Experiment-8 EDM and ECM.pptx

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Hyderabad Campus
Exp.8: WirecutEDM andECM

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Aim of the experiment
Aim: Demonstration of wire cut EDM process and ECM
OBJECTIVE:
 Preparing a job as per dimensions on the wire cut EDM
 Understand the working principle of ECM

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Electrical energy is directly used to cut the material to get the final shape and size
– Electrical discharge machining (EDM)
– Wire cut Electrical Discharge Machining (WCEDM)
Introduction EDM

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Principle
– Metal is removed by producing powerful electric spark discharge between the
tool (cathode) and the work material (anode)
– Also known as Spark erosion machining or electro erosion machining
Electrical Discharge Machining (EDM)

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EDM has the following advantages:
1. Cavities with thin walls and fine features can be produced.
2. Difficult geometry is possible.
3. The use of EDM is not affected by the hardness of the work material.
4. The process is burr-free.
Electrical Discharge Machining (EDM)

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Electrical Discharge Machining (EDM)
Construction and Working

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Principle
– Metal is removed by producing powerful electric spark discharge between the
tool (cathode) and the work material (anode)
– Also known as Spark erosion machining or electro erosion machining
Wire Cut Electrical Discharge Machining (WC-EDM)

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Wire Cut Electrical Discharge Machining (WC-EDM)

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Wire Cut Electrical Discharge Machining (WC-EDM)
0.005- 0.05mm

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Dielectric Fluid
– Fluid medium which doesn’t conduct electricity
– Dielectric fluids generally used are paraffin, white
spirit, kerosene, mineral oil
– Must freely circulate between the work piece and
tool which are submerged in it
– Eroded particles must be flushed out easily
– Should be available @ reasonableprice
– Dielectric fluid must be filtered before reuse so that chip
contamination of fluid will not affect machining accuracy
Wire Cut Electrical Discharge Machining (WC-EDM)

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Wire Cut Electrical Discharge Machining (WC-EDM)
• Applications
– Best suited for production of gears, tools, dies, rotors, turbine blades and
cams
• Disadvantages
– Capital cost is high
– Cutting rate is slow
– Not suitable for large workpieces

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Wire Cut Electrical Discharge Machining (WC-EDM)
• Features / Advantages ofWC EDM
– Manufacturing electrode
– Electrodewear
– Surface finishing
– Complicated shapes
– Time utilization
– Straight holes
– Rejection
– Economical
– Cycle time
– Inspection time

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• ECM is one of the recent and most useful machining process.
• In this process, electrolysis method is used to remove the metal from the
workpiece.
• It is best suited for the metals and alloys which are difficult to be
machined by mechanical machining process.
Introduction ECM

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The electrochemical machining system has
the following modules:
• Power supply
• Electrolyte filtration and delivery system
• Tool feed system
• Working tank
Introduction ECM

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• The tool and the workpiece are held close to each other
with a very small gap (of 0.05 to 0.5mm) between them
by using a servo motor.
• The electrolyte from the reservoir is pumped at high
pressure and flows through the gap between the workpiece
and the tool at a velocity (of 30 to 60m/s).
Working Principle

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• A D.C voltage about 5-30 volts is applied between the
tool and the work piece.
• Due to the applied voltage the current flows through
the electrolyte with +ve charged
ions and –ve charged ions.
• The +ve charged ions moves towards the tool
(cathode) while –ve ions moves towards
the workpiece (anode).
• The electro chemical reaction takes place due to the
flow of ions and it causes the removal
of metal from the workpiece.
Working Principle

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Electrolysis:
– D.C voltage of about 5-30V is applied between the tool and work piece.
– So the current in water flows through the electrolyte (solution of NaCl)
with charged ions.
–Many chemical reactions occurs at the cathode and the anode.
Working Principle

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Working Principle

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 Die Sinking
 Profiling and contouring
 Trepanning
 Grinding
 Drilling
 Micro-machining
 Pulsed ECM
Applications

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ECM is well suited for the
machining of complex
two-dimensional shapes
Delicate parts maybe made
Difficult-to machine geometries
Poorlymachinable materials may be
processed
Little or no toolwear
Disadvantages
Initial tooling can be
timely andcostly
Environmentally
harmful by-products
Complicated tool design
Large power consumption
Advantages and disadvantages

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Hyderabad Campus
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