A CT--CMM benchmark dataset for dimensional validation of internal cavities in LPBF titanium and inconel artefacts

The CT-CMM benchmark data sets contain cone-beam X-ray CT data for additively manufactured metal artefacts with internal hourglass cavities. The primary benchmark includes Ti-6Al-4V and Inconel 625 artefacts measured in rough and chemically milled states. Each primary case is intended to link raw CT projections, reconstructed volumes, CT-derived surface segmentations, nominal CAD, thickness measurements via CMM point clouds, surface roughness measurement, alignment transforms, and derived surface/thickness deviation labels. In addition, high precision 3D scans are included for the chemically milled states of the artefact in order to provide an additional validation point for measurements. The data are intended for evaluating CT reconstruction, segmentation, surface determination, registration, and dimensional metrology workflows against a tactile CMM reference for inaccessible internal geometry. An auxiliary Chinook rotor-hub blade CT data set is included as an additional high-attenuation reconstruction reference, but it is not part of the CMM thickness benchmark. All data were collected on a Comet Yxlon FF35 cone-beam CT system over a 360 degree scan range. The Ti-6Al-4V and Inconel 625 artefacts were scanned with a 20 degree inclination angle, while the Chinook blade was scanned vertically (0 degree inclination). The Ti-6Al-4V and Inconel 625 artefacts were reconstructed with CERA using a single-material beam-hardening correction; surface-determination products were generated in Dragonfly (Fast Surface Finding, FSF) at FSF 0.2, 0.4 and 0.6 for Ti-6Al-4V and at FSF 0.6 plus a deep-learning route for Inconel 625. For the Chinook blade, CERA / LDA reference data and FSF 0.6 surfaces are provided where available. The dataset is published as part of TomoBank and resides permanently at Argonne National Laboratory, find additional details at TomoBank - CT Metrology https://tomobank.readthedocs.io/en/latest/source/data/docs.data.metrology.html#data-sets