Two-stage-like glass transition and the glass-forming ability of a soft magnetic Fe-based glassy alloy

2009 ◽  
Vol 105 (5) ◽  
pp. 053518 ◽  
Author(s):  
Wei Zhang ◽  
Fei Jia ◽  
Xingguo Zhang ◽  
Guoqiang Xie ◽  
Hisamichi Kimura ◽  
...  
Keyword(s):  
Glass Transition ◽  
Glassy Alloy ◽  
Glass Forming Ability ◽  
Soft Magnetic ◽  
Two Stage ◽  
Glass Forming

scholarly journals Glass-Forming Ability and Soft Magnetic Properties of (Co75Ti25)100−xFex (x; 0–20 at.%) Systems Fabricated by SPS of Mechanically Alloyed Nanopowders

Nanomaterials ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 849
Author(s):  
Mohamed Sherif El-Eskandarany ◽  
Naser Ali ◽  
Maryam Saeed
Keyword(s):  
Glass Transition ◽  
Large Diameter ◽  
Core Loss ◽  
Glass Forming Ability ◽  
Magnetic Characteristics ◽  
Order Structure ◽  
Soft Magnetic ◽  
Mechanically Alloyed ◽  
Glass Forming ◽  
Glassy Alloys

Due to their outstanding mechanical properties and soft magnetic characteristics, cobalt-based metallic glassy alloys have stimulated much interesting research. These metastable ferromagnetic materials possess very small magnetocrystalline anisotropy, and almost zero magnetostriction. They reveal low coercivity, extremely low core loss, moderate saturation polarization, and very high magnetism. Despite these attractive physical behaviors, Co-based metallic glasses are difficult to obtain by the melting/casting and conventional rapid solidification techniques due to their poor glass-forming ability. In the present study, we succeed in preparing (Co75Ti25)100−xFex (x; 0–20 at.%) metallic glassy powders, using a mechanical alloying approach. The end product of the as-prepared powders was consolidated into full dense cylinders with large-diameter and thickness (2 × 2 cm), using spark plasma sintering technique. The results have shown that the consolidation step did not lead to any undesired crystallizations or phase transformations, and the as-consolidated buttons maintained their unique short-range order structure. These bulk metallic glassy systems possessed high glass-transition and crystallization temperatures, suggesting their high thermal stability. However, they showed low values of the reduced glass-transition temperatures, indicating that this system is difficult to prepare by the conventional way of preparations.

GLASS FORMING ABILITY OF HARD MAGNETIC Nd55Al20Fe25 BULK GLASSY ALLOY WITH DISTINCT GLASS TRANSITION

2005 ◽  
Vol 19 (22) ◽  
pp. 3493-3500 ◽  
Author(s):  
L. XIA ◽  
C. L. JO ◽  
Y. D. DONG
Keyword(s):  
Glass Transition ◽  
Glassy Alloy ◽  
Bulk Sample ◽  
Glass Forming Ability ◽  
Glassy Matrix ◽  
Section Thickness ◽  
Xrd Pattern ◽  
Glass Forming ◽  
Bulk Glassy Alloy ◽  
Hard Magnetic Properties

Nd 55 Al 20 Fe 25 bulk sample was prepared in the shape of rods 3 mm in diameter by suction casting. The sample exhibits typical amorphous characters in XRD pattern, distinct glass transition in DSC traces and hard magnetic properties. The distinct glass transition, which is invisible in DSC traces of previously reported Nd — Al — Fe ternary BMGs, allows us to investigate the glass forming ability (GFA) of Nd 55 Al 20 Fe 25 alloy using the reduced glass transition temperature Trg and the recently defined parameter γ. However, it is found that the obtained diameter of the Nd 55 Al 20 Fe 25 glassy rod is much larger than the critical section thickness of the BMG predicted by either Trg or γ. The microstructure of Nd 55 Al 20 Fe 25 as-cast rod was studied and the apparent GFA of the alloy was supposed to be enhanced by the metastable nano-precipitates dispersed within the glassy matrix.

