Design of additive manufactured reference block with disk reflectors for sensitivity calibration of ultrasonic angle beam probes

In this paper, a prototype of a reference block with disk reflectors for sensitivity calibration of ultrasonic testing system with angle beam probes was designed and produced. This paper aims to investigate the possibility for sensitivity calibration of ultrasonic angle beam probes with disk reflectors, with flat reference surfaces. The reference blocks with three artificially produced disk reflectors, located at angles of 45°, 60°, and 70°, were made by additive manufacturing technology direct metal laser sintering (DMLS), since DMLS has provided the possibility of producing components with complex inner geometries, which traditional processes could not produce. The exact size of the reference block is obtained by using CT scanning, and the equivalent reflector size (ERS) is estimated by the distance gain size (DGS) diagram and using DGS mode of the ultrasonic instrument by Pulse-Echo. The results are compared with each other and with both the nominal values and the exact size, obtained by CT scan.