IMDEA Materials 3D prints low-loss metallic glass for electric motors
The iron-based alloy stayed fully amorphous at high density without cobalt or rare earths, using a double laser scanning strategy developed with Saarland University
Researchers on the European AM2SoftMag project have 3D printed an iron-based metallic glass with a density above 92% that stays fully amorphous, using a double laser scanning strategy with controlled time delays during laser powder bed fusion.
The alloy, designed at Saarland University (UdS) in Germany, is made of iron, silicon, boron, niobium and nickel and excludes cobalt and rare earth elements, avoiding their related social and supply-chain risks.
Iron-based metallic glasses offer soft magnetic properties that reduce eddy current and magnetic losses, but LPBF’s repeated heating and cooling cycles have traditionally triggered unwanted crystallization in these materials. The new alloy resisted this devitrification to a critical thickness of up to one millimeter, nearly ten times that of commercial alternatives.
The double laser scanning approach also produced a magnetic coercivity of 44 amperes per meter (A/m), a level the researchers described as extraordinarily low and said placed the method among the most effective developed to date for this type of 3D printed material.
Researchers in the Sustainable Metallurgy Group at IMDEA Materials refined the LPBF parameters and used X-ray diffraction, electron microscopy and atom probe tomography to confirm the alloy’s elements were distributed randomly throughout the structure, and to ensure homogeneous mechanical and magnetic properties.
“This new alloy design and its optimized processing through 3D printing allow us to avoid crystallization during manufacturing,” said María Teresa Pérez Prado, Principal Investigator at IMDEA Materials, who led the group and co-authored the study. “The result is a material with excellent magnetic behavior that could, in the future, make a significant contribution to improving the efficiency of electric motors, substantially reducing overall energy waste.”
The AM2SoftMag consortium, which also includes the Italian National Metrology Institute and Technische Universität Berlin, plans to eliminate defects, scale up manufacturing and test the alloy in prototype electric motor rotors and stators.
