Effect of Al on Bulk Amorphization and Magnetic Properties of FeSnPSiB Alloys

Abstract

Structure and magnetic properties of melt-spun multi-component Fe 78Àx Al x Sn 2 P 12 Si 4 B 4 (x ¼ 0, 3, 4, 5 at%) amorphous ribbons and copper-mold-cast rods were investigated. The improvement of thermal stability was recognized with the replacement of Fe by 3$5 at% Al in these Sn-containing alloys. The super-cooled liquid region (ÁT x ), defined by (T x À T g ) where T x is the crystallization temperature and T g the glass transition temperature, increases from 46.5 K as x ¼ 3 to the maximum value 50.2 K as x ¼ 4. With increasing Al content, magnetic properties of annealed Fe 78Àx Al x Sn 2 P 12 Si 4 B 4 (x ¼ 3$5 at%) amorphous ribbons are: saturation magnetization decreases from 1.22 to 1.18 T; coercive force decreases from 3.3 to 2.2 A/m, maximum permeability increases from 137000 to 208000, Curie temperature lowers from 591.1 K to 578.3 K; the electrical resistivity increases from 175 to 188 m-cm; and core loss is about 0.14 W/kg (50 Hz, 1.1 T external magnetic field). Bulk amorphous rods with 1 mm diameter were successfully demonstrated for the composition Fe 74 Al 4 Sn 2 P 12 Si 4 B 4 by a copper mold casting method. Due to the combination of good glass forming ability and superior soft magnetic properties, these alloys will find potential applications in industries.

Magnetic properties and glass-forming ability of modified Fe–P–Si–B bulk amorphous alloys

“…These alloys also exhibit superior soft magnetic properties. As the Al content increases, the saturation magnetization (I s ) slightly decreases from 1.22 to 1.18 T; the coercive force (H c ) decreases from 3.3 to 2.2 A/m and the maximum permeability (m m ) greatly increases from 137,000 (x ¼ 3) to 208,000 (x ¼ 5) [18].…”