Accuracy of fast CT dimensional measurements: a case study on an additively manufactured metal part

X-ray computed tomography (CT) has gained significant traction across various industrial sectors as a dimensional metrology tool, providing holistic characterizations and enhancing the development of new industrial products. However, despite its potential, dimensional CT scanning can be relatively slow, often hindering routine adoption for many applications. This study investigates strategies to optimize CT measurement speed while maintaining measurement accuracy through an experimental approach that includes fast CT scanning configurations, fast CT simulation-based technique, and the adoption of an iterative reconstruction method. Using an additively manufactured metal part as a case study, the research evaluates measurement deviations across different geometrical features. Results indicate promising performance of fast CT scanning for dimensional measurements, as well as the feasibility of using a digital representation to support a fast CT measurement process. Additionally, the constraint split Bregman iterative reconstruction method combined with total variation demonstrates significant improvements over traditional Feldkamp, Davis, Kress reconstruction, achieving up to 90% accuracy enhancement for external features with limited X-ray projections. These findings provide valuable insights for implementing efficient CT metrology in contemporary industry where both speed and accuracy are essential.