Investigation on Optimization of Machining Parameters in Wire EDM using Taguc...
suvendu banerjee(14mt000107)
1. DEVELOPMENT OF WIRE ELECTRICAL
DISCHARGE TURNING SETUP AND ITS
APPLICATION FOR FABRICATION OF
PREFORMED FOR MICRO TOOL
NAME:-SUVENDU BANERJE
ADM NO:-14MT000107
MANUFACTURING(M.TECH)
GUIDED BY:-DR.AMIT RAI DIXIT
3. INTRODUCTION-
In WEDM process, the material is eroded ahead of the wire due to the
thermoelectric sparks generated between the work piece and the electrode. In
this process the work piece experiences no mechanical stresses due to no direct
contact between the work piece and the wire makes the process widely
employed to cut the electrically conductive hard-to-cut material with
irrespective of its hardness and strength .
Fig:-Concept of Wire Electrical Discharge Machining
4. Wire electrical discharge turning (turning with WEDM) is one of the emerging
area, developed to generate cylindrical form on hard and difficult to cut super
alloys such as Titanium and Nickel. In WEDT process the electrical
discharge takes place between the traveling wire and the rotating work piece
(a rotary axis is added to WEDM) to be machined. In this process the desired
cylindrical forms can be obtained by controlling the electrically charged wire in X
and Y directions to remove the unwanted work material.
FIG:- Concept of Wire Electrical Discharge Turning
5. LITERATURE REVIEW
Author and
Year of
publication
Material Process
parameters
Output
parameters
Methodology Remarks
Dr Masuzaw
2000
Micro
electrode
tool
- - - Cylindrical pins - 5 µm in
diameter machined
Qu et. al.
2001 a
Carbide
and Brass
(2D and
cylindrical
)
Wire feed rate,
Part rotation
speed
Spindle error
analysis, MRR
in 2D and
CWEDT
Donaldson
reversal principle
for spindle error
analysis
MRRWEDT>MRRWEDM
BrassMRR > Tungsten
CarbideMRR
Qu et. al.
2001 b
Pulse On time,
wire feed rate
and part
rotational speed
MRR for rough
and good
surface finish,
Surface
roughness
SEM for
measuring
surface
roughness.
Higher RPM & slower Vf
generated smaller pitch and lower
Ra
Achieved Surface Roughness:
0.68 µm
Mohammadi
et. al. 2007
Cemented
steel
Power, Time
Off, Voltage,
Servo volt, Wire
tension, wire
speer, RPM
Surface
roughness,
Roundness
L18 (21×37)
Taguchi standard
orthogonal array
power has a significant effect on
the surface roughness
The effects of wire speed, power,
and servo on roundness are more
significant than time-off, voltage,
wire tension, and rotational speed.
6. Author
and Year
of
publicati
on
Material Process
parameters
Output
parameters
Methodology Result
M J
haddad et.
al. 2009
AISI D3
Tool steel
Power, Voltage,
Pulse off time,
RPM
Surface
roughness,
Surface
roundness,
Recast layer.
Taguchi method,
SEM for
measuring surface
integrity
Under High MRR – Recast layer
40-50 µm, HAZ 20-25 µm
Under low MRR – Recast layer 15-
20 µm, HAZ 8-13 µm
Power and Voltage
Naresh
baki et. al.
2014
TI-6AL-4V
Alloy
RPM, ToN,
ToFF, Peak
current, Wire
feed, Servo volt
Surface
roughness and
MRR
DOE: Taguchi
method
Optimization:
Gray Relational
analysis
Optimal combination: RPM 30,
ToN 10 µs, ToFF 50 µs, Peak
current 150A, Wire feed 3mm/min,
Servo 90V
Significant Parameters: RPM,
ToN and Servo.
Balamurali
et. al. 2015
Stainless
Steel 316
Gap volt, ToN,
ToFF, Wire
speed, RPM
MRR, Surface
roughness
Taguchi method
L27
Gap V decrease MRR increase Ra
decrease, ToN increase MRR
increase Ra increase, ToFF increase
MRR increase Ra decrease, RPM
increase MRR & Ra increase
7. OBJECTIVES:-
To develop WIRE ELECTRICAL DISCHARGE TURNING
(WEDT) setup on conventional WEDM system.
