Ultrasonic machining (USM) is a subtractive assembling measure that eliminates material from the outer layer of a section through high frequency , low amplitude vibrations of a tool against the material surface within the sight of fine rough particles. USM is most normally used to machining of glass, ceramics, zirconia, valuable stones, and solidified prepares. USM permits the cutting of perplexing and non-uniform shape with very high accuracy.

1. Amlan Talukdar
1902007, M1
Department of Mechanical Engineering
Date - 01.09.2021
1
ULTRASONIC MACHINING
(USM)

2. OUTLINE
 Introduction
 Parts
 Working principle
 Process parameters
 Material removal mechanisms
 Advantages and Limitations
 Applications
 Conclusion
 References 2

3.  Ultrasonic machining is a non-conventional machining process in which
the abrasives hits on the work piece to remove the material.
 Ultrasonic machining (USM) is a mechanical material removal process
used to erode holes and cavities in hard or brittle workpieces by using
shaped tools, high-frequency mechanical motion and an abrasive
slurry.
 This process is non-thermal, non-chemical, non-electrical and creates
no change in the metallurgical, chemical or physical properties of the
workpiece material.
 It can be used for machining both electrically conductive and non-
conductive materials.
3
INTRODUCTION (1,4)

4. USM
Tool
Horn or
Concentrato
r
Transducer
Power
supply
Workpiece
Abrasive
gun
Abrasive
slurry
4
PARTS (3)

5. The Ultrasonic Machining consists of different parts as follows: (3)
 Power supply - To starts, the machining process power is required.
 Transducer (electro-mechanical ) - converts an electrical signal to a
mechanical signal whereas electromechanical transducer used to generates
mechanical vibration.
 Horn or Concentrator - mechanically amplifies the vibration to the
required amplitude and accommodates the tool at its tip.
 Tool - should be designed as like when the operation is performed does not
lead to brittle fracture of it.
 Abrasive slurry - A water-based slurry of abrasive particle used as an
abrasive slurry in this machining. (Aluminum oxide, Silicon carbide)
 Abrasive gun - supply an abrasive slurry, which is a mixture of abrasive
grain and the water in between tool-workpiece interface under a definite
pressure.
 Workpiece - perform several techniques like machining very precise and
intricate shaped articles, grinding the brittle materials. 5

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Fig 1. Schematic diagram of USM,
https://www.mech4study.com/2017/
03/ultrasonic-machining-working
Fig 2. USM process,
https://learnmech.com/working-of-
ultrasonic-machining-us/
WORKING PRINCIPLE (3,5)

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 In ultrasonic machining, a tool of desired shape vibrates at an ultrasonic
frequency (19 ~ 25 kHz) with an amplitude of around 15 – 50 μm over
the workpiece.
 Generally the tool is pressed downward with a feed force, F. Between the
tool and workpiece, the machining zone is flooded with hard abrasive
particles generally in the form of a water based slurry.
 As the tool vibrates over the workpiece, the abrasive particles act as the
indenters and indent both the work material and the tool.
 The abrasive particles, as they indent, the work material, would remove the
same, particularly if the work material is brittle, due to crack initiation,
propagation and brittle fracture of the material.
 Hence, USM is mainly used for machining brittle materials, which are poor
conductors of electricity and thus cannot be processed by Electrochemical
and Electro-discharge machining.

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 Amplitude of vibration (a) : 15 – 50 μm
 Frequency of vibration (f) :19 – 25 kHz
 Feed force (F) – related to tool dimensions
 Feed pressure (p)
 Abrasive size : 15 μm – 150 μm
 Abrasive material : Al2O3 , SiC, B4C
 Flow strength of work material
 Flow strength of the tool material
 Contact area of the tool
 Volume concentration of abrasive in water slurry
PROCESS PARAMETERS (5)

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MATERIAL REMOVAL MECHANISMS(7)
Three well-recognized major removal actions are summarized -
 Mechanical abrasion due to direct hammering of larger abrasive particles
on the workpiece surface.
 Microchipping resulted from the impact of free-moving abrasive
particles.
 Cavitation erosion from the abrasive slurry.
(a) hammering action (b) impact action (c) cavitation erosion
Fig 3.
https://www.int
echopen.com/,
Ultrasonic
Machining, by
Jingsi Wang,
2018

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 Ultrasonic Machining can be used to machine brittle, non-conductive
materials, hard and fragile materials.
 Heat is not generated in this machining process.
 It is burr less and distortion fewer processes.
 Operation is noiseless.
 Good surface finish and high accuracy can be achieved.
 Every material can be machined irrespective of its conductivity.
× Material Removal Rate is Low.
× Low penetration rate.
× The energy requirement for cutting is high.
× High Tool wear rate due to the movement of abrasive particles.
ADVANTAGES (3)
LIMITATIONS (3)

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APPLICATIONS (2)
 Used for machining hard and brittle
metallic alloys, semiconductors, glass,
ceramics, carbides etc.
 Machining very precise and intricate
shaped articles.
 Drilling the round holes of any shape.
 Grinding the brittle materials.
 Cutting threads in components made
of hard metals and alloys
 Used to cut industrial diamonds.
 Used for making dies. Fig 5. Machining of advanced
materials with enhanced USM,
DMG MORI, Finland
Fig 4. Complex ceramics products
with USM,
https://www.mfgnewsweb.com/

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CONCLUSION (6)
 USM is of particular interest for the machining of conductive, non -
conductive, brittle materials such as engineering ceramics.
 USM process is purely depends on the work material properties mainly
hardness and fracture toughness, tool properties, abrasives
properties and process settings.
 The machining of materials such as Glass, super alloys, tungsten
carbide,etc to their final dimensions by conventional methods is
extremely tough and generally not possible. To overcome such kinds of
problems, USM can be utilized.

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REFERENCES
[1] Non traditional manufacturing processes- Gary.F Benedict , National Library of
Australia.
[2] https://themechanicalengineering.com/ultrasonic-machining/
[3] https://learnmechanical.com/ultrasonic-machining/
[4] https://www.sciencedirect.com/science/article/pii/S2090447914001476 ,
Parametric optimization of ultrasonic machining process using gravitational search
and fireworks algorithms, by Debkalpa Goswami, Shankar Cakraborty,Department
of Production Engineering, Jadavpur University - 2014
[5] https://nptel.ac.in/content/storage2/courses/112105127/pdf/LM-36.pdf ,
Ultrasonic Machining
[6] https://www.slideshare.net/ultrasonic-machining-72691480
[7] https://www.intechopen.com/chapters/59978, Ultrasonic Machining: A Total
Mechanical Machining Technology Using Loose Abrasive Particles by Jingsi Wang,
2018

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