Ferromagnetic element microalloying and clustering effects in high B s Fe-based amorphous alloys

Fe83(Cox,Niy)(B11Si2P3C1)1-x,y/17 (x, y = 1–3) amorphous alloys with high saturation magnetic flux density (Bs) and excellent soft-magnetic properties were developed and then the microalloying and clustering effects were explored. The microalloying of Co and Ni improves the Bs from 1.65 T to 1.67–1.72 T and 1.66–1.68 T, respectively. The Ni-doped alloys exhibit better soft-magnetic properties, containing a low coercivity (Hc) of about 5.0 A/m and a high Effective permeability (μe) of (8–10) × 103, whereas the microalloying of Co leads to a deteriorative Hc of 5.0–13.0 A/m and a μe of (5–8) × 103. Moreover, microalloying of Ni can increase the ductile-brittle transition (DBT) temperature of the ribbons, while a totally opposite effect is found in the Co-doped alloys. The formation of dense α-Fe(Co,Ni) clusters during annealing process is used to explain the distinct effects of Co and Ni microalloying on the magnetic properties and bending toughness.