FOR 5620:  Simulation-based design and production of load-optimised freeform components by laser metal deposition (DED-LB/M)

• Subject Area: Mechanical and Industrial Engineering ; Computer Science, Systems and Electrical Engineering ; Materials Science and Engineering ; Thermal Engineering/Process Engineering
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 512940050

The objective of the research group is to gain a deep understanding of the design and manufacturing of stress-optimized freeform components. The manufacturing process to be investigated is the robot-based laser metal deposition process (DED-LB/M) using wire as a feeder material, taking into account process-induced residual stresses and subsequent machining processes. The production of topology-optimized components, which require only a fraction of the weight of conventional parts, is the basic idea which also aims at resource-efficient manufacturing. Topology optimization results in stress-optimized complex structures that can no longer be produced or only with large effort using conventional manufacturing processes. The process chain to be investigated is characterized by the following aspects: 1. Maximum geometric flexibility is achieved through 6-axis robot-guided manufacturing combined with (filler) wire material delivery, allowing material deposition at any angle. To realize this, sophisticated path planning methods must be developed, and laser parameters and build strategies must be derived according to the complex weld seam orientations. Additionally, for high reproducibility, information about the melt pool geometry and the actual material deposition achieved must be monitored in real-time and a feedback loop for control has to be implemented. 2. The integration of mechanical machining processes into the process chain allows for post-treatment, such as functional and contact surface machining for assembly and subsequent use of the freeform components. 3. Laser-based surface treatment methods (laser polishing, local heat treatment) are to be integrated into the process to significantly reduce surface roughness and potentially influence the microstructure. Holistic planning and execution of manufacturing and post-processing enable faster production. 4. Consideration and optimization of material properties. Stress-optimized freeform components are a promising application field for additive manufacturing. In combination with precise temperature control through laser-based processes, there is also the possibility to adjust microstructural properties, and thus the strength properties of components according to a required profile. Initially, the materials to be used are the easily weldable, non-corrosive austenitic steel X2CrNiMo17-12-2 (material number 1.4404, AISI 316L), and a martensitically hardenable, also easily weldable LTT (low temperature transformation) alloy.

• DFG Programme: Research Units

Projects

• Characterization of Inhomogeneities Caused by Production within DED-LB/M Structures and Their Impact on Local Phase Stabilities and Mechanical Properties (Applicants Lentz, Jonathan ;  Weber, Sebastian )
• Coordination Funds (Applicant Ostendorf, Andreas )
• Manufacturing-taylored topology optimization for additive manufacturing (Applicant Junker, Philipp )
• Path planning and system structure for the combination of laser deposition welding and milling post-processing in a robot cell for the flexible production of large-volume topology-optimized components (Applicant Kuhlenkötter, Bernd )
• Process development for the manufacturing of complex components by DED-LB/M based on variable process head orientation (Applicant Ostendorf, Andreas )
• Qualification of suitable materials, microstructure formation processes, and characterization of DED-L manufactured components (Applicant Röttger, Arne )
• Real-time capable methods for control (Applicant Mönnigmann, Martin )
• Simulation-based process design for machining additively manufactured components (Applicant Wiederkehr, Petra )

• Spokesperson: Professor Dr.-Ing. Andreas Ostendorf