Ultrasonic machining is a subtractive manufacturing process that removes material from a workpiece surface through high-frequency vibrations of a tool against the material in the presence of abrasive particles. The document discusses the working principle, schematic setup, process parameters, advantages, and applications of ultrasonic machining. It is a machining process suitable for hard and brittle materials that allows for complex shapes to be cut with high precision.

1. Ultrasonic Machining(USM)
Department of Mechanical Engineering
Atria Institute of Technology
Student names USN no.
Veerendra T U 1AT18ME051
Vishal Sanjay Shivam 1AT18ME053
Yash G M 1AT18ME056
Yashwanth B 1AT18ME057
Course Coordinator-
Anjan Kumar
(Assistant Professor)

2. Contents
 1.Definition
 2.Working Principle
 3.Schematic setup of Machine
 4.List of equipment and its functions
 5.Process parameters
 6.Advantages
 7.Limitations
 8.Applications
 9.Reference

3. Definition
• Ultrasonic machining is a subtractive manufacturing process
that removes material from the surface of a part through high
frequency, low amplitude vibrations of a tool against the
material surface in the presence of fine abrasive particles​.
• Ultrasonic machining is an abrasive process which can create any
material into hard and brittle form with the help of its vibrating tool and
the indirect passage of abrasive particles towards the work piece. It is a low
material removal rate machining process.

4. Working Principle
Working principle of Ultrasonic Machining or Ultrasonic
Impact Grinding is described with the help of a schematic
diagram. The shaped tool under the actions of mechanical
vibration causes the abrasive particles dipped in slurry to be
hammered on the stationary workpiece. This causes micro-
indentation fracture on the material.
Small abraded particles are removed along the surface which is
perpendicular to the direction of the tool vibration. When the
material is removed a cavity of the same profile of the tool face
is formed. The abrasive particles gradually erodes as the
machining process continues. As a result fresh abrasive
particles are needed to be supplied in the machining zone.
Abrasive particles associated with the liquid is fed to the
machining zone and it ensures the removal of the worn out
grains and material.

5. Schematic setup of Machine
The schematic setup of Ultrasonic Machine is depicted below:-

6. List of equipment and its functions
The equipments/components of USM and its functions are listed below:-
1)High-frequency generator-
An electronic oscillator is used to generate high-frequency alternating
current. The frequency is in the ultrasonic range (20-40KHz).
2)Work piece-
Workpiece of hard and brittle material can be machined by​USM.​ It is
mounted on a vice, which can be located​at the desired position under the
tool using a two axis table.​ The table can further be lowered or raised
to​accommodate work of different thickness.​

7. 4)Abrasive slurry feeding arrangement-
A constant stream of abrasive suspension is flowed between to tool
and workpiece. This slurry consists of abrasive material like boron carbide,
silicon carbide, diamond dust, etc. mixed with water or oil. The abrasive grit
size is usually in the range of 100-1000 mesh size. The smaller size gives
smoother surface finish, larger grain results faster machining. The flow of
slurry carried away the debris during the machining. The slurry is cooled
down by a cooling system.
3)Tool in a tool holder-
Tool is made of ductile material like mild steel, brass to reduce the
tool ware. They are fastened to the tool holder by brazing to reduce
fatigue. The cavity produced in workpiece has the same geometry
of tool.​

8. 5)Transducer to generate vibration-
Transducer used in USM converts the electrical energy into mechanical
vibration. There are mainly two types of transducer is used in USM;
piezoelectric transducer and magneto strictive transducer.​​
Tool is fed to the machining zone of workpiece .The tool is shaped as same to
the cavity of be produced into the workpiece. The tool is fed to the machining
area. The feed rate is maintained equal to the rate of enlargement of the cavity to be
produced.
6)Ultrasonic Oscillator​​-
This operation uses high frequency electric current which passes to an ultrasonic
oscillator and ultrasonic transducer. The function of the transducer is to convert
electric energy into mechanical energy developing vibrations into the tool.​​
7)Feed Mechanism-

9. Process Parameters
The ultrasonic machining process parameters/variables are:-
1)Vibration frequency and amplitude-
The frequency of vibration is directly proportional to
the material removal rate. The increase in frequency
increase the number blows by the tool per second
and cut more material from surface. For many
materials, the material removal rate is proportional to
the square of amplitude of vibration.

10. 2)Static load on tool- The material removal
rate increase with the static load on tool up to a
maximum value. Beyond this point, the material
removal decreases with the increasing static load.
3)Abrasive material, size- The characteristics of
abrasive like size, shape hardness, etc. are effects its
cutting efficiency. The increase in grain size increases the
material removal rate till grain size equal to the amplitude
of vibration. Beyond this, the increase in grain size
decreases the cutting rate.

11. 4)Slurry composition and property-
The composition of slurry, the concentration of
abrasive particle in slurry and viscosity of slurry effects
the material removal rate. The abrasive grit worn out
rapidly, so periodic replacement of slurry is required.
Since the viscosity of slurry dampens the oscillation of
grits, the material removal rate decreases as the
viscosity increases.
5)Workpiece material and machining area and shape-
The material removal rate depends on the characteristics of workpiece
material like hardness, brittleness, etc. The shape depth of cut required
also effects machining rate.

12. Advantages
• This process is used for drilling both circular and non-circular holes in very
hard materials like carbide, ceramics, etc.
• This process is best suited for brittle materials.
• The machining operation is simple and requires less time.
• This process is economical.
• It is suitable for both conductive and non conductive materials.
• A semi skilled operator can operate the machine.
• Ultrasonic machining doesn’t require heating workpiece. If a workpiece is
sensitive to thermal fluctuations it can be safely machined​.
• High accuracy can be achieved.

13. Limitations
• The metal removal is slow due to micro chipping or erosion mechanism.
• The wear of sonotrode tip occurs more quickly.
• The machining of deep holes is not easy by this method because of the
inability of abrasive slurry to flow at the bottom of the hole (Except
rotary ultrasonic machining).
• Ultrasonic vibration machining can be used only to machine materials
that have hardness value atleast 45 HRC.
• Low material cutting rate.
• High power consumption.
• Low penetration rate.
• The process is limited to the machined surface of a small size.
• Shorter tool life.

14. Applications
1) Step Drilling 2)Grinding the brittle materials

15. 3) Threading 4) Engraving

16. 5) Machining glasses and ceramics 6)Slicing and Broaching
hard materials

17. Reference
• https://www.youtube.com/watch?v=f9u8EnLM2X0
• https://www.youtube.com/watch?v=5w6szZtOg5w​
• https://www.youtube.com/watch?v=qVcwT0FfAIc
• https://www.youtube.com/watch?v=UyK7Ph6yosk
• https://www.youtube.com/watch?v=HTtnAXrzD4w
The reference Youtube links of Ultrasonic Machining is given below-