1. SNS COLLEGE OF ENGINEERING, COIMBATORE- 641 107
SNS COLLEGE OF ENGINEERING, COIMBATORE   DEPARTMENT OF MECHANICAL ENGINEERING  
ULTRASONIC MACHINING PROCESS PARAMETERS Prepared by B.BALAMURALI AP/MECH
ME UMP / TOPIC-14
SNSCEME PRESENTATION

2. Draw the USM working diagram.
RECAP
Draw the USM working diagram.
ME UMP / TOPIC-14
SNSCEME PRESENTATION

3. ULTRASONIC MACHINING
In this machining method ,a slurry of small abrasive particles are forced against the workpiece by means of a vibrating tool and it causes the removal of metal from the workpiece in the form of extremely small chips.
ME UMP / TOPIC-14

4. PROCESS PARAMETERS of USM
MRR
Tool Material
Tool wear Rate
Abrasive materials and abrasive slurry
Surface finish
Work material
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5. Boron carbide is the hardest material and has highest MRR.
Material Removal Rate
Material removal rate per unit time is inversely proportional to the cutting area of the tool.
Boron carbide is the hardest material and has highest MRR.
Wear Ratio – It is defined as the ratio of volume of material removed from the work to volume of material eroded from the tool.
ME UMP / TOPIC-14

6. MRR in USM depends on certain factors Grain size of abrasive
Material Removal Rate
MRR in USM depends on certain factors
Grain size of abrasive
Abrasive materials
Concentration of slurry
Amplitude of vibration
Frequency of ultrasonic waves
ME UMP / TOPIC-14

7. For rough work (200-400 grit size)
Grain size of abrasive
For rough work ( grit size)
For finishing operation ( grit size)
ME UMP / TOPIC-14

8. Abrasive materials
For effective machining, the abrasive materials should be replaced periodically since the dull abrasives stop the cutting action.
Selection of abrasive particles depends on
Material to be machined
Hardness of the material
MRR
Surface finish
Hard abrasives – boron carbide and silicon carbide (Tungsten carbide, die steel)
Soft abrasives - Aluminium oxide (Glass, ceramics)
ME UMP / TOPIC-14

9. Concentration of slurry
A mixture of abrasive grains and water of definite proportion (20-30 percent)
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10. Amplitude of vibration
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11. Frequency of ultrasonic waves
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12. ACTIVITY!!!
MIND REFRESHING……………..
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13. Tough & Ductile tool material is used in USM process.
Low carbon steels & stainless steels used as tool material.
Hollow tool with wall thickness greater than 0.5 to 0.8mm.
Side clearance to the tool (0.06 to 0.36 mm) depending on the grain size of abrasives.
ME UMP / TOPIC-14

14. TOOL WEAR RATE
It is defined as the ratio of volume of material removed from the work to volume of material eroded from the tool.
Tungsten carbide (1.5 : 1)
Glass (100 :1)
Quartz (50 :1)
Ceramics (75 :1)
Hardened tool steel (1 :1)
ME UMP / TOPIC-14

15. ABRASIVE MATERIALS & ABRASIVE SLURRY
For effective machining, the abrasive materials should be replaced periodically since the dull abrasives stop the cutting action.
For rough work ( grit size)
For finishing operation ( grit size)
Hard abrasives – boron carbide and silicon carbide (Tungsten carbide, die steel)
Soft abrasives - Aluminium oxide (Glass, ceramics)
A mixture of abrasive grains and water of definite proportion (20-30 percent)
ME UMP / TOPIC-14

16. SURFACE FINISH
The maximum speed of penetration in soft and brittle materials such as soft ceramics are of the order of 200mm/min.
Penetration rate is lower for hard and tough materials.
Accuracy of this process is +_ 0.006mm & surface finish upto 0.02 to 0.8 micron value can be achieved.
ME UMP / TOPIC-14

17. WORK MATERIAL
Hard and brittle metals, non-metals like glass, ceramics and semiconductors are used as work material in USM process.
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18. WORK MATERIAL
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19. Under Ideal conditions, Penetration rate – 5 mm3/min
LIMITATIONS OF USM
Under Ideal conditions,
Penetration rate – 5 mm3/min
Power – 500 to 1000 watts
MRR on brittle materials – 0.018mm3/joule
Hole tolerance – 25 µm
Surface finish – 0.2 to 0.7 µm
ME UMP / TOPIC-14

20. MCQ What is the penetration rate for USM under ideal condition
15 mm3/min
50 mm3/min
5 mm3/min
23 mm3/min
2. Find the correct grain size of abrasives for finishing operation
grit size
grit size
grit size
grit size
ME UMP / TOPIC-14

21. MCQ 3. Select the correct definition from the following for WEAR RATIO
Wear Ratio – It is defined as the ratio of volume of material removed from the work to volume of material eroded from the tool.
Wear Ratio – It is defined as the ratio of volume of material eroded from the tool to volume of material removed from the work .
ME UMP / TOPIC-14

22. MATCH THE FOLLOWING ABRASIVES WORK MATERIAL Boron carbide Glass
Silicon carbide
Ceramics
Aluminium oxide
Tungsten carbide
Glass powder
Die steel
ME UMP / TOPIC-14

23. ME UMP / TOPIC-14