Orientation effect of pre-introduced shear bands in a bulk-metallic glass on its “work-ductilising”

2008 ◽  
Vol 496 (1-2) ◽  
pp. 285-290 ◽  
Author(s):  
L. He ◽  
M.B. Zhong ◽  
Z.H. Han ◽  
Q. Zhao ◽  
F. Jiang ◽  
...  
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Shear Bands ◽  
Orientation Effect

scholarly journals High density of shear bands in the Vitreloy bulk metallic glass subjected to high-pressure torsion

2021 ◽  
Vol 1008 ◽  
pp. 012031
Author(s):  
Vasily Astanin ◽  
Dmitry Gunderov ◽  
Zhi Qiang Ren ◽  
Ruslan Valiev ◽  
Jing Tao Wang
Keyword(s):  
High Pressure ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
High Pressure Torsion ◽  
Shear Bands ◽  
High Density

scholarly journals Pressure-dependent flow behavior of Zr41.2Ti13.8Cu12.5Ni10Be22.5 bulk metallic glass

2003 ◽  
Vol 18 (9) ◽  
pp. 2039-2049 ◽  
Author(s):  
Jun Lu ◽  
Guruswami Ravichandran
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Inelastic Deformation ◽  
Shear Failure ◽  
Flow Behavior ◽  
Shear Bands ◽  
Ductile Deformation ◽  
Multiaxial Compression ◽  
Dependent Flow ◽  
Tresca Criterion

An experimental study of the inelastic deformation of bulk metallic glass Zr41.2Ti13.8Cu12.5Ni10Be22.5 under multiaxial compression using a confining sleeve technique is presented. In contrast to the catastrophic shear failure (brittle) in uniaxial compression, the metallic glass exhibited large inelastic deformation of more than 10% under confinement, demonstrating the nature of ductile deformation under constrained conditions in spite of the long-range disordered characteristic of the material. It was found that the metallic glass followed a pressure (p) dependent Tresca criterion τ = τ0 + βp, and the coefficient of the pressure dependence β was 0.17. Multiple parallel shear bands oriented at 45° to the loading direction were observed on the surfaces of the deformed specimens and were responsible for the overall inelastic deformation.

Compressive properties of bulk metallic glass with small aspect ratio

2007 ◽  
Vol 22 (2) ◽  
pp. 501-507 ◽  
Author(s):  
F.F. Wu ◽  
Z.F. Zhang ◽  
S.X. Mao
Keyword(s):  
Plastic Deformation ◽  
Aspect Ratio ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Deformation Behavior ◽  
Shear Bands ◽  
Compressive Load ◽  
Small Aspect Ratio ◽  
Compressive Properties ◽  
Deformation Ability

The quasi-static compressive deformation behavior of a Vitreloy 1 bulk metallic glass (BMG) with an aspect ratio of 0.25 was investigated. It is found that the friction and the confinement at the specimen–loading platen interface will cause the dramatic increase in the compressive load, leading to higher compressive strength. In particular, the BMG specimens show great plastic-deformation ability, and plenty of interacted, deflected, wavy, or branched shear bands were observed on the surfaces after plastic deformation. The formation of the strongly interacted, deflected, wavy, or branched shear bands can be attributed to the triaxial stress state in the glassy specimens with a very small aspect ratio.

Compressive Plasticity of Zr-Based Bulk Metallic Glass at Low Temperature

2012 ◽  
Vol 443-444 ◽  
pp. 583-586
Author(s):  
Ya Juan Sun ◽  
Ri Ga Wu ◽  
Hong Jing Wang
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Low Temperatures ◽  
Room Temperature ◽  
Shear Bands ◽  
Strain Curve ◽  
Testing Temperature ◽  
Stress Strain Curve

The mechanical properties of a new Zr-based bulk metallic glass at low temperatures were investigated. The results indicate that the fracture strength increases significantly (4.9%) and the global plasticity increases somewhat when testing temperature is lowered to 123K. The stress-strain curve of the sample deformed exhibits more serrations and smaller stress drop due to formation of more shear bands at low temperature than at room temperature.

Multiple Shear Bands in Zr-Based Bulk Metallic Glass Processed by Severe Plastic Deformation

2018 ◽  
Vol 385 ◽  
pp. 319-324 ◽  
Author(s):  
Evgeniy Boltynjuk ◽  
Evgeniy Ubyivovk ◽  
Dmitriy Gunderov ◽  
Vladimir Mikhalovskii ◽  
Ruslan Z. Valiev
Keyword(s):  
Plastic Deformation ◽  
High Pressure ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
High Pressure Torsion ◽  
Shear Bands ◽  
Processing Temperature ◽  
Structural Studies ◽  
Temperature Shear ◽  
Nm Range

The Zr62Cu22Al10Fe5Dy1 bulk metallic glass was subjected to high pressure torsion (HPT) processing at temperatures of 20 and 150°C. Structural studies were carried out by TEM on the lamella-sample prepared from the HPT-specimens in transversal direction to the specimen plane. TEM studies revealed formation of multiple shear bands with spacings in a 20-50 nm range for both HPT states. Shear bands could be divided in two types: primary and secondary bands. The morphology of shear bands strongly depends on the processing temperature. Shear bands are distributed homogeneously throughout the whole lamella-sample for state processed by HPT at temperature of 20°C. Regions with shear bands are divided by amorphous regions on lamella-sample cut from the sample processed by HPT at temperature of 150°C. Analysis of optical microscopy and SEM data showed that shear bands are distributed throughout the whole volume of HPT-specimens.

