Effect of local residual stress distributions on the crack propagation of microstructurally graded 316L samples build via PBF-LB/M

Laser-based powder bed fusion of metals (PBF-LB/M) is a manufacturing technique suited to manufacture application-oriented components. By varying the process parameters, it is possible to achieve a defined sharp gradient in the microstructure and crystallographic texture resulting in an interface within the component, which influences crack propagation. When investigating the crack growth across the interface, in addition to the microstructure, the residual stress distribution around cracks and the interface must also be considered. For this means local residual stress distributions in microstructurally graded 316L compact tension (CT) samples with a fine-grained, less textured region adjacent to a coarse-grained, strongly textured region are mapped around cracks growing up to or across the interface using high energy synchrotron X-ray diffraction. To confine the gained information to the bulk of the samples a conical slit system is used, restricting the gauge volume to the core of the flat CT sample while still enabling the analysis of multiple hkl-planes. The measurement strategy is adapted to enable the evaluation of the strongly textured and coarse-grained region. In this contribution, first results on this research topic are presented and discussed.