Development of an experimental test setup for in situ strain evaluation during selective laser melting

Selective Laser Melting (SLM) is an Additive Manufacturing (AM) process which still underlies a lack of profound process understanding. This becomes obvious when deformation and crack formation can be observed in SLM parts due to residual stresses. Controlling residual stresses is therefore an important topic of recent research in AM of metals. In order to minimize residual stresses further knowledge considering their cause and physical correlations of process parameters needs to be generated. In this paper an approach of measuring strains layer by layer during the SLM process by means of in situ X-ray diffraction is presented. For this purpose an experimental test setup is being constructed at the Technische Universität Berlin. The system requirements and operating principles are discussed in this paper. Furthermore, details of the current progress of the construction are highlighted.