Techniques for high-fidelity X-ray micro-tomography of additively manufactured metal components

• Published in: Nondestructive testing and evaluation Vol. 35; no. 3; pp. 241 - 251
• Main Authors: Kingston, A.M., Yang, Q., Grewar, M.G., Delgado-Friedrichs, O., Myers, G.R., Latham, S.J., Sheppard, A.P.
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 02.07.2020; Taylor & Francis Ltd
• Subjects: Accuracy; Additive manufacturing; Critical components; Image enhancement; Nondestructive testing; Photon beams; Safety critical; Scanning trajectories; X ray imagery; X ray microtomography; X-ray beam-hardening; X-ray metal artefacts; X-ray scatter; X-ray scattering
• ISSN: 1058-9759; 1477-2671
• DOI: 10.1080/10589759.2020.1778684

Additive manufacturing is revolutionising the production of complex-shaped components and finding widespread application in the industries where production volumes are low and part geometries are complex. High-fidelity 3D imaging of additively manufactured metal parts, as the most effective nondestructive evaluation method, is crucial to maintaining the quality of safety-critical components during manufacturing. However, 3D X-ray imaging of large metallic parts is complicated by strong, nonlinear interactions between the sample and the X-ray beam; phenomena such as beam hardening, photon starvation and X-ray scatter are difficult to account for and cause artefacts in the computed 3D tomographic volume. These artefacts can obscure real defects and cause severe inaccuracies in analysis and evaluation. Here we present several techniques developed in the CTLab at the Australian National University that enhance the micro-tomography instruments' ability to image large, complex metallic components.