TY - GEN
T1 - Hardening by completely and partially absorbed ½<111> and <100> dislocation loops reacting with dislocations in α-Fe.
AU - Terentyev, D.
AU - Bacon, D. J.
AU - Grammatikopoulos, P.
AU - Osetsky, Yu N.
N1 - Publisher Copyright:
© MMM 2008. All rights reserved.
PY - 2008
Y1 - 2008
N2 - Molecular dynamics simulations were used to investigate reactions between an ½<111>{110} edge dislocation with interstitial dislocation loops with Burgers vector equal to either ½111 or 100. The loop size was varied from 0.5 nm up to 8.6 nm, and simulations of both static and dynamic conditions were performed. The results obtained show that small loops (with size up to ~1nm) are easily absorbed by reaction with edge dislocations, independently of their Burgers vector. Large loops are strong obstacles and, depending on the difference in orientation of the dislocation and loop Burgers vectors, are either completely or partially absorbed. The mechanism that provides complete absorption of relatively large loops involves propagation of the reaction segment, formed in favourable dislocation reaction, over the loop surface. This motion is controlled by cross-slip of the screw dislocations formed in a dipole and can involve complicated dislocation reactions. Thus, thermally-activated glide and/or decomposition of the pinning segment formed in the favourable reaction determines both the absorption and critical stress, and therefore depends on temperature, strain rate and loop size.
AB - Molecular dynamics simulations were used to investigate reactions between an ½<111>{110} edge dislocation with interstitial dislocation loops with Burgers vector equal to either ½111 or 100. The loop size was varied from 0.5 nm up to 8.6 nm, and simulations of both static and dynamic conditions were performed. The results obtained show that small loops (with size up to ~1nm) are easily absorbed by reaction with edge dislocations, independently of their Burgers vector. Large loops are strong obstacles and, depending on the difference in orientation of the dislocation and loop Burgers vectors, are either completely or partially absorbed. The mechanism that provides complete absorption of relatively large loops involves propagation of the reaction segment, formed in favourable dislocation reaction, over the loop surface. This motion is controlled by cross-slip of the screw dislocations formed in a dipole and can involve complicated dislocation reactions. Thus, thermally-activated glide and/or decomposition of the pinning segment formed in the favourable reaction determines both the absorption and critical stress, and therefore depends on temperature, strain rate and loop size.
UR - http://www.scopus.com/inward/record.url?scp=85067120618&partnerID=8YFLogxK
M3 - 会议稿件
AN - SCOPUS:85067120618
T3 - Proceedings of 4th International Conference on Multiscale Materials Modeling, MMM 2008
SP - 817
EP - 822
BT - Proceedings of 4th International Conference on Multiscale Materials Modeling, MMM 2008
A2 - El-Azab, Anter
PB - Department of Scientific Computing, Florida State University
T2 - 4th International Conference on Multiscale Materials Modeling, MMM 2008
Y2 - 27 October 2008 through 31 October 2008
ER -