Glass formation in a (Ti, Zr, Hf)–(Cu, Ni, Ag)–Al high-order alloy system by mechanical alloying

In this work, glass formation under high-energy ball milling was investigated for a (Ti0.33Zr0.33Hf0.33)50(Ni0.33Cu0.33Ag0.33)40Al10 high-order alloy system with equiatomic substitution for early and late transition-metal contents. For comparison, an amorphous alloy ribbon with the same composition was prepared using the melt-spinning method as well. Structural features of the samples were characterized using x-ray diffraction, transmission electron microscopy, and differential scanning calorimetry. Mechanical alloying resulted in a glassy alloy similar to that obtained by melt spinning. However, the glass formation was incomplete, and a small amount of unreacted crystallites smaller than 30 nm in size still remained in the final ball-milled product. Like the melt-spun glass, the ball-milled glassy alloy also exhibited a distinct glass transition and a wide supercooled liquid region of about 80 K. Crystallization of this high-order glassy alloy proceeded through two main stages. After the primary nanocrystallization was completed, the remaining amorphous phase also behaved as a glass, showing a detectable glass transition and a large supercooled liquid region of about 100 K.

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Soft Magnetic Properties of Nanocrystalline Fe–Co–B–Si–Nb–Cu Alloys in Ribbon and Bulk Forms

Journal of Materials Research ◽

10.1557/jmr.2003.0390 ◽

2003 ◽

Vol 18 (12) ◽

pp. 2799-2806 ◽

Cited By ~ 36

Author(s):

Akihisa Inoue ◽

Baolong Shen

Keyword(s):

Magnetic Properties ◽

Melt Spinning ◽

Glassy Alloy ◽

Nanocrystalline Alloy ◽

Supercooled Liquid ◽

Supercooled Liquid Region ◽

Exothermic Peak ◽

Liquid Region ◽

Soft Magnetic Properties ◽

Soft Magnetic

Ribbon and bulk nanocrystalline body-centered-cubic (bcc) (Fe,Co) alloys exhibiting good soft magnetic properties were synthesized in Fe71.5-xCoxB13.5Si10Nb4Cu1 system by the simple production processes of melt-spinning or casting and annealing. The glass-type alloys were formed in the Co content range below 30 at.%. These glassy alloys crystallized through two exothermic reactions. The first stage was due to the precipitation of nanoscale bcc-(Fe,Co) phase with a grain size of about 10 nm, and the second stage resulted from the decomposition of the remaining amorphous phase to α–(Fe,Co), (Fe,Co)2B, (Fe,Co)23B6, (Fe,Co)3Si, and (Fe,Co)2Nb phases. The glass transition temperature increased from 820 to 827 K with increasing Co content from 5 to 20 at.%, while the supercooled liquid region decreased slightly from 37 to 30 K because of the nearly constant crystallization temperature. By choosing the 10 at.% Co-containing alloy, we produced cylindrical glassy alloy rods 1.0 and 1.5 mm in diameter by copper mold casting. The subsequent annealing for 300 s at 883 K corresponding to the temperature just above the first exothermic peak caused the formation of nanoscale bcc-(Fe,Co) structure. The bcc-(Fe,Co) alloy rods exhibited good soft magnetic properties of 1.26 T for saturation magnetization and 5.0 A/m for coercive force, which were comparable to those for the corresponding bcc-(Fe,Co) alloy ribbon. The nanocrystalline alloy in a bulk form is encouraging for future use as a new type of soft magnetic material that requires three-dimensional shapes.

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Solid-state synthesis of new glassy Co65Ti20W15 alloy powders and subsequent densification into a fully dense bulk glass

Journal of Materials Research ◽

10.1557/jmr.2005.0344 ◽

2005 ◽

Vol 20 (10) ◽

pp. 2845-2853 ◽

Cited By ~ 15

Author(s):

M. Sherif El-Eskandarany ◽

M. Omori ◽

A. Inoue

Keyword(s):

Glass Transition ◽

Transition Temperature ◽

Glass Transition Temperature ◽

Glassy Alloy ◽

Supercooled Liquid ◽

High Energy ◽

Supercooled Liquid Region ◽

Exothermic Peak ◽

Liquid Region ◽

Plasma Sintering

The mechanical alloying method was used to synthesize a single glassy phase of Co65Ti20W15 alloy powders, using a high-energy ball mill. The glass transition temperature of the end-product, which was obtained after 173 ks of milling time, lies at 786 K, whereas the crystallization takes place at 878 K through a single sharp exothermic peak with an enthalpy change of crystallization of −4.37 kJ/mol. The reduced glass transition temperature was found to be 0.51. This glassy alloy powders exhibit a very large supercooled liquid region (92 K) for a ternary metallic system. The spark plasma sintering method was used to consolidate the glassy powders under an argon gas atmosphere at 843 K with a pressure of 19.6–38.2 MPa. The sample that was consolidated within 180 s maintains its chemically homogeneous glassy structure with a relative density of above 99.6%. Neither the supercooled liquid region nor crystallization temperature was affected by such a rapid consolidation procedure. Thus, the thermal stability of the bulk glassy sample is almost identical with the original glassy powders. The Vickers microhardness of the bulk glassy Co65Ti20W15 reveals high values, ranging between 8.69 and 8.83 GPa. The fabricated bulk glassy alloy shows high compressive strength of 2.44 GPa with a Young’s modulus of 176.81 GPa. Neither yielding stress, nor plastic strain could be detected for this glassy alloy, which its elastic strain is 1.33%.

