Final answer:
In ultrasonic welding, one complete reflection of an ultrasonic beam is referred to as an 'echo'. Other terms like 'pulse wave' describe a sudden disturbance with only a few waves generated, while 'reflection' generally refers to the direction change a wave undergoes upon bouncing off a barrier.
Step-by-step explanation:
In ultrasonic welding, one complete reflection of an ultrasonic beam is known as an Echo. This occurs when ultrasonic waves, emitted from a transducer due to the piezoelectric effect, interact with tissue or other media. Upon striking these media, the waves are reflected back to the transducer, resulting in an echo.
A pulse wave, on the other hand, is a sudden disturbance with only one wave or a few waves generated. Furthermore, a reflection of a wave usually involves a change in the direction of a wave when it bounces off a barrier.
Tuning forks normally create what's termed as a 'periodic wave', but this is not relevant to ultrasonic welding or the main question.
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