Roles of vacancy/interstitial diffusion and segregation in the microchemistry at grain boundaries of irradiated Fe–Cr–Ni alloys
Autor: | Todd Allen, Kevin G. Field, Jeremy T Busby, Ying Yang |
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Rok vydání: | 2016 |
Předmět: |
Nuclear and High Energy Physics
Materials science Alloy Thermodynamics chemistry.chemical_element 02 engineering and technology engineering.material 01 natural sciences Condensed Matter::Materials Science Materials Science(all) Vacancy defect 0103 physical sciences Physics::Atomic and Molecular Clusters Grain boundary diffusion coefficient Effective diffusion coefficient General Materials Science Diffusion (business) CALPHAD 010302 applied physics 021001 nanoscience & nanotechnology Nickel Nuclear Energy and Engineering chemistry engineering Grain boundary 0210 nano-technology |
Zdroj: | Journal of Nuclear Materials. 473:35-53 |
ISSN: | 0022-3115 |
Popis: | This work presents a detailed analysis of the diffusion fluxes near and at grain boundaries of irradiated Fe–Cr–Ni alloys, induced by preferential atom-vacancy and atom-interstitial coupling. The diffusion flux equations were based on the Perks model formulated through the linear theory of the thermodynamics of irreversible processes. The preferential atom-vacancy coupling was described by the mobility model, whereas the preferential atom-interstitial coupling was described by the interstitial binding model. The composition dependence of the thermodynamic factor was modeled using the CALPHAD approach. The calculated fluxes up to 10 dpa suggested the dominant diffusion mechanism for chromium and iron is via vacancy, while that for nickel can swing from the vacancy to the interstitial dominant mechanism. The diffusion flux in the vicinity of a grain boundary was found to be greatly modified by the segregation induced by irradiation, leading to the oscillatory behavior of alloy compositions in this region. |
Databáze: | OpenAIRE |
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