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

The magnetic properties of the substitution of Co and Cu for Fe in Fe85-x-y Co (x) Hf8Zr1 B Cu-6 (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 Delta T (T (x1) - T (g)) = 64 C-ay, 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 Cu-6 (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-ay for 10 min is best for the improvement of the magnetic properties, especially for Fe63Co20Hf8Zr1 B Cu-6(2) 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.