Increase of energy efficiency by utilization of residual stress in electrical steel


DFG-Priority Programme - SPP 2013

Illustration of voltage in electrical sheet Copyright: © IEM

In the second phase of the DFG priority program “Targeted use of internal stresses induced by forming technology in metallic components”, the scientific basis for improving the properties of metallic components through the reproducible and permanent introduction of internal stresses is to be developed. In the sub-project "Targeted use of residual stress in electrical steel sheets to increase energy efficiency", the possibility of reducing permeability through stamping-induced residual stresses based on the Villari effect is investigated. In this way, recesses in the rotor that are used to suppress leakage flux and the filigree sheet metal structures that accompany them can be replaced. In this way, higher rotational speeds of the electrical machines and thus higher power densities can be achieved. In cooperation with the UTG of the Technical University of Munich and the research neutron source Heinz Maier-Leibnitz, the embossing of electrical sheets for the targeted control of the magnetic flux is investigated. After the basic confirmation of the working hypothesis in the first project phase and the proof of the stability of residual stresses induced by forming technology, the focus in the second project phase is on the quantification and further improvement of the material properties. This has already been shown