According to Jan Haubrich, Project Leader at the DLR Institute of Materials Research, "New manufacturing processes are the key to increased performance, improved cost-effectiveness and pave the way for reusable launcher technologies." To achieve this, interdisciplinary teams from several DLR institutes are collaborating on the 3D-LoCoS project. Their goal is to amplify the applications of the 'Laser Powder Bed Fusion' (LPBF) additive manufacturing process, which is adept at creating particularly intricate structures.

One of the project's highlights is a combustion chamber tailored for the LPBF manufacturing process. "We have designed and developed a combustion chamber with a special regenerative cooling concept specifically for the additive LPBF manufacturing process," notes Dmitry Suslov from the DLR Institute of Space Propulsion. The combustion chamber's material comprises a blend of copper, chromium, and zirconium, rendering it both thermally conductive and heat-resistant.

This innovation was tested on the P8 research and technology test stand in Lampoldshausen. Here, both the design and the manufacturing process of the 3D-printed combustion chamber, capable of delivering 25 kilonewtons of thrust, passed with flying colors. After conducting six hot-fire tests, Suslov shared, "With six hot-fire tests, we were able to show the great potential of this new fabrication method and the functionality of the 3D-printed combustion chamber. Now we want to quickly introduce this technology into industrial application." The trials confirmed that additive manufacturing provides ample opportunities in engine component design and construction. Artificial intelligence was harnessed throughout the project, from designing the chamber to executing tests.

However, Jan Haubrich also highlighted the youth of this technology, pointing out that, "Additive manufacturing processes enable an entirely different way of producing components and are a fairly young technology compared to most other processing methods." This method can rapidly and economically print intricate designs. But materials generated through additive manufacturing exhibit different behaviors compared to traditionally processed materials, which calls for more rigorous tests and technological progression. The team plans to further develop the copper combustion chamber into a flight-ready hardware utilizing AI. Collaborative endeavors are also on the horizon to enhance technology transfer to the industry.

Lastly, the design and application of 3D printing in the combustion chamber's production have set new standards. The LPBF process, for instance, introduces novel demands impacting factors like gas impermeability, geometric precision, and surface roughness that are vital for the design. Therefore, the research team meticulously assessed the feasibility of 3D printing the novel combustion chamber design. Successful material tests and prototypes validated the LPBF procedure and manufacturing strategy. This innovative method allowed the combustion chamber to be constructed as a singular unit, requiring a special fabrication system to produce a chamber exceeding 60 centimeters in length in one go.

Related Links
DLR Institute of Materials Research
Space Technology News - Applications and Research