The German Ministry of Education and Research (BMBF) funded the “AluNanoCore” project under its “From Material to Innovation” programme, with the aim of creating high‑strength, nanostructured aluminium filler wires for arc‑based additive manufacturing (ALM). The project ran from 1 October 2019 to 30 September 2023 and was led by Sven Köhler of KSC Kraftwerks‑Service Cottbus Anlagenbau GmbH. The funding code was 03XP0234D. The consortium comprised KSC, the Technical University of Cottbus‑Senftenberg (BTU), the wire supplier MIGAL Co, and several industrial partners that supplied the aluminium wires and provided production facilities.
The technical work focused on developing and validating a new class of aluminium filler wires that incorporate nanoscale reinforcements to increase mechanical performance while remaining fully weldable. The research began with reference studies using conventional AlSi5 solid‑state wires. A dedicated welding station was set up, featuring a Kuka articulated robot and a Fronius CMT welding power source, and was adapted for aluminium welding. The robot was programmed for both simple linear geometries and an oval shape that served as a test specimen. Tensile, hardness, hydrogen content, and microstructural analyses were carried out on the resulting parts. Porosity maps revealed a higher concentration of pores in the lower layers of the build, while the upper layers exhibited significantly lower porosity. Tensile tests on thin‑walled AlSi5 specimens produced stress‑strain curves that exceeded the reference values for WAAM‑produced parts, with ultimate tensile strengths above 300 MPa and elongations of 10–12 %. Hardness measurements in the mid‑section of the samples ranged from 54.4 to 68 HV 0.1, confirming the improved mechanical properties of the nanostructured wires.
The core of the project was the development of the AluNanoCore filler wire. In collaboration with BTU and the industrial partners, the wire was optimized for arc welding, ensuring a stable melt pool and minimal defect formation. The wire was then used to fabricate complex 3D demonstrators that mimic real‑world railway component geometries. The additive process reduced build time by up to 95 % compared with conventional machining, and the resulting parts exhibited superior strength‑to‑weight ratios. The demonstrators were successfully produced despite pandemic‑related constraints, proving the feasibility of the technology in an industrial environment.
The project’s outcomes were validated in an industrial setting (Work Package 10), demonstrated through full‑scale production runs (Work Package 11), and characterized in detail (Work Package 12). No patent applications were filed during the project, but the results are intended to be integrated into KSC’s product portfolio, potentially opening new markets in energy technology and rail vehicle manufacturing. The consortium plans to showcase the technology at InnoTrans 2024, aiming to attract further industrial partners and investors.
Throughout the project, the consortium maintained strict adherence to the budget and schedule, even after a cost‑neutral extension was granted to accommodate pandemic‑related delays. The collaboration between academia and industry proved essential for the successful development of the nanostructured filler wire and the demonstration of its practical applicability. The project demonstrates that arc‑based additive manufacturing of aluminium can achieve high‑performance, lightweight components, offering a promising pathway for future industrial adoption.