 orthogonal array based on the Taguchi method were conducted on input parameters as current, pulse on time, up-time, working time and inter electrode gap.

Inderscience Publishers, May 2013

The present work demonstrates the optimisation process of multiple responses, i.e., material remo... more The present work demonstrates the optimisation process of multiple responses, i.e., material removal rate (MRR) and tool wear rate (TWR) of electrical discharge machining (EDM) by grey Taguchi analysis. The work piece material was AISI P20 tool steel and a cylindrical copper electrode was used with side impulse flushing. The discharge current, pulse on time, work time, lift time, and inter electrode gap (IEG) were the control parameters of EDM. Taguchi method was used to design the experiment using L27 orthogonal array and the effect of the factors on the responses was studied. These results show that MRR decreases with the electrode lift time whereas working time slightly increases it. TWR is directly proportional to work time, and lift time and inter electrode gap has no significant effect on it. The optimal parameter setting for maximum MRR and minimum TWR was obtained by grey relational analysis.

Abstract Quality and productivity are two important aspects have become great concerns in todays ... more Abstract Quality and productivity are two important aspects have become great concerns in todays competitive global market. Every manufacturing/production unit mainly focuses on these areas in relation to the process as well as product developed. Achieving high quality necessarily requires higher degree of skill, sophisticated machine/tools, advanced technology, precise control, immense attention-inspection and considerable time. Improvement of quality results reduction in productivity and vice versa.

CERTIFICATE certify that thesis entitled, "EXPERIMENTAL INVESTIGATION MACHINING PARAMETERS FOR ED... more CERTIFICATE certify that thesis entitled, "EXPERIMENTAL INVESTIGATION MACHINING PARAMETERS FOR EDM USING U-SHAPED ELECTRODE submitted by Mr. SHAILESH KUMAR DEWANGAN fulfillment of the requirements for the award of Master of Technology in Mechanical Engineering with "Production Engineering" Specialization during session 2 Department of Mechanical Engineering National Institute of Technology, Rourkela. hentic work carried out by him under my supervision and guidance. To the best of my knowledge, the matter embodied in this thesis has not been submitted to any other nstitute for award of any Degree or Diploma.

Conference Presentations by Dr. Shailesh Dewangan

Electric discharge machining (EDM) has verified to be an alternate approach for machining complex... more Electric discharge machining (EDM) has verified to be an alternate approach for machining complex and critical shapes on workpiece. In this work described EDM of AISI P20 tool steel in which best process environment (optimal) has been determined to satisfy efficiency of graphite electrode material. Multi objective optimization of various EDM parameters for obtaining favorable preference measures in surface integrity (surface crack density, white layer thickness and surface roughness) using PCA based grey relational analysis has been selected.

In this work predicts Surface Roughness (SR) in Electric Discharge Machining (EDM) using Artifici... more In this work predicts Surface Roughness (SR) in Electric Discharge Machining (EDM) using Artificial Neural Network (ANN) model. Experiment is carried out by using AISI P20 tool steel as a workpiece material and cylindrical copper electrode has been used with side impulse flushing. The pulse current, pules duration, work time, lift time, and inter electrode gap were taken as a control parameters of EDM. Taguchi method using L27 orthogonal array has been considered to design the experiment and the effect of the factor on the responses were studied. Pulse current is most effected as compare to pulse duration of SR. Prediction results have been verified with experimental results and found to be good convenient with the experimental.

This paper demonstrates the optimizing process

Abstract: In this analysis, the optimisation of multiple responses of Electric discharge machinin... more Abstract: In this analysis, the optimisation of multiple responses of Electric discharge machining (EDM) using Fuzzy logic coupled with Taguchi method is attempted. The work piece material was AISI P20 tool steel and a cylindrical copper electrode was used with side impulse flushing. The influence of machining parameters, ie, pulse current (Ip), pulse duration (Ton), work time (Tw), lift time (Tup) and Inter Electrode Gap (IEG) on the Material Removal Rate (MRR) and Surface Roughness (SR) in EDM are examined.

The present work is demonstrates the optimization multiple responses of the Electric discharge ma... more The present work is demonstrates the optimization multiple responses of the Electric discharge machining (EDM) by using Fuzzy logic in integration with Taguchi method. The work piece material was AISI P20 tool steel and a cylindrical copper electrode was used with side impulse flushing. The discharge current, pulse on time, work time, lift time, and antiarc sensitivity (ASEN) were the control parameters of EDM. Taguchi method using L 27 orthogonal array was used to design the experiment and the effect of the factors on the responses were studied. Taguchi method has developed a powerful tool in the design of experiments, but this method can optimized to single performance characteristics at a time. Hence, Taguchi methodology is coupled with fuzzy logic for optimization of multiple quality characteristics. Using the fuzzy logic system optimization of complex multiple performance characteristics is transmuted in to the optimization of single response performance characteristics. Experimental results confirm that this method is efficient for optimization of multiple quality characteristics i.e. MRR and surface finish in EDM.

