TEM Observation of Loops Decorating Dislocations and Resulting Source Hardening of Neutron-Irradiated Fe-Cr Alloys

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TEM Observation of Loops Decorating Dislocations and Resulting Source Hardening of Neutron-Irradiated Fe-Cr Alloys. / Bergner, Frank; Hernández-Mayoral, Mercedes; Heintze, Cornelia; Konstantinovic, Milan; Malerba, Lorenzo; Pareige, Cristelle.

In: Metals, Vol. 10, No. 1, 147, 18.01.2020, p. 1-10.

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Bergner, Frank ; Hernández-Mayoral, Mercedes ; Heintze, Cornelia ; Konstantinovic, Milan ; Malerba, Lorenzo ; Pareige, Cristelle. / TEM Observation of Loops Decorating Dislocations and Resulting Source Hardening of Neutron-Irradiated Fe-Cr Alloys. In: Metals. 2020 ; Vol. 10, No. 1. pp. 1-10.

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@article{c6a51a3ef18847d185b86758bdb816d2,
title = "TEM Observation of Loops Decorating Dislocations and Resulting Source Hardening of Neutron-Irradiated Fe-Cr Alloys",
abstract = "Several open issues remain concerning the quantitative understanding of irradiation hardening in high-Cr steels. One of these issues is addressed here by correlating yield points that are observed in stress-strain curves with dislocation decoration observed by TEM for neutron-irradiated Fe-Cr alloys. It is found that both higher neutron exposure and higher Cr content promote irradiation-induced loops to arrange preferentially along dislocation lines. Consequently, the activation of dislocation sources requires unlocking from the decorating loops, thus resulting in a yield drop. This process is considered within the source hardening model as opposed to the dispersed barrier hardening model, the latter aimed to describe dislocation slip through a random array of obstacles. Microstructure-informed estimates of the unlocking stress are compared with measured values of the upper yield stress. As functions of neutron exposure, a cross-over from the dominance of dispersed-barrier hardening accompanied by smooth elastic-plastic transitions to the dominance of source hardening accompanied by yield drops is observed for Fe-9{\%} Cr and Fe-12{\%} Cr",
keywords = "Iron-chromium alloys, Neutron irradiation, Hardening, Tensile test, Dislocation loop, TEM",
author = "Frank Bergner and Mercedes Hern{\'a}ndez-Mayoral and Cornelia Heintze and Milan Konstantinovic and Lorenzo Malerba and Cristelle Pareige",
note = "Score=10",
year = "2020",
month = "1",
day = "18",
doi = "10.3390/met10010147",
language = "English",
volume = "10",
pages = "1--10",
journal = "Metals",
issn = "2075-4701",
publisher = "MDPI",
number = "1",

}

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TY - JOUR

T1 - TEM Observation of Loops Decorating Dislocations and Resulting Source Hardening of Neutron-Irradiated Fe-Cr Alloys

AU - Bergner, Frank

AU - Hernández-Mayoral, Mercedes

AU - Heintze, Cornelia

AU - Konstantinovic, Milan

AU - Malerba, Lorenzo

AU - Pareige, Cristelle

N1 - Score=10

PY - 2020/1/18

Y1 - 2020/1/18

N2 - Several open issues remain concerning the quantitative understanding of irradiation hardening in high-Cr steels. One of these issues is addressed here by correlating yield points that are observed in stress-strain curves with dislocation decoration observed by TEM for neutron-irradiated Fe-Cr alloys. It is found that both higher neutron exposure and higher Cr content promote irradiation-induced loops to arrange preferentially along dislocation lines. Consequently, the activation of dislocation sources requires unlocking from the decorating loops, thus resulting in a yield drop. This process is considered within the source hardening model as opposed to the dispersed barrier hardening model, the latter aimed to describe dislocation slip through a random array of obstacles. Microstructure-informed estimates of the unlocking stress are compared with measured values of the upper yield stress. As functions of neutron exposure, a cross-over from the dominance of dispersed-barrier hardening accompanied by smooth elastic-plastic transitions to the dominance of source hardening accompanied by yield drops is observed for Fe-9% Cr and Fe-12% Cr

AB - Several open issues remain concerning the quantitative understanding of irradiation hardening in high-Cr steels. One of these issues is addressed here by correlating yield points that are observed in stress-strain curves with dislocation decoration observed by TEM for neutron-irradiated Fe-Cr alloys. It is found that both higher neutron exposure and higher Cr content promote irradiation-induced loops to arrange preferentially along dislocation lines. Consequently, the activation of dislocation sources requires unlocking from the decorating loops, thus resulting in a yield drop. This process is considered within the source hardening model as opposed to the dispersed barrier hardening model, the latter aimed to describe dislocation slip through a random array of obstacles. Microstructure-informed estimates of the unlocking stress are compared with measured values of the upper yield stress. As functions of neutron exposure, a cross-over from the dominance of dispersed-barrier hardening accompanied by smooth elastic-plastic transitions to the dominance of source hardening accompanied by yield drops is observed for Fe-9% Cr and Fe-12% Cr

KW - Iron-chromium alloys

KW - Neutron irradiation

KW - Hardening

KW - Tensile test

KW - Dislocation loop

KW - TEM

UR - https://ecm.sckcen.be/OTCS/llisapi.dll/open/38081144

U2 - 10.3390/met10010147

DO - 10.3390/met10010147

M3 - Article

VL - 10

SP - 1

EP - 10

JO - Metals

JF - Metals

SN - 2075-4701

IS - 1

M1 - 147

ER -

ID: 6772878