LAUSR

Abstract Effect of microalloying on microstructure, magnetic properties and bending ductility of the Fe85.7-85.8Si0.5B9-9.3P3.5-4Cu0.5-0.8C0.2-0.3 alloy ribbons with high Fe content was systematically investigated. It is found that the substitution of 0.1 at. % Cu or 0.2 at. % Cu for (B+P) content inhibits the crystallization and improves the amorphous forming ability of melt-spun Fe85.7-85.8Si0.5B9-9.3P3.5-3.9Cu0.6-0.7C0.2-0.3 alloys. The first crystallization temperature (Tx1) increases slightly with the addition of C or P content, while the second crystallization temperature (Tx2) exhibits a slightly decrease. All amorphous alloys exhibit a large temperature interval between Tx1 and Tx2, which contributes to the thermal stability and leads to the formation of a single α-Fe phase. In the as-spun state, the amorphous alloys have good bending ductility even at high Fe content. After the optimum heat treatments, the Fe85.7-85.8Si0.5B9-9.3P3.5-3.9Cu0.6-0.7C0.2-0.3 nanocrystalline alloys exhibits the excellent soft magnetic properties, such as the highest Ms of 206.4–210.2 emu/g (Bs ≈ 1.95–1.98 T) and the lowest Hc of 6.5–8.4 A/m.