Superior magnetic softness at elevated temperature of Si-rich Fe-based nanocrystalline alloy

2012 ◽  
Vol 112 (8) ◽  
pp. 083922 ◽  
Author(s):  
Rui-min Shi ◽  
Zhi Wang ◽  
Yun-yun Jia ◽  
Zhuan-ping Wen ◽  
Bo-wen Wang ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
Nanocrystalline Alloy ◽  
Magnetic Softness

New Fe-B-P-Cu Nanocrystalline Soft Magnetic Alloys with High Js Combined with Low Coercivity Hc

2012 ◽  
Vol 508 ◽  
pp. 99-105
Author(s):  
Ze Qiang Zhang ◽  
Parmanand Sharma ◽  
Akihiro Makino
Keyword(s):  
Raw Materials ◽  
Nanocrystalline Structure ◽  
Nanocrystalline Alloy ◽  
Amorphous Structure ◽  
Magnetic Alloy ◽  
Soft Magnetic ◽  
Soft Magnetic Alloy ◽  
Air Atmosphere ◽  
Fe Content ◽  
Magnetic Softness

Fe-Si-B Amorphous Alloys with Less than 80 at% Fe Are now in Practical Use due to their Excellent Magnetic Softness (Low Coercivity Hc) Combined with Rather High Saturation Magnetic Polarization (Js) which Basically Owing to the Lack of Intrinsic Magnetic Anisotropy and the High Fe Content, Respectively. In Order to Obtain High Js, High Fe Content Is Required. However, Alloys with High Fe Content Exceeding the Limit Usually Have the as-Quenched Structure Consisting of Coarse α-Fe Grains in the Amorphous Matrix, which Results in Inferior Magnetic Softness. We Have Developed a New Fe85.2B10P4Cu0.8 Nanocrystalline Soft Magnetic Alloy Ribbon (with 5 mm in Width and about 20 µm in Thickness) Made from Industrial Raw Materials in Air Atmosphere. The as-Quenched Structure of Fe85.2B10P4Cu0.8 Alloy Has Heterogeneous Amorphous Structure (a Large Amount of Extremely Small α-Fe Clusters in Addition to Amorphous Phase). Homogeneous Nanocrystalline Structure Composed of α-Fe Grains with a Size ~19 nm Was Realized by Crystallizing the Hetero-Amorphous Alloy. The Nanocrystalline Alloy Exhibit High Js ~ 1.83 T (Comparable to the Commercial Fe-3.5 Mass% Si Steel) and Extremely Low Hc ~ 6.0 A/m. Additionally the Alloy Has a Large Economical and Industrial Advantage of Lower Material Cost and Good Reproductivity, which Has a High Potential for the Power Applications.

Unique influence of heating rate on the magnetic softness of Fe81.5Si0.5B4.5P11Cu0.5C2 nanocrystalline alloy

2019 ◽  
Vol 471 ◽  
pp. 148-152 ◽  
Author(s):  
Lixian Jiang ◽  
Yan Zhang ◽  
Xing Tong ◽  
Tsuyoshi Suzuki ◽  
Akihiro Makino
Keyword(s):  
Heating Rate ◽  
Nanocrystalline Alloy ◽  
Magnetic Softness

Evidence for a shear mechanism for the precipitation of γ-zirconium hydride in zirconium

1978 ◽  
Vol 36 (1) ◽  
pp. 658-659
Author(s):  
G.J.C. Carpenter
Keyword(s):  
Elevated Temperature ◽  
Strain Field ◽  
Zirconium Hydride ◽  
Zirconium Atom ◽  
Atom Diffusion ◽  
Solvus Temperature ◽  
Hexagonal Close Packed ◽  
Partial Dislocations ◽  
The Face

In zirconium-hydrogen alloys, rapid cooling from an elevated temperature causes precipitation of the face-centred tetragonal (fct) phase, γZrH, in the form of needles, parallel to the close-packed <1120>zr directions (1). With low hydrogen concentrations, the hydride solvus is sufficiently low that zirconium atom diffusion cannot occur. For example, with 6 μg/g hydrogen, the solvus temperature is approximately 370 K (2), at which only the hydrogen diffuses readily. Shears are therefore necessary to produce the crystallographic transformation from hexagonal close-packed (hep) zirconium to fct hydride.The simplest mechanism for the transformation is the passage of Shockley partial dislocations having Burgers vectors (b) of the type 1/3<0110> on every second (0001)Zr plane. If the partial dislocations are in the form of loops with the same b, the crosssection of a hydride precipitate will be as shown in fig.1. A consequence of this type of transformation is that a cumulative shear, S, is produced that leads to a strain field in the surrounding zirconium matrix, as illustrated in fig.2a.

Microstructural characterization of a rapidly solidified Al-Fe-V-Si alloy for elevated temperature applications

1988 ◽  
Vol 46 ◽  
pp. 550-551
Author(s):  
R. E. Franck ◽  
J. A. Hawk ◽  
G. J. Shiflet
Keyword(s):  
High Temperature ◽  
Elevated Temperature ◽  
Grain Growth ◽  
Volume Fraction ◽  
Microstructural Characterization ◽  
Second Phase ◽  
Microstructural Stability ◽  
Elevated Temperature Strength ◽  
Temperature Applications

Rapid solidification processing (RSP) is one method of producing high strength aluminum alloys for elevated temperature applications. Allied-Signal, Inc. has produced an Al-12.4 Fe-1.2 V-2.3 Si (composition in wt pct) alloy which possesses good microstructural stability up to 425°C. This alloy contains a high volume fraction (37 v/o) of fine nearly spherical, α-Al12(Fe, V)3Si dispersoids. The improved elevated temperature strength and stability of this alloy is due to the slower dispersoid coarsening rate of the silicide particles. Additionally, the high v/o of second phase particles should inhibit recrystallization and grain growth, and thus reduce any loss in strength due to long term, high temperature annealing.The focus of this research is to investigate microstructural changes induced by long term, high temperature static annealing heat-treatments. Annealing treatments for up to 1000 hours were carried out on this alloy at 500°C, 550°C and 600°C. Particle coarsening and/or recrystallization and grain growth would be accelerated in these temperature regimes.

Effects of annealing temperature on the microstructure and initial permeability of nanocrystalline alloy Fe73.5Cu1Mo3Si13.5B9

1998 ◽  
Vol 13 (11) ◽  
pp. 3241-3246 ◽  
Author(s):  
X.Y. Zhang ◽  
J.W. Zhang ◽  
F.R. Xiao ◽  
J.H. Liu ◽  
K.Q. Zhang ◽  
...  
Keyword(s):  
Annealing Temperature ◽  
Nanocrystalline Alloy ◽  
Initial Permeability
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