Micro-Computed-Tomography Qualification of Printed Photopolymers

X-ray micro-computed tomography can reveal pores, inclusions, channels and internal geometric departures in printed photopolymers without sectioning the part. Its three-dimensional output is attractive for qualification, but a reconstructed volume is not a direct map of physical truth. Detectability depends on attenuation contrast, source spot, magnification, detector sampling, acquisition noise, reconstruction, artefact correction and the orientation and morphology of each indication. Quantitative porosity additionally depends on the segmentation rule, region of interest and treatment of partial-volume voxels.

This review defines a bounded qualification architecture for micro-CT examination of vat-photopolymerised and related printed photopolymers. It distinguishes nominal voxel size from spatial resolution, visible indication from validated defect, and repeatable segmentation from metrologically supported volume fraction. It develops controls for specimen geometry, scan setup, reconstruction, threshold selection, detectability experiments and uncertainty. Porosity analysis, dimensional comparison and defect localisation are treated as different measurement tasks that require separate validation. The central conclusion is that micro-CT supports qualification only when the complete measurement chain and its task-specific detection limit are demonstrated on representative material and geometry. The review does not select among non-destructive evaluation modalities and does not prescribe universal acceptance criteria.