NDT: Ultrasonics

The phased array ultrasonic inspection (PA-UT) is a non-destructive testing method used for the detection of defects in materials, such composites and metals.

Conventional inspection system consists of a single ultrasonic piezoelectric transducer operating as transmitter and receiver (for UT reflection mode). The piezoelectric generates an ultrasonic pulse which propagates through the material and reflecting at discontinuity positions (like cracks, debondings) or at bottom face of the part.

The reflected pulse is registered and the position in thickness is obtained according to the speed of the ultrasonic signal in the media and travelled time.

Ultrasonics Phased Array (PA-UT) is based in the use of multi-element transducer, individually excited, and including if required different amplitudes and delays generating a wave front in the desired direction. Similarly, the receiver combines the signals of the elements generating a single representation of the reflected pulses.