[1B2] Automated laser-induced phased arrays for the rapid ultrasonic inspection of AM components
G Davis, P Kamintzis, P Lukacs, D Pieris and T Stratoudaki
University of Strathclyde, UK
Laser-induced phased array (LIPA) is a novel ultrasonic array approach that can perform fast and efficient remote ultrasonic imaging. Since LIPAs operate based on the principles of laser ultrasonics (LU), they can be deployed in extreme environments, such as additive manufacturing and welding, and in places of restricted access, such as nuclear reactors. LIPAs are synthesised in post-processing by acquiring ultrasonic data: a signal is captured for each combination of generation and detection laser positions by scanning the generation and detection laser. It is a non-destructive, remote and couplant-free method. This study demonstrates the potential of LIPAs for the inspection of metallic components by introducing an automated approach to ultrasonic data acquisition where the synthesised array elements are adapted, on the fly, to the demands of the inspected structure, such as the geometry, material and defects encountered. The advantage is a significant reduction in data volume and acquisition time, making the technique suitable for in-process inspection. This selective matrix capture (SMC) data acquisition method is a two-stage method, where the first stage uses a few array elements to identify the presence and location of defects, which is then fed in to the second stage to optimise the new element locations tailored for best defect characterisation, hence achieving faster inspection times and lower data volume without compromising image quality. We present how the SMC can be automated for the adaptation of LIPA during the first stage of SMC on a metallic sample. This is achieved by parallel post-processing of ultrasonic images generated using the total focusing method (TFM) algorithm and observing the noise distribution and the intensity peaks in the ultrasonic images while the data acquisition is being performed.
