Glass-forming ability and magnetic properties of CoFeMoYB bulk glassy alloys with large supercooled liquid region

Abstract

Co-based bulk glassy alloys with diameters up to 4 mm were formed in Co 41+ x Fe 28Mo 4Y 5− x B 22 ( x = 0–1.5) system. The effect of Y content on the glass-forming ability and soft-magnetic properties of the Co-based bulk glassy alloys was investigated. With an increase of Y content from 3.5 to 5 at%, in addition to slight increases of glass transition temperature from 843 to 847 K and supercooled liquid region increases from 73 to 94 K, the addition of Y was found to be effective in approaching alloy to a eutectic point. Except for high glass-forming ability, the Co-based bulk glassy alloys exhibit good soft-magnetic properties, i.e., high saturation magnetization of 0.80–0.87 T, low coercive force of 2.87–3.34 A/m, high effective permeability at 1 kHz of 1.26–1.74 × 10 4 under a field of 1 A/m.