INPRESSCO, Apr 1, 2014

Inderscience Publishers, May 2013

Electric discharge machining (EDM) has verified to be an alternate approach for machining complex... more Electric discharge machining (EDM) has verified to be an alternate approach for machining complex and critical shapes on workpiece. In this work described EDM of AISI P20 tool steel in which best process environment (optimal) has been determined to satisfy efficiency of graphite electrode material. Multi objective optimization of various EDM parameters for obtaining favorable preference measures in surface integrity (surface crack density, white layer thickness and surface roughness) using PCA based grey relational analysis has been selected.

This paper demonstrates the optimizing process

In this experiment using AISI D2 tool steel material with copper electrode and three process vari... more In this experiment using AISI D2 tool steel material with copper electrode and three process variables (factors) as discharge current (Ip), pulse duration (Ton), and duty cycle (ζ). Response surface methodology was used to investigate the relationships and parametric interactions between the three controllable variables on the material removal rate (MRR). To study the proposed second-order polynomial model for MRR, we used the central composite experimental design to estimation the model coefficients of the three factors, which are believed to influence the MRR in EDM process. The response was modeled using a response surface model based on experimental results. The significant coefficients were obtained by performing analysis of variance (ANOVA) at 5% level of significance. It was found that discharge current, pulse duration, and duty cycle significant effect on the MRR. This methodology is very effectual, needs only 20 experiments to assess the conditions, and model sufficiency was very satisfactory as the coefficient of determination was 0.995.

The correct selection of manufacturing conditions is one of the most important aspects to take in... more The correct selection of manufacturing conditions is one of the most important aspects to take into consideration in the majority of manufacturing processes and, particularly, in processes related to Electrical Discharge Machining (EDM). In This experiment using AISI P20 tool steel material, it has a grooving rang of application in Plastic moulds, frames for plastic pressure dies, hydro forming tools The EDM process is finding out the effect of machining parameter such as discharge current , pulse on time (Ton) and diameter of tool. Using U-shaped cu tool electrode with internal flushing system was used. A well-designed experimental scheme was used to reduce the total number of experiments. Parts of the experiment were conducted with the L18 orthogonal array based on the Taguchi method. Observed values in the experiments were determined by which factor is most affected by the Responses of MRR (Material removal rate), TWR (Tool wear rate) and over cut.

This paper highlights the prediction of Surface Roughness (SR) in Electric Discharge Machining (E... more This paper highlights the prediction of Surface Roughness (SR) in Electric Discharge Machining (EDM) using Artificial Neural Network (ANN) model. Experiment is carried out by using AISI P20 tool steel as a workpiece material and cylindrical copper electrode has been used with side impulse flushing. The discharge current, pules duration, work time, lift time, and inter electrode gap were taken as a control parameters of EDM. Taguchi method using L 27 orthogonal array has been considered to design the experiment and the effect of the factor on the responses were studied. Pulse current is most effected as compare to pulse duration of SR. Prediction results have been verified with experimental results and found to be good convenient with the experimental.

The present work is proposed to solve multi-response optimisation problem in Electric discharge m... more The present work is proposed to solve multi-response optimisation problem in Electric discharge machining (EDM) using Grey-fuzzy logic method. The responses are Material Removal Rate (MRR), Tool Wear Rate (TWR) and Surface Roughness (SR) of EDM. The work piece material was AISI P20 tool steel and a cylindrical copper electrode with side impulse flushing was used as a tool. The discharge current, pulse on time, work time, lift time, and Inter Electrode Gap (IEG) were the control parameters of EDM. Taguchi method using L 27 orthogonal array was used to design the experiment and the effect of the factors on the responses were studied. The optimal parameter setting for maximum MRR and Minimum TWR and SR was obtained by Grey-fuzzy logic method.

The objective of this research is to study the influence of Process parameters and electrode shap... more The objective of this research is to study the influence of Process parameters and electrode shape configuration on the Machining characteristics of die sinking EDM. The present work aims to study the effect of different electrode shapes (Circular, rectangular and triangular) With constant cross sectional area of 280 mm2 on material removal rate (MRR), surface roughness (SR) and Electrode wear rate (EWR) for AISI P20 tool steel workpiece material and pure copper As electrode material. The optimization of the parameters of the EDM machining will be carried out by using the taguchi's method for design of experiments (DOE). The objective of the analysis is to identify the Optimum electrode shapes in terms of higher MRR, minimum EWR and excellent surface finish. The different parameters considered while carrying out the experiments on the Die-Sinking EDM will be the current applied, pulse on time and pulse off time required etc.

