Softening-induced plastic flow instability and indentation size effect in metallic glass

S. Wang, Y. F. Ye, B. A. Sun, C. T. Liu, San-Qiang Shi, Y. Yang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

38 Citations (Scopus)


Despite the absence of microstructural features, metallic glasses (MGs) could display size-dependent hardness at the submicron scale. While most early studies attributed this size effect to Weibull statistics, here we propose a mechanism related to shear softening induced flow instability that can give rise to a deterministic indentation size effect in MGs. In line with this mechanism, an explicit relation is derived linking the size dependency of hardness to a critical length scale that governs the transition from a stable to unstable plastic flow in MGs. Through a series of carefully designed spherical indentation tests, this mechanism is experimentally justified, from which we are able to extract the critical transition length for a Zr-based MG at different indentation strain rates. On the basis of the combined theoretical/experimental efforts, our current work provides a quantitative insight into the indentation size effect in MGs.
Original languageEnglish
Pages (from-to)70-85
Number of pages16
JournalJournal of the Mechanics and Physics of Solids
Publication statusPublished - 1 Jan 2015


  • Indentation
  • Metallic glasses
  • Shear instability
  • Strength scaling

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering


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