1. EXPERIMENTAL STUDIES OF EFFECT
OF COMPOSITE ELECTRODE ON DIE
STEEL USING EDM
A Synopsis report submitted in partial fulfilment of the
requirement for the award of degree of
MASTER OF ENGINEERING
In
MECHANICAL ENGINEERING
By
SHEKH SHAHJADA
(1465307)
Under the guidance
of
Prof. Pankaj Chhabra
HOD, Department of Mechanical Engineering
Surya School of Engineering & Technology, PTU
2. ABSTRACT
• Electrical discharge machining (EDM) is a non-conventional
machining method used to machine materials with high
degree of dimensional accuracy.
• In this research work the effect of composite material
electrode fabricated by powder metallurgy technique to
machine die steels will be studied.
• Properties like material removal rate, micro hardness and
electrode wear will be studied.
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3. INTRODUCTION
• EDM: Electric Discharge Machining (EDM) is a
non-conventional machining process in which metal
is removed using thermoelectric energy.
• PM: Powder metallurgy is a process in which the
powder of metals is heated below their melting point
so they can attain bonding.
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4. EDM
• Basic components of EDM.
• In EDM process, discrete electric discharges (sparks)
are generated between the workpiece-electrode and
the tool-electrode immersed in a dielectric medium.
4
5. Process parameters
• Some of the parameters which depend on the
tool performance in EDM machining
i. material removal rate (MRR)
ii. surface roughness of the workpiece
iii. tool wear
• Tool performance is highly influenced by the
composition of the metals.
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6. • Different results can be obtained by simply varying
the composition of the tool material and powder
metallurgy (PM) is a very efficient method for
making these tool-electrodes.
• Through this method we can easily control the
properties of the electrode by varying the
composition and input parameters of compacting and
sintering processes in PM.
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8. Advantages of PM processed
electrodes
• No additional machining.
• No waste products, hence very economical.
• Reasonably complex shapes can be produced.
• Possible to produce parts with a combination of
materials. For example metals and ceramics
• Metals like tungsten that cannot be manufactured
by other methods can be done by PM.
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9. About the workpiece
• EN24 steel is a popular grade of through-
hardening alloy steel used in components such as
gears, shafts, studs and bolts.
• EN24 can be further surface-hardened to create
components with enhanced wear resistance by
process like nitriding.
• EN8 is a medium strength steel, good tensile strength.
Suitable for shafts, stressed pins, studs, keys.
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10. Literature review
• George and Philip [1] examined the
performance of the EDM process and tool
wear using copper tool and die steel as
workpiece. They discussed the interaction of
the main electrical parameters such as
discharge current, polarity, pulse width and
pulse energy.
10
11. • Scott et al. [2] showed their study on the
optimization of cutting parameters which
were efficient in MRR and surface finish. They
investigated that if the discharge current and
the pulse duration is increased then the
surface finish also increases.
11
12. • N. Tosun et al [3] studied the variation of workpiece
surface roughness with varying pulse duration, open
circuit voltage, wire speed and dielectric fluid
pressure was experimentally investigated in Wire
Electrical Discharge Machining (WEDM).
• Brass wire with 0.25 mm diameter and SAE 4140
steel with 10 mm thickness were used as tool and
workpiece materials in the experiments, respectively.
It was found experimentally that the increasing pulse
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13. Cont.
duration, open circuit voltage and wire speed, increase
the surface roughness whereas the increasing dielectric
fluid pressure decreases the surface roughness.
The variation of workpiece surface roughness with
machining parameters was modeled by using a power
function.
The level of importance of the machining parameters
on the workpiece surface roughness was determined
by using analysis of variance (ANOVA).
13
14. • Yu et al. [4] compared machining
characteristics between dry EDM milling, oil
EDM milling and oil die sinking EDM and
found that dry EDM milling is most
advantageous to three-dimensional milling of
cemented carbide considering the total
machining time and cost.
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15. • H.K. Kansal and coworkers [5] carried out there research in
powder mixed EDM (PMEDM). In this research they used an
electrically conductive powder along with the dielectric which
reduced its insulating strength.
• Pellicer et al. [6] presented the influence of the main EDM
process parameters and different tool geometries on basic
process performance measures.
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16. • In addition, material removal rate, surface
roughness and different dimensional and
geometrical micro-accuracies were analyzed
through statistical methods. Results help to
select appropriate EDM process parameters to
machine parts depending on product
requirements.
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17. • Parveen Goyal [7] investigated that less EWR
is observed in copper-manganese composite
electrode when copper to manganese weight
ratio is 80-20 rather than using Cu-Mn weight
ratio as 70-30.
