Investigation of Viscosity Measurements of Molten Fe-Si-B-Nb Alloys

The properties of Iron-based metallic glasses, such as glass-forming ability and soft magnetic properties, (MGs) have been widely investigated. However, seldom reports are available concerning the properties of these iron-based melts. In the present work, the viscosity of superheated Fe-Si-B-Nb metallic glass forming liquids (MGFLs) was measured by a torsional oscillating viscometer. It has been found that the crucial condition to get viscosity data using graphite crucibles is to reach a superheated degree of at least 250 K for melts prior to measurements. The viscosity increases monotonically with a decrease in temperature before solidification, without distinct changes of dynamic mechanism during cooling. The present work indicates that these iron-based melts are heterogeneous even above the liquidus temperature. This finding helps to understand the melts of iron-based MGs and to improve the production process of iron-based glass ribbons.

Download Full-text

Effect of B2O3 Fluxing on Glass-Forming Ability and Soft Magnetic Properties of Fe(-Co)-B-Si-Nb Bulk Metallic Glasses

Materials Science Forum ◽

10.4028/www.scientific.net/msf.783-786.1895 ◽

2014 ◽

Vol 783-786 ◽

pp. 1895-1900 ◽

Cited By ~ 1

Author(s):

Teruo Bitoh

Keyword(s):

Magnetic Properties ◽

Metallic Glasses ◽

Bulk Metallic Glasses ◽

Glass Forming Ability ◽

The Other ◽

Maximum Diameter ◽

Soft Magnetic Properties ◽

Copper Mold ◽

Soft Magnetic ◽

Glass Forming

The effect of B2O3 fluxing on the glass-forming ability (GFA), the structure and the soft magnetic properties of Fe (-Co)-B-Si-Nb bulk metallic glasses (BMGs) has been investigated. The large Fe-Co-B-Si-Nb BMG specimens with diameters up to 7.7 mm, which is approximately 1.5 times as large as that of the maximum diameter of the copper mold cast one (= 5 mm), were prepared by the fluxing and water quenching. Thus the GFA of the Fe-Co-B-Si-Nb BMG are improved by the fluxing. It was confirmed that the soft magnetic properties of the Fe-Co-B-Si-Nb BMG are also improved by the fluxing. On the other hand, it was found for the Co-free Fe-B-Si-Nb BMG that the B2O3 fluxing promotes the precipitation of the α-Fe (-Si) and Fe2B phases in the central region of the specimens; i.e., the GFA of the Fe-B-Si-Nb BMG is decreased by the fluxing. The Fe-B-Si-Nb BMG specimens show a flat hysteresis loop, indicating a good linear relationship between the magnetic induction and the applied magnetic field. These results of the Fe-B-Si-Nb BMG show that it is possible to develop a new soft magnetic material that exhibits constant permeability, which is necessary for producing inductors and choke coils.

Download Full-text

Unveiling the role of Y content in glass-forming ability and soft magnetic properties of Co-Y-B metallic glasses by experiment and ab initio molecular dynamics simulations

Journal of Alloys and Compounds ◽

10.1016/j.jallcom.2022.163637 ◽

2022 ◽

pp. 163637

Author(s):

Shuang Ma ◽

Yuzhu Ran ◽

Xinyu Liang ◽

Li Jiang ◽

Yanhui Li ◽

...

Keyword(s):

Molecular Dynamics ◽

Magnetic Properties ◽

Metallic Glasses ◽

Glass Forming Ability ◽

Ab Initio Molecular Dynamics ◽

Soft Magnetic Properties ◽

Soft Magnetic ◽

Glass Forming ◽

Dynamics Simulations

Download Full-text

Co-Based Bulk Metallic Glasses with Good Soft-Magnetic Properties and High Strength

Materials Science Forum ◽

10.4028/www.scientific.net/msf.898.703 ◽

2017 ◽

Vol 898 ◽

pp. 703-708 ◽

Cited By ~ 1

Author(s):

Qi Kui Man ◽

Ya Qiang Dong ◽

Chun Tao Chang ◽

Xin Min Wang ◽

Run Wei Li

Keyword(s):

Magnetic Properties ◽

Metallic Glass ◽

Bulk Metallic Glass ◽

Metallic Glasses ◽

Bulk Metallic Glasses ◽

Eutectic Point ◽

Glass Forming Ability ◽

Soft Magnetic Properties ◽

Soft Magnetic ◽

Glass Forming

The thermal stability, glass-forming ability, soft-magnetic properties and mechanical properties of Co46Fe19+xB22.5Si5.5Nb7–x (x=0–2) bulk metallic glasses were investigated. The 5.5 at% Nb addition was found to be effective in approaching alloy to a eutectic point, resulting in an increase in glass-forming ability. By copper mold casting, bulk metallic glass rods with diameters up to 5 mm were produced. Except for high glass-forming ability, the bulk metallic glasses also exhibit good soft-magnetic properties, i.e., low coercive force of 1.34–2.14 A/m, high effective permeability at 1 kHz of 2.26–3.06×104, and high fractures strength (σf) of 4010–4460 MPa. This Co-based bulk metallic glass system with high strengths and excellent soft-magnetic properties is promising for future applications as a new functional material.

Download Full-text