Enhancement of glass-forming ability of Fe-based bulk metallic glasses with high saturation magnetic flux density

The effects of substituting Fe with Ni on thermal properties, glass-forming ability (GFA) and magnetic properties of Fe76-xNixMo3.5P10C4B4Si2.5 (x=0-30 at.%) alloys were investigated in detail. The breadth of the supercooled liquid region was found to gradually increase from 42 to 55 K with increasing Ni content to 30 at.%. When x=5 at.%, the alloy composition approached a eutectic point, resulting in an increase in GFA. As a result, FeNiMoPCBSi bulk metallic glasses with critical diameters up to 5.5 mm were successfully synthesized by copper mold casting. These glassy alloys exhibit a high saturation magnetic flux density of 0.75-1.21 T and excellent soft magnetic properties, i.e., low coercive force of 1.1-2.0 A/m, and high effective permeability of 14400-19700 at 1 kHz under a field of 1 A/m. The reasons for the high stability of the supercooled liquid, and the high GFA as well as excellent soft magnetic properties are discussed in this article. Copyright 2012 Author(s). This article is distributed under a Creative Commons Attribution 3.0 Unported License. [http://dx.doi.org/10.1063/1.4733340]