Design, calculation and manufacturing of filigree structures with laser beam melting

• Applicants: Dr.-Ing. Bernhard Müller; Professor Dr.-Ing. Ralph Stelzer
• Subject Area: Engineering Design, Machine Elements, Product Development ; Production Automation and Assembly Technology
• Term: from 2016 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 289647464

Additve manufacturing processes such as laser beam melting offer the possibility of cost-efficiently manufacturing complex geometries from metallic materials. While the process chain established for the production of solid components already reliably delivers good results, filigree lattice structures can show significant geometric andqualitative deviations. These discrepancies have so far hindered the productive use of additively manufactured lattices in load-bearing components. In the initial research project, the applicants have developed an alternative process chain which makes it possible to integrate fine lattice structures directly into components in the CADenvironment and then produce them dimensionally accurate, using appropriate exposure strategies. For this purpose, software components such as a CAD plug-in and slicing algorithms as well as manufacturing fundamentals like exposure strategies and laserparameters for the material Ti6Al4V have been developed. However, the geometric and qualitative advantages are limited to periodic lattices and require a considerable manual effort for qualification. These deficits are to be eliminated in the proposed project. The aim is to investigate the dependency of the quality criteria, typically relevant for structural components, on the geometric and technological specifications more closely than it was possible in the initial project. In this course, an experimental plan is to be developed by which the number of necessary individual experiments for the adaption ofspecific manufacturing scenarios can be reduced. By a separate consideration and improvement of the mechanically decisive area at the transition between the individual struts and the nodes, the mechanical performance of the lattice structures shall be further increased. On the software side, an integration of non-regular lattice structures is aimed at, as this allows an ideal adaptation of the component to the individual application and load case. The focus continues to be on self-similar and also conformal irregular lattices, generated from simulation results. Aspects of manufacturing issues tobe investigated focus on the evolution of the developed exposure strategies. On the one hand, it is a matter of further improving the lattice quality, in particular an increase of the surface quality and a reduction of the powder adhesion to the struts by developing andtesting adapted scan strategies and parameters. On the other hand it is a matter of a concept to reduce the effort required to qualify the workflow for new production scenarios.

• DFG Programme: Research Grants