Project Details
Projekt
Qualification of suitable materials, microstructure formation processes, and characterization of DED-L manufactured components
Applicant
Professor Dr.-Ing. Arne Röttger
Subject Area
Materials in Sintering Processes and Generative Manufacturing Processes
Mechanical Properties of Metallic Materials and their Microstructural Origins
Mechanical Properties of Metallic Materials and their Microstructural Origins
Term
since 2025
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 512940050
The overall scientific goal of this subproject is to describe the microstructure formation process in the DED-L processing of cored wires made of tool steel. In addition to the description of the microstructure formation process from the melt and the solid state (alternating heat input) with homogeneous heat dissipation, the influence of unsteady heat dissipation as a result of DED-L-processing of complex geometry (topology-optimized design) on the microstructure formation process should be understood. A tool for hot forming with internal cavities is considered as an application example to use the collected findings for further technological applications. The starting point for the investigations is the topology-optimized structures, which are processed via DED-L. The samples produced are fundamentally examined with respect to the locally formed microstructure (diffraction experiments using X-rays and synchrotron radiation, SEM with the adapted methods EBSD, EDX), and the local properties (nanoindentation). The connection between the locally formed microstructure, the phase stability when manufacturing complex-shaped structures (unsteady heat dissipation = locally different microstructure formation), and the associated local properties should be investigated in detail. With the knowledge gained about the locally resulting properties, the model for topology optimization and the processing parameters can be adopted. The data necessary to map the local time-temperature curves are determined by measuring the temperatures and the melt pool geometry. They are incorporated into the simulations to map the microstructure formation process using the phase field and Calphad methods. Further investigations are concerned with developing a fundamental understanding of how to specifically influence the microstructures or properties near the surface by post-processing. It will also be examined whether re-melting close to the surface with subsequent hardening and tempering can achieve homogeneous microstructures and material properties over the surface of complex-shaped and DED-L-processed components.
DFG Programme
Research Units
