RAMU.G , ASST PROFF ,AIET

1. PRESENTED ON :- UNCONVENTIONAL MACHINING PROCESS
PRESENTED BY :- RAMU.G , ASST PROFF, AIET

2. Outline
 AJM
 LBM
 EDM
 USM
 EBM
 ECM
DEPARTMENT OF MECHANICAL ENGINEERING 04/25/17

3. Machining Process
 Manufacturing processes can be broadly divided into two
groups:
a) Primary manufacturing processes : Provide basic shape
and size
b) Secondary manufacturing processes : Provide final shape
and size with tighter control on dimension, surface
characteristics
 Material removal processes once again can be divided
into two groups
1. Conventional Machining Processes
2. Non-Traditional Manufacturing Processes or non-
conventional Manufacturing processes
DEPARTMENT OF MECHANICAL ENGINEERING 04/25/17

4. Classification
 1. Mechanical Processes
• Abrasive Jet Machining (AJM)
• Ultrasonic Machining (USM)
• Water Jet Machining (WJM)
• Abrasive Water Jet Machining (AWJM)
 2. Electrochemical Processes
• Electrochemical Machining (ECM)
• Electro Chemical Grinding (ECG)
• Electro Jet Drilling (EJD)
 3. Electro-Thermal Processes
• Electro-discharge machining (EDM)
• Laser Jet Machining (LJM)
• Electron Beam Machining (EBM)
 4. Chemical Processes
• Chemical Milling (CHM)
• Photochemical Milling (PCM)
DEPARTMENT OF MECHANICAL ENGINEERING 04/25/17

5. Needs for Non Traditional Machining
• Extremely hard and brittle materials or Difficult to machine
materials are difficult to machine by traditional machining
processes.
• When the work piece is too flexible or slender to support
the cutting or grinding forces.
• When the shape of the part is too complex.
• Intricate shaped blind hole – e.g. square hole of 15 mmx15
mm with a depth of 30 mm
• Deep hole with small hole diameter – e.g. φ 1.5 mm hole
with l/d = 20
• Machining of composites.
DEPARTMENT OF MECHANICAL ENGINEERING 04/25/17

6. Conventional Machining VS Unconventional Machining
 In Conventional machining process, the cutting tool
and work piece are always in physical contact, with
a relative motion against each other, which results in
friction and a significant tool wear.
 In Unconventional machining processes, there is no
physical contact between the tool and work piece.
Although in some non-traditional processes tool
wear exists, it rarely is a significant problem.
DEPARTMENT OF MECHANICAL ENGINEERING 04/25/17

7. Outline of AJM
 Definition
 Schematic Diagram of AJM
 Typical AJM parameters
 Applications
 Limitations
 Advantages
 Disadvantages
 Video of Cutting Process
DEPARTMENT OF MECHANICAL ENGINEERING 04/25/17