Investigation of input parameters of WEDT on output response.
Application of WEDT for fabrication of preformed for micro
tool.
Development of preformed for MICRO ECM, MICRO EDM
8. EXPERIMENTATION:-
The experiments are conducted on a high precision 4- axis CNC WEDM .
The wire EDM machine was equipped with a rotary axis in order to produce
cylindrical forms. TUNGSTEN work piece of 1mm diameter with 6mm
length was used to perform the turning experiments on WEDM
Conventional design:-
wire used – Zinc coated brass wire of 0.25 mm
Dielectric – Deionized water
Process parameters – Spindle rotation speed, Voltage, Depth of cut
Output parameter – Diameter Deviation, Surface Roughness, Surface Waviness
Design of experiment - Taguchi L9 (34)Orthogonal Array Design
MICRO EDM and MICRO ECM were done on the preformed tool
9. Fig:- Schematic Of WEDT Setup Fig:- Actual WEDT Setup
Fig:- WEDT Operation Fig:-Specimen After Cut
MACHINED SURFACE
10. Fig:-Workpiece After MICRO ECMFig:-MICRO ECM Operation
Fig:-MICRO EDM Operation Fig:-Workpiece After MICRO EDM
11. RESULTS AND DISCUSSION
L9 (34) Taguchi standard orthogonal array, factors and factor levels were
selected for determining optimal process setting conditions, significant factors,
and their interactions.
After performing the experiments successfully the work-pieces final diameter,
roughness value (Ra) and waviness (Wa) values were measured in optical
microscope
After getting all the dimensions the diameter deviation (∆d) is being calculated
by using the following equation
∆d= (Theoretical diameter) – (Actual Diameter) =Dtheo - Dact
Theoretical diameter = (Blank Size) – (2* Depth of Cut)
Actual Diameter = The diameters taken along the machined surface
Diameter deviation = mean of ∆d
19. DEPOSITED ELEMENTS AND THEIR COMPOSITION
Element Weight% Atomic%
W M 82.88 27.79
C K 4.90 25.13
O K 12.22 47.08
Element Weight% Atomic%
W M 59.87 10.86
C K 17.96 49.87
O K 17.19 35.83
Na K 1.15 1.67
Cl K 1.14 1.07
K K 0.45 0.38
Th M 2.25 0.32
WEDT
MACHINED
SURFACE
BLANK SURFACE
Element Weight% Atomic%
W M 27.18 2.96
C K 30.54 50.97
O K 31.74 39.76
Na K 1.50 1.31
Al K 2.65 1.97
S K 0.21 0.13
Cl K 1.27 0.72
K K 1.29 0.66
Ca K 0.47 0.24
Ti K 2.76 1.15
Fe K 0.39 0.14
Element Weight% Atomic%
W M 68.14 15.14
C K 16.51 56.14
O K 9.92 25.32
Na K 0.60 1.07
Cl K 0.40 0.46
K K 1.26 1.32
Th M 3.17 0.56
MICRO EDM
Machined
Surface
MICRO ECM Machined Surface
20. COCLUSIONS
It was observed after MICRO EDM operation that the diameter of one of
the preformed tool reduced only 30μm in 1hr 5 minutes.
It was observed after MICRO ECM operation that the diameter of one of
the preformed tool reduced 150μm in 5 minutes
It was observed craters, spherical nodules, globules of debris ,coral reef
and micro cracks in both machined surface of WEDT and MICRO EDM
Cracks are being generated due to thermal and tensile stress. The nature of
the cracks is due to the deionized water
In the MICRO ECM machined surface all shallow craters, globules of
debris, and pockmarks formed by entrapped gases escaping from the re-
deposited material reduced to a great amount
21. SCOPE FOR FUTURE WORK
Diameter of the tool can also be reduced less than 100μm by
using those combining techniques
The issues such as residual stress after machining with WEDT
may be investigated.
The issue of eccentricity after machining with WEDT may be
investigated on the existed WEDM setup
The research work could be further extended over a variety of
exotic advanced materials.
The possible use of cryogenic treated wire electrode for
machining of nonconductive and composite materials (Ceramic,
fiberglass etc.) could also be investigated
