Overview
CEN ISO/ASTM/TR 52906:2022 - Additive manufacturing - Non-destructive testing - Intentionally seeding flaws in metallic parts - is a technical report and best-practice guide for creating reproducible, nondestructively detectable flaw replicas in metal parts produced by powder-bed fusion (PBF) and directed energy deposition (DED). Endorsed by CEN and published jointly by ISO/ASTM, the document describes practical approaches to mimic real additive-manufacturing (AM) defects for NDT validation, training, and performance assessment.
Key topics
- Seeding categories: three primary approaches are defined:
- CAD seeding (design-introduced flaws)
- Build-parameter manipulation (process-induced flaws)
- Subtractive (post-production) methods (mechanical, EDM, laser drilling)
- Applicable AM processes and heat sources: guidance covers PBF and DED workflows and considers laser beam (LB), electron beam (EB) and arc processes (AP).
- Flaw types discussed: pores/voids, entrapped unsintered powder, high-density inclusions, surface-connected flaws, and replicas introduced by machining or energy-based drilling.
- Material and post-processing contexts: seeding methods applicable to as-deposited, post-heat-treated, and HIP-processed materials; also covers flaws made detectable by post-processing.
- Limitations and exclusions: geometrical measurement and dimensional tolerancing are out of scope; intimate “kissing bonds” (very close-contact disbonds) currently have no proven controlled seeding method and are excluded.
- Safety and IP: the report warns users to establish appropriate safety practices and notes potential patent implications.
Applications
- NDT method development and validation: create controlled flaw replicas to verify performance of ultrasound, X-ray/CT, eddy-current and other NDT techniques for AM metallic parts.
- Calibration and qualification: develop reference artifacts for inspector qualification, procedure validation, and acceptance testing.
- Training and education: produce representative defects for operator training and image interpretation.
- R&D and process optimization: help AM process engineers study defect formation mechanisms by intentionally inducing known defects via CAD or parameter changes.
- Industry sectors: particularly relevant to aerospace, medical devices, automotive, and any safety-critical component manufacturers using AM and requiring robust NDT.
Who should use this standard
- NDT engineers and inspectors
- Additive manufacturing process engineers
- Quality managers and certification bodies
- Research laboratories and OEMs developing AM parts and inspection protocols
Related standards
- ISO/ASTM 52900 - AM terminology
- ISO/ASTM TR 52905 - complementary AM NDT guidance (referenced)
- ISO 17296-2 - AM process descriptions
- ASTM B243, ASTM E7, ASTM E1316 - metallurgy and NDT terminology referenced in the report
Keywords: additive manufacturing, non-destructive testing, NDT, flaw seeding, PBF, DED, metallic parts, CAD seeding, build parameter manipulation, seeded replicas.