Sustainable air kisses Researchers rely on 3D printing for green aviation and aerospace

The "ReFuelEU Aviation" regulation aims to reduce aviation CO₂ emissions by 60 percent by 2050 (compared to 1990). Additive manufacturing could help achieve this goal...

In addition to the "ReFuelEU Aviation" regulation, a comprehensive EU Space Law (EUSL) is also being added, as noted by researchers from the Fraunhofer Institute for Laser Technology (ILT) in Aachen. This law sets out rules for sustainability in the space industry of the future. How can aerospace be made greener in light of these regulations? This is also questioned by Luke Schüller, a research associate at Fraunhofer ILT, in a specialist article. He can immediately provide an answer: "Strict political climate protection requirements can be implemented with lightweight construction, 3D printing, and new high-performance materials." A key role is played by the LPBF process (Laser Powder Bed Fusion), in which metal powder is fused layer by layer using a laser beam to create 3D components. This method allows for the production of complex and high-strength components that are not only lighter but also more resilient than components manufactured using conventional methods—important characteristics for the aviation of tomorrow.

With special powder into the hydrogen future

The ILT is therefore working on corresponding developments within the framework of the research initiative "TIRIKA" (Technologies and Innovations for Resource-Conserving, Climate-Friendly Aviation) of the Federal Ministry for Economic Affairs and Climate Action. The focus is on the use of hydrogen as an emission-free energy carrier for aviation. The researchers have already developed special powders with material manufacturers that meet the high demands of the aviation industry for hydrogen propulsion. The experts have developed LPBF processes for commercial materials and have finally validated them through various testing procedures in collaboration with partners. Through targeted process adjustments in the LPBF process, a relative component density of over 99.5 percent and a high build rate of over 100 cm³/h can be achieved, emphasizes Schüller. The aluminum alloys are not only light and strong but also resistant to contact with hydrogen, which can lead to embrittlement and material fatigue at high temperatures and pressures. This makes them ideal candidates for use in future emissions-free hydrogen engines. Additionally, the new powders, due to the uniform laser melting process, allow for the production of complex geometries and functional structures that are not feasible with casting or forging.

This is how 0.4-millimeter particles are detected electronically

During the additive manufacturing process, precise sensors detect artifacts as small as 0.4 millimeters directly in the powder bed as well as in the melting process. This information allows time-consuming downstream inspections to be minimized and production efficiency to be significantly increased. Advanced processes, however, influence not only the quality and efficiency of production but also its environmental impact. The ILT relies on Life Cycle Assessment (LCA) when evaluating the environmental friendliness of additive manufacturing processes. This assessment considers the entire life cycle of a component, spanning from raw material procurement through manufacturing to recycling. Life Cycle Assessment is regarded as an indispensable tool for evaluating the environmental impacts of products throughout their entire life cycle and for identifying sustainable alternatives. To effectively implement this comprehensive process, it is crucial to obtain high-quality and meaningful data early in the digital value chain.

A complex process scores in three ways

Three important arguments support this initially very laborious path! First, data enables a faster and more efficient design of start-up processes for new products. Second, they support the assessment of quality, cost, energy, and resource consumption in the production cycle. And third, they contribute to greater transparency in the processes and thus to the optimization of the entire manufacturing chain, as the project partners enumerate. The results of the LCA analyses showed that despite the comparatively high energy consumption during the LPBF process, the ecological footprint of additive manufacturing is significantly smaller than that of conventional production methods. 3D printing is therefore particularly suitable for the repair of components because it minimizes material losses and conserves resources.