scholarly journals The Influence of 3d and 4d Transition Metals on the Glass Forming Ability of Ternary FeCo-Based Alloys

2021 ◽  
Vol 52 (5) ◽  
pp. 1861-1868
Author(s):  
Z. Śniadecki
Keyword(s):  
Driving Force ◽  
Glass Forming Ability ◽  
Enthalpies Of Formation ◽  
Magnetic Flux Density ◽  
Magnetic Saturation ◽  
Transition Elements ◽  
Metal Substitution ◽  
Crucial Step ◽  
Glass Forming ◽  
Ability Parameter

AbstractThermodynamic modeling was used to determine enthalpies of formation and other thermodynamic parameters describing glass forming ability of Fe-Co-TM (TM = V, Nb, Cr, Mo) alloys. FeCo-based alloys are considered as candidates for applications as high magnetic flux density materials due to their high magnetic saturation and low magnetic anisotropy. Nevertheless, mechanical properties, especially the lack of ductility, are their main weakness. Therefore, further optimization by vitrification, further heat treatment and alloying should be considered. As the most crucial step is the synthesis of amorphous precursors, discussion is concentrated on the effect of transition metal substitution on the glass forming ability. The highest glass forming ability was reported for Fe-Co-Nb alloys. It can be also noted that the driving force for vitrification can be improved by substitution of Fe by other transition elements, as glass forming ability parameter ∆PHS reaches the lowest values for Fe-less compositions.

Glass Forming Ability of Ca-Based Bulk Metallic Glasses

2011 ◽  
Vol 171 ◽  
pp. 121-126 ◽  
Author(s):  
Ashmi T. Patel ◽  
Kirit N. Lad ◽  
Arun Pratap
Keyword(s):  
Metallic Glasses ◽  
Driving Force ◽  
Bulk Metallic Glasses ◽  
Energy Difference ◽  
Glass Forming Ability ◽  
Point Of View ◽  
Undercooled Liquid ◽  
Free Energy Difference ◽  
Glass Forming ◽  
Gibbs Free Energy Difference

Knowledge of glass forming ability (GFA) of amorphous metallic alloys is very important from both theoretical and practical point of view. Thermodynamically, the Gibbs free energy difference, ΔG between the undercooled liquid and the corresponding crystalline state is driving force for crystallization. As a consequence, it is a good indicator for glass forming ability of metallic glasses. A novel expression for ΔG has been used to estimate the GFA of recently developed Ca-based bulk metallic glasses viz. Ca53Mg23Cu24,Ca65Mg15Cu20,Ca40Mg25Cu35, Ca50Mg22.5Cu27.5 and Ca55Mg15Cu30. Different GFA criteria are also evaluated for systems taken up in the study and effect of addition of variation in composition of Ca-Mg-Cu system is also investigated. Present work suggests that among different GFA criteria, ΔG is the best criterion for the prediction of GFA for Ca-based bulk metallic glasses.

Optimization of Glass Forming Ability of Al-Ni-Si Alloys by a Thermodynamic and Kinetic Approach

2013 ◽  
Vol 773-774 ◽  
pp. 466-470
Author(s):  
Yi Cao ◽  
Kevin J. Laws ◽  
Michael Ferry
Keyword(s):  
Driving Force ◽  
Amorphous Structure ◽  
Glass Forming Ability ◽  
Glass Forming ◽  
Glassy Alloys ◽  
Novel Approach ◽  
Short Range Ordering ◽  
Packing Efficiency ◽  
Efficient Packing ◽  
Mould Casting

This study reports the glass forming ability (GFA) of Al-Ni-Si alloys with selected compositions based on atomic packing efficiency and driving force criteria. Higher GFA was observed in the Al-rich lower liquidus temperature regions of the Al-Ni-Si system indicating that these compositions exhibit a lower driving force for crystallization. Five glassy alloys that were calculated to consist of densely packed atomic short-range ordering were found to retain an amorphous structure upon copper mould casting. The result of GFA in the Al-Ni-Si system provides a novel approach to develop new metallic glasses considering both the thermodynamic stability and sluggish crystallisation kinetics through efficient packing.

