Soft Magnetic Properties of Microcrystalline Fe-Al-Si-Ni-Zr-B Alloys

The magnetic properties of Zr- and B-doped Supersendust (Fe-Al-Si-Ni) alloy ribbons were studied. Although the ribbons became brittle and their magnetization decreased with increases in the Zr and B contents, their soft magnetic properties were improved. Ribbons with ductility after melt quenching and fairly low coercivity after annealing were obtained when about 1.5 at% Zr and 8 at% B were added. The structural change from an amorphous to a microcrystal-line state led to a decrease in the magnetostriction and coercivity and an increase in the initial permeability. Microcrystalline Fe69.7Al7Si9.8Ni4Zr1.5B8 alloy exhibited high permeability of about 25,000.