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Microstructural Investigations of Rapidly Solidified Al-Co-Y Alloys

Advances in Materials Science and Engineering ◽

10.1155/2013/163537 ◽

2013 ◽

Vol 2013 ◽

pp. 1-7 ◽

Cited By ~ 3

Author(s):

B. Avar ◽

M. Gogebakan ◽

M. Tarakci ◽

Y. Gencer ◽

S. Kerli

Keyword(s):

Melt Spinning ◽

Alloy System ◽

Supercooled Liquid ◽

Amorphous Structure ◽

Supercooled Liquid Region ◽

Liquid Region ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

Glass Forming ◽

Rapidly Solidified

The alloys with different compositions in the Al-rich corner of the Al-Co-Y ternary system were prepared by conventional casting and further processed by melt-spinning technique. The microstructure and the thermal behavior of the alloys were analyzed by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and differential thermal analysis (DTA). It was found that only rapidly solidified Al85Co7Y8alloy exhibited the best glass forming ability (GFA) and a fully amorphous structure. Besides, Al85Co13Y2and Al85Co2Y13alloy ribbons were fully crystalline, whereas Al85Co10Y5and Al85Co5Y10alloy ribbons consisted of some crystalline phases within an amorphous matrix. The SEM results showed the same trend that the crystalline phase fraction decreases with the approaching into best glass former. From DSC results, only Al85Co7Y8amorphous alloy exhibited a glass transition temperature (Tg) at 569 K, and its supercooled liquid region (ΔTx=Tx−Tg) was found to be 17 K. Moreover, other calculated GFA parameters for this alloy system were also discussed.

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Mechanically induced solid-state reaction for synthesizing glassy Co75Ti25 soft magnet alloy powders with a wide supercooled liquid region

Journal of Materials Research ◽

10.1557/jmr.2002.0357 ◽

2002 ◽

Vol 17 (9) ◽

pp. 2447-2456 ◽

Cited By ~ 9

Author(s):

M. Sherif El-Eskandarany ◽

Wei Zhang ◽

A. Inoue

Keyword(s):

Glass Transition ◽

Transition Temperature ◽

Glass Transition Temperature ◽

Ball Milling ◽

Glassy Phase ◽

Glassy Alloy ◽

Supercooled Liquid ◽

High Energy ◽

Supercooled Liquid Region ◽

Liquid Region

A single phase of glassy Co75Ti25 alloy powders was synthesized by high-energy ball milling the elemental powders at room temperature, using the mechanical alloying method. The final product of the glassy alloy, which is obtained after ball milling for 86 ks, exhibits soft magnetic properties with polarization and coercivity values of 0.67 T and 2.98 kA/m, respectively. This binary glassy alloy, in which its glass transition temperature (Tg) lies at a rather high temperature (833 K), transforms into face-centered-cubic Co3Ti (ordered phase) at 889 K through a single sharp exothermic reaction with an enthalpy change of crystallization (ΔHx) of −2.35 kJ/mol. The supercooled liquid region before crystallization ΔTx of the synthesized glassy powders shows an extraordinary high value (56 K) for a metallic binary system. The reduced glass transition temperature [ratio between Tg and liquidus temperatures, Tl (Tg/Tl)] was 0.56. We also demonstrated postannealing experiments of the mechanically deformed Co/Ti multilayered composite powders. The results show that annealing of the powders at 710 K leads to the formation of a glassy phase (thermally enhanced glass formation reaction). Its heat formation was measured directly and found to be −0.56 kJ/mol. The similarity in the crystallization and magnetization behaviors between the two classes of as-annealed and as-mechanically alloyed glassy powders implies the formation of the same glassy phase.

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

Materials Science Forum ◽

10.4028/www.scientific.net/msf.833.79 ◽

2015 ◽

Vol 833 ◽

pp. 79-84 ◽

Cited By ~ 1

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.

