NDT standards development
Project challenges
There are no Non-destructive Testing (NDT) standards covering the emerging manufacturing processes of Additive Manufacturing (AM)
Business challenge
Process Innovation
Sector
Aerospace
Technology or capability
Metrology & NDT
Project Challenges
Dr Ben Dutton from the MTC is leading this development: ISO TC261/ASTM F42 JG59 “Additive Manufacturing — Non-Destructive Testing and Evaluation — Standard Guideline for Defect Detection in Metallic Parts”
This project was via MTC members, BSI, ISO, ASTM.
There are no Non-destructive Testing (NDT) standards covering the emerging manufacturing processes of Additive Manufacturing (AM), either in-process or post-process, which:
- Are required to assess quality of final parts;
- Makes it difficult to certify manufactured parts;
- Impedes the part being put into service.
MTC's Solution
MTC identified typical flaw types in AM and generated a defect classification.
This defect classification was used to review relevant existing NDT standards for casting and welding within the International Standard Organisation (ISO).
A structure for NDT standards in AM was proposed, highlighting the area that requires validation/development of new standards, and the existing standards that can be copied across from welding and casting.
For defects that are not covered in existing NDT standards, potential NDT techniques were recommended.
Standard artefact designs for validation of NDT techniques were proposed.
It is not easy to generate standards in new and evolving areas, but I feel the project has made a great start in developing the standard which is registered as an ISO work item
Alex Price, Lead Programme Manager - BSI Group
The Outcome
- Post-build AM flaws were identified based on work from FP7 European AMAZE project. Potential flaws in powder bed fusion (PBF) and direct energy deposition (DED) were identified.
- A comprehensive review of current NDT standards for casting and welding was performed. The following defects were considered not being covered by such; therefore, require new standards: layer defects, cross layer defects, unconsolidated powder, trapped powder and inclusions.
- A structure to follow current and new standards was generated, indicating NDT technics potential to detect these AM unique defect types.
- Artefact designs for a generic star and à la carte geometries were recommended for NDT technique validation.
Benefits to the Client
- The creation of NDT standards for AM will give confidence in the quality of the components made through this process. This has significant impact for both manufacturer and end user.
- Members had a strong influence on the standard, which will be used in industry.
- MTC members, such as GE Power, have seen the value of this work and have agreed to continue to support as single client work, with particular interest on à la carte designs. In addition, MTC members are interested in utilizing the artefacts to collaborate in validating such artefacts.
- Breaking barriers to the acceptance of additively manufactured components and increasing market access.
- The improved standards will accelerate the growth of additive manufacturing in industry.
