Researchers at the Chemnitz University of Technology succeeded in printing complete electric motors with the aid of metallic and ceramic pastes, which are formed in layers by an extrusion process and then sintered. Last year, the same team already presented a 3D printed coil that can withstand temperatures of over 300°C. In the meantime, they managed to produce all relevant components of an electric machine in one 3D multi-material printing process. These include electrical conductors made of copper, which, together with iron or ferrous alloys, cause the formation and alignment of magnetic fields as well as the electrical insulation made of ceramic, which insulates the conductors against each other and against the magnetic circuit parts made of iron.
The aim of the approximately two-and-a-half years of work has so far been to push the limit on the operating temperature of electrical machines upwards. The researchers achieved this goal by replacing the conventional polymer-based insulation materials with ceramics with a much higher temperature resistance. The permissible winding temperature of conventional insulation systems of up to 220°C can thus be significantly exceeded, so that the operating temperature of electrical machines is only limited by the ferromagnetic properties of the iron, which remain intact up to 700°C.