Atomistic calculations of dislocation core energy in aluminium
A robust molecular dynamics simulation method for calculating dislocation core energies has been developed. This method has unique advantages: it does not require artificial boundary conditions, is applicable for mixed dislocations, and can yield highly converged results regardless of the atomistic system size. Utilizing a highfidelity bond order potential, we have applied this method in aluminium to calculate the dislocation core energy as a function of the angle β between the dislocation line and Burgers vector. These calculations show that, for the facecentredcubic aluminium explored, the dislocation core energy follows the same functional dependence on β as the dislocation elastic energy: Ec = A·sin ^{2}β + B·cos ^{2}β, and this dependence is independent of temperature between 100 and 300 K. By further analysing the energetics of an extended dislocation core, we elucidate the relationship between the core energy and radius of a perfect versus extended dislocation. With our methodology, the dislocation core energy can be accurately accounted for in models of plastic deformation.
 Authors:

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 Sandia National Lab. (SNLCA), Livermore, CA (United States)
 Publication Date:
 Report Number(s):
 SAND20161998J
Journal ID: ISSN 24699950; PRBMDO; 619853; TRN: US1700711
 Grant/Contract Number:
 AC0494AL85000; 165724
 Type:
 Accepted Manuscript
 Journal Name:
 Physical Review B
 Additional Journal Information:
 Journal Volume: 95; Journal Issue: 5; Journal ID: ISSN 24699950
 Publisher:
 American Physical Society (APS)
 Research Org:
 Sandia National Lab. (SNLCA), Livermore, CA (United States)
 Sponsoring Org:
 USDOE National Nuclear Security Administration (NNSA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 36 MATERIALS SCIENCE
 OSTI Identifier:
 1344462
 Alternate Identifier(s):
 OSTI ID: 1344132; OSTI ID: 1344473
Zhou, X. W., Sills, R. B., Ward, D. K., and Karnesky, R. A.. Atomistic calculations of dislocation core energy in aluminium. United States: N. p.,
Web. doi:10.1103/PhysRevB.95.054112.
Zhou, X. W., Sills, R. B., Ward, D. K., & Karnesky, R. A.. Atomistic calculations of dislocation core energy in aluminium. United States. doi:10.1103/PhysRevB.95.054112.
Zhou, X. W., Sills, R. B., Ward, D. K., and Karnesky, R. A.. 2017.
"Atomistic calculations of dislocation core energy in aluminium". United States.
doi:10.1103/PhysRevB.95.054112. https://www.osti.gov/servlets/purl/1344462.
@article{osti_1344462,
title = {Atomistic calculations of dislocation core energy in aluminium},
author = {Zhou, X. W. and Sills, R. B. and Ward, D. K. and Karnesky, R. A.},
abstractNote = {A robust molecular dynamics simulation method for calculating dislocation core energies has been developed. This method has unique advantages: it does not require artificial boundary conditions, is applicable for mixed dislocations, and can yield highly converged results regardless of the atomistic system size. Utilizing a highfidelity bond order potential, we have applied this method in aluminium to calculate the dislocation core energy as a function of the angle β between the dislocation line and Burgers vector. These calculations show that, for the facecentredcubic aluminium explored, the dislocation core energy follows the same functional dependence on β as the dislocation elastic energy: Ec = A·sin2β + B·cos2β, and this dependence is independent of temperature between 100 and 300 K. By further analysing the energetics of an extended dislocation core, we elucidate the relationship between the core energy and radius of a perfect versus extended dislocation. With our methodology, the dislocation core energy can be accurately accounted for in models of plastic deformation.},
doi = {10.1103/PhysRevB.95.054112},
journal = {Physical Review B},
number = 5,
volume = 95,
place = {United States},
year = {2017},
month = {2}
}