Effect of Co and Cu Content on Magnetic Properties of High Induction Fe-Based Amorphous Alloys

Abstract

The magnetic properties of the substitution of Co and Cu for Fe in Fe85−x−y Co x Hf8Zr1 B 6Cu y (x = 0, 10, 20, 30, 40; y = 0, 0.5, 1, 2) amorphous alloys were investigated. The XRD patterns revealed the as-spun alloy ribbons to be structurally amorphous. Their characteristic temperatures (e.g., T g, T x1, and T p1) show the same trend varied with the Co content. The alloys with Co content of x = 20 (Cu-free) exhibit a minimum value for characteristic temperatures T g, T x1, and T p1. Results show that Fe65Co20Hf8Zr1 B 6 alloy has the best amorphous forming ability with ΔT (T x1 − T g) = 64 ∘C, and the saturation magnetization (B s) and coercivity (H c) reach the maximum about 1.16 T and 11.8 A/m, respectively. Bit Cu doping greatly reduces the H c of Fe65−y Co20Hf8Zr1 B 6Cu y (y = 0, 0.5, 1, 2) alloys, and the H c reaches to the minimum value about 6.9 A/m at 0.5 at.% Cu content. After annealing, the B s of Cu-free alloy is basically stable at about 1.15 T, and the H c increases rapidly from 11.8 to 55.8 A/m. But, for Cu-doped alloys, annealing at 550 ∘C for 10 min is best for the improvement of the magnetic properties, especially for Fe63Co20Hf8Zr1 B 6Cu2 alloy; the B s increases obviously from 1.00 to 1.31 T; and the H c value remains low, from 7.3 to 7.8 A/m.