Structure and migration of heavily irradiated grain boundaries and dislocations in Ni in the athermal limit
Journal Article
·
· Physical Review Materials
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- Paul Scherrer Inst. (PSI), Villigen (Switzerland)
The microstructural evolution at and near preexisting grain boundaries (GBs) and dislocations in materials under high radiation doses is still poorly understood. In this work, we use the creation relaxation algorithm (CRA) developed for atomistic modeling of high-dose irradiation in bulk materials to probe the athermal limit of saturation of GB and dislocation core regions under irradiation in fcc Ni. We find that, upon continuously subjecting a single dislocation or GB to Frenkel pair creation in the athermal limit, a local steady-state disordered defect structure is reached with excess properties that fluctuate around constant values. Case studies are given for a straight screw dislocation which elongates into a helix under irradiation and several types of low- and high-angle GBs, which exhibit coupled responses such as absorption of extrinsic dislocations, roughening, and migration. A positive correlation is found between the initial GB energy and the local steady-state GB energy under irradiation across a wide variety of GB types. Metastable GB structures with similar density in the defect core region but different initial configurations are found to converge to the same limiting structure under CRA. The mechanical responses of pristine and irradiated dislocations and GB structures are compared under an applied shear stress. Irradiated screw and edge dislocations are found to exhibit a hardening response, migrating at larger flow stresses than their pristine counterparts. Mobile GBs are found to exhibit softening or hardening responses depending on GB character. Although some GBs recover their initial pristine structures upon migration outside of the radiation zone, many GBs sustain different flow stresses corresponding to altered mobile core structures.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE Laboratory Directed Research and Development (LDRD) Program; USDOE National Nuclear Security Administration (NNSA)
- Grant/Contract Number:
- 89233218CNA000001
- OSTI ID:
- 2467398
- Alternate ID(s):
- OSTI ID: 2473318
- Report Number(s):
- LA-UR--24-24385
- Journal Information:
- Physical Review Materials, Journal Name: Physical Review Materials Journal Issue: 9 Vol. 8; ISSN 2475-9953
- Publisher:
- American Physical Society (APS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
Influence of peak pressure and temperature on the structure/property response of shock-loaded Ta and Ta-10W
Interaction Of Vacancies And Helium Atoms With A/2 <111> Screw Dislocations In Α-Fe
A spatially-resolved model of neutron-irradiated tungsten coupling stochastic cluster dynamics and finite deformation plasticity
Journal Article
·
Sun Oct 01 00:00:00 EDT 1995
· Metallurgical Transactions, A
·
OSTI ID:131436
Interaction Of Vacancies And Helium Atoms With A/2 <111> Screw Dislocations In Α-Fe
Book
·
Tue Apr 01 00:00:00 EDT 2008
·
OSTI ID:966303
A spatially-resolved model of neutron-irradiated tungsten coupling stochastic cluster dynamics and finite deformation plasticity
Journal Article
·
Mon Nov 18 19:00:00 EST 2024
· Journal of Nuclear Materials
·
OSTI ID:2560683