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18. Research gaps
• As observed from the above literature review we can say
that satisfactory work has been done in this field.
• Research done till date is quite impressive but still, more
research can be done using different parameters so that
we can refine EDM up to the best possible state.
• Some parameters used in this research work are copper
and composite electrodes on Die steel (EN 24, EN 8) as
workpiece.
• EN24 steel is a popular grade of through-hardening alloy steel used in
components such as gears, shafts, studs and bolts, its hardness is in the
range 248/302 HB
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19. RESEARCH OBJECTIVES
• To fabricate the composite material electrode
• To Compare copper electrode and composite
material electrode
• To Study the parameters
i. Material removal rate.
ii. Electrode wear rate.
iii. Surface micro hardness of die steel.
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20. METHODOLOGY TO BE ADOPTED
• The Electric discharge machining of Die steel
(EN 24 and EN 8) will be conducted using
copper and composite electrodes. The
experiments will be conducted considering
the properties of the electrode materials
which are shown below in the table 1.1
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21. Table 1.1
21
S.no. METALS
1 Copper (cu)
2 Tin (Sn)
3 Manganese (Mn) 1519 K (1246 °C) 2334 K (2061 °C) 196 Mpa
PHYSICAL PROPERTIES
MELTING POINT
1357.77 K (1084.62 ⁰C)
BOILING POINT BRINELL HARDNESS
2835 K (2562 ⁰C) 235-878 Mpa
505.08 K (231.93 °C) 2875 K (2602 °C) 50–440 MPa
ELECTRIC PROPERTIES
ELECTRIC RESISTIVITY
16.78nΩ.m
115 nΩ·m
1.44 µΩ·m120 Gpa21.7 µm/(m·K) at 25 °C 7.81 W/(m·K)
BULK MODULUS
140 GPa
MECHANICAL PROPERTIES
THERMAL EXPANSION
16.5 µm/(m.K) at 25⁰C
THERMAL CONDUCTIVITY
401 N/(m.K)
66.8 W/(m·K) 58 GPa22.0 µm/(m·K) at 25 °C
22. WORK JUSTIFICATION
• EDM using powder metallurgy composite electrodes
is to be done because it can reduce the surface
roughness and can also increase the micro hardness at
the surface of the workpiece.
• This can improve the overall efficiency of the EDM
process. The combination of copper and tin or copper
and manganese can be really effective as a composite
electrode for EDM.
• This is because copper, tin and manganese are good
electric conductors and have high melting and boiling
points.
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23. WORK DONE TILL DATE
• Two sintered electrodes, one of copper and
another composite of tin and copper are
prepared
• Then studied the surface properties by
• Scanning electron microscopy (SEM)
• Energy-dispersive X-ray spectroscopy (EDS).
23
24. • The figures of EDS spectrum of electorde
surface and SEM micrograph of electrode
surface are shown below.
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28. REFFRENCES
• [1] V. George and P. K. Philip, “Analysis of EDM
performance and tool wear in copper-die steel
system—a review,” in Proceedings of the 8th
AIMTDR Conference, IIT, Bombay, 1978, pp. 521–
525.
• [2] D. Scott, S. Boyina, and K. P. Rajurkar, “Analysis
and optimization of parameter combinations in
wire electrical discharge machining,” Int. J. Prod.
Res., vol. 29, no. 11, pp. 2189–2207, 1991.
28
29. • [3] N. Tosun, C. Cogun, and A. Inan, “The
effect of cutting parameters on workpiece
surface roughness in wire EDM,” Mach. Sci.
Technol., vol. 7, no. 2, pp. 209–219, 2003.
• [4] Z. Yu, T. Jun, and K. Masanori, “Dry
electrical discharge machining of cemented
carbide,” vol. 149, pp. 353–357, 2004.
29
30. • [5] H. K. Kansal, S. Singh, and P. Kumar,
“Technology and research developments in
powder mixed electric discharge machining
(PMEDM),” J. Mater. Process. Technol., vol. 184,
no. 1–3, pp. 32–41, 2007
• [6] N. Pellicer, J. Ciurana, and J. Delgado, “Tool
electrode geometry and process parameters
influence on different feature geometry and
surface quality in electrical discharge machining
of AISI H13 steel,” pp. 575–584, 2011.
30
31. • [7] P. Goyal, “Effect of EDM Process
Parameters on Composite Material Electrode
Wear,” no. 11, pp. 11–13, 2014
31
