The document presents a research presentation on investigating the effects of process parameter changes in electrical discharge machining (EDM) of super alloys. It discusses EDM techniques such as dry EDM, powder mixed EDM, and near-dry EDM. It identifies inconel super alloys as materials of interest for aerospace applications. The objectives are outlined as optimizing near dry EDM parameters to increase material removal rate and reduce tool wear rate and surface roughness when machining inconel super alloys. The research methodology involves using Taguchi design of experiments to analyze process parameters and develop models. The expected outcomes are improved material removal rate and reduced tool wear rate and surface roughness for machining nickel-based super alloys using near

1. Vishwakarma Institute Of Technology, Pune
Mechanical Engineering Department
Title:-“Investigation into effects of process parameter change in EDM of
Super alloys”
Research Scholar:-Apurva A Kulkarni
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2. Content
• Introduction
• Motivation
• Literature Survey
• Problem Statement
• Objective
• Research Methodology
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3. INTRODUCTION
• EDM technique developed in late 1940.
• EDM is Electrical Discharge Machining and is well known as non
contact machining technique .
• EDM is basically a thermo-electric process, has the ability to machine any
conductive materials regardless of their mechanical and chemical properties.
• It is based on removing material from a part by means of a series of
repeated electrical discharges between tool called the electrode and the
workpiece in presence of dielectric fluid[1]
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4. Applications of EDM
• EDM used for shaping difficult-to-cut materials such as Inconel, Titanium,
high speed steel etc.
• It has been extensively used to fabricate dies and mold’s.
• It is also used for manufacturing of medical components and finishing
parts for aerospace and automotive industry.
• It is very effective in machining very hard and high-strength material
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5. LIMITATIONS OF EDM
• EDM is releasing a variety of harmful substances in the form of liquid, solid and
gaseous wastes, which result in serious health issues, and environmental issues.
• These harmful substances can enter the body of the worker through ingestion,
inhalation, and skin contact which is not satisfactory for green manufacturing.
• A the manufacturing process is considered to be an energy intensive activity, which
also affects the environment.
• The main problems encountered are Low MRR, High TWR,Poor Surface finish
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6. Dielectric Medium
• The dielectric medium plays an essential role in the EDM process.
• Works as the insulation medium between the polarized electrodes to induce
discharge
• Also influences the plasma channel expansion and material erosion during the
discharge, and the debris flushing and discharge gap reconditioning after the
discharge.
• Therefore, understanding and selecting the right dielectric medium with proper
electrical, mechanical and thermal properties is considered a thrust area of
this research.
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7. Dielectric Medium
• According to the type of dielectric medium used, there are several categories
of EDM processes, including
• Wet EDM,
• Powder mixed dielectric (PMD) EDM,
• Dry EDM
• Near-dry EDM
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8. Novel VARIANTS FOR EDM OF
SUPERALLOY
POWDER MIXED
DRY EDM
NEAR DRY EDM
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9. They are classified based on dielectric medium
used
• Wet EDM:- liquid dielectric medium
• Powdered EDM:-A suitable material in fine powder is mixed with
dielectric fluid.(Three phase)
• Dry EDM :-Gas is used as dielectric medium(single phase)
• Near-Dry EDM:-mixture of gas and liquid is used(Two phae)
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10. DRY EDM
• In dry EDM, tool electrode is shaped to be thin walled pipe.
• High-pressure air or gas is supplied through the pipe.
• The function of the gas is to eliminate the debris from the gap and to cool
the inter electrode gap.
• The technique was initiated to diminish the pollution caused by the use of
liquid dielectric which leads to creation of vapour during machining and the
cost to handle the waste.
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11. Advantages Dry EDM
• Most likely advantages of DEDM process are negligible tool wear, low
residual stresses and better precision.
• simplicity in machine building, it does not require advanced and spacious
dielectric circulation and cooling mechanism, thus contributes to reduction
in manufacturing cost.
• Observed negligible TWR with minimum environmental hazards.
• Air and oxygen are commonly used gas dielectric medium in dry EDM.
