Unconventional Machining Process

1. UNIT-IV
ADVANCED
MANUFACTURING PROCESS

2. Abrasive Jet Machining (AJM)

4. Abrasive Jet Machining

5. Arrangement of Abrasive Jet
Machining (AJM)
.

6. Construction details
.
Gas
Used
Nitrogen , Carbon di-oxide ,
compressed air
Abrasive Particles
Used
Aluminium oxide , Silicon
Carbide, Glass Powder ,
Dolomite and Specially
Prepared sodium bicarbonate
Nozzle
Tungsten Carbide ,
Synthetic Sapphire (Ceramic)

7. .
.

8. Construction details
• Aluminium oxide (Al2O3 ) - 10 to 50 microns
• Silicon Carbide (SiC) - 25 and 50 Microns
• Glass Powder - 0.3 to 0.6 mm
Abrasive Particle Sizes

10. .
.
Nozzle
Life
Tungsten
Carbide
Synthetic
Sapphire
12 to 20
Hours
Average of
300 Hours

11. .
• .
The Shape and Size of Cut is controlled by a
movement adjusting mechanism given to
work piece or Tool
Cam Mechanism
Pantograph
Mechanism

12. .
.
Air Pressure
2 Kg/cm2 to 8 Kg/cm2

13. AJM

14. MRR - PARAMETERS

15. MASS FLOW RATE

16. Abrasive Grain Size
OR

17. Gas Pressure

18. Velocity of Abrasive particles

19. Mixing Ratio

20. Stand off Distance

21. Stand of distance

22. .

23. Advantages
1. We can cut all kind of materials
2. No heat produced in process , so no thermal damage
3. Very thin and brittle material can be machined
4. Low initial investment
5. Good Surface Finish
6. Intricate holes can be cut in hard and brittle material

24. Dis-Advantages
1. Low MRR
2. Soft Material cannot be machined
3. Machining accuracy is poor
4. Nozzle Wear Rate is High
5. Abrasive Powder cannot be reused
6. Embedding of Abrasive particle in work piece is the high
damage thing in this process
7. It requires Dust Collection System

25. Application

26. Characteristics
of AJM

27. .
WATER JET
MACHINING

28. Introduction

29. Principle

30. PARTS
Pump
Accumulator
Control Valve
Regulating Chamber
Nozzle

31. .
.
Pump or
Intensifier
Used to Increase the water Pressure
Up to 1500 – 4000 N / mm2

32. .
.
Accumulator
Used to Store the water
Used to avoid water Pulsation

33. .
.
Nozzle
Used to Increase the velocity of water jet
Made up of Sintered Diamond, Tungsten Carbide and
Synthetic Sapphire
Nozzle Exit Diameter 0.05 – 0.35mm
Velocity of Water Jet From Nozzle 920 m/s

34. .
.
Regulating
Chamber
Used to Control the flow of water jet to Nozzle

35. WJM

36. PROCESS PARAMETERS

37. MRR

38. MRR

39. MRR

40. .

41. .

42. ADVANTAGES

43. DIS-ADVANTAGES

44. APPLICATION

45. .
.

46. .

47. Hydro-dynamic jet Machining
Abrasive Water jet Machining

48. Hydro-dynamic
jet Machining
Abrasive Water jet
Machining

49. Characteristics of AWJM

50. ULTRASONIC
MACHINING
PROCESS
USM
.

51. .
.
Ultrasonic
Waves of High
Frequency

52. Sound
.INFRA SONIC
WAVES
ULTRA SONIC
WAVES
AUDIBLE
WAVES

53. SUITABLE

54. PRINCIPLE

56. .
Ultrasonic
Generator
Used to convert the current from low
frequency to high frequency

57. Abrasive Slurry

58. .
Transducer
Used to convert
Electrical energy
into Mechanical
Vibrations

59. .
Tool Holder
Made up of Titanium alloy , Monel ,
Aluminium, Stainless steel

60. .
Tool
Material
Low Carbon Material
and Stainless steel
The tool is brazed,
soldered or Fastened
mechanically to the
transducer through a
tool holder

