LAUSR

Abstract Effects of the substitution of Si by P on the amorphous forming ability (AFA), soft magnetic properties, and bending ductility of the Fe84.2Si6-xB9PxCu0.5C0.3 (x = 2.0–4.0) alloys were investigated. It finds that the partial substitution of P for Si promotes the formation of amorphous structure. The AFA of alloys is sensitive to the relevant metalloid elements, and the effect of minor C on the AFA is greater than that of B and P elements. The substitution of Si by P decreases the onset temperature of the second crystallization and promotes the possibility of precipitation of the secondary phase. Besides, an increase in P content effectively inhibits the excessive growth of the α-Fe grains, which contributes to the reduction of grain size and Hc. The amorphous alloys exhibit good bending ductility and high hardness induced by the increase of P content. After optimal heat treatments, the Fe84.2Si6-xB9PxCu0.5C0.3 nanocrystalline alloys exhibit excellent soft magnetic properties, such as higher Ms of 194.6–196.2emu/g and lower Hc of 6.1–6.6 A/m. This work helps us to elucidate the crystallization mechanism induced by the composition and is important for achieving excellent soft magnetic properties, good bending ductility and high hardness.