Localized investigation of magnetic bulk property deterioration of electrical steel

The knowledge of manufacturing related magnetic property degeneration in electrical steel laminations is essential for selecting correct obstructing material grades and designing efficient electrical machines. Until now these effects stay undiscovered due to the lack of adequate investigation methods that reveal local information on troubling lamination areas. Here we show how the use of a non-destructive testing method based on a neutron grating interferometry setup provides spatially-resolved information about the local bulk domain wall density. Different representative manufacturing techniques are compared in terms of magnetic flux density deterioration such as punching, mechanically cutting by guillotine as well as laser fusion cutting applying industrial high power laser beam sources.