Lecture notes in mechanical engineering, Jun 4, 2022

The International Journal of Advanced Manufacturing Technology, 2013

This paper deals with multi-objective optimization of machining parameters for energy saving. Thr... more This paper deals with multi-objective optimization of machining parameters for energy saving. Three objectives including energy, cost, and quality are considered in the optimization model, which are affected by three variables, namely cutting depth, feed rate, and cutting speed. In the model, energy consumption of machining process consists of direct energy (including startup energy, cutting energy, and tool change energy) and embodied energy (including cutting tool energy and cutting fluid energy); machining cost contains production operation cost, cutting tool cost, and cutting fluid cost; and machining quality is represented by surface roughness. With simulation in Matlab R2011b, the multi-objective optimization problem is solved by NSGA-II algorithm. The simulation results indicate that cutting parameters optimization is beneficial for energy saving during machining, although more cost may be paid; additionally, optimization effect on the surface roughness objective is limited. Inspired by the second result, optimization model eliminating quality objective is studied further. Comparing the non-dominated front of three-objective optimization with the one of two-objective optimization, the latter is proved to have better convergence feature. The optimization model is valuable in energy quota determination of workpiece and product.

Procedia Materials Science, 2014

Abrasive Jet Machining (AJM) is a non-conventional machining process that carried a high-pressure... more Abrasive Jet Machining (AJM) is a non-conventional machining process that carried a high-pressure air stream with small abrasive particles to impinge the work surface through a nozzle. In this paper drilling experiment was done on glass as the work piece and aluminum oxide (Al2O3) as abrasive powder on AJM. The effect of Overcut (OC) and Material Removal Rate (MRR) of glass material was finding by using L9 Orthogonal Array (OA) based on Taguchi design. The multi-objective optimization of AJM process using the Taguchi's quality loss function has been carried out for responses of AJM. The air pressure and stand-off-distance are considering control parameter.

In this work predicts Surface Roughness (SR) in Electric Discharge Machining (EDM) using Artifici... more In this work predicts Surface Roughness (SR) in Electric Discharge Machining (EDM) using Artificial Neural Network (ANN) model. Experiment is carried out by using AISI P20 tool steel as a workpiece material and cylindrical copper electrode has been used with side impulse flushing. The pulse current, pules duration, work time, lift time, and inter electrode gap were taken as a control parameters of EDM. Taguchi method using L 27 orthogonal array has been considered to design the experiment and the effect of the factor on the responses were studied. Pulse current is most effected as compare to pulse duration of SR. Prediction results have been verified with experimental results and found to be good convenient with the experimental.

Procedia Materials Science, 2014

Engineering Science and Technology, an International Journal, 2015

Ultrasonic welding has been used in the market over the past twenty years and serving to the manu... more Ultrasonic welding has been used in the market over the past twenty years and serving to the manufacturing industries like aviation, medical, microelectronics and many more due to various hurdles faced by conventional fusion welding process. It takes very short time (less than one second) to weld materials, thus it can be used for mass production. But many times, the problems faced by industries due to this process are the poor weld quality and strength of the joints. In fact, the quality and success of the welding depend upon its control parameters. In this present study, the control parameters like vibration amplitude, weld pressure and weld time are considered for the welding of dissimilar metals like aluminum (AA1100) and brass (UNS C27000) sheet of 0.3 mm thickness. Experiments are conducted according to the full factorial design with four replications to obtain the responses like tensile shear stress, T-peel stress and weld area. All these data are utilized to develop a non-linear second order regression model between the responses and predictors. As the quality is an important issue in these manufacturing industries, the optimal combinations of these process parameters are found out by using fuzzy logic approach and genetic algorithm (GA) approach. During experiments, the temperature measurement of the weld zone has also been performed to study its effect on different quality characteristics. From the confirmatory test, it has been observed that, the fuzzy logic yields better output results than GA. A variety of weld quality levels, such as "under weld", "good weld" and "over weld" have also been defined by performing micro structural analysis.

