Effect of Yttrium Addition on Glass-Forming Ability and Magnetic Properties of Fe–Co–B–Si–Nb Bulk Metallic Glass

Teruo Bitoh,Dai Watanabe

doi:10.3390/met5031127

Abstract

The glass-forming ability (GFA) and the magnetic properties of the [(Fe0.5Co0.5)0.75B0.20Si0.05]96Nb4−xYx bulk metallic glasses (BMGs) have been studied. The partial replacement of Nb by Y improves the thermal stability of the glass against crystallization. The saturation mass magnetization (σs) exhibits a maximum around 2 at. % Y, and the value of σs of the alloy with 2 at. % Y is 6.5% larger than that of the Y-free alloy. The coercivity shows a tendency to decrease with increasing Y content. These results indicate that the partial replacement of Nb by Y in the Fe–Co–B–Si–Nb BMGs is useful to simultaneous achievement of high GFA, high σs, and good soft magnetic properties.

Highlights

The Fe-based bulk metallic glasses (BMGs) are expected as a new class of soft magnetic materials with extremely low core losses [1]
We have investigated the effect of the replacement of Nb by Y on glass-forming ability (GFA) and the magnetic properties of the [(Fe0.5Co0.5)0.75B0.20Si0.05]96Nb4 alloy
This result suggests that the soft magnetic properties are improved by replacing Nb with Y, which means the increase of GFA. This is considered to be due to the reduction of the free volume in an amorphous phase [2,3,4]. It has been confirmed by the glass-forming ability (GFA) of the [(Fe0.5Co0.5)0.75B0.20Si0.05]96Nb4−xYx bulk metallic glasses (BMGs) is improved by replacing Nb with Y by the continuous heating transformation (CHT) diagram

Summary

Introduction

The Fe-based bulk metallic glasses (BMGs) are expected as a new class of soft magnetic materials with extremely low core losses [1]. The BMGs have large glass-forming ability (GFA) and, they can be used to prepare amorphous alloys with thicknesses of few millimeters by casting. The soft magnetic properties of the Fe-based BMGs are better than those of ordinary. Metals 2015, 5 amorphous alloys which require extremely high cooling rate, typically 105–106 K/s, for amorphous formation due to their low GFA [2,3,4]. One of the disadvantages of the Fe-based soft magnetic BMGs is the smaller saturation magnetization (typically 1.2 T or less) compared with the ordinary Fe-based amorphous alloys. The demands on soft magnetic materials include higher combined magnetization and permeability.

Methods

Results

Conclusion