Microstructure versus Flaw : Mechanisms of Failure and Strength in Nanostructures

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal

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Author(s)

Detail(s)

Original languageEnglish
Pages (from-to)5703-5709
Journal / PublicationNano Letters
Volume13
Issue number11
Online published29 Oct 2013
Publication statusPublished - 13 Nov 2013
Externally publishedYes

Abstract

Understanding failure in nanomaterials is critical for the design of reliable structural materials and small-scale devices with nanoscale components. No consensus exists on the effect of flaws on fracture at the nanoscale, but proposed theories include nanoscale flaw tolerance and maintaining macroscopic fracture relationships at the nanoscale with scarce experimental support. We explore fracture in nanomaterials using nanocrystalline Pt nanocylinders with prefabricated surface notches created using a "paused" electroplating method. In situ scanning electron microscopy (SEM) tension tests demonstrate that the majority of these samples failed at the notches, but that tensile failure strength is independent of whether failure occurred at or away from the flaw. Molecular dynamics simulations verify these findings and show that local plasticity is able to reduce stress concentration ahead of the notch to levels comparable with the strengths of microstructural features (e.g., grain boundaries). Thus, failure occurs at the stress concentration with the highest local stress whether this is at the notch or a microstructural feature.

Research Area(s)

  • fracture, mechanical properties, molecular dynamics, nanocrystalline, Size effect

Citation Format(s)

Microstructure versus Flaw : Mechanisms of Failure and Strength in Nanostructures. / Gu, X. Wendy; Wu, Zhaoxuan; Zhang, Yong-Wei; Srolovitz, David J.; Greer, Julia R.

In: Nano Letters, Vol. 13, No. 11, 13.11.2013, p. 5703-5709.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal