Structural Study of Fe-Based Glassy Alloys with a Large Supercooled Liquid Region

2000 ◽  
Vol 644 ◽  
Author(s):  
M. Imafuku ◽  
S. Sato ◽  
T. Nakamura ◽  
H. Koshiba ◽  
E. Matsubara ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Random Network ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
X Ray Diffraction ◽  
Size Mismatch ◽  
Atomic Structures ◽  
Glassy Alloys ◽  
The Difference

AbstractThe thermal stability and local atomic structures of glassy Fe70M10B20 (M = Hf, Zr, Nb, W and Cr) alloys were analyzed by DSC, ordinary X-ray diffraction and AXS measurements. The random network of the trigonal prism-like structure of (Fe,M)3B with edge-sharing, was identified in all the Fe70M10B20 (M = Hf, Zr, Nb, W and Cr) alloys in spite of the wide variety of thermal stability upon heating. Several unique primary precipitated crystalline phases, such as Fe23B6 type and Fe-M phases, were observed in the alloys exhibiting a high thermal stability. These crystallization reactions require relatively long range rearrangements of the constituents and hence the thermal stability of the glassy phase increases, leading to the appearance of a large supercooled liquid region upon heating. These phenomena may be originated from the difference in the chemical affinity and the atomic size mismatch between M and Fe or B.

Formation of Ni57Zr20Ti22Pb1 Amorphous Powders by Mechanical Alloying

2007 ◽  
Vol 539-543 ◽  
pp. 2767-2772
Author(s):  
Pee Yew Lee ◽  
S.S. Hung ◽  
Jason S.C. Jang ◽  
Giin Shan Chen
Keyword(s):  
Thermal Stability ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
Atomic Size ◽  
X Ray ◽  
Amorphous Powders ◽  
Thermal Stability Of

In the current study, the amorphization behavior of mechanically alloyed Ni57Zr20Ti22Pb1 powder was examined in details. The conventional X-ray diffraction results confirm that the fully amorphous powders formed after 5 hours of milling. The thermal stability of the Ni57Zr20Ti22Pb1 amorphous powders was investigated by differential scanning calorimeter (DSC). As the results demonstrated, the glass transition temperature (Tg) and the crystallization temperature (Tx) are 760 K and 850 K, respectively. The supercooled liquid region is 90 K. The appearance of wide supercooled liquid region may be mainly due to the Pb additions which cause the increasing differences in atomic size of mechanically alloyed Ni57Zr20Ti22Pb1 powders.

Effects of Minor Additions on Ni- and Be-Free Ti-Based Bulk Glassy Alloys

2015 ◽  
Vol 833 ◽  
pp. 79-84 ◽  
Author(s):  
Sheng Li Zhu ◽  
Guo Qiang Xie ◽  
Akihisa Inoue ◽  
Zhen Duo Cui ◽  
Xian Jin Yang ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Glassy Alloy ◽  
Alloy System ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Glass Forming Ability ◽  
Liquid Region ◽  
Glass Forming ◽  
Glassy Alloys ◽  
Si Addition

We investigated the effects of addition elements (Sn, Al, Si, Ag, Fe, Cr) with a small amount on the glass-forming ability, thermal stability and mechanical properties of the Ti-Zr-Cu-Pd glassy alloy system. The results revealed that minor Sn addition improved the glass-forming ability, thermal stability and plasticity, Si addition enlarged the supercooled liquid region, and Fe addition improved the plasticity, while minor additions of Si, Ag, Fe, and Cr lowered the glass-forming ability, and Al and Cr additions were harmful to the plasticity of the Ti-Zr-Cu-Pd glassy alloy system.

Amorphization Behavior of Ni57Zr20Ti22Ge1 Powders by Mechanical Alloying

2011 ◽  
Vol 479 ◽  
pp. 48-53
Author(s):  
Kai Chen Kuo ◽  
Pee Yew Lee ◽  
Jai Yush Yen
Keyword(s):  
Thermal Stability ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
Atomic Size ◽  
X Ray ◽  
Amorphous Powders ◽  
Thermal Stability Of

In the current study, the amorphization behavior of mechanically alloyed Ni57Zr20Ti22Ge1 powder was examined in details. The conventional X-ray diffraction results confirm that the fully amorphous powders formed after 5 hours of milling. The thermal stability of the Ni57Zr20Ti22Ge1 amorphous powders was investigated by differential scanning calorimeter (DSC). As the results demonstrated, the glass transition temperature (Tg) and the crystallization temperature (Tx) are 761 K and 839 K, respectively. The supercooled liquid region ΔT is 78 K. The appearance of wide supercooled liquid region may be mainly due to the Ge additions which cause the increasing differences in atomic size of mechanically alloyed Ni57Zr20Ti22Ge1 powders.

