13. WORKING OF SONAR
SONAR works using ultrasonic waves. A transmitter and
receiver are used in SONAR techniques. The whole device has
been loaded into the ship. Ultrasonic waves or ultrasound are
generated by the transmitter. These waves travel across water.
Waves pass through water and hit objects submerged or on
the seabed. These waves are reflected by objects or the
seabed after they strike. As a result, the receiver collects these
waves. The ultrasonic waves are then converted into electrical
signals, which are studied to determine underwater
conditions and obstacles.
16. Ultrasonic welding
• Ultrasonic welding is a solid-state welding process in which
joining of materials (metals and plastics) occur without
melting. In ultrasonic welding, high-frequency mechanical
vibrations are transferred to the parts to be joined, which
cause sliding one part over another. The joining occurs as a
result of heat generated by friction and severe plastic
deformation. Ultrasonic welding is the fastest welding
technique with a weld time of ranges from 0.1 to 1 s.
