This document discusses electron beam machining (EBM). EBM uses a focused beam of high-velocity electrons to melt and vaporize material from a workpiece. It operates within a vacuum chamber at pressures of 10^-5 mm Hg. The electron gun generates the beam using a tungsten filament, grid cup, and anode. The beam is focused by electromagnetic lenses and its path is controlled by deflector coils. EBM can machine any material, achieves close tolerances with no tool wear, and concentrates heat at a small spot. However, it requires high vacuum and power while providing a low material removal rate. Applications include microdrilling and machining materials with low thermal conductivity.

1. SEMINAR TOPIC ON:-
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2. CONTENTS:-
 INTRODUCTION
 MECHANISM
 TOOL MATERIAL
 MEDIUM
 MECHINING RATIO
 ADVANTAGES
 DISADVANTAGES
 APPLICATION
 CONCLUSION
 REFERENCES
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3. INTRODUCTION
Electron Beam Machining
 EBM is a metal removal process by a high
velocity focused stream of electrons. As
the electrons strike the work piece with
high velocity ,their kinetic energy is
transformed into thermal energy which
melts and vaporizes the material.
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5. MECHANISM OF EBM:-
 The complete EBM setup is enclosed in a
vacuum chamber which carries vacuum of
the order of 10^-5mm of mg .
 This chamber carries a door through which the W/P
is placed over the tool then the door is enclosed .
 The electro gun is mainly responsible for emission
of electrons consists of 3 main parts these are
(1)tungsten filament
(2)grid up
(3)anode
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6. EBM
Tungsten
filament
Grid cup
anode
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7.  The filament is connected to the
negative terminal & acts as cathode.
 Similarly anode is connected to positive
terminal & acts as anode.
 A potential difference of 50-150 kilo volt
is maintain between to the filament &
anode .due to high voltage .the filament
weir is heated to a temperature of about
2500c with system with the result cloud
of electron is emitted by the filament
,which is directed by the grid cup to
travel downward .
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8.  Then this high velocity electro beam passes
through the tungsten diaphragm & then
electromagnetic lens .the electro magnetic lens
converge the stream of electro beam to a one
point that is sport on the W/P.
 The electro magnetic deflector coil deflect the
electromagnetic beam on to the W/P through
which the path of the cut can control .
 The table on which the W/P is loaded can also
be to feed the W/P is needed when the high
velocity electro beam impinge on the W/P the
K.E of the electro beam is converted in to the
heat hence the material removal process is
done.
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9. TOOL MATERIAL
ELECTRON GUN
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10. MEDIUM:-
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VACUUM
Medium is used in perfect vacuum which is a order of 10^-5mm
of Mg

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12. MECHINING RATIO
MECHININGRATIO=
material removal rate/tool wear
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13. ADVANTAGE
 Any material can be machined.
 In any physical or casting damage so tool
wear is zero so close dimension can be
achieved.
 It is an excellent for micro machining .
 Heat can be concentrated on a vertical spot
on the W/P.
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14. DISADVANTAGES
 Maintaining perfect vacuum is very difficult.
 W/P size is limited due to the requirement of
vacuum chamber.
 Out of all unconventional process EBM gives
lowest material removal rate.
 Power consumption is very high.
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15. APPLICATION:-
 Micro drilling operation up to (0.002mm)for
thin orifice dias for wear drawing , part of
electro microscope & injector nozzles for
diesel engine .
 Very effective for material of low heat
conductivity & high melting point.
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