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Refractory Mo–Si-Based Glassy Alloy Designed for Ultrahigh Strength and Thermal Stability

Journal of Materials Research ◽

10.1557/jmr.2005.0372 ◽

2005 ◽

Vol 20 (11) ◽

pp. 2910-2913 ◽

Cited By ~ 5

Author(s):

X.Q. Zhang ◽

W. Wang ◽

E. Ma ◽

J. Xu

Keyword(s):

Thermal Stability ◽

Glass Transition ◽

Metallic Glasses ◽

Glassy Alloy ◽

Supercooled Liquid ◽

Supercooled Liquid Region ◽

Liquid Region ◽

High Glass Transition Temperature ◽

Mechanically Alloyed ◽

Ultrahigh Strength

Mechanically alloyed Mo44Si26Ta5Zr5Fe3Co12Y5 multicomponent glassy alloy exhibits an exceptionally high glass transition temperature of 1202 K and a crystallization temperature of 1324 K, as well as an ultrahigh hardness of 18 GPa. This example is used to demonstrate metallic glasses that possess extraordinary thermal stability and ultrahigh strength and, at the same time, a wide supercooled liquid region (122 K) that is needed for processing into bulk forms through powder metallurgy routes.

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Effects of Annealing on Enthalpy Recovery and Nanomechanical Behaviors of a La-Based Bulk Metallic Glass

Metals ◽

10.3390/met11040579 ◽

2021 ◽

Vol 11 (4) ◽

pp. 579

Author(s):

Ting Shi ◽

Lanping Huang ◽

Song Li

Keyword(s):

Glass Transition ◽

Transition Temperature ◽

Glass Transition Temperature ◽

Metallic Glass ◽

Bulk Metallic Glass ◽

Structural Relaxation ◽

Supercooled Liquid ◽

Supercooled Liquid Region ◽

Liquid Region ◽

Nanoindentation Measurement

Structural relaxation and nanomechanical behaviors of La65Al14Ni5Co5Cu9.2Ag1.8 bulk metallic glass (BMG) with a low glass transition temperature during annealing have been investigated by calorimetry and nanoindentation measurement. The enthalpy release of this metallic glass is deduced by annealing near glass transition. When annealed below glass transition temperature for 5 min, the recovered enthalpy increases with annealing temperature and reaches the maximum value at 403 K. After annealed in supercooled liquid region, the recovered enthalpy obviously decreases. For a given annealing at 393 K, the relaxation behaviors of La-based BMG can be well described by the Kohlrausch-Williams-Watts (KWW) function. The hardness, Young’s modulus, and serrated flow are sensitive to structural relaxation of this metallic glass, which can be well explained by the theory of solid-like region and liquid-like region. The decrease of ductility and the enhancement of homogeneity can be ascribed to the transformation from liquid-like region into solid-like region and the reduction of the shear transition zone (STZ).

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Bulk glassy Zr-based alloys prepared by consolidation of glassy alloy powders in supercooled liquid region

Materials Science and Engineering A ◽

10.1016/s0921-5093(96)10664-x ◽

1997 ◽

Vol 226-228 ◽

pp. 458-462 ◽

Cited By ~ 16

Author(s):

Hidemi Kato ◽

Yoshihito Kawamura ◽

Akihisa Inoue ◽

Tsuyoshi Masumoto

Keyword(s):

Glassy Alloy ◽

Supercooled Liquid ◽

Supercooled Liquid Region ◽

Liquid Region

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Comments on “Fabrication of ternary Mg–Cu–Gd bulk metallic glass with high glass-forming ability under air atmosphere” [H. Men and D.H. Kim, J. Mater. Res. 18, 1502 (2003)]

Journal of Materials Research ◽

10.1557/jmr.2004.19.2.427 ◽

2004 ◽

Vol 19 (2) ◽

pp. 427-428 ◽

Cited By ~ 2

Author(s):

Z.P. Lu ◽

C.T. Liu

Keyword(s):

Glass Transition ◽

Metallic Glasses ◽

Supercooled Liquid ◽

Supercooled Liquid Region ◽

Glass Forming Ability ◽

Bulk Amorphous Alloy ◽

Liquid Region ◽

Glass Forming ◽

Air Atmosphere ◽

Acta Mater

A new Mg-based bulk amorphous alloy (i.e., Mg65Cu25Gd10) has successfully been developed by Men and Kim [H. Men and D.H. Kim, J. Mater. Res. 18, 1502 (2003)]. They showed that this alloy exhibits significantly improved glass-forming ability (GFA) in comparison with Mg65Cu25Y10 alloy. However, this improved GFA cannot be indicated by the supercooled liquid region ΔT and the reduced glass-transition temperature Trg. As shown in the current comment, the new parameter γ, Tx/(Tg + Tl) defined in our recent papers [Z.P. Lu and C.T. Liu, Acta Mater. 50, 3501 (2002); Z.P. Lu and C.T. Liu, Phys. Rev. Lett. 91, 115505 (2003)] can well gauge GFA for bulk metallic glasses, including the current Mg-based alloys.

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