Structure and glide of Lomer and Lomer-Cottrell dislocations: Atomistic simulations for model concentrated alloy solid solutions

Abu-Odeh, Anas; Allaparti, Tarun; Asta, Mark

doi:10.1103/physrevmaterials.6.103603

Title: Structure and glide of Lomer and Lomer-Cottrell dislocations: Atomistic simulations for model concentrated alloy solid solutions

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Abstract

Lomer (L) and Lomer-Cottrell (LC) dislocations have long been considered to be central to work hardening in face-centered cubic (FCC) metals and alloys. These dislocations act as barriers of motion for other dislocations, and can serve as sites for twin nucleation. Recent focus on multicomponent concentrated FCC solid solution alloys has resulted in many reported observations of LC dislocations. While these and L dislocations are expected to have a role in the mechanical behavior of these alloys, little is understood about how variations in composition and associated fault energies change the response of these dislocations under stress. Here we present atomistic simulations of L and LC dislocations in a model Cu-Ni system and find that changes in composition and applied stress conditions result in a wide variety of responses, including changes in core configuration and (100) glide. The results are compared to and extend previous literature related to the nature of L/LC core structures and how they vary with respect to intrinsic materials properties and stress states. This study also provides insights into mechanisms such as twin nucleation that could have important implications for work hardening in FCC solid-solution alloys.

Authors:

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University of California, Berkeley, CA (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). Materials Sciences Division
University of California, Berkeley, CA (United States)

Publication Date:: Mon Oct 31 00:00:00 EDT 2022

Research Org.:: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)

Sponsoring Org.:: USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division (MSE)

OSTI Identifier:: 2328540

Grant/Contract Number:: AC02-05CH11231

Resource Type:: Accepted Manuscript

Journal Name:: Physical Review Materials

Additional Journal Information:: Journal Volume: 6; Journal Issue: 10; Journal ID: ISSN 2475-9953

Publisher:: American Physical Society (APS)

Country of Publication:: United States

Language:: English

Subject:: 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; disclinations and dislocations; twinning; disordered alloys; solid solutions

Citation Formats


                    Abu-Odeh, Anas, Allaparti, Tarun, and Asta, Mark. Structure and glide of Lomer and Lomer-Cottrell dislocations: Atomistic simulations for model concentrated alloy solid solutions.  United States: N. p., 2022. 
Web.  doi:10.1103/physrevmaterials.6.103603.

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                    Abu-Odeh, Anas, Allaparti, Tarun, & Asta, Mark. Structure and glide of Lomer and Lomer-Cottrell dislocations: Atomistic simulations for model concentrated alloy solid solutions.  United States.  https://doi.org/10.1103/physrevmaterials.6.103603

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                    Abu-Odeh, Anas, Allaparti, Tarun, and Asta, Mark. Mon .  
"Structure and glide of Lomer and Lomer-Cottrell dislocations: Atomistic simulations for model concentrated alloy solid solutions".  United States.  https://doi.org/10.1103/physrevmaterials.6.103603.  https://www.osti.gov/servlets/purl/2328540.

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@article{osti_2328540,

  title        = {Structure and glide of Lomer and Lomer-Cottrell dislocations: Atomistic simulations for model concentrated alloy solid solutions},

  author       = {Abu-Odeh, Anas and Allaparti, Tarun and Asta, Mark},

  abstractNote = {Lomer (L) and Lomer-Cottrell (LC) dislocations have long been considered to be central to work hardening in face-centered cubic (FCC) metals and alloys. These dislocations act as barriers of motion for other dislocations, and can serve as sites for twin nucleation. Recent focus on multicomponent concentrated FCC solid solution alloys has resulted in many reported observations of LC dislocations. While these and L dislocations are expected to have a role in the mechanical behavior of these alloys, little is understood about how variations in composition and associated fault energies change the response of these dislocations under stress. Here we present atomistic simulations of L and LC dislocations in a model Cu-Ni system and find that changes in composition and applied stress conditions result in a wide variety of responses, including changes in core configuration and (100) glide. The results are compared to and extend previous literature related to the nature of L/LC core structures and how they vary with respect to intrinsic materials properties and stress states. This study also provides insights into mechanisms such as twin nucleation that could have important implications for work hardening in FCC solid-solution alloys.},

  doi          = {10.1103/physrevmaterials.6.103603},

  journal      = {Physical Review Materials},

  number       = 10,

  volume       = 6,

  place        = {United States},

  year         = {Mon Oct 31 00:00:00 EDT 2022},

  month        = {Mon Oct 31 00:00:00 EDT 2022}

}

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