When people think of glass, they usually imagine a fragile and brittle material, not something used as the foundation for high-performance electromechanical components. However, researchers at Saarland University in Germany have utilized glass-like metal to significantly boost the efficiency of electric motors.

How Electric Motors Work and Energy Losses

Electric motors, found in everything from electric toothbrushes to cars, have a rotating rotor inside a stationary stator, which creates a constantly changing magnetic field. This process causes repeated reorientation of tiny magnetic regions within the metal. In materials with a crystalline structure, this leads to internal resistance, resulting in microscopic friction and energy loss as heat—known as iron losses.

Limitations of Traditional Materials

Modern motors are typically made from soft, coarse-grained iron alloys. Despite optimization, these alloys still suffer relatively high energy losses during magnetization reversal due to hysteresis. To reduce these losses, researchers aim to replace traditional crystalline alloys with amorphous, glass-like materials that lose almost no energy when the magnetic field changes.

Properties of Metallic Glasses

Unlike conventional metals, metallic glasses lack a crystalline lattice. Their atoms are arranged randomly, giving them an amorphous, glass-like structure. The absence of a rigid crystalline framework allows magnetic domains to reorient freely as the magnetic field changes, which greatly reduces energy loss and heat generation.

Strength and Manufacturing

Despite the name, metallic glass is often stronger than steel. The term "glass" refers solely to the amorphous atomic structure of the material. This structure is achieved by carefully selecting the composition, melting, and rapidly cooling the alloy so that atoms do not have time to form a crystalline lattice.

To manufacture electric motor components, the team used laser powder bed fusion—a type of 3D metal printing. In this process, metallic alloy powder is melted layer by layer with a laser and rapidly cooled, preserving its amorphous, glass-like state. This approach maintains the necessary magnetic properties of the material.

Developing New Alloys

The main goal of the project was to create a metallic glass alloy with the right characteristics to replace traditional electric motor materials and be suitable for 3D printing. The researchers tested hundreds of alloys for resistance to crystallization and identified three compositions suitable for reliably producing fully glass-like metallic motor components.

Potential Impact

Given the widespread use of electric motors, introducing new materials could lead to more efficient and durable motors with lower energy losses and reduced heat generation. This opens up possibilities for faster and more energy-efficient electric vehicles, drones with longer flight times, e-bikes with greater range, and industrial machines that consume less energy while maintaining high productivity.

Funding and Support

The project is supported by the European Union and has received over 3.5 million euros through the AM2SoftMag consortium (Additive Manufacturing of Amorphous Metals for Soft Magnetics).