Introduction Motivation Advanced Materials Rapid Solidification Processing Mechanical Alloying Outline of the Book Metallic Glasses Distinction between Crystals and Glasses Differences between Amorphous Alloys and Metallic Glasses The Concepts of Glass Formation Thermodynamics and Kinetics of Glass Formation Methods to Synthesize Metallic Glasses Bulk Metallic Glasses Potential Resources of Literature on Metallic Glasses Glass-Forming Ability of Alloys Critical Cooling Rate Reduced Glass Transition Temperature Deep Eutectics Topological Models Bulk Metallic Glasses Inoue Criteria Exceptions to the Above Criteria New Criteria Transformation Temperatures of Glasses Thermodynamic Modeling Structural and Topological Parameters Physical Properties Computational Approaches Miscellaneous Criteria Criteria for Glass Formation by Non-Solidification Methods Synthesis of Bulk Metallic Glasses Principles of Rapid Solidification Processing General Techniques to Achieve High Rates of Solidification Melt Spinning Bulk Metallic Glasses Bulk Metallic Glass Casting Methods Bulk Metallic Glass Composites Mechanical Alloying Bulk Metallic Glass Foams Crystallization Behavior Methodology Crystallization Modes in Melt-Spun Ribbons Differences in the Crystallization Behavior between Melt-Spun Ribbons and Bulk Metallic Glasses Thermal Stability of Metallic Glasses Crystallization Temperatures and Their Compositional Dependence Annealing of Bulk Metallic Glasses Effect of Environment Effect of Pressure during Annealing Physical Properties Density Thermal Expansion Diffusion Electrical Resistivity Specific Heat Viscosity Corrosion Behavior Terminology and Methodology Copper-Based Bulk Metallic Glasses Iron-Based Bulk Metallic Glasses Magnesium-Based Bulk Glassy Alloys Nickel-Based Bulk Metallic Glasses Titanium-Based Bulk Metallic Glasses Zirconium-Based Bulk Metallic Glasses Other Bulk Metallic Glassy Alloys Mechanical Behavior Deformation Behavior Deformation Maps Temperature Rise at Shear Bands Strength Ductility Fatigue Yield Behavior BMG Composites Magnetic Properties Soft Magnetic Materials Nanocrystalline Alloys Hard Magnetic Materials Applications Special Characteristics of Bulk Metallic Glasses Structural Applications Chemical Applications Magnetic Applications Miscellaneous Applications Epilogue Size and Shape Mechanical Properties Magnetic Properties Fundamental Properties Index References appear at the end of each chapter.

Bulk Metallic Glasses

The current status of research and development in Fe-based bulk metallic glasses (BMGs) is reviewed. Bulk metallic glasses are relatively new materials possessing a glassy structure and large section thickness. These materials have an exciting combination of properties such as high mechanical strength, good thermal stability, large supercooled liquid region and potential for easy forming. Ever since the first synthesis of an Fe-based BMG in an Fe–Al–Ga–P–C–B system in 1995, there has been intense activity on the synthesis and characterisation of Fe-based BMGs. These BMGs exhibit some unique characteristics which have not been obtained in conventional Fe-based crystalline alloys. This uniqueness has led to practical uses of these bulk glassy alloys as soft magnetic and structural materials. This review presents the recent results on the glass-forming ability, structure, thermal stability, mechanical properties, corrosion behaviour, soft magnetic properties and applications of Fe-based bulk glassy a...

https://www.tandfonline.com/doi/pdf/10.1179/1743280412Y.0000000007

Iron-based bulk metallic glasses

https://iopscience.iop.org/article/10.1088/1468-6996/10/5/053001/pdf

Electric current activated/assisted sintering (ECAS): a review of patents 1906–2008

Fe-based bulk metallic glasses: Glass formation, fabrication, properties and applications

Fabrication of Fe-based bulk metallic glass by selective laser melting: A parameter study

A magnetic powder core comprises a molded article of a mixture of a glassy alloy powder and an insulating material. The glassy alloy comprises Fe and at least one element selected from Al, P, C, Si, and B, and has a texture primarily composed of an amorphous phase. The glassy alloy exhibits a temperature difference ΔTx, which is represented by the equation ΔTx=Tx−Tg, of at least 20 K in a supercooled liquid, wherein Tx indicates the crystallization temperature and Tg indicates the glass transition temperature. The magnetic core precursor is produced mixing the glassy alloy powder with the insulating material, compacting the mixture to form a magnetic core precursor, and annealing the magnetic core precursor at a temperature in the range between (Tg−170) K and Tg K to relieve the internal stress of the magnetic core precursor. The glassy alloy exhibits low coercive force and low core loss.

