Electron beam machining (EBM) involves directing a high-velocity beam of electrons in a vacuum chamber to melt or vaporize material from a workpiece. The electron beam is generated in a gun and focused onto a small spot on the workpiece using magnetic coils. This localized heating allows for precise material removal with minimal heat effects. EBM can machine nearly any material and produces close tolerances, but requires expensive equipment and vacuum systems. Common applications include machining wire drawing dies and manufacturing semiconductor and optical components.

1. Electron Beam Machining
J. Hemwani. GPC, Betul

2. EBM ---Working Principle
▪Workpiece placed in vacuum chamber
▪ High-voltage electron beam directed toward workpiece
▪ Energy of electron beam melts/ vaporizes selected
region of workpiece
▪ Electron beam moved by deflection coils
J. Hemwani. GPC, Betul

3. J. Hemwani. GPC, Betul

4. J. Hemwani. GPC, Betul

5. EBM – PROCESS
▪ Electron beam (negatively charged particles) is generated
in an electron beam gun.
▪The workpiece to be machined is located under the
electron beam and is kept under vacuum.
▪ Electron beam gun provides high velocity electrons over
a very small spot size.
▪ Due to pattern of electrostatic field produced by grid cup,
electrons are focused and made to flow in the form of a
converging beam through anode.
J. Hemwani. GPC, Betul

6. EBM – PROCESS
▪The electrons are accelerated while passing through the
anode by applying high voltage at anode.
▪ A magnetic deflection coil is used to make electron
beam circular and to focus electron beam at a point , this
results in localized heating.
▪ The high-energy focused electron beam is made to
impinge on the work piece with a spot size of 10 – 100
μm • The kinetic energy of the electrons, upon striking the
workpiece, changes to heat, which melts and vaporizes
minute amounts of the material.
J. Hemwani. GPC, Betul

7. EBM – ADVANTAGES
✓ • Extremely close tolerances can be maintained
✓ • Heat affected zone are minimum
✓ • It can machine almost any material irrespective of their
mechanical properties
✓ • The beam can be concentrated on a very small area
✓ • It produces better surface finish and narrow kerf
✓ • Thermal distortion is least
✓ • The process is fast because it is entirely non-
mechanical.
J. Hemwani. GPC, Betul

8. EBM – LIMITATIONS
▪ The equipment cost is very high because of vaccume
maintained.
▪ The interaction of the electron beam with work piece
surface produces hazardous X-ray. Hence shielding is
necessary.
▪ Because of very low material removal rate, the process is
economical only for small Material Removal .
▪ Skilled labour is required to operate the machine (Gun).
▪ The process can machine only thinner parts.
J. Hemwani. GPC, Betul

9. EBM – APPLICATIONS
➢ EBM is particularly suitable for micro-machining i.e.
producing very small diameter holes – down to 0.002 in.
➢Major applications of EBM include Machining of wire
drawing dies having small cross sectional area.
➢ EBM is also used as an alternative to light optics
manufacturing methods in the semiconductor industry.
➢EBM is useful for high-resolution lithography and for the
manufacture of complex integrated circuits.
➢EBM welding is also used for aircraft engine parts.
J. Hemwani. GPC, Betul

10. EBM CHARACTERISTICS
❖• Mechanics of material removal – melting, vaporization
❖• Medium – vacuum
❖• Tool – beam of electrons moving at very high velocity
❖• Maximum MRR = 10 mm3 /min
❖• Specific power consumption = 450 W/mm3 /min
❖•Critical parameters – accelerating voltage, beam diameter, work
speed, melting temperature
❖• Materials application – all materials
❖•Shape application – drilling fine holes, cutting contours in sheets,
cutting narrow slots
❖• Limitations – very high specific energy consumption, necessity of
vacuum, expensive machine
J. Hemwani. GPC, Betul

11. J. Hemwani. GPC, Betul