Additive Design and Manufacturing potentialities in Fraunhofer EMI will be presented. A study from the Amalia project (Additive Manufacturing of Metallic Auxetic Structures and Materials for Lightweight Armour 2022 – 2025) involving two main work fields of our working group, design optimization for additive manufacturing and material optimization during L-PBF process, will be shown.

Laser powder bed fusion (L-PBF) offers many possibilities not only in terms of component design freedom but also in in-situ modification of materials properties. L-PBF has the potential to create novel functionally graded microstructures (FGMi) with properties tailored to specific applications. As build material for the investigated sandwich structures with lattice core three steel alloys were investigated and their properties were empirically optimized for the use in the lattice structures.

An exploration of different modelling concepts of additive manufactured lattice structures under high-speed dynamic loading will be presented. To validate the different approaches, experimental investigations on the most promising lattice structures and steel (30CrMoNb5-2 low alloy steel) were performed. The structures are additive manufactured and their structural behaviour under high-speed dynamic loading is investigated and analysed using digital image correlation.

The experimental results show good agreement with the predicted optimized structural high-speed dynamic response, depending on the cell topology. This study shows that material properties of 30CrMoNb5-2 steel could be tailored during AM process. A functionally graded microstructure (FGMi) for this steel and application with a hardness range from approximately 380 to 510 HV10 could be achieved. Analysis based on EBSD (electron backscattering diffraction) could be successfully used to reveal micro and macro graduation regarding tempering state through the sample.