Ultrasonic waves are sound waves which propagate
at a frequency, beyond the human ear to respond.
The vibrating tool oscillating at ultrasonic
frequency is used to remove the material from
work surface. Slurry of abrasive particles is
drawn in between tool and work surface. The tool
is pressed against the work piece with a small
load and is fed downwards continuously. The tool
never comes in contact with work piece. The
shape of tool is a mirror image of desired
The arrangement consists of an acoustic head having frequency generator
and magneto strictive transducer. It converts the mechanical motion into
high frequency vibrations and these vibrations are transmitted to the
tool. Tool should have high fatigue strength as it has to transfer
vibrations. The tool is made of ductile and rough material. It has a
shape of cavity to be produced in workpiece. The tool is made to vibrate
against the workpiece surface. Gravity type or spring loaded feed
mechanism is provided to the tool to apply working force. The slurry of
abrasive particles is maintained between the workpiece and the tool. The
tool imparts the necessary force on workpiece for cutting action. A gap
of the order of 0.02 to 0.1 mm is maintained between the tool and the
workpiece. The abrasive particles erode the workpiece to produce desired
shape. Counterweight is applied to provide feed mechanism and to apply
working force during machining.
Very little heat is produced in this process.
Extremely hard and brittle materials like ceramics, diamond, sapphire,
glass can be machined by this process.
This process is suitable for electrical conductive as well as non
conductive materials. Higher surface finish can be obtained.
The tool is commonly made of soft steels and nickel.
Ultrasonic waves can be generated by piezoelectric or magneto strictive
A surface finish of 0.02 to 0.8 microns can be attained by this process.
Holes, as small as 0.1 mm can be drilled by this method.