Researchers at Saarland University are developing new metallic glass alloys that could reduce energy losses in electric motors used in devices like drones and e-bikes. The team, led by Professor Ralf Busch, is using 3D printing to manufacture motor components from these amorphous materials. The European Union is supporting their research with €3.5 million.
Electric motors lose energy during operation due to “iron loss,” which occurs when magnetic fields inside the motor constantly change direction. In conventional crystalline metals, tiny magnetic elements must flip orientation during each field reversal, creating internal friction and wasting energy as heat. “The losses decrease dramatically when the crystallites are extremely small, i.e. nanocrystalline in structure, or when the crystal structure is absent altogether, i.e. the material is glass-like or amorphous,” says Ralf Busch.
The team’s metallic glass alloys contain 70-80% iron and lack the crystal lattice structure found in conventional metals. This amorphous arrangement allows magnetic regions to reorient more freely when magnetic fields change, reducing energy waste. “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,” explains Busch.
Finding suitable alloys required testing hundreds of compositions across five chemical elements. The researchers identified three alloys that resist crystallization and work with 3D printing processes. The team uses laser powder bed fusion to build motor components layer by layer, with each layer measuring 50 micrometers thick.
The AM2SoftMag project includes partners from Spain, Italy, Poland, and Germany, with industrial partner Heraeus AMLOY Technologies handling the 3D printing of magnetic components. Professor Matthias Nienhaus, a drive technology expert at Saarland University, notes that “the challenge now is to develop the process so that it works reliably in practice and at industrial scale.”
Source: eurekalert.org