NDE for Additive Manufacturing

By means of additive manufacturing (AM) complex-shaped parts can be manufactured using a broad range of different materials. The latter can be supplied in the form of powder, wire, paste material, or even as foil. Various technologies are covered by the term “Additive Manufacturing" for example, direct energy deposition (DED), laser powder bed fusion (LPBF), fused filament fabrication (FFF), or binder jetting printing (BJP). In all varieties, parts are manufactured layer by layer which results in changed material properties compared to conventional manufacturing routes, for example, mechanical properties or fatigue life. To reach a conformal material deposition without defects such as lack of fusion, delamination or cracking, an optimal process window with well-chosen parameters (e.g., beam power, spot size, scanning speed) has to be identified. For nondestructive evaluation (NDE), different approaches can be used to classify AM manufactured parts regarding their defect structure and consequentially their performance: 1. Process optimization and understanding of defect formation in order to prevent defects 2. In situ measurements by a variety of integrated sensors and (IR) cameras for direct process observations 3. Post-processing NDE methods such as ultrasonic testing, X-ray, or computer tomography (CT) If the three approaches are simultaneously executed, a prediction of the effect of defects can be made for certain cases.