8. Definition of AJM :-
 In AJM, the material removal takes place due to
impingement of the fine abrasive particles. These
particles move with the high speed air (or gas) stream.
 The abrasive particles are typically of 0.025 mm
diameter and the air discharges at a pressure of several
atmosphere.
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9. Schematic Diagram of AJM
Aluminum oxide
Boron Nitride
Diamond Dust
Dryair,nitrogenorco2
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10. Working of Abrasive jet machining: (AJM):
 The nozzle is made of a hard material like Tungsten
Carbide here fine grained abrasive particles are fed
from the Hooper into the mixing chamber.
 High pressure air is forced in to the mixing chamber.
 The stream of abrasive particles bombards the work
piece at a very high speed and removes the work
material due to erosion.
 The abrasive particle feed rate is controlled by the
amplitude of vibration of the mixing chamber.
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11. Typical AJM Parameters
 Abrasive
 Aluminum oxide for Al and Brass.
 SiC for Stainless steel and Ceramic
 Bicarbonate of soda for Teflon
 Glass bed for polishing.
 Size
 10-15 Micron
 Quantity
 5-15 liter/min for fine work
 10-30 liter/min for usual cuts.
 50-100 liter/min for rough cuts
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12. Typical AJM Parameters
 Medium
 Dry air, CO2, N2
 Quantity: 30 liter/min
 Velocity: 150-300 m/min
 Pressure: 200-1300 KPa
 Nozzle
 Material: Tungsten carbide
 Stand of distance: 2.54-75 mm
 Diameter: 0.13-1.2 mm
 Operating Angle: 60° to vertical
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13. Typical AJM Parameters
 Factors affecting MRR:
 Types of abrasive and abrasive grain size
 Flow rate
 Stand off distance
 Nozzle Pressure
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14. Nozzle
 The nozzle is one of the most vital elements
controlling the process characteristics. Since it is
continuously in contact with the abrasive grains
flowing at a high speed, the material must be hard to
avoid any significant wear.
 One of the most important factors in AJM is the
distance between the work surface and the tip of the
nozzle, normally called the nozzle distance
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15. Nozzle Tip Distance
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16. Applications:-
 For drilling holes of intricate shapes in hard and brittle
materials
 For machining fragile, brittle and heat sensitive
materials.
 AJM can be used for drilling, cutting, deburring,
cleaning and etching.
 Micro-machining of brittle materials
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17. Limitations:-
 MRR (Material removal rate) is rather low (around
~ 15 mm^3/min for machining glass).
 Abrasive particles tend to get embedded particularly
if the work material is ductile.
 Tapering occurs due to flaring of the jet.
 Environmental load is rather high.
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18. Advantages:-
 Extremely fast setup and programming.
 No start hole required.
 There is only one tool.
 Low capital cost.
 Less vibration.
 No heat generation in work piece.
 Environmentally Friendly.
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19. Disadvantages:-
 Low metal removal rate.
 Abrasive powder cannot be reused.
 Tapper is also a problem.
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20. Video of cutting process
DEPARTMENT OF MECHANICAL ENGINEERING 04/25/17

21. Any Questions ???
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22. Outline of LBM
 Definition
 Schematic Diagram of LBM
 Working of LBM
 Applications
 Limitations
 Advantages
 Disadvantages
 Video of Cutting Process
DEPARTMENT OF MECHANICAL ENGINEERING 04/25/17

23. Definition of LBM :-
 Laser-beam machining is a thermal material-removal
process that utilizes a high-energy, coherent light
beam to melt and vaporize particles on the surface of
metallic and non-metallic work pieces.
 Lasers can be used to cut, drill, weld and mark. LBM
is particularly suitable for making accurately placed
holes.
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24. Principle of Laser beam machining (LBM):
 Conversion of electrical energy into heat energy to
emit laser beam energy.
 Laser beam is focused on lance then create high
energy the high energy concentration on work piece
then work piece is melt and vaporized of metal.
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25. Working of LBM
 The diagram of LBM is
shown in figure.
 Laser is stand for Light
Amplification by
Simulated Emulsion of
Radiation.
 The work piece is placed
on the aluminum work
table which material is
hard not cut by laser
beam.
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26. Working of LBM
 Ruby rod is used into
form of cylindrical
crystal both ends of ruby
rod are finished to optical
tolerance.
 The flash lamp wound
around the ruby rod and
connected to power
supply.
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27. Working of Laser beam machining (LBM):
 The ruby rod becomes high efficient on low
temperature and low efficient on high temperature. It is
thus continuous cooled with water, air or liquid
nitrogen.
 When the light beam has been amplified sufficiently
and intensity beam of light comes out form partially
reflected end it is focused on the work piece at the
focused very high temperature which vaporized and
removes the metal on work piece.
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28. Applications:-
 LBM can make very accurate holes as small as 0.005
mm in refractory metals ceramics, and composite
material without warping the work pieces.
 It is used for welding of thin metal sheet.
 Leaser can be used for cutting as well as drilling.
 Heat treatment.
 It is used for cutting complex profile.
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29. Limitations:-
 Uneconomic on high volumes compared to stamping
 Limitations on thickness due to taper
 High capital cost
 High maintenance cost
 Assist or cover gas required
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30. Advantages:-
 Very hard and abrasive material can be cut.
 Sticky materials are also can be cut by this process.
 It is a cost effective and flexible process.
 High accuracy parts can be machined.
 No cutting lubricants required
 No tool wear
 Narrow heat effected zone
 No contact between tool and work piece.
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31. Disadvantages:-
 Investment cost is more.
 Skilled operator is required.
 Operating cost is more.
 Flash lamp life is too short.
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32. Summary:-
 Mechanics of material removal : Melting, Vaporization
 Medium : Normal atmosphere
 Tool : Higher power laser beam
 Maximum material removal rate: 5 mm^3/min
 Specific power consumption : 1000 W/mm^3/min
 Materials application : All materials
 Shape application : Drilling fine holes
 Limitations : Very power consumption, cannot cut materials
with high heat conductivity and high reflectivity
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33. Video of Cutting process
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34. Video of Cutting process
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35. Any Questions ???
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36. Outline of EDM
 Definition
 Schematic Diagram of EDM
 Working of EDM
 Applications
 Advantages
 Disadvantages
 Video of Cutting Process
DEPARTMENT OF MECHANICAL ENGINEERING 04/25/17

