Electric Discharge Machining is shortly called as EDM. In EDM the metal is removed due to erosion caused by rapidly occurring discharge between the tool and workpiece. The mechanism involved in Material removal is melting and evaporation.

1. Technical Seminar
On
Electric Discharge Machining
( Non Conventional Machine )
Presented by :
CHINTAM GURURAM PRASAD
14691A0345
MECHANICAL ENGINEERING
MITS
5/7/2018

2. CONTENTS
• Introduction
• Electric Discharge Machining ( EDM )
• Impact of parameters on EDM
• Dielectric Fluid
• Tools Used
• Workpiece
• Advantages and Limitations
• Applications
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3. Introduction
• Non Conventional Machining
As we all know that in Non Conventional Machining
the extra material from tool will be separated with
»No Contact between tool and workpiece.
»Specific power consumption is very large.
»Metal removal rate is low.
»Used for machining very hard materials
»Especially used for precision work
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4. Intoduction
Electric Discharge Machining is
shortly called
as
EDM
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5. Electric Discharge Machining
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In EDM the metal is removed due to erosion caused
by rapidly occurring discharge
between the tool and workpiece.
The mechanism involved in
Material removal is melting
and evaporation.

6. Electric Discharge Machining
• In EDM
• Positive terminal erodes out faster so work piece is
made as anode.
• Negative terminal is connected to tool which acts as
a cathode
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7. Impact of Parameters
• The parameters that has impact on the EDM while
machining are :
– Pulse On Time
– Pulse off Time
– Current
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8. Dielectric Fluid
The use of liquid dielectric fluid provides the
following main advantages
• It acts as Vehicle to drive away the chips and thus
preventing them from sticking to the surface of tool.
• It helps in increasing the Metal Removal Rate (MRR) by
promoting spark between tool and work.
• It acts as coolant medium.
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9. Dielectric Fluid
• Requirement of Dielectric Fluid
»Low viscosity
»Non toxic Vapors
»Non Flammable
»Chemically Stable
»Low cost
»Easily available
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10. Dielectric Fluid
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• In EDM the dielectric Fluids Used as
– The liquid dielectric like hydrocarbon
– Some light oils like
• White Kerosene
• Transformer oil
• Paraffin Oil etc.,

11. Tools Used
• In EDM, tools also erodes due to spark. Hence the
selection of tool depends on
»Wear ratio
»Ease of tool fabrication and
»Cost of the material
• Tool materials :
– The mostly used electrode material are copper,
Tungsten alloy, Cast Iron, Steel, Silver Tungsten alloy,
graphite.
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12. Workpiece
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• In EDM only good conductors of electricity can be
machined irrespective of hardness.

13. Advantages and Limitations
• Every machine has some advantages and disadvantages.
As for our EDM machine concern
• Advantages :
– High MRR
– Good Surface Finish
– Complex cavities can be cut
• Limitations :
– High tool wear
– Only good conductors can be machined
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14. Applications
EDM are most commonly used for machining
»Blind , complex cavities
»Hard material dies
»Making holes in dies
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15. THANK YOU
5/7/2018