The Technical University of Munich (TUM) is working with its research reactor FRM II, Colibrium Additive, and the Friedrich-Alexander University Erlangen-Nuremberg (FAU) to develop 'light yet extremely resilient' aluminium components for aerospace.
Together, the partners are exploring the use of metal laser powder bed fusion to process such parts.
Laser powder bed fusion, while enabling the printing of high-precision parts and greater design freedom than conventional techniques, has historically struggled to process high-strength aluminium alloys, such as those required for load-bearing structural elements in aircraft and spacecraft. Typically, parts printed with these alloys tend to crack when cooled.
The project is pursuing a new approach in which 'special additives' in the metal powder react chemically during the printing process and form finely distributed ceramic particles in the submicrometre range. These particles are said to influence crystal growth in the material by promoting a fine-grained, uniform microstructure. By reducing the formation of cracks, the process is said to enable the industrial use of aluminium alloys previously considered virtually impossible to print. The partners say it leads to lower weight, higher load-bearing capacity and more sustainable production through material savings.
Colibirum Additive is contributing its additive manufacturing technology and expertise to the project and is working closely with TUM and FAU to develop the appropriate process parameters for the LPBF process. FAU analyses printed materials and their mechanical properties, in particular using microscopic methods. Researchers at FRM II are responsible for the comprehensive investigation and quality testing of the materials using neutron methods.
Several specialised methods are used at FRM II: Neutron diffraction allows phase distributions and internal stresses to be determined precisely, key parameters for assessing strength and stability. Neutron imaging (radiography and tomography) makes it possible to visualise even the finest cracks or pores deep inside the samples in a non-destructive manner. In general, the greater sensitivity of neutrons compared to X-rays is used to better understand the material's microstructure.
The project has been funded by the Federal Ministry of Education, Technology and Space (BMFTR) with a total of €1.17 million as part of the Action Plan for Research into the Universe and Matter (ErUM).
