An iron-nickel soft magnetic alloy with extremely high magnetic permeability under a weak magnetic field. In order to increase the
resistivity and improve the process performance, Mo, Cr, Cu and other elements are often added to the Fe-Ni binary alloy. In
addition to Fe-Ni alloys, there are also iron-silicon aluminum alloys and amorphous cobalt-based alloys belonging to permalloys.
Permalloy has excellent soft magnetic properties. The initial permeability μi is 37.5~125mH/m, the maximum permeability μm can
reach 125~375mH/m, the coercivity Hc is 0.8A/m, and the resistivity ρ is 60. ~85μΩ·cm. The alloy is smelted in a vacuum induction
furnace and is made into cold-rolled strips, cold-drawn wires or hot-rolled (forged) plates and bars after hot and cold plastic
deformation. Used to make audio transformers, transformers, magnetic amplifiers, magnetic modulators, chokes, audio heads, etc.