37. Principle of EDM:
 Electrical discharge machining (EDM), sometimes also
referred to as spark machining, spark eroding, burning, die
sinking, wire burning or wire erosion, is a manufacturing
process whereby a desired shape is obtained using electrical
discharges (sparks).
 Material is removed from the work piece by a series of rapidly
recurring current discharges between two electrodes , separated
by a die-electric liquid and subject to an electric voltage. One
of the electrodes is called the tool-electrode, or simply the
"tool" or "electrode", while the other is called the workpiece-
electrode, or "workpiece".
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38. Working of EDM
 The diagram of electro
discharge machining shown in
figure.
 EDM is thermal erosion process
whereby material is melted and
vaporized from an electrically
conductive work piece immerse
in a liquid dielectric with a
series of spark discharge
between the tool electrode and
the work piece created by a
power supply.
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39. Working of EDM
 The electrode and the work
piece are separated by a
dielectric medium.
 The dielectric medium is like
as kerosene, paraffin or light
oil.
 The strong electrostatic field
between the electrode and work
piece produce emission of
electrons from the cathode.
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40. Working of EDM
 In this gap between tool and
work piece get ionized. The
liquid is force to sparking
zone.
 Due to high temperature, the
metal at the sparking zone
melts instantaneously.
 The material of the tool is
usually a material which
conduct electricity and which
can be easily shaped.
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41. Advantages:-
 Smaller holes can be easy machined.
 No contact between tool and work piece then tool life
is increase.
 Any complex shape can be machined.
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42. Disadvantages:-
 Tool life is not longer.
 Power consumption is high.
 Cycle time is more
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43. Summary:-
 Mechanics of material removal : Electrolysis
 Medium : Conducting electrolyte
 Tool : Cu, Brass, Steel
 Gap : 50-300 µm
 Maximum material removal rate: 15*10^3 mm^3/min
 Specific power consumption : 7 W/mm^3/min
 Materials application : All conducting metals and alloys
 Shape application : Blind complex cavities, curved surfaces,
through cutting, large through cavities
 Limitations : High speed energy consumption, not applicable
with electricity non-conducting materials
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44. Video of Cutting process
DEPARTMENT OF MECHANICAL ENGINEERING 04/25/17

45. Any Questions ???
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46. Outline of USM
 Definition
 Schematic Diagram & working of USM
 Applications
 Advantages
 Disadvantages
 Summary
 Video
DEPARTMENT OF MECHANICAL ENGINEERING 04/25/17

47. Principle of Ultrasonic machining(USM):
 In this method with the help of piezoelectric
transducer tool is vibrate at high frequency in a
direction normal to the surface being machined
abrasive slurry are used for the remove the metal from
work piece.
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48. Working of USM
 The USM diagram shown in
figure.
 In ultrasonic machining a
tool vibrate longitudinally
at 20 to 30 kHz with
amplitude between 0.01 to
0.06 mm is pressed on to
the work surface with light
force.
 The electronic oscillator
and amplifier is also known
as generator.
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49. Working of USM
 It converts the electrical
energy of low frequency
to high frequency.
 At the time high
frequency current is
passed through the coil
therefore change in
electromagnetic field
which produces
longitudinal strain.
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50. Working of USM
 As the tool vibrate with
specific frequency the
abrasive slurry mix with
water and grain of definite
proportion is made to flow
under pressure through the
tool work piece interface. The
flow of slurry through the
work tool interface actually
causes thousand of
microscopic grain to remove
the work material by
abrasion.
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51. Applications:-
 USM is best suitable for hard, brittle material, such as
ceramics, carbides, glass, precious stone etc.
DEPARTMENT OF MECHANICAL ENGINEERING 04/25/17