scholarly journals An Analytical Method for Studying the Stress-Strain Relations of Bulk Metallic Glass Matrix Composites under Tension

2018 ◽  
Vol 27 (6) ◽  
pp. 096369351802700
Author(s):  
Yunpeng Jiang
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Analytical Method ◽  
Glass Matrix ◽  
Shear Bands ◽  
Matrix Composites ◽  
Stress Strain ◽  
Glass Matrix Composites ◽  
Softening Stage

In this contribution, an analytical model was formulated to predict the tensile stress-strain relations of bulk metallic glass matrix composites (BMGCs) based on Weng's theoretical frame for dual-ductile composites. For in-situ BMGCs, BMG matrix also exhibits the elastic-plastic deform response as well as the dendrite phases during the stretching. The shear bands are regarded as Mode-I cracks, and whereby the strain-softening stage in the stress-strain curves can be well reflected. Furthermore, multi-particle representative volume element based FEM modelling was employed to clearly explain the failure mechanisms in BMGCs as a necessary complement. The predictions are in reasonable agreement with the experimental results. The presented analytical method will shed some light on optimizing the microstructures, and is of convenience in the engineering applications.

Effect of Structure Relaxation on the Plastic Deformation Behaviour in a Zr-Based BMG under Indenter

2009 ◽  
Vol 618-619 ◽  
pp. 437-441
Author(s):  
Hao Wen Xie ◽  
Peter D. Hodgson ◽  
Cui E Wen
Keyword(s):  
Plastic Deformation ◽  
Shear Band ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Free Volume ◽  
Cast Alloy ◽  
Deformation Behaviour ◽  
Shear Bands ◽  
Structure Relaxation ◽  
Effect Of Structure

Vickers and nano indentations were performed on a structurally relaxed Zr41Ti14Cu12.5Ni10Be22.5 bulk metallic glass (BMG), and the evolution of the shear bands in the relaxed BMG was investigated and compared to that in the as-cast alloy. Results indicate that the plastic deformation in the BMG with structure relaxation is accommodated by the semicircular (primary) and radial (secondary) as well as tertiary shear bands. Quantitatively, the shear band density in the relaxed alloy was much lower than that in the as-cast alloy. The annihilation of free volume caused by the annealing was responsible for the embrittlement of the sample with structure relaxation.

Stereophotogrammetric Investigation of Overload and Cyclic Fatigue Fracture Surface Morphologies in a Zr–Ti–Ni–Cu–Be Bulk Metallic Glass

2000 ◽  
Vol 15 (4) ◽  
pp. 898-903 ◽  
Author(s):  
A. Tatschl ◽  
C. J. Gilbert ◽  
V. Schroeder ◽  
R. Pippan ◽  
R. O. Ritchie
Keyword(s):  
Fracture Surface ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Shear Bands ◽  
Three Dimensional ◽  
Crack Tip ◽  
Cyclic Fatigue ◽  
Fracture Plane ◽  
Reconstruction Technique ◽  
Fracture Surfaces

Fracture surfaces of a recently developed Zr41.2Ti13.8Cu12.5Ni10.0Be22.5 (at.%) bulk metallic glass were investigated using a three-dimensional surface reconstruction technique. Stereoscopic scanning electron microscopy of both fatigue and overload fracture surfaces permitted the creation of digital elevation models that were used to quantify important fracture surface features. Characterization of the surfaces revealed striations of nearly constant spacing on fatigue surfaces and a vein morphology characteristic in amorphous metals on the overload fracture surfaces. Additionally, at the onset of critical failure, crack-tip openings of ˜16 μm were observed that were consistent with measured values of fracture toughness. Interestingly, at the onset of fracture, deformation was confined to one side of the fracture plane, possibly because of the asymmetric emission of shear bands from the crack tip, consistent with the highly inhomogeneous nature of deformation in this alloy.

The more shearing, the thicker shear band and heat-affected zone in bulk metallic glass

2008 ◽  
Vol 23 (8) ◽  
pp. 2133-2138 ◽  
Author(s):  
H. Guo ◽  
J. Wen ◽  
N.M. Xiao ◽  
Z.F. Zhang ◽  
M.L. Sui
Keyword(s):  
Aspect Ratio ◽  
Shear Band ◽  
Metallic Glass ◽  
Shear Deformation ◽  
Bulk Metallic Glass ◽  
Heat Affected Zone ◽  
Shear Bands ◽  
Source Model ◽  
Ion Milling ◽  
Low Aspect Ratio

In a compression test for a Zr-based bulk metallic glass, a dominant shear band was preserved before fracture by a cylindrical stopper. A heat-affected zone (HAZ) ∼10 μm thick together with shear band was discovered in the center of the deformed sample by preferential ion milling. By using a low aspect ratio sample for compression, diverse micron-scaled HAZs among multiple shear bands were also revealed. Based on above experimental results and the isothermal source model, it was found that the thickness of shear band and its HAZ increased continuously with the progression of shear deformation.

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