TY - JOUR
T1 - Local stress analysis of partial dislocation interactions with symmetrical-tilt grain boundaries containing E-structural units
AU - Mohan, Sivasakthya
AU - Li, Ruizhi
AU - Chew, Huck Beng
N1 - The authors acknowledge the support provided by Dr Ali Sayir under the AFOSR Aerospace Materials for Extreme Environment Program (award no. FA9550-15-1-0117), as well as computational time provided by XSEDE (award no. TG-MSS130007) and the Blue Waters sustained-petascale computing project which is supported by the National Science Foundation (awards OCI-0725070 and ACI-1238993) and the state of Illinois.
PY - 2018/9/2
Y1 - 2018/9/2
N2 - Grain boundaries containing porous E-structural units (SUs) are known to readily emit dislocations under tension. Using molecular dynamics simulations, we study the interactions between <112>{111} Shockley partial dislocations and <110> symmetrical-tilt Ni grain boundaries containing E-SUs. We show that the incoming Shockley partials can be accommodated by porous E-SUs along the grain boundary. However, the partial-absorption process disrupts the short-range interactions of incipient dislocations along the boundary, which generates high local tensile and compressive stress regimes emanating from the impingement sites. For the favoured (Formula presented.) grain boundary comprising only of E-SUs, incipient Shockley partials originating from E-SUs located within the tensile stress regime are subsequently re-emitted into the neighbouring grain. We demonstrate that the critical strength for re-emission of Shockley partials can be delineated into contributions from tensile stress generated by partial-absorption, intrinsic grain boundary tractions, as well as external loading. In the presence of other types of SUs, the incoming Shockley partials can also be transmitted through the boundary, or be stably absorbed by the boundary with no subsequent re-emission, depending on the impingement site.
AB - Grain boundaries containing porous E-structural units (SUs) are known to readily emit dislocations under tension. Using molecular dynamics simulations, we study the interactions between <112>{111} Shockley partial dislocations and <110> symmetrical-tilt Ni grain boundaries containing E-SUs. We show that the incoming Shockley partials can be accommodated by porous E-SUs along the grain boundary. However, the partial-absorption process disrupts the short-range interactions of incipient dislocations along the boundary, which generates high local tensile and compressive stress regimes emanating from the impingement sites. For the favoured (Formula presented.) grain boundary comprising only of E-SUs, incipient Shockley partials originating from E-SUs located within the tensile stress regime are subsequently re-emitted into the neighbouring grain. We demonstrate that the critical strength for re-emission of Shockley partials can be delineated into contributions from tensile stress generated by partial-absorption, intrinsic grain boundary tractions, as well as external loading. In the presence of other types of SUs, the incoming Shockley partials can also be transmitted through the boundary, or be stably absorbed by the boundary with no subsequent re-emission, depending on the impingement site.
KW - Structural-unit model
KW - dislocation interaction
KW - grain boundary
KW - local stress-fields
KW - molecular dynamics simulations
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U2 - 10.1080/14786435.2018.1486049
DO - 10.1080/14786435.2018.1486049
M3 - Article
AN - SCOPUS:85048831801
SN - 1478-6435
VL - 98
SP - 2345
EP - 2366
JO - Philosophical Magazine
JF - Philosophical Magazine
IS - 25
ER -