Project description
This project contributes to the development of new compositions and processing routes for Compositionally Complex Alloys (CCA) with improved properties that make them attractive for future applications. In particular, this work aims to assess the suitability of particle reinforced CCA processed by Laser Powder Bed Fusion (L-PBF) for applications at low temperatures and in exposure to hydrogen.
The MarioCCArt project corresponds to the second funding period of the Priority Program SPP2006 of the German Research Foundation, DFG, and is carried out in collaboration with IWT Bremen (V. Uhlenwinkel) and MPIE Düsseldorf (G. Dehm). In the first phase of the project, atomization and additive manufacturing of particle-reinforced High Entropy Alloy (HEA) was proved to be a successful manufacturing technology for these steels. In this second phase, the focus lies on the understanding of mechanical behavior, microstructure development and deformation mechanisms of the additively manufactured HEA. The main project innovation deals with the reinforcement of the HEA matrix with second-phase particles of dissimilar melting points and sizes, which are introduced either through 1) the in-situ approach, where a forced precipitation of nitrides during atomization in nitrogen is pursued; and 2) the ex-situ approach, where commercially available particles are blended to the metal matrix before L-PBF processing. The effect that the processing route has on the dispersion of the matrix, the possible reaction with the metal matrix, i.e. whether the particles melt or whether in the contrary they retain their initial size and composition, together with the influence on the microstructure and mechanical performance of the steel is addressed here .
UniBwM’s role in the project will be to lead the mechanical performance inspection, i.e. strength, fracture toughness and fatigue resistance of the steels in correlation to the microstructure at room and cryogenic temperatures as well as under pressurized hydrogen conditions.
