2001 Volume 42 Issue 12 Pages 2572-2575
This paper deals with the formation and soft magnetic properties of Co(Fe)-M-B (M=transition Metals) glassy alloys in thin sheet and bulk ring forms prepared by single role melt spinning and copper mold casting methods. This multicomponent system was found to exhibit a distinct glass transition and a wide supercooled liquid region (ΔTx) exceeding 70 K before crystallization. The high thermal stability of the supercooled liquid has enabled us to produce the bulk glassy alloys. The Co–Fe–Ta–B alloy samples with a ring form of φ7 mm×φ3 mm×t1 mm consist of a single glassy phase. These bulk amorphous samples exhibit excellent soft magnetic properties, which are nearly the same as those of the corresponding melt-spun glassy thin sheets: the coercivity (Hc) and saturation magnetic flux density (Bs) are 0.25 A/m and 0.49 T, respectively. These good soft magnetic properties suggest structural homogeneity resulting from its high glass-forming ability. The excellent soft magnetic properties are useful for industrial application.
