A model of enhanced strain rate sensitivity in nanocrystalline and ultrafine-grained metals

A. G. Sheinerman, S. Bobylev

Research outputpeer-review

Abstract

A model is suggested that describes enhanced strain rate sensitivity of nanocrystalline and ultrafine-grained metals. Within the model, plastic deformation of such metals incorporates dislocation transmission across grain boundaries (GBs) in the stress fields of dislocation pileups, the emission of individual dislocations from GBs as well as GB sliding accommodated by GB dislocation climb and/or Coble creep. The model predicts a strong increase in the strain rate sensitivity and a decrease in the activation volume with decreasing grain size, in accord with experimental data. We also considered the effect of GB sliding and Coble creep on the anomalous dependence of the activation volume on temperature observed in nanocrystalline Ni. It is demonstrated that although an account for GB sliding and Coble creep leads to the appearance of cusps in the temperature dependence of the activation volume, these mechanisms alone cannot be responsible for the observed anomalous dependence of the activation volume on temperature.

Original languageEnglish
Pages (from-to)1-10
Number of pages10
JournalReviews on Advanced Materials Science
Volume57
Issue number1
Publication statusPublished - 2018

Cite this

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title = "A model of enhanced strain rate sensitivity in nanocrystalline and ultrafine-grained metals",
abstract = "A model is suggested that describes enhanced strain rate sensitivity of nanocrystalline and ultrafine-grained metals. Within the model, plastic deformation of such metals incorporates dislocation transmission across grain boundaries (GBs) in the stress fields of dislocation pileups, the emission of individual dislocations from GBs as well as GB sliding accommodated by GB dislocation climb and/or Coble creep. The model predicts a strong increase in the strain rate sensitivity and a decrease in the activation volume with decreasing grain size, in accord with experimental data. We also considered the effect of GB sliding and Coble creep on the anomalous dependence of the activation volume on temperature observed in nanocrystalline Ni. It is demonstrated that although an account for GB sliding and Coble creep leads to the appearance of cusps in the temperature dependence of the activation volume, these mechanisms alone cannot be responsible for the observed anomalous dependence of the activation volume on temperature.",
keywords = "PLASTIC-DEFORMATION, ACTIVATION VOLUME, SIZE DEPENDENCE, BOUNDARY, STRENGTH, FCC, TEMPERATURE, DIFFUSION, DUCTILITY, BEHAVIOR",
author = "Sheinerman, {A. G.} and S. Bobylev",
year = "2018",
language = "English",
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pages = "1--10",
journal = "Reviews on Advanced Materials Science",
issn = "1606-5131",
publisher = "Институт проблем машиноведения РАН",
number = "1",

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TY - JOUR

T1 - A model of enhanced strain rate sensitivity in nanocrystalline and ultrafine-grained metals

AU - Sheinerman, A. G.

AU - Bobylev, S.

PY - 2018

Y1 - 2018

N2 - A model is suggested that describes enhanced strain rate sensitivity of nanocrystalline and ultrafine-grained metals. Within the model, plastic deformation of such metals incorporates dislocation transmission across grain boundaries (GBs) in the stress fields of dislocation pileups, the emission of individual dislocations from GBs as well as GB sliding accommodated by GB dislocation climb and/or Coble creep. The model predicts a strong increase in the strain rate sensitivity and a decrease in the activation volume with decreasing grain size, in accord with experimental data. We also considered the effect of GB sliding and Coble creep on the anomalous dependence of the activation volume on temperature observed in nanocrystalline Ni. It is demonstrated that although an account for GB sliding and Coble creep leads to the appearance of cusps in the temperature dependence of the activation volume, these mechanisms alone cannot be responsible for the observed anomalous dependence of the activation volume on temperature.

AB - A model is suggested that describes enhanced strain rate sensitivity of nanocrystalline and ultrafine-grained metals. Within the model, plastic deformation of such metals incorporates dislocation transmission across grain boundaries (GBs) in the stress fields of dislocation pileups, the emission of individual dislocations from GBs as well as GB sliding accommodated by GB dislocation climb and/or Coble creep. The model predicts a strong increase in the strain rate sensitivity and a decrease in the activation volume with decreasing grain size, in accord with experimental data. We also considered the effect of GB sliding and Coble creep on the anomalous dependence of the activation volume on temperature observed in nanocrystalline Ni. It is demonstrated that although an account for GB sliding and Coble creep leads to the appearance of cusps in the temperature dependence of the activation volume, these mechanisms alone cannot be responsible for the observed anomalous dependence of the activation volume on temperature.

KW - PLASTIC-DEFORMATION

KW - ACTIVATION VOLUME

KW - SIZE DEPENDENCE

KW - BOUNDARY

KW - STRENGTH

KW - FCC

KW - TEMPERATURE

KW - DIFFUSION

KW - DUCTILITY

KW - BEHAVIOR

M3 - Article

VL - 57

SP - 1

EP - 10

JO - Reviews on Advanced Materials Science

JF - Reviews on Advanced Materials Science

SN - 1606-5131

IS - 1

ER -