Bulk glassy Fe-Mo-Ga-P-C-B-Si alloys with high glass-forming ability and good soft magnetic properties

Abstract

The effect of Mo and Si additions on the glass-forming ability (GFA) of Fe 77-xMo xGa 3P 10C 4B 4Si 2 alloys was investigated. The addition of 2 at%Mo combined with 2 at%Si was found to be effective for the extension of the supercooled liquid region (ΔT x) defined by the difference between glass transition temperature (T g) and crystallization temperature (T x). The ΔT x value is 33 K for the Fe 77Ga 3P 12C 4B 4 alloy, and increases to 60 K for the Fe 75Mo 2Ga 3P 10C 4B 4Si 2 glassy alloy. In addition, this glassy alloy exhibits a high reduced glass transition temperature (T g/T l) of 0.6. The large ΔT x and high T g/T l enabled us to prepare the Fe 75Mo 2Ga 3P 10C 4B 4Si 2 bulk glassy alloy successfully with a diameter of 2 mm and high saturation magnetization (l s,) of 1.27 T. The Fe 75Mo 2Ga 3P 10C 4B 4Si 2 glassy alloy also exhibits good soft magnetic properties, i.e., high effective permeability at 1 kHz of 1.1 × 10 4 and low coercive force of 5 A/m. © 2005 The Japan Institute of Metals.