Thermal energy based machining processes like electron beam machining (EBM), laser beam machining (LBM), and plasma arc machining (PAM) work by focusing heat energy on a portion of the work material to melt and vaporize it. EBM works by focusing a beam of electrons, LBM uses a focused laser beam, and PAM uses an ionized gas plasma jet at very high temperatures. These processes can machine hard and exotic materials with high precision and no tool contact. However, they require specialized equipment, skilled operators, and have high operating costs. Common applications include cutting, drilling, welding, and surface treatment of metals.

1. THERMAL ENERGY BASED
PROCESSES

2. PRINCIPLE
Here the machining is done by usage of heat
energy.
The heat energy is focused on a particular
portion for melt & Vaporize the work material
Example :
1. Electron Beam Machining (EBM)
2. Laser Beam Machining (LBM)
3. Plasma Arc Machining (PAM)

3. ELECTRON BEAM MACHINING (EBM)

4. ELECTRON
BEAM
MACHINING
(EBM)

5. PRINCIPLE - EBM

6. TYPES OF EBM

11. Process parameters

12. Process parameters
1.Control of current

13. Process parameters
2.Control of Spot Diameter

17. Process parameters
3.Control of Focal Distance of magnetic lens

18. LASER BEAM MACHINING
Photon Emission

19. History - Laser
• The laser was successfully fired on May 16, 1960. In a July 7, 1960
press conference in Manhattan,Maiman
Theodore Harold "Ted" Maiman (July 11, 1927
– May 5, 2007) was an American engineer and
physicist credited with the invention of the first
working laser Maiman's laser led to the
subsequent development of many other types
of lasers.

20. Differences
.

21. PRINCIPLE OF LASER BEAM PRODUCTION

22. 1.Spontaneous Emission
2.Stimulated Emission

23. ACCURACY

24. TYPES OF LASER
1. Gas lasers
2. Solid lasers
3. Liquid lasers
4. Semi Conductor lasers

25. SOLID LASER
RUBY LASER
Synthetic Ruby rod made up of crystal of aluminium oxide

26. LASER BEAM MACHINING
.

27. LASER BEAM MACHINING
Flash tube filled
with Xenon, argon
or krypton Gases
250 – 1000
watts power
Few
Chromium
Atoms are
placed in Ruby
rod for
absorbing
Green light

28. . Cooling of ruby rod is necessary – Because they
are less efficient in high temperature

29. .

30. .

31. MACHINING APPLICATIONS OF LASER
1. Laser in Metal Cutting
2. Laser in Drilling
3. Laser in Welding
4. Laser in Surface Treatment
5. Trimming
6. Blanking
7. Micromachining applications

32. LASER IN METAL CUTTING
• .

33. LASER IN DRILLING
.

34. Laser in Surface Treatment
A thin layer of cobalt alloy coating is applied on
Turbine blade for heat and Wear Resistance.
A thin Ceramic coating is applied on metal
Surface for heat and Wear Resistance.
Its also used to seal the micro cracks which are
usually present in hard – Chromium
electroplates

35. Advantages of LBM
1. All Kind of metals are machined
2. Micro holes are possible
3. Soft materials like rubber can be machined
4. No tool wear and contact with w/p
5. Automated process
6. Controlling of beam is easy

36. 1. High initial Cost
2. Operating cost is high
3. Required skilled labours
4. Rate of production is low
5. Need safety equipments
6. Life of flash lamp is low
7. The machined holes are not straight and round
Disadvantages of LBM

37. PLASMA ARC MACHINING
OR
PLASMA JET MACHINING
IONIZED GAS
High velocity jet of high temp. ionized Gas

38. INTRODUCTION
SOLID GAS or LIQUID
Heated
LIQUID
Heated
GAS
GAS
Heated
FREE electrons and
IONIZED GAS

39. PLASMA GAS
When a gas is heated to a sufficiently high
temperature of the order of 11000 – 28000
degree Celsius, it becomes partially ionized its
known as PLASMA
PLASMA
It’s a mixture of Free electrons + Partially ionized gas
and Neutral Atoms

40. WORKING PRINCIPLE

41. Plasma arc
machining

42. ACCURACY

43. GASES USED IN PAM

44. TYPES OF PLASMA ARC TORCHES

45. Direct Arc Plasma Torch
PILOT ARC
A Pre arc (Pilot arc) is
created b/w electrode and
nozzle
when this pre arc touches the
work piece the current flows
from work piece to electrode .
This make main arc b/w
electrode and work piece. So
now pre –Arc is switched off

46. Transferred arc process
Direct Arc Plasma Torch
• The arc is formed between the electrode(-) and the work piece(+).
• In other words, arc is transferred from the electrode to the work
piece.
• A transferred arc possesses high energy density and plasma jet
velocity. For this reason it is employed to cut and melt metals.
Besides carbon steels this process can cut stainless steel and
nonferrous metals also where oxyacetylene torch does not
succeed. Transferred arc can also be used for welding at high arc
travel speeds. A pilot arc is established between the electrode and
the nozzle. As the pilot arc touches the job main current starts
flowing between electrode and job, thus igniting the transferred
arc. The pilot arc initiating unit gets disconnected and pilot arc
extinguishes as soon as the arc between the electrode and the job
is started. The temperature of a constricted plasma arc may be of
the order of 8000 - 250000C.

47. In-Direct Arc Plasma Torch
.

48. Non-transferred arc process
In-Direct Arc Plasma Torch
• The arc is formed between the electrode(-) and the water cooled
nozzle(+).
• Arc plasma comes out of the nozzle as a flame.
• The arc is independent of the work piece and the work piece does
not form a part of the electrical circuit. Just like an arc flame (as in
atomic hydrogen welding), it can be moved from one place to
another and can be better controlled. The non transferred plasma
arc possesses comparatively less energy density as compared to a
transferred arc plasma and it is employed for welding and in
applications involving ceramics or metal plating (spraying). High
density metal coatings can be produced by this process. A non-
transferred arc is initiated by using a high frequency unit in the
circuit.

49. Advantages of PAM

50. Dis-Advantages of PAM

51. Applications of PAM