New Metallic Alloy Designed to Reduce Energy Losses in Electric Motors

  • IMDEA Materials participates in a study that uses 3D printing to improve the efficiency of electric motors.
  • New 3D printing parameters enable the production of a metallic glass with performance superior to existing materials.

Researchers from the European AM2SoftMag project have developed a new iron-based metallic glass that could lead to 3D-printed components for the manufacture of more efficient electric motors.

The new alloy, designed by researchers at Saarland University (UdS) in Germany, is free of critical elements with significant social impacts, such as cobalt, and elements with unstable supply chains, such as rare earths. In addition, it can be 3D printed in a fully amorphous state and with a density exceeding 92%, giving it exceptional magnetic properties.

The breakthrough, recently published in Acta Materialia, has the potential to improve energy efficiency in the electric transportation sector.

Iron-based metallic glasses are renowned for their excellent soft magnetic properties, which significantly reduce both eddy current losses, responsible for unnecessary heating of components, and magnetic losses.

However, manufacturing these materials through Laser Powder Bed Fusion (LPBF) has traditionally caused undesirable crystallisation due to repeated heating and cooling cycles during processing.

The new alloy, composed of iron, silicon, boron, niobium, and nickel, exhibits greater resistance to devitrification than current commercial materials, achieving a critical thickness of up to one millimetre without crystallising, nearly ten times greater than that of commercial alternatives.

The research demonstrates that the use of a double laser scanning strategy combined with controlled time delays enables the production of components with a density exceeding 92% and a fully amorphous structure. Thanks to this technique, the researchers also achieved an extraordinarily low magnetic coercivity of just 44 amperes per meter (A/m).

These results place the method among the most effective developed to date for this type of material processed by 3D printing.

At IMDEA Materials, researchers from the Sustainable Metallurgy Group, led by Prof. María Teresa Pérez Prado, optimised the LPBF manufacturing parameters. The team also confirmed through X-ray diffraction, electron microscopy, and atom probe tomography that the chemical elements are distributed completely randomly throughout the structure, ensuring homogeneous mechanical and magnetic properties across the entire component.

“This new alloy design and its optimised processing through 3D printing allow us to avoid crystallisation during manufacturing,” explained Prof. Pérez Prado, one of the authors of the publication and Principal Investigator at IMDEA Materials.

“The result is a material with excellent magnetic behaviour that could, in the future, make a significant contribution to improving the efficiency of electric motors, substantially reducing overall energy waste.”

The consortium’s next steps, involving UdS, IMDEA Materials, the Italian National Metrology Institute, and Technische Universität Berlin, will focus on eliminating defects, scaling up the manufacturing process, and evaluating the performance of these new materials in real prototypes of high-efficiency electric motor rotors and stators.

This work has been carried out within the framework of the AM2SoftMag project, funded by the European Innovation Council through the HORIZON-EIC-2021-PATHFINDEROPEN-01 grant (GA: 101046870).