The mechanism of power-law scaling behavior by controlling shear bands in bulk metallic glass

Wang, Z.; Qiao, J.W.; Wang, G.; Dahmen, Karin A.; Liaw, Peter K.; Wang, B.C.; Xu, Bingshe

doi:10.1016/j.msea.2015.05.074

Cited by 30 publications

(7 citation statements)

References 50 publications

(66 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the present double-side-notched specimens, the resultant complex stress field under applied loading can result in more plastic deformation in the stress-concentrated region to form a stable plastic-flow stage before the catastrophic failures, which can evolve into a critical state. Some studies have also reported that in the compression tests of BMGs, the BMG specimens with large macroscopic plasticity exhibit power-law scaling behavior 61 or even some characteristics of the self-organized criticality (SOC) behavior 21 62 . However, such characteristics of the critical behavior highly depend on the applied strain rate 34 35 .…”

Section: Discussionmentioning

confidence: 99%

Loading-rate-independent delay of catastrophic avalanches in a bulk metallic glass

Chen

Chan

Wang

et al. 2016

Sci Rep

Self Cite

View full text Add to dashboard Cite

The plastic flow of bulk metallic glasses (BMGs) is characterized by intermittent bursts of avalanches, and this trend results in disastrous failures of BMGs. In the present work, a double-side-notched BMG specimen is designed, which exhibits chaotic plastic flows consisting of several catastrophic avalanches under the applied loading. The disastrous shear avalanches have, then, been delayed by forming a stable plastic-flow stage in the specimens with tailored distances between the bottoms of the notches, where the distribution of a complex stress field is acquired. Differing from the conventional compressive testing results, such a delaying process is independent of loading rate. The statistical analysis shows that in the specimens with delayed catastrophic failures, the plastic flow can evolve to a critical dynamics, making the catastrophic failure more predictable than the ones with chaotic plastic flows. The findings are of significance in understanding the plastic-flow mechanisms in BMGs and controlling the avalanches in relating solids.

show abstract

Section: Discussionmentioning

confidence: 99%

Loading-rate-independent delay of catastrophic avalanches in a bulk metallic glass

Chen

Chan

Wang

et al. 2016

Sci Rep

Self Cite

View full text Add to dashboard Cite

show abstract

“…3, an upward trend of the increase of the amplitudes of the load drops was observed in the single-side-notched specimens. The upward trend of the amplitudes of the load drops with small increasing rate has been widely observed in BMG compression tests, and such trend is known to have no significant effect on the plastic-flow dynamics and can be ignored during statistical analysis of the plastic-flow dynamics131536. However, in the present single-side-notched specimens, the upward trend has a large increasing rate, which follows a power-law scaling.…”

Section: Resultsmentioning

confidence: 63%

“…For example, the use of multiple samples13 and complex stress fields14 can drive the chaotic plastic flow to evolve to a critical dynamics to delay such catastrophic failures. The critical plastic-flow dynamics of BMGs can also be obtained by tailoring sample geometries (aspect ratio)15, testing temperatures16 and applied strain rates16. However, differing from the dislocation-mediated plastic deformation of crystals, where the critical dynamics were observed under both compression717 and tension tests518, the plastic-flow dynamics of BMGs under tension have not been reported.…”

mentioning

confidence: 99%

Flaw-induced plastic-flow dynamics in bulk metallic glasses under tension

Chen

Yue

Tsui

et al. 2016

Sci Rep

View full text Add to dashboard Cite

Inheriting amorphous atomic structures without crystalline lattices, bulk metallic glasses (BMGs) are known to have superior mechanical properties, such as high strength approaching the ideal value, but are susceptible to catastrophic failures. Understanding the plastic-flow dynamics of BMGs is important for achieving stable plastic flow in order to avoid catastrophic failures, especially under tension, where almost all BMGs demonstrate limited plastic flow with catastrophic failure. Previous findings have shown that the plastic flow of BMGs displays critical dynamics under compression tests, however, the plastic-flow dynamics under tension are still unknown. Here we report that power-law critical dynamics can also be achieved in the plastic flow of tensile BMGs by introducing flaws. Differing from the plastic flow under compression, the flaw-induced plastic flow under tension shows an upward trend in the amplitudes of the load drops with time, resulting in a stable plastic-flow stage with a power-law distribution of the load drop. We found that the flaw-induced plastic flow resulted from the stress gradients around the notch roots, and the stable plastic-flow stage increased with the increase of the stress concentration factor ahead of the notch root. The findings are potentially useful for predicting and avoiding the catastrophic failures in tensile BMGs by tailoring the complex stress fields in practical structural-applications.

show abstract

“…In the present work, the serrated-flow amplitudes range from 5 to 25 MPa, and the serrated flow behavior goes through a stable state at this range. It is reported that the stable range is from 20 to 35 MPa at an aspect ratio of 1:1 for the Zr-based BMG compression test at the strain rate of 2 × 10 −4 s −1 [34]. Owing to the change of the stress state, the burst size will increase with decreasing aspect ratios [33].…”

Section: Resultsmentioning

confidence: 98%

Serration Behavior in Pd77.5Cu6Si16.5 Alloy

Zhong¹,

Li²,

Yuan³

et al. 2016

Metals

View full text Add to dashboard Cite

Abstract:The strain-rate-dependent plasticity under uniaxial compression at the strain rates of 2 × 10 −3 , 2 × 10 −4 and 2 × 10 −5 s −1 in a Pd 77.5 Cu 6 Si 16.5 alloy is investigated. At different strain rates, the serration events exhibit different amplitudes and time scales. The intersection effects take place obviously, and the loading time is much longer than the relaxation time in the serration event at three strain rates. However, the time intervals between two neighboring serrations lack any time scale, and the elastic energy density displays a power-law distribution at the strain rate of 2 × 10 −3 s −1 , which means that the self-organized critical (SOC) behavior emerges with increasing strain rates.

show abstract

The mechanism of power-law scaling behavior by controlling shear bands in bulk metallic glass

Cited by 30 publications

References 50 publications

Loading-rate-independent delay of catastrophic avalanches in a bulk metallic glass

Loading-rate-independent delay of catastrophic avalanches in a bulk metallic glass

Flaw-induced plastic-flow dynamics in bulk metallic glasses under tension

Serration Behavior in Pd77.5Cu6Si16.5 Alloy

Contact Info

Product

Resources

About