Ultrasonic welding uses high frequency ultrasonic vibrations to generate frictional heat and join materials under pressure. The vibrations are generated between 15-60 kHz by a transducer and transmitted to the parts through a sonotrode. Welding times are typically less than 3 seconds. Dissimilar materials and thin materials can be welded with minimal surface deformation and heat affected zones.

5. In ultrasonic welding, frictional heat produced by
the ultrasonic waves and force is used for the joining
process. Ultrasonic waves(15 to 60 kHz) are transferred
to the material under pressure with a sonometer.
Welding times are lower than 3 s .The welding can
proceed with or without the application of external
heat.

7. Spot Welding.
Line Welding.
- Linear Sonotrode
Continuous Seam Welding.
- Roller Sonotrode
Spot Welding.

9. Produce high frequency ultrasonic vibrations.
Converts the electrical signal in to a mechanical vibration.
Modifies the amplitude of vibrations.
Applies the mechanical vibrations to the parts to be welded.

14. The parts are placed between a fixed shaped nest(anvil) and
a sonotrode (horn) connected to a transducer, and a 20kHz
low – amplitude acoustic vibration is emitted.
Common frequencies used in ultrasonic welding of thermos
plastics are 15kHz, 20kHz, 30kHz, 35kHz, 40kHz and 70kHz.
The ultrasonic energy melts the point between the parts
creating a joint.

15. A static clamping force is
applied perpendicular to
the interface between the
work pieces.
The contacting sonotrode
oscillates parallel to the
interface.
Combined effect of static
and oscillating force
produces deformation
which promotes welding.

17. Heat affected zone is minimized.
Very thin materials can be welded.
Surface deformation is minimum.
Welding of glass is also possible.
No defects due to gases, arc and filler metal.
Pressure uses are lower, and welding time are shorter.
Dissimilar materials can be joined.
Welding can be made through some surface coating.

18. Restricted to join thin materials.
Competitively not economical.
Materials being welded may tend to the tip(sonotrode) and anvil.

19. Manufacturing of toys.
Joining of electrical and electronic components.
Welding aluminium wire and sheet.
Mobiles, sports shoes, laminations, cars, etc.
Packing, medical industries, computers.