Heads up, metalcasters. Another metal 3D-printing development appears likely to present a new challenge to investment casting and other foundry capabilities. A process for multi-material additive manufacturing has been defined at Germany’s Fraunhofer Institute for Foundry, Composite and Processing Technology (IGCV), aiming to refine techniques for producing components for rocket systems. ArianeGroup, Europe’s primary contractor for civilian and military space programs is among more than a dozen partners in the R&D effort.
The objective of the EU-funded Enlighten project is to reduce production costs and development times for a “low-cost, innovative, and green high-thrust” rocket engine, while improving material efficiency and strengthening Europe’s proficiency in space technologies. A coordinated research effort seeks to demonstrate that engine.
The work is focused on laser powder-bed fusion (LPBF) additive manufacturing. Specifically, they determined to melt multiple alloy powders simultaneously and incorporate those materials in a single component build. By combining different alloys during printing they intend to produce parts with localized material properties, including variations in hardness, magnetic behavior, and corrosion resistance.
“With this manufacturing process, we can adapt components directly on the computer and print them immediately,” according to Fraunhofer IGCV’s Constantin Jugert. “The enormous flexibility saves us lead times and allows for rapid iterations when requirements change. This saves weeks in development.”
As proof of their work the team showed a multi-material rocket valve demonstrator comprised of alternating magnetic and non-magnetic steel alloys. They noted the component will promote flight stability functions in future launch vehicles.
Lab evaluations of the part confirmed high material density and accurate placement of the different alloy regions, which the team noted showed that the printed structure can meet functional performance requirements. They are now comparing their printed valve with versions produced by conventional machining and welding, to evaluate differences in functionality, production efficiency, cost, and manufacturing cycle time.
Ariane provided industrial requirements for future launch systems as research parameters for the effort.
In parallel, Fraunhofer IGCV and KU Leuven (a Belgian research university and Enlighten program participant) investigated the metallurgical challenges to joining dissimilar materials during multi-material LPBF processing. Past attempts to “print” titanium and nickel alloys together resulted in defective interfaces and the formation of brittle intermetallic phases.
To address the issue researchers introduced a thin interlayer of molybdenum between the titanium and nickel alloy layers. Lab testing and simulation revealed that the interlayer prevented direct interaction between the titanium and nickel materials and allowed formation of a sound metallurgical bond. This result will be important in the future development of functionally integrated, lightweight components with dissimilar-metal interfaces.
The Enlighten researchers also aim to develop a magnetic separation system capable of automatically segregating and recovering mixed powders generated during 3D printing. This would reduce material costs and emissions by making powder reuse more efficient.
The team also is exploring closed-loop quality control systems that combine thermography, sensor technology, and real-time melt pool monitoring. These systems would automatically adjust process parameters during printing to maintain consistent quality and support scalable production.
For foundries and diecasters this research highlights product designers’ interest in multi-material processing, as well as expanded use of digital process control in product design. There is also a need to define methods for joining dissimilar materials, as well as the ongoing focus on sustainability in connection with raw material management.
The Enlighten project’s link to aerospace programs underscores the commercial importance of that customer group, but the research objectives could influence production methods for tooling, energy, automotive components, and other areas involving complex castings for high-performance applications.
