Yet, it is necessary to provide critical flaw size and orientation for any part made by AM regardless of the part geometry, stress, and material properties. In addition to potentially new or unknown defect types in metal parts made by AM, finished AM parts also typically have greater ranges of porosity and lack of fusion, with defects distributed throughout the part, rendering sizing of relevant flaws difficult.
Therefore, instead of defining a critical crack for a part made by AM, it is probably better to validate NDE techniques that are known to not miss standard-sized flaws at a specified probability and confidence level.
Physical reference standards
Qualification and certification
 J. M. Waller, B. H. Parker, K. L. Hodges, E. R. Burke, J. L. Walker , Nondestructive Evaluation of Additive Manufacturing - State-of-the-Discipline Report – NASA - Nov 2014
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