61. Working of USM

62. Transducer
convert the high
frequency
electrical energy
into Mechanical
Vibrations
Oscillator convert the
Low frequency electrical
energy into high
frequency electrical
energy
20 – 30 HZ
Vibrations are
transferred to
tool material
Abrasive Slurry
Passed
Between the
vibrating tool
and work piece
The
refrigeration
system used
to cool the
abrasive
slurry to 5 –
6 Degree
celcius

63. COMPARISON

64. TRANSDUCER

65. TYPES OF TRANSDUCER

66. MAGNETOSTRICTIVE TRANSDUCER
.
Change in length is independent of
the direction of the magnetic field
But depend only on the
magnitude of the field and
Nature of the material

67. MAGNETOSTRICTIVE TRANSDUCER

68. MAGNETOSTRICTIVE TRANSDUCER
LT battery used to
heat the filament
So electrons are
produced
Those electrons
are accelerated
by HT Battery
So AC current
Produced in the
circuit

69. So Rod start
to vibrate
due to
magnetostric
tive effect
This vibrations rod
create Ultrasonic
Waves , which sent out
MAGNETOSTRICTIVE TRANSDUCER

70. MAGNETOSTRICTIVE TRANSDUCER
The Longitudinal Extension
and contraction of the Rod AB
produce an EMF in the coil L2

71. Resonance
Frequency of the
oscillatory circuit
Frequency of Vibrating
Rod
=
Resonance will occur when
At resonance , the rod vibrates vigorously and ultrasonic
waves are produced at high frequencies

72. Advantages –
Magnetostrictive Transducer

73. Disadvantages –
Magnetostrictive Transducer

74. PIEZOELECTRIC TRANSDUCER
Its more efficient than magnetostrictive transducer
The modern USM are of this type.

75. PIEZOELECTRIC
effect
crystal

76. Definition - Piezoelectric
• Piezoelectric transducers are a type of electro
acoustic transducer that convert the electrical
charges produced by some forms of solid
materials into energy.
• The word "piezoelectric" literally means
electricity caused by pressure.

77. Circuit

78. Arrangement of the circuit

79. Working LT battery used to
heat the filament
So electrons are
produced
Those electrons are
accelerated by HT Battery
So AC current
Produced in the
circuit
This AC current Passes
through L1 and L2 and
its transferred to
Secondary circuit
This AC current passed to the plates A and B and it make the
Crystal to vibrate due to the principle of inverse piezoelectric
effect. The vibrations of crystal creates Ultrasonic waves

80. Resonance

81. Advantages – Piezoelectric transducer
Disadvantages – Piezoelectric transducer
1. Piezoelectric quartz is high cost
2. Cutting and shaping of crystal is very complex.

82. CONCENTRATOR or HORN

83. STRAIGHT AND TAPER ROD AS HORN

84. HORN

85. NODAL POINT
CLAMPING

86. FEED MECHANISM

87. .
1. Its high sensitive
2. Compact in size

88. .
1. Feed rate is high

89. MRR
MRR Per unit time

90. Wear Ratio

91. Factors considered for MRR
in USM

92. Grain size of Abrasives

93. Abrasive material
It Depend on
1.The type of material to be machined
2. Requirement of Surface finish
For Machining - Tungsten Carbide
- Die Steel
Boron Carbide
Silicon Carbide
Abrasives
For Machining - Glass
- Ceramics
Aluminium oxide

94. Concentration of Slurry
Abrasive Slurry = Abrasive Particles + Water

95. Amplitude of Vibration
MRR increase with the increase of Amplitude of Vibration

96. Frequency
MRR increases with the increase of Ultrasonic wave
Frequency

97. Process Parameters

98. Tool Material
Lengthy tool causes overstresses
So tool should be short and rigid
Process Parameters

99. Process Parameters
Wear Ratio
1.5 : 1 For Tungsten Carbide Work Pieces
100 : 1 For Glass Work Pieces
50 : 1 For Quartz Work Pieces
75 : 1 For Ceramics
1 : 1 For Hardened tool steel Work Pieces

100. Abrasive Material and
Cutting Power
Process Parameters

101. Advantages of USM

102. Disadvantages of USM

103. Applications

104. Recent Development

105. UNIT-3
ELECTRICAL ENERGY BASED
PROCESSES

106. .

107. Specifications
Voltage = 250 V
GAP = 0.005 – 0.05 mm
Temperature = 10000 degree celcius
Spark occur = 10 – 30 micro seconds
Current density = 15 – 500 A