Geometrical Aspects of Dislocation-Obstacle Interaction in Iron

Panagiotis Grammatikopoulos; David Bacon; Yuri Osetsky

Geometrical Aspects of Dislocation-Obstacle Interaction in Iron

Panagiotis Grammatikopoulos, David Bacon, Yuri Osetsky^*

^*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

Abstract

Experiments and atomic-scale computer simulations have shown that nano-scale voids and copper precipitates can be strong obstacles to the glide of dislocations in neutron-irradiated iron. Simulations have shown that voids are strong obstacles and that an edge dislocation climbs by absorbing vacancies
at it breaks away from voids. The obstacle strength of copper precipitates is enhanced by a dislocation-induced structural transformation if they are large enough and the temperature is low enough. Most simulations have the centre of a spherical void or precipitate on the slip plane of an edge dislocation. The present work investigates how the strength of 2 and 4 nm voids and precipitates varies with the distance of their centre from the slip plane at temperatures across the range 0 to 450 K. The strength of voids is highest when their centre coincides with the slip plane, but this is not the case for small precipitates, which do not transform from the bcc structure. The strength of both type of obstacle, and the extent of climb at voids and transformation of large precipitates are not symmetric with respect to the position of their centre from the slip plane. The results are discussed in terms of the atomic mechanisms involved.

Original language	American English
Title of host publication	Advances in Science and Technology
Publisher	Trans Tech Publications Ltd
Pages	109-117
Volume	73
State	Published - 27 Oct 2010
Externally published	Yes

Keywords

molecular dynamics simulation
Radiation damage
dislocations
alpha-iron
voids
copper precipitates

Cite this

@inproceedings{42fb9e48691545de838f83e81c36d832,

title = "Geometrical Aspects of Dislocation-Obstacle Interaction in Iron",

abstract = "Experiments and atomic-scale computer simulations have shown that nano-scale voids and copper precipitates can be strong obstacles to the glide of dislocations in neutron-irradiated iron. Simulations have shown that voids are strong obstacles and that an edge dislocation climbs by absorbing vacanciesat it breaks away from voids. The obstacle strength of copper precipitates is enhanced by a dislocation-induced structural transformation if they are large enough and the temperature is low enough. Most simulations have the centre of a spherical void or precipitate on the slip plane of an edge dislocation. The present work investigates how the strength of 2 and 4 nm voids and precipitates varies with the distance of their centre from the slip plane at temperatures across the range 0 to 450 K. The strength of voids is highest when their centre coincides with the slip plane, but this is not the case for small precipitates, which do not transform from the bcc structure. The strength of both type of obstacle, and the extent of climb at voids and transformation of large precipitates are not symmetric with respect to the position of their centre from the slip plane. The results are discussed in terms of the atomic mechanisms involved.",

keywords = "molecular dynamics simulation, Radiation damage, dislocations, alpha-iron, voids, copper precipitates",

author = "Panagiotis Grammatikopoulos and David Bacon and Yuri Osetsky",

year = "2010",

month = oct,

day = "27",

language = "American English",

volume = "73",

pages = "109--117",

booktitle = "Advances in Science and Technology",

publisher = "Trans Tech Publications Ltd",

}

TY - GEN

T1 - Geometrical Aspects of Dislocation-Obstacle Interaction in Iron

AU - Grammatikopoulos, Panagiotis

AU - Bacon, David

AU - Osetsky, Yuri

PY - 2010/10/27

Y1 - 2010/10/27

N2 - Experiments and atomic-scale computer simulations have shown that nano-scale voids and copper precipitates can be strong obstacles to the glide of dislocations in neutron-irradiated iron. Simulations have shown that voids are strong obstacles and that an edge dislocation climbs by absorbing vacanciesat it breaks away from voids. The obstacle strength of copper precipitates is enhanced by a dislocation-induced structural transformation if they are large enough and the temperature is low enough. Most simulations have the centre of a spherical void or precipitate on the slip plane of an edge dislocation. The present work investigates how the strength of 2 and 4 nm voids and precipitates varies with the distance of their centre from the slip plane at temperatures across the range 0 to 450 K. The strength of voids is highest when their centre coincides with the slip plane, but this is not the case for small precipitates, which do not transform from the bcc structure. The strength of both type of obstacle, and the extent of climb at voids and transformation of large precipitates are not symmetric with respect to the position of their centre from the slip plane. The results are discussed in terms of the atomic mechanisms involved.

AB - Experiments and atomic-scale computer simulations have shown that nano-scale voids and copper precipitates can be strong obstacles to the glide of dislocations in neutron-irradiated iron. Simulations have shown that voids are strong obstacles and that an edge dislocation climbs by absorbing vacanciesat it breaks away from voids. The obstacle strength of copper precipitates is enhanced by a dislocation-induced structural transformation if they are large enough and the temperature is low enough. Most simulations have the centre of a spherical void or precipitate on the slip plane of an edge dislocation. The present work investigates how the strength of 2 and 4 nm voids and precipitates varies with the distance of their centre from the slip plane at temperatures across the range 0 to 450 K. The strength of voids is highest when their centre coincides with the slip plane, but this is not the case for small precipitates, which do not transform from the bcc structure. The strength of both type of obstacle, and the extent of climb at voids and transformation of large precipitates are not symmetric with respect to the position of their centre from the slip plane. The results are discussed in terms of the atomic mechanisms involved.

KW - molecular dynamics simulation

KW - Radiation damage

KW - dislocations

KW - alpha-iron

KW - voids

KW - copper precipitates

M3 - Conference contribution

VL - 73

SP - 109

EP - 117

BT - Advances in Science and Technology

PB - Trans Tech Publications Ltd

ER -

Geometrical Aspects of Dislocation-Obstacle Interaction in Iron

Abstract

Keywords

Fingerprint

Cite this