Ultrasonic machining (USM) is a non-traditional process that utilizes high-frequency vibrations to drive abrasives in a slurry against a workpiece, suitable for machining hard and brittle materials without significant structural changes. Key components of USM include a transducer, tool horn, tool, and abrasive slurry, with techniques for feeding the tool such as gravity, spring-loaded, pneumatic or hydraulic systems. Advantages of USM include its ability to machine various materials with precision, while disadvantages include low metal removal rates and high tool wear, with applications across industries including dentistry and cutting intricate shapes.

1. MANUFACTURING
PROCESS
19M302

2. ULTRASONIC
MACHINING
21M101 Abdeali Morudwala
21M117 Jagadeesh
21M133 Mohamed Bayaskhan
21M152 Shivani

3. Content
 Definition
 Components
 Process
 Advantage of USM
 Disadvantage of USM
 Applications
 Machining characteristics
 Design of horn

4. DEFINITION
Ultrasonic Machining is a non-traditional process,
in which abrasives contained in a slurry are driven
against the work by a tool oscillating at low
amplitude (25-100 microns) and high frequency
(15-30 kHz).

5. COMPONENTS OF AN ULTRASONIC MACHINE
1. Transducer
2. Tool horn
3. Tool
4. Abrasive slurry
The major components of an ultrasonic
machine are :

6. COMPONENTS OF USM
Transducer :
The high frequency electrical signal is transmitted to traducer
which converts it into high frequency low amplitude vibration.
Essentially transducer converts electrical energy to mechanical
vibration.
There are two types of transducer used
1. Piezo electric transducer
2. Magneto-strictive transducer.

7. COMPONENTS OF USM
Tool Horn :
The tool holder holds and connects the tool to the transducer. Material of tool should
have good acoustic properties, high resistance to fatigue cracking. Commonly used tool
holders are Monel, titanium, stainless steel. Tool holders are more expensive, demand
higher operating cost.
Tool :
Tools are made of relatively ductile materials like Brass, Stainless steel or Mild steel so
that Tool wear rate (TWR) can be minimized. The value of ratio of TWR and MRR
depends on kind of abrasive, work material and tool materials.

8. COMPONENTS OF USM
Abrasive slurry :
• The abrasive selected should be harder than the material being machined.
• Typical abrasives used are aluminium oxide, silicon carbide and boron
carbide.
• The choice of grain size depends upon the finish desired. The abrasive is
suspended in a liquid with about 30 – 60 % by volume of abrasive .
• The liquid serves several functions. It acts as an acoustic bond between the
vibrating tool and workpiece, to give efficient transfer of energy between the
two.

10. PROCESS OF USM
• As the tool vibrates with a specific frequency, an
abrasive slurry is made to flow through the tool work
interface.
• The impact force arising out of vibration of the tool
end and the flow of slurry through the work tool
interface actually causes thousands of microscopic
abrasive grains to remove the work material by
abrasion.

11. TOOL FEED MECHANISM
There are four types of feed mechanism which are
commonly used in USM:
1. Gravity feed mechanism
2. Spring loaded feed mechanism
3. Pneumatic or hydraulic feed mechanism
4. Motor controlled feed mechanism.

12. 1. Gravity feed mechanism
• In this mechanism counter,
balance weights are used to
apply the required load to the
head through pulley and rope
arrangement.
• In order to reduce friction
ball, bearings are used.
• Gravity feed mechanisms are
simple in construction, but
this mechanism is insensitive
and inconvenient to adjust.

13. 2. Spring loaded feed mechanism
• In this mechanism spring
pressure is used to feed the
tool during the machining
operation.
• This type of mechanism is
quite sensitive and easy to
adjust.

14. 3. Pneumatic or hydraulic feed mechanism
• In this mechanism,
hydraulic cylinder is used
to give a linear motion of
the tool.
• High feed rate and
accurate positioning are
possible with hydraulic
feed mechanism.

15. ADVANTAGES OF USM
• Used to machine hard, brittle, fragile and non-
conductive material
• No significant changes in physical structure of work
material
• Non-metal can very well be machined by USM
• Distortion less process
• It can be adopted in conjunction with other new
technologies like EDM,ECG,ECM.

16. DISADVANTAGES OF USM
• Low Metal removal rate
• Difficult to drill deep holes
• Tool wear rate is high due to abrasive particles
• Tools made from brass, tungsten carbide, MS or tool steel will wear by the
action of abrasive grit
• can be used only when the hardness of work is more than 45 HRC

17. APPLICATIONS OF USM
• Machining of cavities in electrically non-conductive ceramics
• Used to machine fragile components
• Large number of holes of small diameter
• USM enables a dentist to drill a hole of any shape on teeth without any pain
• USM can be used to cut industrial diamonds
• Used for machining round, square, irregular shaped holes
• Used in machining of dies
• USM can perform machining operations like drilling, grinding and milling operations

19. MACHINING CHARACTERISTICS
1) Effect of amplitude on MRR
Increase in amplitude of vibration increases MRR.

20. MACHINING CHARACTERISTICS
2) Effect of Frequency on MRR
Frequency used for machining process must be
resonant frequency

21. MACHINING CHARACTERISTICS
3) Effect of abrasive grain size
An increase in abrasive grain size results in higher
MRR but poorer surface finish

22. MACHINING CHARACTERISTICS
4) Effect of Applied static load (Feed force)
MRR increase with the feed force..

23. MACHINING CHARACTERISTICS
5) Effect of Slurry, Tool and Work Material
• MRR increases with slurry concentration.
• Narrower rectangular tool gives more MRR
compared to square cross section.
• Conical tool gives twice MRR compared to
cylindrical tool.
• Brittle material can be cut at higher rates than
ductile materials.

24. DESIGN OF HORN (VELOCITY TRANSFORMER)
The function of horn ( also called concentrator) is to amplify and focus vibration of the
transducer to an adequate intensity for driving the tool to fulfill the cutting operation.
They are made of a hard, non magnetic and easily machinable steel having good
fatigue strength like K-Monel ,Metal bronze and Mild steel. Linearly tapered and
exponentially taped horns have lengths equal to one-half of the wave length of sound in
the metal of which they are made.

25. DESIGN OF HORN
1) Design of Exponential Concentrator of Circular
cross section
Let us consider case of exponential horn with circular
cross section. This type of the horn is used for
cutting large diameter through holes in work
piece.

26. DESIGN OF HORN
2) Design of Exponential Concentrator of
Rectangular cross section
Let us consider case of exponential horn with
Rectangular cross section. This type of the horn is
widely used in ultrasonic cutting

27. DESIGN OF HORN
3) Design of Exponential Concentrator of hollow
cylindrical cross section
Let us consider case of exponential horn with hollow
cylindrical cross section. This type of the horn is widely
used trepanning that is cutting along contours of the
desired opening.

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