Final PM SINGH (EDM) Presentation

8/3/2019 Final PM SINGH (EDM) Presentation

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EDM( Electric Discharge Machining )

Prakash Mohan Singh

Mech. Engg. 3rd year

2810440002


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EDM - Electrical Discharge Machining is a process of metal removalby means of energy release by repetitive spark discharges. theseelectrical discharges occur between an electrode (Cutting Tool) and anelectro-conductive workpiece and minute particles are eroded fromboth electrode and workpiece.


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INTRODUCTION

Electrical discharge machining die sinking has proved

valuable in the machining of super tough, electrically conductive

materials, such as the new space-age alloys. These metals would

have been difficult to machine by conventional methods. EDM has

made it relatively simple to machine intricate shapes that would be

impossible to produce with conventional cutting tools. This process

is continually finding more applications in the metal-cutting industry.

It is used extensively in the plastics industry to produce cavities of

almost any shape in the steel molds.


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Discharge gap

Metal sticks

The metal of both endsbecomes powder andprecipitate

The circuit for making metallic powder in the referencepublished in Germany in 1919 is indicated.

HISTORY OF EDM


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Transistorized circuit EDM

Servomechanism

Control circuit


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Gap controller

Electrode

Workpiece

EDMcircuit by Lazarenko (RC circuit)


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PRINCIPLE OF EDM

Electrical discharge machining is a controlled metal removaltechnique whereby an electric spark is used to cut (erode) theworkpiece, which takes a shape opposite to that of the cutting toolor electrode.The cutting tool (electrode) is made from electrically

conductive material, usually carbon. The die sinking electrode,made to the shape of the cavity required, and the workpiece areboth submerged in a dielectric fluid, (a light lubricating oil). Thisdielectric fluid should be a nonconductor (or poor conductor) ofelectricity.


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VARIOUS TYPES OF ELECTRICDISCHARGE MACHINES-

Electrode

Workpiece

a. Wire EDM

In wire EDM, the spark jumps from the wire electrode to theworkpiece and erodes metal both from the wire electrode and theworkpiece.


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b. Ram EDM

Workpiece

Electrode

generally used to produce blind cavities


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c. Small Hole EDM Drilling

Also known as fast hole EDM drilling or hole popper

Uses a hollow electrode to drill holes by means of electricaldischarge machining by eroding material from the workpiece


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Materials that can be EDMed

Inconel

Aluminum

Vasconal 300

Tool Steels: 01, A2, D2, S7 Aluminum Bronze PCD DiamondCarbide Copper Nitronic

Ferro-Tic Brass Beryllium CopperCPM 10V Cold Roll Steel Hastalloy4130 Hot Rolled Steel StelliteGraphite Stainless Steels Titanium


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SAFETY

a. Check that the workpiece has been set in a proper way.


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b. Check that the electrode has been set securely.


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c. Check that there is no abnormality in the discharge cable.


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d. flashing

EDMing with flushing alone must be avoided


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e. If a metallic injection nozzle is used, make sure that it will

not come into contact with the electrode.


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f. Make sure that the table travel will not cause any interference

with the nozzle.


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g. Check that the fluid level has been set properly.

Set the dielectric fluid level at not less than 50mm above the

top of the workpiece.


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APPLICATION

EDM product

widely used by the mould-making tool and die industries

Especially in the aerospace, automobile and electronics industries

Dies for producing jewelry and badges by the coinage (stamping)process


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ADVANTAGES

Complex shapes that would otherwise be difficult toproduce with conventional cutting tools

Extremely hard material to very close tolerances

There is no direct contact between tool and work

piece. Therefore delicate sections and weakmaterials can be machined without any distortion


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DISADVANTAGES

The slow rate of material removal.

The additional time and cost used for creatingelectrodes for ram/sinker EDM

Reproducing sharp corners on the workpiece isdifficult due to electrode wear

Specific power consumption is very high


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REFERENCES

Manufacturing technology by P.C.Sharma.

Exploring advanced manufacturing

technologies by By Stephen F. Krar, Arthur Gill.

Manufacturing Technology by B.L.Raghuvansi.


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THANK YOU

Documents

Final PM SINGH (EDM) Presentation