FePBNbCr Soft Magnetic Glassy Alloys “SENNTIX” with Low Loss Characteristics for Commercial Inductor Cores

2010 ◽  
Vol 654-656 ◽  
pp. 1098-1101 ◽  
Author(s):  
Hiroyuki Matsumoto ◽  
Akiri Urata ◽  
Yasunobu Yamada ◽  
Akihisa Inoue
Keyword(s):  
Corrosion Resistance ◽  
Resin Composite ◽  
Core Loss ◽  
Glass Forming Ability ◽  
Metal Alloys ◽  
Magnetic Flux Density ◽  
Liquid Region ◽  
Glass Forming ◽  
Glassy Alloys ◽  
Wide Range

The inductor for a power supply is expected to have higher efficiency and capability of dealing satisfactorily with large current. Additionally, high corrosion resistance characteristics are also required for commercial inductors in practical use of. Thereby, we focused on Fe-based glassy metal alloys with both high magnetization and low magnetic anisotropy ［1］, and developed the novel glassy metal alloys with a chemical composition Fe97-x-yPxByNb2Cr1. In this glassy metal alloy, 1 at % Cr is the optimum composition for the realization of higher corrosion resistance as well as a high magnetic flux density. The glassy Fe97-x-yPxByNb2Cr1 (x=5-13, y=7-15) alloy exhibits the high glass-forming ability leading to the large thickness of 110-150 μm and low coercive force of 2.5-3.1 A/m due to higher structural homogeneity in wide range of composition. The large critical thickness of this alloy should be caused by the high glass-forming ability (GFA) due to the existence of the super cooled liquid region (Tx) of roughly 30 K. Therefore a Fe77P7B13Nb2Cr1 powder/resin composite core displays a much lower core loss of 650 W/m3 than the conventional amorphous Fe75Si10B12Cr3 powder/resin composite core by approximately 1/3.

Fe-Metalloid Metallic Glasses with High Magnetic Flux Density and High Glass-Forming Ability

2007 ◽  
Vol 561-565 ◽  
pp. 1361-1366 ◽  
Author(s):  
Akihiro Makino ◽  
Takeshi Kubota ◽  
Masahiro Makabe ◽  
Chun Tao Chang ◽  
Akihisa Inoue
Keyword(s):  
Metallic Glasses ◽  
Bulk Metallic Glasses ◽  
Glass Forming Ability ◽  
Soft Magnetic Materials ◽  
Magnetic Flux Density ◽  
Essential Property ◽  
Soft Magnetic ◽  
Metal Elements ◽  
Glass Forming ◽  
High Efficient

Fe-based bulk metallic glasses with good soft magnetic softness, high strength and relatively low material cost should have greatest potential for wide variety of applications among many kinds of bulk metallic glasses (BMGs). However, the glass-forming metal elements such as Al, Ga, Nb, Mo and so forth in the Fe-based BMGs significantly decrease saturation magnetization (Js) which is a essential property as soft magnetic materials. Since the coexistence of high Js and high glass-forming ability (GFA) has been earnestly desired from academia to industry, however, has been left unrealized over many years. Here, we present a Fe76Si9B10P5 bulk glassy alloy exhibiting with unusual combination of high Js of 1.51 T comparable to the Fe-Si-B amorphous alloy ribbons with thickness of about 25 μm in now practical use, because of not-containing the glass-forming metal elements, and high GFA leading to a rod with a diameter of 2.5 mm. This alloy composed of familiar and low-priced elements also has extremely low coercivity which should enable ultra-high efficient transformers, therefore, has a great advantage for engineering and industry, and thus significantly improves energy saving, conservation of earth resources and environment.

Fe-Metalloid Metallic Glasses with High Magnetic Flux Density and High Glass-Forming Ability

2007 ◽  
pp. 1361-1366
Author(s):  
Akihiro Makino ◽  
Takeshi Kubota ◽  
Masahiro Makabe ◽  
Chun Tao Chang ◽  
Akihisa Inoue
Keyword(s):  
Magnetic Flux ◽  
Flux Density ◽  
Metallic Glasses ◽  
Glass Forming Ability ◽  
Magnetic Flux Density ◽  
Glass Forming

Induction period of the crystallization of silver nitrate solutions in ethylene glycol

1991 ◽  
Vol 56 (10) ◽  
pp. 2142-2147
Author(s):  
Ivo Sláma
Keyword(s):  
Ethylene Glycol ◽  
Silver Nitrate ◽  
Induction Period ◽  
Glass Forming Ability ◽  
Transformation Theory ◽  
Concentration Region ◽  
Glass Forming ◽  
Temperature Transformation ◽  
Silver Nitrate Solutions ◽  
Nitrate Solutions

The dependence of the induction period of crystallization on supercooling was examined for the silver nitrate-ethylene glycol system over the concentration region of silver nitrate lome fraction of 0 to 0.12. Addition of AgNO3 to ethylene glycol was found to increase considerably the critical induction period of crystallization, although to a lesser extent than Ca(NO3)2, CaCl2, ZnCl2, LiCl and LiNO3 do. The effect of these salts on the critical induction period of crystallization in dimethylsulfoxide, dimethylformamide, dimethylacetamide and methanol was compared in terms of the solvent-rich composition limit of the glass-forming ability. By using the TTT(Time-Temperature-Transformation) theory, it has been deduced that the effect of the salts on the critical induction period of crystallization of ethylene glycol is probably due to the different dependences of viscosity on their concentration in ethylene glyco in the supercooling region.

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