Soft Magnetic Properties of Ring Shape Bulk Glassy Fe–Al–Ga–P–C–B–Si Alloy Prepared by Copper Mold Casting

Structural and soft magnetic properties were investigated for a bulk glassy Fe 70 Al 5 Ga 2 P 9.65 C 5.75 B 4.6 Si 3 alloy in a ring shape form with an outer diameter of 10 mm, an inner diameter of 6 mm and a thickness of I mm prepared by copper mold casting. The bulk sample composes of an amorphous single phase. The supercooled liquid region (Δ T x ) defined by the difference between the crystallization temperature (T x ) and glass transition temperature (T g ) for the bulk glassy alloy is about 60 K, being in agreement with that of the corresponding amorphous alloy ribbon. Saturation magnetization (σ s ) and Curie temperature (T c ) for the bulk sample are about 1.2 T and 620 K, respectively, both of which agree with those of the melt-spun ribbon. Furthermore, the maximum permeability (μ max ) and the coercivity (H c ) for the bulk glassy sample in as cast state are about 110000 and 2.2 A/m, respectively. These excellent soft magnetic properties are presumably due to a higher degree of structural homogeneity resulting from its high glass-forming ability. It is concluded that the good soft magnetic properties combined with high glass-forming-ability and castability of the Fe-Al-Ga-P-C-B-Si glassy alloy hold promise for its development as a future engineering magnetic material.