What materials are the electromagnetic systems of electrical devices made of?

For electromagnetic systems of electrical devices, use so-called soft magnetic materials characterized by low coercive force, narrow hysteresis loop and high magnetic permeability… These materials are characterized by a magnetization curve, which is the dependence of magnetic induction on magnetic field strength.

Read more about soft magnetic materials here: Magnetic materials used in the manufacture of electrical devices

For permanent magnets Apply hard magnetic materials characterized by high coercive force, wide hysteresis loop and low magnetic permeability.

From a wide variety of ferromagnetic materials used in electrical appliances, ferroalloys (which are mainly composed of iron) and ferrites (non-metallic pressed materials from a mixture of iron oxides with oxides of nickel, lead, zinc, etc., subjected to annealing at T = 1100 — 1400 OC in the production process). Ferrites are characterized by a very high content electrical resistance — in 106 times higher than those of electrical steels, which is why they are used at very high frequencies without significant losses for eddy currents… Ferroalloys include electrical steel (iron alloys, mainly with silicon, from 0.5 to 4.5%) and permaloid (iron alloys, mainly with nickel).

Permanent magnets, possessing the property of long-term residual magnetization, are made of magnetically hard materials characterized by a wide hysteresis loop and possessing a large reserve of magnetic energy in the magnetized state. Forging materials (carbon, chromium, tungsten and cobalt steel) and alloys of iron, nickel and aluminum are used for the production of permanent magnets.