Additive manufacturing (AM) offers new possibilities in manufacturing and designing products. The aerospace and automotive industries are main drivers because of the possibility of manufacturing lighter structures that reduce weight and save fuel. During the manufacturing process, different discontinuities or defects can occur, depending on the applied AM technology. To ensure constant manufacturing quality of the parts, regular sampling or 100% inspection using nondestructive testing (NDT) techniques is required. In particular, computed tomography (CT) allows a contactless investigation and includes different analysis techniques (such as nominal-actual comparison, porosity analysis, wall thickness analysis, and so on). As an advantage to other techniques, it can even evaluate parts with a very complex inner structure. The following article gives an overview of the AM technology, particularly selective laser melting (SLM), and commonly occurring discontinuities and their possible causes. Furthermore, the functionality of a CT system and the reconstruction process will be explained. In Part 2, we will show a few examples of AM parts under different types of analysis. The limits of this NDT technique will be discussed as well.
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