Nondestructive Characterization of Laser Powder Bed Fusion Components Using High-Frequency Phased Array Ultrasonic Testing

The use of metal additive manufacturing (AM) technologies is growing rapidly in many industries owing to their ability to produce complex designs, to light-weight critical components, and to consolidate assemblies. Laser powder bed fusion (LPBF) is a metal AM technology that offers finer feature resolution when compared with other metal AM technologies, with ongoing challenges in controlling the process to guarantee defect-free parts. Manufacturing of end-use products via LPBF with a high degree of internal feature design complexity results in an increased demand for demonstrating the performance of various nondestructive evaluation (NDE) tools. In this work, the use of high-frequency (50 MHz) phased array ultrasonic testing (PAUT) for the nondestructive evaluation of a cubic AlSi10Mg sample manufactured by the LPBF process is demonstrated. Artificial internal features with various sizes and shapes are implanted into this sample. The sample is tested offline by high-frequency PAUT from different directions and the position and shape of defects are evaluated. The sample is then subjected to X-ray computed tomography (XCT) and the results are compared with those obtained by ultrasonic testing. Very good agreement is observed between PAUT and XCT results and defects with dimensions as small as 0.75 mm are successfully identified.