Research on Ultrasonic Imaging of Oblique Cracks with Angle Probe

Oblique crack is one of the common defects in industrial ultrasonic testing. The angle probe can detect oblique defects more efficiently. The path of the ultrasonic wave in the multi-layer medium can be calculated by the ray tracing technique. Then it can be used in synthetic aperture imaging algorithm for improving ultrasonic imaging resolution. In this paper, the new forward interpretation algorithm is used to image the internal oblique crack. The better result is shown in comparing with the traditional SAFT algorithm for straight probe.