Soft magnetic properties of bulk Fe-based amorphous alloys prepared by copper mold casting

Abstract

Fe-based amorphous alloys in Fe-(Al,Ga)-(P,B,C,Si) system were found to exhibit a wide supercooled liquid region exceeding 50 K before crystallization. The high stability of the supercooled liquid enabled the production of cylindrical bulk amorphous alloys with diameters up to 2 mm by copper mold casting. The Fe-based bulk amorphous alloys exhibit ferromagnetism with the Curie temperature of about 600 K. The saturation magnetization (Bs), coercivity (Hc) and permeability (/spl mu//sub c/) at 1 kHz in as-quenched state are 1.07 T, 12.7 A/m and 3600, respectively, for Fe/sub 73/Al/sub 5/Ga/sub 2/P/sub 11/C/sub 5/B/sub 4/ and 1.14 T, 0.5 A/m and 3200, respectively for Fe/sub 72/Al/sub 5/Ga/sub 2/P/sub 10/C/sub 6/B/sub 4/Si/sub 1/. Besides, the use of the Fe-based amorphous alloys enabled the production of thick amorphous ribbons above 100 /spl mu/m in thickness and the thick samples also exhibit good soft magnetic properties. The success of synthesizing the bulk Fe-based amorphous alloys with good soft magnetic properties is promising for future development as a new type of soft magnetic materials.