| Mar 16, 2026 |
Iron-based metallic glass alloys compatible with 3D printing reduce energy losses in electric motors by eliminating crystal structure friction.
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(Nanowerk News) Researchers at Saarland University have developed iron-based metallic glass alloys that can be shaped using 3D printing into electric motor components with far lower energy losses than conventional parts. The amorphous alloys, which contain no crystal structure, allow magnetic fields to reverse direction with minimal resistance, addressing a key source of wasted energy in motors found in e-bikes, drones, and household devices. An international consortium backed by the EU has identified three compositions suitable for printing fully glass-like motor parts.
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Key Findings
- Three iron-based amorphous alloys have been identified that resist crystallization and can be processed using laser-based 3D printing.
- Motor components made from these metallic glasses reduce hysteresis losses because their disordered atomic structure lets magnetic domains reorient without obstruction.
- The alloys eliminate the need for critical elements such as cobalt, offering both performance and sustainability advantages.
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Electric motors convert electricity into motion, but never with perfect efficiency. A portion of the input energy is always lost as heat, and these losses increase at higher speeds and in smaller devices. The underlying problem is a phenomenon called iron loss, caused by the constant reversal of magnetic fields during motor operation.
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In a standard motor, a spinning rotor creates an alternating magnetic field inside a stationary stator. Each time the field reverses, microscopic magnetic regions in the metal must flip their orientation. In the crystalline iron alloys used today, this flipping encounters friction from the ordered atomic lattice, turning useful electrical energy into waste heat. The smaller the motor, the worse this effect becomes.
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“We are looking into ways of cutting these efficiency losses by improving the materials used in electric motors,” said Ralf Busch, professor at Saarland University. “In today’s motors, the stator and rotor components are made from conventional soft magnetic, coarse-grained iron alloys. Although these alloys are already optimized, they still exhibit relatively high hysteresis losses during re-magnetization. We want to replace these conventional crystalline alloys with amorphous, glass-like alloys, as they lose hardly any energy during re-magnetization.”
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Busch explained that losses drop sharply when crystallites shrink to nanocrystalline dimensions, and fall even further when crystal structure disappears altogether, leaving an amorphous material. His team has spent four years pursuing this approach with international partners through the EU-funded AM2SoftMag project.
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Metallic glass and conventional metal differ at the atomic level. Ordinary metals have atoms arranged in repeating lattice patterns. In metallic glasses, atoms are locked into a disordered arrangement with no long-range periodicity. If the mixture of atomic species is chosen carefully, the atoms freeze in place as the molten alloy cools, settling into fixed positions before any lattice can form, much like conventional glass.
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“Because metallic glasses have no crystallites, the magnetic regions – known as Weiss domains – are not obstructed and can reorient freely when the magnetic field changes,” said Busch. “The magnetic properties of metallic glasses are therefore exceptionally well suited for use in electric motors.”
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This ease of re-magnetization translates directly into lower iron losses in motor components. It also brings a materials benefit. “Simply by changing the material, we can lower energy consumption in a whole range of everyday electric motors and, ultimately, extend the range of e-scooters or drones. Another positive contribution of our work is that by using amorphous metals we no longer have to deal with critical alloying elements such as cobalt,” said Busch.
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Despite the name, metallic glass is not brittle. It is stronger than steel, and it can be processed much like plastic, moulded into virtually any shape. In this project, motor components are manufactured using Laser Powder Bed Fusion, a metal 3D printing technique. A laser melts powdered alloy material, and cooling is controlled so that layers just 50 micrometres thick build up one by one into parts made entirely of amorphous metallic glass, free of crystalline regions that would impair magnetic performance.
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The alloys used contain 70 to 80 percent iron. Busch is a longstanding researcher in the metallic glass field who has collaborated with NASA and the German Aerospace Center and tested novel glass-like metals in microgravity aboard the International Space Station. His group holds several patents for alloys with unusual properties and has recently filed another.
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Finding compositions that satisfy all requirements proved to be one of the project’s hardest challenges. Each alloy had to form a glass, possess suitable magnetic characteristics, and remain compatible with 3D printing. With five elements per alloy, the search space was five-dimensional.
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“We selected hundreds of alloys and tested their resistance to crystallization,” said Busch. “In an alloy containing five elements, that meant searching through a five-dimensional compositional space. If an alloy fails, it’s back to the drawing board for a complete redesign. The breakthrough came just over a year ago.” Three alloys emerged that resist crystallization and possess the right combination of properties for printing fully glass-like motor parts.
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The European consortium behind the project includes Isabella Gallino, who secured the original grant at Saarland University in 2022 and has since moved to TU Berlin. Industrial partner Heraeus AMLOY Technologies handles the 3D printing of magnetic components. Other members are Teresa Pérez Prado at the IMDEA Materials Foundation in Madrid, specializing in metal 3D printing, Paola Tiberto at Italy’s National Institute for Metrological Research in Turin, focused on magnetic property measurement, and Tomasz Choma at AMAZEMET in Warsaw, a specialist in metal powder production.
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With the material science now established, attention turns to scaling. “The challenge now is to develop the process so that it works reliably in practice and at industrial scale,” said Matthias Nienhaus, professor of drive technology at Saarland University. The team is refining the parameters of the Laser Powder Bed Fusion process and developing new processing methods with partners across Spain, Italy, Poland, and Germany, working toward motor components that could bring measurable efficiency gains to the next generation of electrical devices.
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