Oxidation Behavior in Super-Plastic Microforming of Zr65Cu17.5Ni10Al7.5 Bulk Metallic Glass

The influence of oxidation behavior on super-plastic microforming of bulk metallic glass Zr65Cu17.5Ni10Al7.5in the super-cooled liquid region was investigated. Samples were heated in air from room temperature to 395°C, 410°C, and 430°C, respectively, and kept under each temperature for 40 minutes. The increased weight of samples and the thickness of oxide layer were measured. Subsequently, the sample was compressed under 410°C with a micro gear silicon mold. In result, the oxide layer of the gear cracked and could be easily removed; also, the X-ray diffractometer showed that the gear core below the oxide layer remained an amorphous structure. It can be concluded that the oxidation behavior of Zr65Cu17.5Ni10Al7.5does not affect the super-plastic deformation, which indicates the feasibility of super-plastic microforming process in air.

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Oxidation Behavior of Cu60Zr30Ti10 Bulk Metallic Glass

Journal of Materials Research ◽

10.1557/jmr.2005.0182 ◽

2005 ◽

Vol 20 (6) ◽

pp. 1396-1403 ◽

Cited By ~ 25

Author(s):

C.Y. Tam ◽

C.H. Shek

Keyword(s):

Metallic Glass ◽

Oxide Layer ◽

Bulk Metallic Glass ◽

Photoelectron Spectroscopy ◽

Oxidation Kinetics ◽

Oxide Surface ◽

X Ray ◽

Rate Law ◽

Cu Content ◽

Surface Morphologies

The oxidation kinetics of Cu60Zr30Ti10 bulk metallic glass and its crystalline counterpart were studied in oxygen environment over the temperature range of 573–773 K. The oxidation kinetics, measured with thermogravimetric analysis, of the metallic glass follows a linear rate law between 573 and 653 K and a parabolic rate law between 673 and 733 K. It was also found that the oxidation activation energy of metallic glass is lower than that of its crystalline counterpart. The x-ray diffraction pattern showed that the oxide layer is composed of Cu2O, CuO, ZrO2, and metallic Cu. Cu enrichment on the topmost oxide layer of the metallic glass oxidized at 573 K was revealed by x-ray photoelectron spectroscopy while there was a decrease in Cu content in the innermost oxide layer. The oxide surface morphologies observed from scanning electron microscopy showed that ZrO2 granules formed at low temperatures while whiskerlike copper oxides formed at higher temperatures.

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Influence of annealing on structural relaxation, crystallization, and deformation behavior of a Zr41.2Ti13.8Cu12.5Ni10Be22.5 bulk metallic glass

Journal of Materials Research ◽

10.1557/jmr.2007.0253 ◽

2007 ◽

Vol 22 (7) ◽

pp. 1849-1858 ◽

Cited By ~ 3

Author(s):

Kwang Seok Lee ◽

Jürgen Eckert ◽

Hyun-Joon Jun ◽

Young Won Chang

Keyword(s):

Mechanical Properties ◽

Metallic Glass ◽

Bulk Metallic Glass ◽

Deformation Behavior ◽

Structural Changes ◽

Supercooled Liquid ◽

Supercooled Liquid Region ◽

Liquid Region ◽

Compression Tests ◽

X Ray

The influence of annealing on the structural changes and the mechanical properties of Zr41.2Ti13.8Cu12.5Ni10Be22.5 (Vit-1) bulk metallic glass was systematically studied by varying the annealing times at 703 K. The evolution of the structural state at a relatively high temperature within the supercooled liquid region was studied by thermal analysis, x-ray diffraction, high-resolution transmission electron microscopy, extended x-ray absorption fine structure, and dilatometric measurements. The deformation behavior and the mechanical properties were also examined by carrying out hardness and compression tests for the specimens annealed for various times.

