Stochastic theory for jerky deformation in small crystal volumes with pre-existing dislocations

  • Ng K
  • Ngan A
  • 22

    Readers

    Mendeley users who have this article in their library.
  • 38

    Citations

    Citations of this article.

Abstract

A statistical theory is proposed to describe the jerky deformation of micron-sized crystal pillars. The probability for a specimen surviving the applied load without generating a strain burst of a given order is analytically expressed in terms of the nucleation rate of that burst. The survival probability can be measured from an ensemble of macroscopically similar deformation experiments to obtain the nucleation rate. From experiments on aluminium pillars, the nucleation rate is found to increase with the pillar size and to decrease with the burst order, indicating that more sources are present in a larger specimen and that the available nucleating sources are progressively exhausted by the occurrence of bursts. The activation volume measured is roughly independent of the pillar size and burst order, indicating a constant mechanism for burst nucleation. A statistical theory is proposed to describe the jerky deformation of micron-sized crystal pillars. The probability for a specimen surviving the applied load without generating a strain burst of a given order is analytically expressed in terms of the nucleation rate of that burst. The survival probability can be measured from an ensemble of macroscopically similar deformation experiments to obtain the nucleation rate. From experiments on aluminium pillars, the nucleation rate is found to increase with the pillar size and to decrease with the burst order, indicating that more sources are present in a larger specimen and that the available nucleating sources are progressively exhausted by the occurrence of bursts. The activation volume measured is roughly independent of the pillar size and burst order, indicating a constant mechanism for burst nucleation.

Author-supplied keywords

  • Aluminium
  • Deformation
  • Dislocations
  • Nanoindentation
  • Statistical mechanics

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Authors

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free