The document provides an overview of Wire Cut Electric Discharge Machining (WEDM), emphasizing its principles, setup, and operational parameters. Key components include a power supply system, dielectric system using deionized water, CNC control system, and wire drive system, with various controlling parameters influencing material removal rate and surface finish. The advantages include high precision and unattended operation, while disadvantages involve limitations on material types and depth of cut.

1. UNIT I
NON CONVENTIONAL MACHINING PROCESSES-
WEDM
S.G.R. Education Foundation
G H RAISONI COLLEGE OF ENGINEERING AND MANAGEMENT
AHMEDNAGAR
NAAC ACCREDITED
(APPROVED BY AICTE, NEW DELHI, RECOGNIZED BY GOVT. OF MAHARASHTRA & AFFILIATED TO SAVITRIBAI PHULE PUNE UNIVERSITY)
- Prof. Aniket V. Joshi
Asst. Professor
Mechanical Engineering Department
GHRCEM, A’Nagar.

2. WIRE CUT ELECTRIC DICSCHARGE
MACHINING (WEDM)
 Basic principle is same as EDM
 Employs electrical energy to
remove metal from workpiece
without touching it
 Process can be used only when
through cut has to be taken or cut
is to be taken from outer side of
workpiece
 Uses copper or tungsten wire of
0.3 mm dia. as tool
 Deionized water is used as
dielectric fluid
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3. Working principle of wedm
• Heat energy generated by a spark is used to remove
unwanted material from the workpiece
• Wire of dia. 0.3 mm used as electrode or tool
• Gap between wire and workpiece is 0.5 mm
• Wire is continuously moving at constant speed
• Dielectric fluid is constantly flushed in the area of machining
• When switch ON the supply, spark get generated and
dielectric fluid gets ionized allowing current to flow
between tool and workpiece.
• Due to heat, melting of metal takes place and melted
particles driven away by the dielectric fluid.
• Desired shape is achieved by table motions through control
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4. Set-up for wedm
 Basic elements of WEDM are:
1) Power supply system
2) Dielectric system
3) CNC control system
4) Wire drive system
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5. Set-up for wedm
1) Power supply system:
- Workpiece is mounted on a
table
- Tool (-ve, cathode), workpiece
(+ve, anode)
- Anode and cathode
connected to DC power
supply
- Supply is in the form of pulse
- Voltage supplied is 50 V
- Because of small size of wire,
it cannot carry current more
than 30A
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6. Set-up for wedm
2) Dielectric fluid system:
- Deionized water is used as
dielectric fluid
- It gives high metal removal
rate and better surface
finish
- Nozzle is employed in
machining area
- Both workpiece and wire
are constantly flushed
- As serves as coolant.
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3) CNC control System:
- Used for the movement of
work table
- Table has movement in two
axis (direction)
- For taking contouring cuts,
table can be moved in both
directions simultaneously

7. Set-up for wedm
4) Wire drive system:
- this system performs three functions
a) To feed fresh wire for machining
b) To take-up the used wire
c) To maintain the tension in the wire
- Wire is used only once, because due to spark, wire surface
does not remain round
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8. Controlling parameters
for wedm
1) Discharge current:
- Material removal rate increases with current
- Increasing current increases crater depth to a certain
value, beyond that yield a smoother surface
- Current limit is 30A
2) Pulse duration:
- Directly proportional to MRR
- Inversely proportional to surface roughness
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9. Controlling parameters for
wedm
3) Pulse frequency:
- Directly proportional to MRR
- Pulse frequency is about 1 MHz
- Results in reduced crater size or better surface finish
4) Cutting Rate:
- Wire speed is between 205 to 150 mm/sec.
- Depends upon thickness of workpiece
- Maximum possible depth of cut is 90 mm
- Average machining rate is 10-15 mm2/min
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10. Controlling parameters for
wedm
5) Wire tension:
- Required to keep the wire straight
- A series of tension rollers is provided to keep the required
tension
- 50-60% of wire tensile strength
6) Dielectric flow:
- Nozzle is employed
- Continue and enough supply required to allow sparking
- Fluid can be reused only after filtration
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11. Advantages of wedm
 Straight holes can be produces to close tolerances
 Can be operated unattended for longer period of time
 High accuracy
 Good surface finish
 Very sharp angles can be cut
 Eliminates the need of post-machining
heat treating and possible part distortion
 Parts produced are burr-free
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12. disadvantages of wedm
o Wire can not be reused
o Proper tension needs to be
maintained
o Only electrically conductive material
can be machined
o Residual stresses are induced in the
workpiece
o limit for maximum depth of
workpiece is 90 mm
o A hole is necessary in the workpiece
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13. Applications of wedm
WE
DM
Punches &
dies used in
press tools
Production
of moulds
and dies
Complex
contours
Simple flat
shapes with
superior
quality edge
Cylindrical
pins up to
5 mm dia.
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14. 14
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