Engineering Science and Technology, an International Journal, 2015

Surface integrity remains one of the major areas of concern in electric discharge machining (EDM)... more Surface integrity remains one of the major areas of concern in electric discharge machining (EDM). During the current study, grey-fuzzy logic-based hybrid optimization technique is utilized to determine the optimal settings of EDM process parameters with an aim to improve surface integrity aspects after EDM of AISI P20 tool steel. The experiment is designed using response surface methodology (RSM) considering discharge current (Ip), pulse-on time (T on), tool-work time (T w) and tool-lift time (T up) as process parameters. Various surface integrity characteristics such as white layer thickness (WLT), surface crack density (SCD) and surface roughness (SR) are considered during the current research work. Grey relational analysis (GRA) combined with fuzzy-logic is used to determine grey fuzzy reasoning grade (GFRG). The optimal solution based on this analysis is found to be Ip ¼ 1 A, T on ¼ 10 ms, T w ¼ 0.2 s, and T up ¼ 0.0 s. Analysis of variance (ANOVA) results clearly indicate that T on is the most contributing parameter followed by Ip, for multiple performance characteristics of surface integrity.

ABSTRACT This paper demonstrates the optimizing process of multiple Responses for Electrical Disc... more ABSTRACT This paper demonstrates the optimizing process of multiple Responses for Electrical Discharge Machining (EDM) of AISI P20 tool steel parts via the L 27 Orthogonal array (OA) based on Taguchi design. This methodology uses three different tool materials such as Copper, Brass and Graphite. The machine parameters included tool material, pulse on time, Discharge current, Work time, Lift time, and Impulse Flushing pressure following EDM. All six machining parameter are design by Taguchi method using L 27 orthogonal array based on Taguchi design and observed that which factor is most affected by the Responses of Material Removal Rate, and Tool Wear Rate. Keyword -Electrical Discharge Machining (EDM), AISI P20 tool steel, Impulse Flushing pressure.

ABSTRACT The present work is demonstrates the optimization multiple responses of the Electric dis... more ABSTRACT The present work is demonstrates the optimization multiple responses of the Electric discharge machining (EDM) by using Fuzzy logic in integration with Taguchi method. The work piece material was AISI P20 tool steel and a cylindrical copper electrode was used with side impulse flushing. The discharge current, pulse on time, work time, lift time, and anti-arc sensitivity (ASEN) were the control parameters of EDM. Taguchi method using L 27 orthogonal array was used to design the experiment and the effect of the factors on the responses were studied. Taguchi method has developed a powerful tool in the design of experiments, but this method can optimized to single performance characteristics at a time. Hence, Taguchi methodology is coupled with fuzzy logic for optimization of multiple quality characteristics. Using the fuzzy logic system optimization of complex multiple performance characteristics is transmuted in to the optimization of single response performance characteristics. Experimental results confirm that this method is efficient for optimization of multiple quality characteristics i.e. MRR and surface finish in EDM.

ABSTRACT The present work is proposed to solve multi-response optimisation problem in Electric di... more ABSTRACT The present work is proposed to solve multi-response optimisation problem in Electric discharge machining (EDM) using Grey-fuzzy logic method. The responses are Material Removal Rate (MRR), Tool Wear Rate (TWR) and Surface Roughness (SR) of EDM. The work piece material was AISI P20 tool steel and a cylindrical copper electrode with side impulse flushing was used as a tool. The discharge current, pulse on time, work time, lift time, and Inter Electrode Gap (IEG) were the control parameters of EDM. Taguchi method using L 27 orthogonal array was used to design the experiment and the effect of the factors on the responses were studied. The optimal parameter setting for maximum MRR and Minimum TWR and SR was obtained by Grey-fuzzy logic method.

ABSTRACT The present work is demonstrates the optimization of multiple performance characteristic... more ABSTRACT The present work is demonstrates the optimization of multiple performance characteristics [Material Removal Rate (MRR) and Surface Roughness (SR)] in Electric Discharge Machining (EDM) using Taguchi Method and Grey Relation Analysis (GRA). The workpiece material was Mild Steel and a cylindrical copper electrode was used with side flushing. Machining process parameters selected were Discharge current (Ip), Pulse on time (T on) and Duty cycle (T au). The Taguchi method was used to design the experimental using L 9 orthogonal array and the effect of the factors on the responses where studied. The optimal parameter setting for maximum MRR and minimum SR was obtained by GRA.

Advanced Materials Research, 2012

Quality and productivity are two important aspects have become great concerns in today's competit... more Quality and productivity are two important aspects have become great concerns in today's competitive global market. Every manufacturing/ production unit mainly focuses on these areas in relation to the process as well as product developed. Achieving high quality necessarily requires higher degree of skill, sophisticated machine/ tools, advanced technology, precise control, immense attention-inspection and considerable time. Improvement of quality results reduction in productivity and vice versa. Thus, optimality must be maintained between quality as well as productivity. The case study highlights EDM of stainless steel in which best process environment (optimal) has been determined to satisfy productivity and quality requirements simultaneously. Material Removal Rate (MRR) during the process has been considered as productivity estimate with the aim to maximize it. Where as surface roughness i.e. (R a value) of the machined surface has been chosen as surface quality estimate with the requirement to minimize it. These two contradicting requirements have been simultaneously satisfied by selecting an optimal process environment (optimal parameter setting). Desirability Function (DF) approach coupled with Taguchi method has been used to solve the problem.