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14. Disadvantage
• Despite several advantages of dry EDM process, it’s one of the major
limitation is low material removal ability in respect of conventional die
sinking EDM process
• low material removal rate (MRR) and low surface quality due to debris
reattachment were the major limitation of the dry EDM
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15. POWDER MIXED
• A appropriate material in powder form is mixed into the dielectric fluid..
• The powder particles organize themselves under the sparking area and collect
in clusters. The chain formation helps in bridging the gap distance between
both the electrodes which causes the early explosion.
• Rapidly sparking within discharge takes place and causes quicker erosion
from the work piece surface
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16. Advantages & Disadvantage of Powder EDM
• Some conductive powder can reduce the surface roughness and the tendency
of cracks in middle finish
• It is revealed that literature review on three-phase dielectric medium is still
lacking.
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17. NEAR DRY EDM
• In near dry EDM,used liquid-gas mist as the dielectric, delivered through a
rotating tubular electrode. Result revealed that at the low discharge energy
input, near-dry EDM exhibits good machining stability and smooth surface
finish.
• They observed that the surface finish was expected to be further improved in
near-dry EDM by reducing, the pulse duration. The proposed process
produced mirror like surface finish as illustrated in Figure 5
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19. NEAR DRY EDM(NDEDM)
• Use of two-phase medium in ND-EDM improved the MRR and
eliminated the problem of debris deposition .
• Moreover, good machining stability and surface finish were also achieved .
TWR was negligible as compared to wet EDM with all combinations of
dielectric mediums.
• Most commonly used two-phase (liquid-gas)) dielectric medium are the
kerosene-air , deionized water-air and air-water
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20. Advantage
• Near-dry EDM exhibits the advantage of good machining stability and
surface finish at low discharge energy input.
• To improve the surface finish in near-dry EDM, low pulse duration and low
discharge current were identified as the key factors
• Near-dry EDM process has the most MRR and the least SR.
• It is eco –friendly variant of conventinal EDM
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21. WHY SUPER ALLOYS?
• The use of super alloys can allow the operating temperature to be increased from
1200F to 1300F
 Resistance to thermal creep deformation.
 Excellent mechanical strength
 Good surface stability.
 Fatigue resistance at temperature upto and above 1100℃.
 Resistance to corrosion and oxidation.
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22. Super Alloy consumption in Industry
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Two third of super alloy production is
consumed by the aerospace industry for the
manufacturing of jet engines and associated
components.

23. Super alloys are grouped into four major
categories
Nickel base
alloy
Cobalt base
alloy
Iron base
alloy
Titanium Base
alloy
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24. MOTIVATION
• Steps towards green manufacturing through EDM process is need to be studied as hydrocarbon oil
based dielectric fluid is an issue of environmental disruption.
• Replacement of dielectric to rectify the problem is one of the main concerns in EDM research. So it is
need to study dry-EDM, near-dry EDM and EDM in water, conceived as an environment friendly
alteration EDM process referred as a green EDM process.
• Space travel is soon going to be reality and India will be the major player in the space race. as a faculty
I find it my responsibility to explore into new research fields where education can contribute to the
future generation.
• As said Space travel will be the reality soon, it becomes obvious that R&D industry will move
towards inventing new technologies to create a process which will give robustness at the time of
escape from the planet and landing. Time and distance will shrink in size and it becomes necessity to
investigate the effect of EDM on superalloys which will be used in aerospace industry.
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25. Literature Survey
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26. Hyperlink for Literature Survey
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28. RESEARCH GAP
• The researchers have categories the wide range of published works relating
to the EDM process into three main areas, namely optimizing the process
variables, monitoring and control the process, and EDM developments.
• Various researchers explored innovative techniques to enhance MRR.
However, in majority of research publications, it had been ascertained that
researchers were solely inquisitive about finding the optimum process
condition for output responses by considering different electrodes materials
or kind of dielectrics used
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29. RESEARCH GAP
After studying various research papers it is found that
1.Very few research is available on machining of super alloys by using near
dry EDM method
2.Optimization of process parameters in Near Dry EDM process
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30. PROBLEM STATEMENT
• To find optimum combination of input process parameters such as peak
current (Ip), open voltage (vg) ,pulse on time (Ton) and duty factor() for
machining of Inconel supper alloy on EDM.
