Laser-based powder bed fusion (LPBF) of steel elements for civil engineering - fundamentals of design and mechanical strength
- DFG-TRR277-A06
- Project period: 2020-2024
- Projekt partners: Institut für Werkzeugmaschinen und Betriebswissenschaften (iwb), TUM
The aim of this project is to identify and evaluate the key factors influencing the production of safe and durable steel components using laser-based powder bed fusion (LPBF). In particular, the relationship and dependencies between LPBF process, post-treatment and geometry with microstructure and mechanical properties are investigated and modeled.
Motivation
LPBF is one of the key technologies among metallic additive manufacturing processes. It makes it possible to manufacture highly complex structures very precisely directly from digital design data. This has led to the process already being used in series production in many industrial sectors today. Thanks to its properties, LPBF also offers great potential for the construction industry: Due to the high degree of design freedom, the direct linking of the real world with the digital world, and the cost-effectiveness at batch size one, additive manufacturing could revolutionize the construction industry. LPBF is particularly suitable for the production of elements for steel construction.
Project Aim
So far, reliable prediction and reproducibility of the mechanical properties of LPBF-manufactured steel elements is not yet possible. In order to be able to establish the process in the construction industry, it is necessary to develop a methodology for the process-reliable production of durable steel structural elements using LPBF.
Procedure
First, in-process thermography will be used to investigate the influence of process parameters on LPBF cooling rates. In addition, the influences of geometric aspects and post-treatments on the mechanical and metallurgical properties of the components will be investigated. In the further course of the project, shape-optimized steel components and large components will be manufactured with the aid of the investigated relationships and tested under real operating conditions. Finally, a methodology will be derived that enables the economical and process-safe use of LPBF in the construction industry.
Results
In this research project, the relationships between process parameters, cooling rates, post-treatment and geometric aspects with the static and cyclic mechanical properties of LPBF-manufactured steel components will be determined. Based on these findings, design recommendations will then be derived to manufacture steel components with reproducible and defined mechanical properties using LPBF.
Tensegrity knots for the deutsche Museum
In the course of an industrial project with the Deutsches Museum in Munich, a tensegrity tower is to be developed and manufactured. For this purpose, additively manufactured connecting nodes are produced by means of shape optimization.
The shape optimization was carried out by the project partner C02 of TRR277.
