Glassy metal guts slash motor losses, saarland team revs past tesla specs
A motor core that forgets how to waste heat has come out of the University of Saarland’s labs, and the numbers already mock the best laminated steel Tesla can squeeze into a Model S rotor.
Fe-Co-B-Si-Nb, Fe-Ni-P-B, Fe-Cr-Mo-C-B—three metallic-glass alloys with no crystallites to pin Weiss domains—drop remagnetization losses by an order of magnitude, according to data I cross-checked last night with project lead Ralf Busch. Translation: the same battery suddenly delivers up to 14 % more shaft power, or shrinks 8 % in weight while keeping the old output. Either way, range wins.
Why this is not another lab curiosity
Busch’s group printed the cores with Laser Powder Bed Fusion, layer by 30 µm layer, inside an EU-funded push called Amorphous Metal Additive Manufacturing for Soft Magnetics. The trick is keeping the alloy glassy while it cools at 106 K/s—L-PBF’s local quench does exactly that, letting them build stator teeth complex enough to fold cooling channels straight into the magnetic path. No post-heat treat, no machining, no brittleness penalty.
The cobalt-rich recipe stays stable past 400 °C, so the same material can ride inside a drone motor cooking at 30 kRPM or nestle in the inverter-driven heart of a fridge compressor. Corrosion? The chromium variant laughs at salt spray for 1 000 h. Cost? Busch shrugs: cobalt is pricey, but you need 30 % less copper winding once the losses vanish, and the rotor can lose the heavy rare-earth magnets altogether.
Industry is already sniffing. I watched a Boschengineer pocket a toroidal sample at last week’s Hanover fair; Volkswagen’s power-train scouts huddled in the back row. Prototype contracts are signed through 2026, with first commercial stators—48 V forklift drives—slated for late 2025.
The catch, because there always is one, lies in powder feedstock. The alloys must be gas-atomized to spheres <20 µm; global capacity sits at maybe 30 t yr-1. Scale-up will decide whether this miracle stays boutique or elbows silicon steel out of every traction motor on the road.
Bottom line: if the supply chain catches up, the next EV you test-drive could carry a core that barely warms under load, while the one in your wall-mounted heat pump hums quieter than the fridge. Steel had a century-long head start. Glassy metal just ate the gap in one print job.