​Although the exploitation of AM technologies continues to accelerate, a key barrier to adoption of AM is the need for in-process monitoring and process control [1, 2].
 
Equivalence-based and model-based certifications require reliable data set to validate complex multi-physics models. To move towards the certify-as-you-build scheme, industries call for sound in-situ process monitoring and quality control. 

The most promising non destructive technique (NDT) for complex geometry parts made by additive manufacturing appears to be x-ray radiography and computer tomography (CT). Both techniques are very well established NDT methods. But little is known about the defect detection limits in dense component manufactured by Selective Laser Melting. Here we present preliminary results to help understand the X-ray defect detection limits in Hastelloy X parts manufactured by SLM [1].

Many of the existing non destructive evaluation (NDE) standard procedures applied to conventionally wrought, forged, and molded metal components are generally applicable to parts made by AM. However, specific challenges must be addressed by newer AM-specific standardized NDE procedures. In addition, there is a recognized need to develop in-process monitoring techniques to inspect parts during the build process.