Controlled normal/shear loading and shear fracture in bulk metallic glasses

Hsueh, Chun‐Hway; Bei, Hongbin; Liu, Chang; George, E.P.; Becher, Paul

doi:10.1016/j.intermet.2009.03.008

Cited by 8 publications

(8 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On the other hand, according to the recent theory of Furukawa and Tanaka 43 , only simply shear stress alone can cause instability within a liquid whose local density is intrinsically heterogeneous or fluctuating. This process occurs as the shear-induced enhancement of density fluctuation is self-amplified by the enhancement of dynamic and elastic asymmetry between denser and less dense regions, and results in cavitation in shear band, which has been verified both by experiments and theoretical studies 44 45 46 . By incorporating the general viscoelastic constitutive equations and free-volume concept of glassy materials into the Navier-Stokes equation, Furukawa and Tanaka quantitatively showed that, in theory, a compressible viscoselastic glassy liquid can become mechanically unstable under the simple shear above a critical shear strain rate :…”

Section: Discussionmentioning

confidence: 70%

The Critical Criterion on Runaway Shear Banding in Metallic Glasses

Sun

Yang

Wang

et al. 2016

Sci Rep

View full text Add to dashboard Cite

The plastic flow of metallic glasses (MGs) in bulk is mediated by nanoscale shear bands, which is known to proceed in a stick-slip manner until reaching a transition state causing catastrophic failures. Such a slip-to-failure transition controls the plasticity of MGs and resembles many important phenomena in natural science and engineering, such as friction, lubrication and earthquake, therefore has attracted tremendous research interest over past decades. However, despite the fundamental and practical importance, the physical origin of this slip-to-failure transition is still poorly understood. By tracking the behavior of a single shear band, here we discover that the final fracture of various MGs during compression is triggered as the velocity of the dominant shear band rises to a critical value, the magnitude of which is independent of alloy composition, sample size, strain rate and testing frame stiffness. The critical shear band velocity is rationalized with the continuum theory of liquid instability, physically originating from a shear-induced cavitation process inside the shear band. Our current finding sheds a quantitative insight into deformation and fracture in disordered solids and, more importantly, is useful to the design of plastic/tough MG-based materials and structures.

show abstract

Section: Discussionmentioning

confidence: 70%

The Critical Criterion on Runaway Shear Banding in Metallic Glasses

Sun

Yang

Wang

et al. 2016

Sci Rep

View full text Add to dashboard Cite

show abstract

“…In principle, one can select either the Mohr-Coulomb (MC) or Drucker-Prager (DP) model to estimate r r , both of which have been widely accepted as the yielding criterion for MGs in the MG literature. 19,[22][23][24] Here, both two are utilized for the sake of comparison. After the necessary derivations, one can readily obtain the following formulas:…”

Section: A Residual Stressmentioning

confidence: 99%

Hardness, yield strength, and plastic flow in thin film metallic-glass

Chu

Chen

et al. 2012

Journal of Applied Physics

View full text Add to dashboard Cite

Lithiation-induced tensile stress and surface cracking in silicon thin film anode for rechargeable lithium battery J. Appl. Phys. 112, 093507 (2012) Mechanical and thermal behaviors of nitrogen-doped Zr-Cu-Al-Ag-Ta--An alternative class of thin film metallic glass Appl. Phys. Lett. 101, 181902 (2012) Effect of relative humidity on crack propagation in barrier films for flexible electronics J. Appl. Phys. 112, 083520 (2012) Torsion fracture of carbon nanocoils J. Appl. Phys. 112, 084311 (2012) Additional information on J. Appl. Phys. Thin film metallic-glasses (TFMGs) are a promising structural material for fabricating the next generation of micro-and nano-devices; however, a comprehensive study is still lacking today for understanding their mechanical behaviors. In this article, we present a systematic study on the Zr 53 Cu 29 Al 12 Ni 6 TFMGs with varying thicknesses. Other than the intrinsic factor of structural amorphousness, our study pinpoints other extrinsic variables that could affect the hardness and yield strength of the TFMGs. Furthermore, the experimental results from microcompression show that the plastic flow in the TFMG-based micropillars exhibit strong sample size-and-shape dependence, which manifests as a smooth plastic deformation transition from the inhomogeneous to homogeneous mode when the TFMG-based micropillars with a submicron-scale film thickness are deformed into the shape of a low aspect ratio. V C 2012 American Institute of Physics.

show abstract

“…In addition to these Mode I (tension or compression) tests, Hsueh et al . 14 15 performed combined compression/shear tests with various degrees of mode mixity (i.e., the ratio of Mode II to Mode I components). As shown in Fig.…”

mentioning

confidence: 99%

“…Based on the measured load-displacement curves, Hsueh et al . 14 15 developed a continuum plasticity model that considers the pressure effect in the yield surface, which however cannot address the importance of the non-uniform deformation fields and the shear band arrangements in these experiments.…”

mentioning

confidence: 99%

“…This work presents a mechanistic analysis of the shear band arrangements in double edge notched BMGs, with a focus on the geometric constraints and the dependence on the mode mixity of the applied load. As opposed to the vast number of continuum plasticity simulations 3 4 8 11 12 13 14 15 , our analysis has a direct connection to the shear banding process, including their initiation from the material instability point of view and the shear band evolution from the free-volume-based constitutive model.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Instability Analysis and Free Volume Simulations of Shear Band Directions and Arrangements in Notched Metallic Glasses

Gao

Bei

2016

Sci Rep

View full text Add to dashboard Cite

As a commonly used method to enhance the ductility in bulk metallic glasses (BMGs), the introduction of geometric constraints blocks and confines the propagation of the shear bands, reduces the degree of plastic strain on each shear band so that the catastrophic failure is prevented or delayed, and promotes the formation of multiple shear bands. The clustering of multiple shear bands near notches is often interpreted as the reason for improved ductility. Experimental works on the shear band arrangements in notched metallic glasses have been extensively carried out, but a systematic theoretical study is lacking. Using instability theory that predicts the onset of strain localization and the free-volume-based finite element simulations that predict the evolution of shear bands, this work reveals various categories of shear band arrangements in double edge notched BMGs with respect to the mode mixity of the applied stress fields. A mechanistic explanation is thus provided to a number of related experiments and especially the correlation between various types of shear bands and the stress state.

show abstract

Controlled normal/shear loading and shear fracture in bulk metallic glasses

Cited by 8 publications

References 25 publications

The Critical Criterion on Runaway Shear Banding in Metallic Glasses

The Critical Criterion on Runaway Shear Banding in Metallic Glasses

Hardness, yield strength, and plastic flow in thin film metallic-glass

Instability Analysis and Free Volume Simulations of Shear Band Directions and Arrangements in Notched Metallic Glasses

Contact Info

Product

Resources

About