Low-loss magnetic powder core, and switching power supply, active filter, filter, and amplifying device using the same

PROBLEM TO BE SOLVED: To provide amorphous soft magnetic alloy powder which has high saturation magnetization and low core loss and which is almost spherical and manufactured by water atomization method, and to provide a green compact core and radio wave absorber using the same. SOLUTION: This amorphous soft magnetic alloy powder is formed substantially spherical by the water atomization method. The powder mainly consists of Fe and contains at least P, C and B, and is formed of amorphous soft magnetic alloy powder consisting of an amorphous phase with a temperature interval ΔTx of the supercooled liquid of ≥ 20K. A green compact core is formed by solidifying the granulated mixture of this amorphous soft magnetic alloy powder, insulator and lubricant. The radio wave absorber is formed by mixing the amorphous soft magnetic alloy powder the particles of which is flattened and insulator. COPYRIGHT: (C)2004,JPO

Amorphous soft magnetic alloy powder, and green compact core and radio wave absorber using the same

Structure and soft magnetic properties of the bulk Fe 70 Al 5 Ga 2 P 9.65 C 5.75 B 4.6 Si 3 glassy alloy prepared by pulse current sintering with uniaxial pressure were investigated. The sample consolidated in the temperature range of the supercooled liquid region consists only of amorphous phase and has a very high relative density of 99%. The flux density under applied field of 800 A/m ( B 800 ), maximum permeability ( μ max ) and coercive force ( H c ) for the sample sintered at 703 K in as-made state are 1.08 T, 7600 and 12.0 A/m, respectively. B 800 and μ max are improved to 1.17 T and 8000 by annealing at 723 K for 3.6 ks. The soft magnetic properties of the bulk Fe-based glassy alloy are superior to those of the bulk Fe-Si-B alloy consolidated amorphous powders. It is considered that the high relative density and good soft magnetic properties for the bulk Fe-based glassy alloy depend upon its high structural homogeneity originated from its high deformability, that is based on the viscous flow arisen from the appearance of supercooled liquid region.

Structure and soft magnetic properties of bulk Fe-Al-Ga-P-C-B-Si glassy alloys prepared by consolidating amorphous powders

Structural and soft magnetic properties were investigated for a bulk glassy Fe 70 Al 5 Ga 2 P 9.65 C 5.75 B 4.6 Si 3 alloy in a ring shape form with an outer diameter of 10 mm, an inner diameter of 6 mm and a thickness of I mm prepared by copper mold casting. The bulk sample composes of an amorphous single phase. The supercooled liquid region (Δ T x ) defined by the difference between the crystallization temperature (T x ) and glass transition temperature (T g ) for the bulk glassy alloy is about 60 K, being in agreement with that of the corresponding amorphous alloy ribbon. Saturation magnetization (σ s ) and Curie temperature (T c ) for the bulk sample are about 1.2 T and 620 K, respectively, both of which agree with those of the melt-spun ribbon. Furthermore, the maximum permeability (μ max ) and the coercivity (H c ) for the bulk glassy sample in as cast state are about 110000 and 2.2 A/m, respectively. These excellent soft magnetic properties are presumably due to a higher degree of structural homogeneity resulting from its high glass-forming ability. It is concluded that the good soft magnetic properties combined with high glass-forming-ability and castability of the Fe-Al-Ga-P-C-B-Si glassy alloy hold promise for its development as a future engineering magnetic material.

Soft Magnetic Properties of Ring Shape Bulk Glassy Fe–Al–Ga–P–C–B–Si Alloy Prepared by Copper Mold Casting

The present invention provides an Fe-base soft magnetic alloy and a laminated magnetic core formed by using the alloy which contains Fe as a main component and at least one element M and B selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Mo and W, in which at least 50% of the crystalline structure comprises fine crystalline grains having an average crystal grain size of 30 nm or less and a body-centered cubic structure, and the fracture strain at 300° C. or less is 1. The ratios of the components Fe, and elements M and B are 75 to 93 atomic %, 4 to 9 atomic % and 0.5 to 18 atomic %, respectively. The alloy may contain other additive elements such as Cr, Ru, Hr, Ir, Si, Al, Ge, Ga and the like.

Shoji Yoshida

Papers

Low-loss magnetic powder core, and switching power supply, active filter, filter, and amplifying device using the same

Amorphous soft magnetic alloy powder, and green compact core and radio wave absorber using the same

Structure and soft magnetic properties of bulk Fe-Al-Ga-P-C-B-Si glassy alloys prepared by consolidating amorphous powders

Soft Magnetic Properties of Ring Shape Bulk Glassy Fe–Al–Ga–P–C–B–Si Alloy Prepared by Copper Mold Casting

FE-base soft magnetic alloy and laminated magnetic core by using the same