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Fragmentation of Co-Fe-Ta-B Bulk Metallic Glass

Materials Science Forum ◽

10.4028/www.scientific.net/msf.782.553 ◽

2014 ◽

Vol 782 ◽

pp. 553-556

Author(s):

Jozef Miškuf ◽

Kornel Csach ◽

Alena Juríková

Keyword(s):

Fracture Surface ◽

Metallic Glass ◽

Bulk Metallic Glass ◽

Metallic Glasses ◽

Room Temperature ◽

Amorphous Structure ◽

External Loading ◽

Small Particles ◽

Failure Characteristics ◽

Crack Propagation Direction

The main limitation of bulk metallic glasses for their application as structural materials is the large brittleness under the external loading. We analyzed the failure characteristics of Co43Fe20Ta5.5B31.5(at.%) bulk metallic glass deformed in a compression at the room temperature and a low strain rate. Under loading the amorphous structure can store high elastic energy. During the failure this energy is released and the alloy breaks into small particles or powder exhibiting a fragmentation mode. The nanoscale fracture surface morphology respects the micromechanisms of failure of the amorphous structure. The fracture surface consists of a smooth mirror cleavage zone and a river pattern zone with the nanosized dimples arranged in lines respecting the periodic corrugation zones oriented perpendicular to the crack propagation direction.

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Fatigue Behavior of Zr58Cu15.46Ni12.74Al10.34Nb2.76Y0.5 Bulk Metallic Glass Fabricated by Industrial-Grade Zirconium Raw Material

Metals ◽

10.3390/met11020187 ◽

2021 ◽

Vol 11 (2) ◽

pp. 187

Author(s):

Shichao Zhou ◽

Tao Zhang ◽

Lugee Li ◽

Jiedan Yang ◽

Min Zhang ◽

...

Keyword(s):

Metallic Glass ◽

Bulk Metallic Glass ◽

Endurance Limit ◽

Stress Amplitude ◽

Fatigue Behavior ◽

Amorphous Structure ◽

Raw Material ◽

X Ray ◽

Industrial Grade ◽

Fatigue Endurance

In this work, the fatigue behavior of a low-cost Zr58Cu15.46Ni12.74Al10.34Nb2.76Y0.5 (at%) bulk metallic glass (BMG) fabricated by industrial-grade Zirconium raw material was investigated under three-point bending loading mode. X-ray, fatigue tests under different stress amplitude and fatigue fractography were conducted in order to characterize the amorphous structure, fatigue stress-life (S-N) curve and fracture mechanism, respectively. It is found that the X-ray diffraction (XRD) result showed a fully amorphous structure due to high glass-forming ability, cracks initiated from inclusions near the rectangular corners at tensile surfaces and the fatigue endurance limit (~168 MPa) and fatigue ratio (~0.13) termed as fatigue endurance limit divided by ultimate tensile strength in stress amplitude were comparable to the similar BMG prepared by high pure raw materials.

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Explosive Welding of ZrTiCuNiBe Bulk Metallic Glass to Crystalline Metallic Plates

Materials Science Forum ◽

10.4028/www.scientific.net/msf.566.119 ◽

2007 ◽

Vol 566 ◽

pp. 119-124 ◽

Cited By ~ 10

Author(s):

Akira Chiba ◽

Yoshihito Kawamura ◽

Minoru Nishida

Keyword(s):

Metallic Glass ◽

Bulk Metallic Glass ◽

Metallic Glasses ◽

Explosive Welding ◽

Bulk Metallic Glasses ◽

Supercooled Liquid ◽

Amorphous Structure ◽

Supercooled Liquid Region ◽

Liquid Region ◽

Slow Cooling

Recently, a number of amorphous alloys that possess high glass-forming ability and a wide supercooled liquid region before crystallization have been discovered. Especially, bulk metallic glasses, which are made in bulk form with a thickness of ~10 mm at slow cooling rates of the order of 1~100 K/s, have been noted as an industrial application. Hence the welding of bulk metallic glasses to other materials is very important. Explosive welding of most popular Zr41.2Ti13.8Cu10Ni12.5Be22.5 bulk metallic glass to crystalline pure Ti and SUS304 plates is investigated in this paper. The BMGs was found to retain the amorphous structure and the original mechanical properties. The sound bonding with other materials is expected to push forward the application of bulk metallic glass for industrial usage.