Formation of Bulk Glassy Fe75–x–yCrxMoyC15B10 Alloys and Their Corrosion Behavior

2002 ◽  
Vol 17 (3) ◽  
pp. 701-704 ◽  
Author(s):  
Shujie Pang ◽  
Tao Zhang ◽  
Katsuhiko Asami ◽  
Akihisa Inoue
Keyword(s):  
Corrosion Resistance ◽  
Alloy System ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Large Temperature ◽  
Liquid Region ◽  
High Corrosion Resistance ◽  
High Corrosion ◽  
Glassy Alloys ◽  
Mold Casting

Formation of bulk Fe-based glassy alloys with high corrosion resistance was succeeded in the Fe75–x–yCrxMoyC15B10 alloy system. A large temperature interval of supercooled liquid region (ΔTx) of 40–90 K was obtained over a wide composition range for the Fe75?x–yCrxMoyC15B10 alloys. The Fe75–x–yCrxMoyC15B10 alloys were prepared in a bulk glassy form with diameters of 1.0–2.5 mm by copper mold casting. The bulk glassy Fe75–x–yCrxMoyC15B10 alloys exhibited high corrosion resistance in 1 N HCl solution. The glassy alloys containing Cr were spontaneously passivated with a wide passive region before the transpassive dissolution of Cr. The passive current density decreased significantly with an increase of alloying Cr content, indicating that the addition of Cr was effective on enhancing the corrosion resistance. Excess addition of Mo for replacing Fe in the present alloys was detrimental for the corrosion resistance.

Crystallization Pathway in the Bulk Metallic Glass Zr41.2Ti13.8Cu12.5Ni10Be22.5

1996 ◽  
Vol 455 ◽  
Author(s):  
S. Schneider ◽  
P. Thiyagarajan ◽  
U. Geyer ◽  
W. L. Johnson
Keyword(s):  
Scattering Length ◽  
Primary Crystallization ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
X Ray Diffraction ◽  
Amorphous Phases ◽  
New Family ◽  
Transmission Electron ◽  
Composition Fluctuations

AbstractA new family of multicomponent metallic alloys exhibits an excellent glass forming ability at moderate cooling rates of about 10K/s and a wide supercooled liquid region. These glasses are eutectic or nearly eutectic, thus far away from the compositions of competing crystalline phases. The nucleation of crystals from the homogeneous amorphous phase requires large thermally activated composition fluctuations for which the time scale is relatively long, even in the supercooled liquid. In the Zr41.2Ti13.8Cu12.5Ni10Be22.5 alloy therefore a different pathway to crystallization is observed. The initially homogeneous alloy separates into two amorphous phases. In the decomposed regions, crystallization probability increases and finally polymorphic crystallization occurs. The evolution of decomposition and succeeding primary crystallization in the bulk amorphous Zr41.2Ti13.8Cu12.5Ni10Be22.5 alloy have been studied by small angle neutron. Samples annealed isothermally in the supercooled liquid and in the solid state exhibit interference peaks indicating quasiperiodic inhomogeneities in the scattering length density. The related wavelengths increase with temperature according to the linear Cahn-Hilliard theory for spinodal decomposition. Also the time evolution of the interference peaks in the early stages is consistent with this theory. At later stages, X-ray diffraction and transmission electron microscopy investigations confirm the formation of nanocrystals in the decomposed regions.

Ni-based bulk glassy alloys with large supercooled liquid region exceeding 90K

2005 ◽  
Vol 13 (11) ◽  
pp. 1166-1171 ◽  
Author(s):  
Dmitri V. Louzguine-Luzgin ◽  
Takeyuki Shimada ◽  
Akihisa Inoue
Keyword(s):  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
Glassy Alloys

scholarly journals (Fe,Co,Ni)–B–Si–Nb Bulk Glassy Alloy With Super-High Strength and Some Ductility [Article Retracted]

2005 ◽  
Vol 20 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Baolong Shen ◽  
Akihisa Inoue
Keyword(s):  
Plastic Strain ◽  
Glassy Alloy ◽  
Functional Materials ◽  
High Strength ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
Glassy Alloys ◽  
Strength Alloy ◽  
Bulk Glassy Alloy

Glassy [(Fe0.8Co0.1Ni0.1)0.75B0.2Si0.05]96Nb4 alloy rods with glass transition temperature of 835 K, followed by a large supercooled liquid region of 55 K were produced in the diameter range up to 2 mm by copper mold casting. The glassy alloy rods exhibit super-high true fracture strength of 4225 MPa combined with elastic strain of 0.02 and true plastic strain of 0.005. The super-high strength alloy simultaneously exhibits high magnetization of 1.1 T, low coercivity of 3 A/m, and high permeability of 1.8 × 104 at 1 kHz. The success of synthesizing a super-high strength Fe-based bulk glassy alloy with some compressive plastic strain and good soft magnetic properties is encouraging for future development of Fe-based bulk glassy alloys as new engineering and functional materials.

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