• The output response parameters studied will be (Material removal rate)
MRR, (Electrode wear rate) EWR and surface roughness (Ra), this problem
studied with different methods and best method will be suggested
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31. Objectives
1. Optimization of near dry EDM process parameters (Discharge current,
pulse on time, and duty factor)
2.To Study effect of different dielectric fluid on MRR of super alloys
3.To Study effect of different tool material on MRR ,TWR,SR
4.Analysis of MRR,TWR,SR
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32. RESEARCH METHODOLOGY
• Analysis of the effect of process parameters in near-dry EDM. The models will be
developed using Taguchi method.
• Traditional Experimental design such as full factorial utilizes large number of experimental
run when factors are more. Thus they are of much time consuming and complicated.
But Taguchi design of experiment uses small number of runs to study the effect of process
parameters by using orthogonal array in its design.
• Taguchi method mainly focuses on the average performance characteristics data close
to the ideal target data rather than any other data within specified range, thereby improving
the quality of product.
• Taguchi method is easy and time savvy, thus can be directly applied to any engineering
situations. Taguchi design employs statistical tool called ANOVA (Analysis of variance)
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33. Taguchi method Steps
• a. Identify the main function and its side effects.
• b. Identify the noise factors, testing condition and quality characteristics.
• c. Identify the objective function to be optimized.
• d. Identify the control factors and their levels.
• e. Select a suitable Orthogonal Array and construct the Matrix
• f. Conduct the Matrix experiment.
• g. Examine the data; predict the optimum control factor levels and its performance
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34. EXPECTED OUTCOME
• Increased MRR, Reduced TWR, Reduced SR of Ni based super alloy by
Near Dry EDM method
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35. Future scope
1.Most of the published work focuses on electrode wear rate, material
removal rate and surface finish. Further study should concentrate more on
developing dry EDM as a precision machining operation. For which,
along with electrode wear rate, material removal rate and surface finish other
performance variables such as over-cut, process repeatability should also be
considered.
2.In most of the dry-EDM process, either air or oxygen is used as a dielectric.
Further work may explore the use of nitrogen and inert gases as a dielectric
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36. 3.Under specific machining conditions, a mixture of gas and organic deionized
water may cause higher material removal rate than hydrocarbon oil.
4.The development of dry and near-dry EDM technique focused much on to
improve the MRR since MRR is lower than that of traditional EDM machining.
Very few studies reported surface integrity of machined parts
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37. Time frame
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Activities
2019-
2020 2020 2021 2021 2022
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Course work and Problem
identification
Communication for review paper
publication
Literature survey and review
Experimental setup
Instruments calibration
Experiments and data acquisition
Data reduction analysis and
communication for publication
Thesis writing and publication

38. References
[1] Mohd Abbas, N., Solomon, D. G., and Fuad Bahari, M., 2007, “A Review on Current Research Trends in
Electrical Discharge Machining (EDM),” Int. J. Mach. Tools Manuf., 47(7–8), pp. 1214–1228.
[2] Leão, F. N., and Pashby, I. R., 2004, “A Review on the Use of Environmentally-Friendly Dielectric Fluids in
Electrical Discharge Machining,” Journal of Materials Processing Technology, 149, pp. 341–346.
[3] Kunieda, M., Yoshida, M., and Taniguchi, N., 1997, “Electrical Discharge Machining in Gas,” CIRP Ann. -
Manuf. Technol., 46(1), pp. 143–146.
[4] Jeswani, M. L., 1981, “Electrical Discharge Machining in Distilled Water,” Wear, 72(1), pp. 81– 88.
[5] Lin, C.-T., Chow, H.-M., Yang, L.-D., and Chen, Y.F., 2007, “Feasibility Study of Micro-Slit EDM Machining
Using Pure Water,” Int. J. Adv. Manuf. Technol., 34(1–2), pp. 104–110.
[6] Kang, S. H., and Kim, D. E., 2005, “Effect of Electrical Discharge Machining Process on Crack
Susceptibility of Nickel Based Heat Resistant Alloy,” Mater. Sci. Technol., 21(7), pp. 817–823.
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39. Thank You!!!
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