Testing the similarity conditions in the CT measurement of additively manufactured lattice structures

Published

October 8, 2021

Author(s)

Maxwell R. Praniewicz, Massimiliano Ferrucci, Jason Fox, Christopher Saldana

Abstract

X-ray computed tomography (CT) enables the non-destructive measurement of hidden internal features that are inaccessible by tactile or optical coordinate measuring systems. This makes CT the technology of choice for inspecting complex components made by additive manufacturing (AM), lattice structures being a prime example. Uncertainty assessment in CT dimensional measurements is limited to the substitution method, which prescribes strict similarity conditions between the test object and a separate, calibrated reference object. The notoriously rough surfaces and form deviations in AM components present a challenge in terms of ensuring similarity with respect to the idealized reference object, particularly as these deviations pertain to changes in X-ray penetration lengths during CT measurement. Currently, though, there is no literature on how to quantify 'similarity' and to what extent these conditions can be stressed while ensuring that uncertainty in the CT measurement of AM parts can be correctly determined. In this study, we investigate the effect that varying degrees of dissimilarity in object shape and size have on the image quality of their tomographic reconstruction in the context of establishing a quantitative measure of similarity.

Proceedings Title

Proceedings of the Joint Special Interest Group meeting between euspen and ASPE Advancing Precision in Additive Manufacturing

Conference Dates

September 21-23, 2021

Conference Location

St. Gallen (Online), CH

Conference Title

Joint Special Interest Groupe meeting between euspen and ASPE, Advancing Precision in Additive Manufacturing

Pub Type

Conferences

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Citation

Praniewicz, M. , Ferrucci, M. , Fox, J. and Saldana, C. (2021), Testing the similarity conditions in the CT measurement of additively manufactured lattice structures, Proceedings of the Joint Special Interest Group meeting between euspen and ASPE Advancing Precision in Additive Manufacturing , St. Gallen (Online), CH, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=932806 (Accessed October 4, 2024)