Compositional Dependence of Thermal Stability and Soft Magnetic Properties for Fe-Al-Ga-P-C-B Glassy Alloys

1998 ◽  
Vol 554 ◽  
Author(s):  
T. Mizushima ◽  
A. Makino ◽  
S. Yoshida ◽  
A. Inoue
Keyword(s):  
Magnetic Properties ◽  
Composition Range ◽  
Glassy Alloy ◽  
Alloy System ◽  
Supercooled Liquid Region ◽  
Glass Forming Ability ◽  
Liquid Region ◽  
Soft Magnetic Properties ◽  
Soft Magnetic ◽  
Glass Forming

AbstractStructure, glass forming ability and soft magnetic properties for Fe-Al-Ga-P-C-B glassy alloy system were investigated in the compositional range of Fe from 69 to 78 at%, (Al+Ga) from 2 to 12 and (P+C+B) from 17 to 28. The saturation magnetization (σ5) rises gradually with increase of Fe concentration. The maximum value of 70K for supercooled liquid region (ΔTx=Tx-Tg, Tx: crystallization temperature, Tg: glass transition temperature:) and the maximum thickness of 180 μm for glass formation (tmax,) are found in the composition range around Fe=70at% and (Al+Ga)=7at%. The highest permeability (μc) of 20,000 at 1kHz and the lowest coercive force (Hc) of 2 A/m at the sample thickness of 30 μm can be also obtained at this composition. It was ascertained that the composition regions to yield the maximum glass forming ability and lowest magnetostriction were in agreement with that in which the most excellent soft magnetic properties were yielded. This results allow us to assume that the excellent soft magnetic properties for this glassy alloy system in the limited composition range are presumably due to high structural homogeneity resulting from significantly high glass-forming ability.

Soft Magnetic Bulk Glassy Alloy Synthesized by Flux Melting and Water Quenching

2007 ◽  
Vol 539-543 ◽  
pp. 1921-1925 ◽  
Author(s):  
Akihiro Makino ◽  
Teruo Bitoh ◽  
Akihisa Inoue ◽  
A. Lindsay Greer
Keyword(s):  
Cooling Rate ◽  
Glassy Alloy ◽  
Glass Forming Ability ◽  
Water Quenching ◽  
Soft Magnetic ◽  
Glass Forming ◽  
Large Bulk ◽  
Mold Casting ◽  
Molten Flux ◽  
Bulk Glassy Alloy

The flux treatment was applied to increase the glass-forming ability of a glassy [(Fe0.5Co0.5)0.75B0.20Si0.05]96Nb4 alloy. The large bulk glassy specimen with diameter of 7.7 mm was prepared by water quenching the melt immersed in the molten flux of B2O3. The diameter of the specimens is approximately 1.5 times as large as the previous result, even though the cooling rate of copper mold casting should be much higher than that of water quenching. The critical cooling rate for a glassy phase is 150 - 170 K/s, which is much slower than 500 K/s without the flux treatment. The flux treatment improves the glass-forming ability by cleaning the molten metal where heterogeneous nucleation is difficult to take place.

Glass Formation and Glass Forming Ability of Alloys Near Eutectic Composition

2000 ◽  
Vol 644 ◽  
Author(s):  
Y. Li
Keyword(s):  
Glass Transition ◽  
Glass Formation ◽  
Eutectic Composition ◽  
Glass Forming Ability ◽  
Critical Section ◽  
Bulk Glass ◽  
Melting Behaviour ◽  
Eutectic Alloys ◽  
Section Thickness ◽  
Glass Forming

AbstractOnset temperature, Tm and offset temperature (liquidus) Tl of melting of a series of bulk glass forming alloys based on La, Mg, and Pd have been measured by studying systematically the melting behaviour of these alloys using DTA or DSC. Bulk metallic glass formation has been found to be most effective at or near their eutectic points and less effective for off-eutectic alloys. Reduced glass transition temperature Trg given by Tg/Tl is found to show a stronger correlation with critical cooling rate or critical section thickness for glass formation than Trg given by Tg/Tm.

scholarly journals Bulk Glassy Co43Fe20Ta5.5B31.5 Alloy with High Glass-Forming Ability and Good Soft Magnetic Properties

2001 ◽  
Vol 42 (10) ◽  
pp. 2136-2139 ◽  
Author(s):  
Baolong Shen ◽  
Hisato Koshiba ◽  
Akihisa Inoue ◽  
Hisamichi Kimura ◽  
Takao Mizushima
Keyword(s):  
Magnetic Properties ◽  
Glass Forming Ability ◽  
Soft Magnetic Properties ◽  
Soft Magnetic ◽  
Glass Forming
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