TRR277 A06 – Laser Powder Bed Fusion (LPBF) of Steel Ele-ments for Construction – Basics of Design and Mechanical Resilience

This project aims at the identification and evaluation of the significant factors influencing the production of resilient and durable steel components by laser-based powder bed fusion (LPBF). In particular, the relationship and dependencies between the LPBF process, post-treatment and geometry with the microstructure and mechanical properties are investigated and modeled.

Motivation

LPBF is one of the key technologies among metallic additive manufacturing processes. It enables highly complex structures to be manufactured very precisely directly from a digital design model. As a result, LPBF is already being used in series production in various industrial sectors. Due to its characteristics, LPBF also offers a high potential for the construction industry: Owing to the high degree of design freedom, the direct link between the real and digital world, as well as the economic efficiency at batch size one, additive manufacturing could revolutionize the construction industry. Hereby, the LPBF is particularly suitable for the production of elements for steel construction.

Objective

At present, a precise prediction or reproducible achievement of defined mechanical properties of LPBF-manufactured steel elements is not possible. To establish the application of LPBF in the construction industry, it is necessary to develop a methodology for the reliable production of durable steel structural elements by using LPBF.

Approach

Initially, the influence of process parameters on the cooling rates at LPBF is analyzed using in-process thermography. Besides, the influence of geometric aspects and post-treatments on the mechanical and metallurgical properties of the components will be examined. In the further course of the project, shape-optimized steel construction elements and large components will be designed using the determined interrelations and then produced. Subsequently, the elements will be tested under real operating conditions. Finally, a methodology is to be derived, which enables the economic and process-safe use of LPBF in the construction industry.

 

In-process thermography in LPBF

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 are determined. Based on these findings, design recommendations will be derived to manufacture steel components with reproducible and defined mechanical properties using LPBF.

Acknowledgment

The German Research Foundation (DFG) funds this project as part of the SFB/ TRR 277 – Additive Manufacturing in Construction – The Challenge of Large Scale (Projekt number 414265976).
We would like to express our sincere gratitude for this.

Project duration 01.01.2020 - 31.12.2023
Project partner
Chair of Metal Structures (TUM)
Funding German Research Foundation (DFG)