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Title: Evolution of nanoscale interstitial dislocation loops under coupling effect of stress and temperature

Abstract

The properties of nano-scale interstitial dislocation loops under the coupling effect of stress and temperature are studied using atomistic simulation methods and experiments. The decomposition of a loop by the emission of smaller loops is identified as one of the major mechanisms to release the localized stress induced by the coupling effect, which is validated by the TEM observations. The classical conservation law of Burgers vector cannot be applied during such decomposition process. The dislocation network is formed from the decomposed loops, which may initiate the irradiation creep much earlier than expected through the mechanism of climb-controlled glide of dislocations.

Authors:
; ; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Fusion Energy Sciences (FES) (SC-24)
OSTI Identifier:
1358476
Report Number(s):
PNNL-SA-124673
Journal ID: ISSN 1359-6462; AT2030110
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Scripta Materialia; Journal Volume: 136
Country of Publication:
United States
Language:
English

Citation Formats

Gao, Ning, Shen, Tielong, Kurtz, Richard, Wang, Zhiguang, and Gao, Fei. Evolution of nanoscale interstitial dislocation loops under coupling effect of stress and temperature. United States: N. p., 2017. Web. doi:10.1016/j.scriptamat.2017.03.008.
Gao, Ning, Shen, Tielong, Kurtz, Richard, Wang, Zhiguang, & Gao, Fei. Evolution of nanoscale interstitial dislocation loops under coupling effect of stress and temperature. United States. doi:10.1016/j.scriptamat.2017.03.008.
Gao, Ning, Shen, Tielong, Kurtz, Richard, Wang, Zhiguang, and Gao, Fei. Sat . "Evolution of nanoscale interstitial dislocation loops under coupling effect of stress and temperature". United States. doi:10.1016/j.scriptamat.2017.03.008.
@article{osti_1358476,
title = {Evolution of nanoscale interstitial dislocation loops under coupling effect of stress and temperature},
author = {Gao, Ning and Shen, Tielong and Kurtz, Richard and Wang, Zhiguang and Gao, Fei},
abstractNote = {The properties of nano-scale interstitial dislocation loops under the coupling effect of stress and temperature are studied using atomistic simulation methods and experiments. The decomposition of a loop by the emission of smaller loops is identified as one of the major mechanisms to release the localized stress induced by the coupling effect, which is validated by the TEM observations. The classical conservation law of Burgers vector cannot be applied during such decomposition process. The dislocation network is formed from the decomposed loops, which may initiate the irradiation creep much earlier than expected through the mechanism of climb-controlled glide of dislocations.},
doi = {10.1016/j.scriptamat.2017.03.008},
journal = {Scripta Materialia},
number = ,
volume = 136,
place = {United States},
year = {Sat Jul 01 00:00:00 EDT 2017},
month = {Sat Jul 01 00:00:00 EDT 2017}
}
  • A general expression for the creep strain produced by a distribution of dislocation loops is derived and applied to the nucleation (assumed subject to Boltzmann statistics) of prismatic loops in bcc and fcc metals and alloys subjected to neutron irradiation. The nucleation of the loops is considered to take place in several stages, viz., an initial growth of small platelets of atoms on (110) planes (bcc metals) or Frank loops on (111) planes (fcc metals), followed by urfaulting and then conservative rotation to the pure edge orientation. The equations for the creep strain for low applied stresses explicitly contain termsmore » relating to the various stages involved in the nucleation of the loops and show, inter alia, that rotation to the pure edge orientation does not cancel the strain produced by prior unfaulting. (auth)« less
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