Electrical Steel: Strong Magnetic Fields Due to Sharp Tools

In an electric drive, magnetic fields have to be created in order to transform electric energy into kinetic energy. The magnetic properties of the motor's main components, referred to as electrical steel sheets, are the decisive factor in the efficiency of the electric motor. Scientists at the Technical University of Munich (TUM) have investigated the way these steel sheets are processed and have concluded that using blunt cutting tools deteriorates the magnetic properties of the steel sheets significantly.

Current criticism of electro-mobility usually focuses on long battery charging times and inadequate range. Researchers are working to increase the efficiency of electric drives in order to reduce the energy requirements of electric vehicles. This involves a large number of individual components, in particular electrical steel sheets: These sheets are important since the magnetic fields that move the motor using attractive and repulsive forces are generated within them.

Depending on the motor's design, a variety of different holes have to be cut in the steel sheets, for example to make room for copper coils built into the motor. Each steel sheet is "stamped" individually in a press, using the same principle as a hole punch. Special cutting tools are used to ensure that the specified geometries are created in the steel sheets. Finally, the steel sheets are put together in order to form the desired shape.