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Volume changes in Vitreloy bulk metallic glass during room temperature high-pressure torsion

Journal of Materials Research ◽

10.1557/jmr.2008.0416 ◽

2008 ◽

Vol 23 (12) ◽

pp. 3409-3414 ◽

Cited By ~ 12

Author(s):

Zsolt Kovács ◽

Erhard Schafler ◽

Ádám Révész

Keyword(s):

High Pressure ◽

Metallic Glass ◽

Bulk Metallic Glass ◽

Room Temperature ◽

High Pressure Torsion ◽

Two Dimensional ◽

X Ray Diffraction ◽

Volume Changes ◽

X Ray ◽

Dimensional Mapping

Commercial Zr44Ti11Cu10Ni10Be25 bulk metallic glass (Vitreloy 1b) disk was subjected to extreme plastic deformation by high-pressure torsion at room temperature. Two-dimensional mapping by high-intensity synchrotron x-ray diffraction in the plane of the shear deformation reveals no evidence of nanocrystallization; however, average effective volume changes as a function of the deformation can be evaluated.

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Plasticity in Bulk Metallic Glass Composites Containing Dual Amorphous Phases

Materials Science Forum ◽

10.4028/www.scientific.net/msf.539-543.2026 ◽

2007 ◽

Vol 539-543 ◽

pp. 2026-2030 ◽

Cited By ~ 6

Author(s):

J.K. Lee ◽

H.J. Kim ◽

Taek Soo Kim ◽

Jung Chan Bae

Keyword(s):

Metallic Glass ◽

Bulk Metallic Glass ◽

Amorphous Phase ◽

Glass Matrix ◽

Supercooled Liquid ◽

Amorphous Structure ◽

Supercooled Liquid Region ◽

Liquid Region ◽

Glass Composites ◽

Amorphous Phases

Bulk metallic glass (BMG) composites with dual amorphous phases were fabricated by spark plasma sintering of a mixture of Cu-based and Zr-based amorphous powders in their overlapped supercooled liquid region. The Zr-based amorphous phases are well distributed homogeneously in the Cu-based metallic glass matrix after consolidation. The BMG composite still remains as an amorphous structure after consolidation. The BMG composite with dual amorphous phases shows macroscopic plasticity after yielding, and the plastic strain increased to around 3.4% in the BMG composite containing 30 vol% Zr-based amorphous phase. The successful consolidation of BMG composite with enhanced plasticity was achieved by introducing a second amorphous phase in the metallic glass matrix.

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Homogeneity of the superplastic Zr64.13Cu15.75Ni10.12Al10 bulk metallic glass

Journal of Materials Research ◽

10.1557/jmr.2009.0395 ◽

2009 ◽

Vol 24 (10) ◽

pp. 3116-3120 ◽

Cited By ~ 10

Author(s):

Lian-Yi Chen ◽

Yuewu Zeng ◽

Qing-Ping Cao ◽

Byung-Joo Park ◽

Yimeng Chen ◽

...

Keyword(s):

Metallic Glass ◽

Bulk Metallic Glass ◽

Room Temperature ◽

Structural Heterogeneity ◽

Specimen Preparation ◽

Intrinsic Structure ◽

X Ray ◽

X Ray Scattering ◽

Transmission Electron ◽

Structural Heterogeneities

A recent report on the “room temperature superplasticity” in the Zr64.13Cu15.75Ni10.12Al10 bulk metallic glass [Y.H. Liu et al., Science315, 1385 (2007)] was ascribed to the distinctive micrometer-sized structural heterogeneity. To verify the microstructure in this alloy, transmission electron microscopy (TEM) and anomalous small-angle x-ray scattering experiments were conducted. The results show that no micrometer-sized or nanometer-sized structural heterogeneities can be found. The micrometer-sized dark and bright regions that were previously reported as the reason for the plasticity are artifacts caused by TEM specimen preparation, rather than the intrinsic structure feature of this alloy. This finding is important for further studying the unique properties of this alloy.

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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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