AJM and WJM

Unconventional Machining process

1. UNIT-IV ADVANCED MANUFACTURING PROCESS

2. Abrasive Jet Machining (AJM)

3. Abrasive Jet Machining

4. Arrangement of Abrasive Jet Machining (AJM) .

5. 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)

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7. Construction details Aluminium oxide (Al 2 O 3 ) - 10 to 50 microns Silicon Carbide ( SiC ) - 25 and 50 Microns Glass Powder - 0.3 to 0.6 mm Abrasive Particle Sizes

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

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

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

11. AJM

12. MRR - PARAMETERS

13. MASS FLOW RATE

14. Abrasive Grain Size OR

15. Gas Pressure

16. Velocity of Abrasive particles

17. Mixing Ratio

18. Stand off Distance

19. Stand of distance

20. .

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

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

23. Application

24. Characteristics of AJM

25. . WATER JET MACHINING

26. Introduction

27. Principle

28. PARTS Pump Accumulator Control Valve Regulating Chamber Nozzle

29. . . Pump or Intensifier Used to Increase the water Pressure Up to 1500 – 4000 N / mm 2

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

31. . . 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

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

33. WJM

34. PROCESS PARAMETERS

35. MRR

36. MRR

37. MRR

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40. ADVANTAGES

41. DIS-ADVANTAGES

42. APPLICATION

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45. Hydro-dynamic jet Machining Abrasive Water jet Machining

46. Hydro-dynamic jet Machining Abrasive Water jet Machining

47. Characteristics of AWJM

48. ULTRASONIC MACHINING PROCESS USM .

49. . . Ultrasonic Waves of High Frequency

50. Sound . INFRA SONIC WAVES ULTRA SONIC WAVES AUDIBLE WAVES

51. SUITABLE

52. PRINCIPLE

53. .

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

55. Abrasive Slurry

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

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

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

59. Working of USM

60. . 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

61. COMPARISON

62. TRANSDUCER

63. TYPES OF TRANSDUCER

64. 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

65. MAGNETOSTRICTIVE TRANSDUCER

66. 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

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

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

69. 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

70. Advantages – Magnetostrictive Transducer

71. Disadvantages – Magnetostrictive Transducer

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

73. PIEZOELECTRIC effect crystal

74. 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.

75. Circuit

76. Arrangement of the circuit

77. 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

78. Resonance

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

80. CONCENTRATOR or HORN

81. STRAIGHT AND TAPER ROD AS HORN

82. HORN

83. NODAL POINT CLAMPING

84. FEED MECHANISM

85. . Its high sensitive Compact in size

86. . 1. Feed rate is high

87. MRR MRR Per unit time

88. Wear Ratio

89. Factors considered for MRR in USM

90. Grain size of Abrasives

91. 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

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

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

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

95. Process Parameters

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

97. 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

98. Abrasive Material and Cutting Power Process Parameters

99. Advantages of USM

100. Disadvantages of USM

101. Applications

102. Recent Development TOOL WITH DIAMOND DUST

103. UNIT-3 ELECTRICAL ENERGY BASED PROCESSES

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105. 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