The magnetic motors of electric motors (stators and rotors), with few exceptions, are currently manufactured, based on thin metal blades (low carbon steel plates) with a thickness of less than 1 mm, assembled in sheet metal packages.
Some higher performance motors are made from silicon steel sheets, with about 3% silicon. The total process for the elaboration of these nuclei consists basically in lamination, packaging, stamping, a treatment for electrical insulation and fixation.
With respect to low carbon steel plates, the process for insulation is based on a heat treatment, where the plate packs are inserted in ovens for a certain time, and then the surface oxidation of the plates exists, and as a result, the formation Of an insulating layer of iron oxide between the joint sheets.
Some types of silicon steel sheets are offered by manufacturers with a paint based oxide on one of the surfaces. Magnetic cores enveloped by coils (windings), where they travel alternating currents, form an alternating magnetic flux.
For this reason, these nuclei are exposed to the action of parasitic currents, also called Foucault currents, which are responsible for significant loss of power in these nuclei.