52. Advantages:-
 Any materials can be machined regardless of their
electrical conductivity.
 Especially suitable for machining of brittle materials.
 Machined parts by USM possess better surface finish
and higher structural integrity.
 USM does not produce thermal, electrical and
chemical abnormal surface.
DEPARTMENT OF MECHANICAL ENGINEERING 04/25/17

53. Disadvantages:-
 Tool wears fast in USM.
 Machining area and depth is restraint in USM.
 High cost of tooling.
 MMR is low.
DEPARTMENT OF MECHANICAL ENGINEERING 04/25/17

54. Summary:-
 Mechanics of material removal : Brittle fracture caused by
impact of abrasive grains due to tool vibrating at high
frequency.
 Medium : Slurry
 Tool : Soft Steel
 Gap : 25-40 µm
 Frequency : 15-30kHz
 Amplitude : 25-100 µm
 Specific power consumption : 1000 W/mm^3/min
 Materials application : Metals and alloys, semiconductors, non-
metals
 Shape application : Round and irregular holes
 Limitations : Very low mrr, tool wear, depth of holes and
cavities smallDEPARTMENT OF MECHANICAL ENGINEERING 04/25/17

55. Video of Cutting process
DEPARTMENT OF MECHANICAL ENGINEERING 04/25/17

56. Outline
 Definition
 Schematic Diagram of EBM
 Working of EBM
 Applications
 Limitations
 Advantages
 Video of Cutting Process
DEPARTMENT OF MECHANICAL ENGINEERING 04/25/17

57. Definition of EBM :-
 Electron Beam Machining (EBM) is a thermal
process. Here a steam of high speed electrons
impinges on the work surface so that the kinetic
energy of electrons is transferred to work producing
intense heating.
 Depending upon the intensity of heating the work
piece can melt and vaporize.
 The process of heating by electron beam is used for
annealing, welding or metal removal.
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58. EBM:
 During EBM process very high velocities can be
obtained by using enough voltage of 1,50,000 V can
produce velocity of 228,478 km/sec and it is focused
on 10 – 200 μM diameter.
 Power density can go up to 6500 billion W/sq.mm.
Such a power density can vaporize any substance
immediately.
 Complex contours can be easily machined by
maneuvering the electron beam using magnetic
deflection coils
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59. EBM:
 To avoid a collision of the accelerating electrons with
the air molecules, the process has to be conducted in
vacuum. So EBM is not suitable for large work pieces.
 Process is accomplished with vacuum so no
possibility of contamination.
 No effects on work piece because about 25-50μm
away from machining spot remains at room
temperature and so no effects of high temperature on
work
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60. Working of EBM
 The EBM beam is
operated in pulse mode.
 This is achieved by
appropriately biasing the
biased grid located just
after the cathode.
 Switching pulses are given
to the bias grid so as to
achieve pulse duration of
as low as 50 μs to as long
as 15 ms.
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61. Working of EBM
 Beam current is directly
related to the number of
electrons emitted by the
cathode or available in the
beam.
 Beam current once again
can be as low as 200μ amp
to 1 amp. Increasing the
beam current directly
increases the energy per
pulse.
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62. Working of EBM
 Similarly increase in pulse duration also enhances
energy per pulse.
 High-energy pulses (in excess of 100 J/pulse) can
machine larger holes on thicker plates.
 A higher energy density, i.e., for a lower spot size, the
material removal would be faster though the size of
the hole would be smaller.
 The plane of focusing would be on the surface of the
work piece or just below the surface of the work
piece.
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63. Applications:-
 Used for producing very small size holes like holes in
diesel injection nozzles, Air brakes etc.
 Used only for circular holes.
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64. Limitations:-
 Material removal rate is very low compared to other
convectional machining processes.
 Maintaining perfect vacuum is very difficult.
 The machining process can’t be seen by operator.
 Work piece material should be electrically conducting.
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65. Advantages:-
 Very small size holes can be produced.
 Surface finish produced is good.
 Highly reactive metals like Al and Mg can be
machined very easily.
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66. Summary:-
 Mechanics of material removal : Melting, Vaporization
 Medium : Vacuum
 Tool : Beam of electron moving at very high velocity
 Maximum material removal rate: 10 mm^3/min
 Specific power consumption : 450 W/mm^3/min
 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
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67. Video of Cutting process
DEPARTMENT OF MECHANICAL ENGINEERING 04/25/17

68. Any Questions ???
04/25/17

69. THANK YOU