Measurement, 2015

The surface integrity and dimensional accuracy remain critical concern in electrical discharge ma... more The surface integrity and dimensional accuracy remain critical concern in electrical discharge machining (EDM). The current research work aims at investigating the influence of various EDM process parameters like pulse current (Ip), pulse-on time (T on), tool work time (T w) and tool lift time (T up) on various aspects of surface integrity like white layer thickness (WLT), surface crack density (SCD) and surface roughness (SR). The dimensional accuracy, characterized by over cut (OC), has also been studied in the similar way. A response surface methodology (RSM)based design of experiment has been considered for this purpose. The present study also recommends an optimal setting of EDM process parameters with an aim to improve surface integrity aspects after EDM of AISI P20 tool steel. This has been achieved by simultaneous optimization of multiple attributes (i.e. WLT, SCD, SR and OC) using Fuzzy-TOPSIS-based multi-criteria decision making (MCDM) approach. The optimal solution was obtained based on five decision makers' preferences on the four responses (i.e. WLT, SCD, SR, and OC). From this analysis, an optimal condition of process parameters of Ip= 1A, T on = 10µs, T w = 0.2s, and T up = 1.5s has been determined. Furthermore, sensitivity analysis is also carried out to study the sensitivity or robustness of five decision makers' preference of optimal machining parameters. Form this study, decision makers' preference for surface crack density has been found to be the most sensitive response and therefore should be chosen first and analyzed very carefully.

International Journal of Mechatronics and Manufacturing Systems, 2013

The present work demonstrates the optimisation process of multiple responses, i.e., material remo... more The present work demonstrates the optimisation process of multiple responses, i.e., material removal rate (MRR) and tool wear rate (TWR) of electrical discharge machining (EDM) by grey Taguchi analysis. The work piece material was AISI P20 tool steel and a cylindrical copper electrode was used with side impulse flushing. The discharge current, pulse on time, work time, lift time, and inter electrode gap (IEG) were the control parameters of EDM. Taguchi method was used to design the experiment using L 27 orthogonal array and the effect of the factors on the responses was studied. These results show that MRR decreases with the electrode lift time whereas working time slightly increases it. TWR is directly proportional to work time, and lift time and inter electrode gap has no significant effect on it. The optimal parameter setting for maximum MRR and minimum TWR was obtained by grey relational analysis.

INTERNATIONAL JOURNAL OF MANUFACTURING TECHNOLOGY AND INDUSTRIAL ENGINEERING (IJMTIE), 2011

Lecture Notes in Mechanical Engineering, 2019

Quality and productivity are two essential facets developed in present competitive global market.... more Quality and productivity are two essential facets developed in present competitive global market. In the present study, wire EDM process of AISI P20 tool steel optimized the quality as well as productivity simultaneously. MRR in the terms of productivity, this can be maximized and overcut in terms of quality that can be minimized. This study highlights AISI P20 tool steel of best combination of machining parameter setting with Taguchi design of experimental technique, of WIRE EDM. The selected input parameters are pulse-on time (Ton), wire feed (f) and pulse-off time (Toff). The objective of this paper is to achieve the maximum MRR and the minimum overcut. They used copper wire of 0.25 mm diameter as a tool, and dielectric fluid was used in distilled water,; L9 orthogonal array based on Taguchi design has been used. These two responses (MRR and overcut) have been converted into signal quality characteristics for optimal process environment (optimum input parameters setting). Principal component analysis (PCA) combined with grey relational analysis (GRA) with Taguchi design of experiment techniques has been used to solve the problem.

During the process of electric discharge machining (EDM), the spark is generated between tool and... more During the process of electric discharge machining (EDM), the spark is generated between tool and workpiece which is controlled by a servo-controller. This spark can be categorized into five different types and can be used to eliminate material and affect the quality of the surface. Different process parameters affect discharge characteristics in the EDM process, while machining, the various sets of current–voltage waveforms affect the value of EDM, which can be captured by signals. In this work, different EDM waveforms are conformed followed by the analysis of the experiment using wavelet transforms. The influence of different EDM parameters like discharge current (Ip), pulse-on time (Ton), and duty cycle (Tau) on the different discharge characteristics of EDM pulses has also been investigated.