Ultrasonic phased array testing to quantify material texture for metal additive manufacturing

Metal additive manufacturing (AM) processes result in complex microstructures, porosity, material texture, and residual stresses. These properties may vary throughout AM parts. Ultrasonic nondestructive evaluation (NDE) is essential for understanding the processes leading to these variations. However, the use of single-element transducers to scan AM parts with complex geometries can be challenging. Such measurements may require multiple scans to level a surface or excite various wave types within a part. On the contrary, phased array ultrasonic transducers (PAUTs) can be much more efficient for these studies. In this presentation, custom AM sample designs are discussed which allow multiple ultrasonic wave speeds to be measured using a PAUT. The manufactured samples were assessed with the sectorial scan feature of the PAUT to scan multiple positions and directions quickly without moving the probe. Data from these scans were then used to estimate material wave speeds, material texture, and residual stress along multiple directions within the samples. The results from these scans were also compared with experiments that used single-element ultrasonic transducers. This presentation will describe the sample designs, the experiments, and the analysis in order to highlight the usefulness of PAUTs for scanning AM parts.