Ultrasonic phased array is a combination of ultrasonic probe chips. A plurality of piezoelectric wafers are arranged according to a certain regular distribution, and then each wafer is excited for a predetermined delay time. The ultrasonic waves emitted by all wafers form a complete wavefront, which can effectively control the shape and direction of the emitted ultrasonic beam (wavefront) and realize the scanning, deflection and focusing of the ultrasonic beam. Compared with single probe or multi-probe system, it can better determine the shape, size and direction of discontinuity.

Ultrasonic phased array detection technology uses multi-array transducers with different shapes to generate and receive ultrasonic beams. By controlling the different delay time of transmitting (or receiving) pulses of each array element in the transducer array, the phase relationship of sound waves when they arrive at (or come from) a certain point in the object can be changed, so that the focus and beam direction can be changed, and the scanning, deflection and focusing of ultrasonic beams can be realized. Then the combination of mechanical scanning and electronic scanning is used to realize image imaging.

Usually, a one-dimensional linear array probe is used. Piezoelectric wafers are arranged in a straight line, and the focused sound field is flaky, which can obtain two-dimensional images of defects and is widely used in industry.