Crystal Plasticity with Micromorphic Regularization in Assessing Scale Dependent Deformation of Polycrystalline Doped Copper Alloys

It is planned that doped copper overpacks will be utilized in the spent nuclear fuel repositories in Finland and in Sweden. The assessment of long-term integrity of the material is a matter of importance. Grain structure variations, segregation and any possible manufacturing defects in microstructur...

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Main Authors: Matti Lindroos, Tom Andersson, Jarkko Metsäjoki, Anssi Laukkanen
Format: Article
Language:English
Published: MDPI AG 2021-08-01
Series:Crystals
Subjects:
Online Access:https://www.mdpi.com/2073-4352/11/8/994
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author Matti Lindroos
Tom Andersson
Jarkko Metsäjoki
Anssi Laukkanen
author_facet Matti Lindroos
Tom Andersson
Jarkko Metsäjoki
Anssi Laukkanen
author_sort Matti Lindroos
collection DOAJ
description It is planned that doped copper overpacks will be utilized in the spent nuclear fuel repositories in Finland and in Sweden. The assessment of long-term integrity of the material is a matter of importance. Grain structure variations, segregation and any possible manufacturing defects in microstructure are relevant in terms of susceptibility to creep and damage from the loading evolution imposed by its operating environment. This work focuses on studying the microstructure level length-scale dependent deformation behavior of the material, of particular significance with respect to accumulation of plasticity over the extensive operational period of the overpacks. The reduced micromorphic crystal plasticity model, which is similar to strain gradient models, is used in this investigation. Firstly, the model’s size dependent plasticity effects are evaluated. Secondly, different microstructural aggregates presenting overpack sections are analyzed. Grain size dependent hardening responses, i.e., Hall-Petch like behavior, can be achieved with the enhanced hardening associated with the micromorphic model at polycrystalline level. It was found that the nominally large grain size in the base material of the overpack shows lower strain hardening potential than the fine grained region of the welded microstructure with stronger strain gradient related hardening effects. Size dependent regularization of strain localization networks is indicated as a desired characteristic of the model. The findings can be utilized to provide an improved basis for modeling the viscoplastic deformation behavior of the studied copper alloy and to assess the microstructural origins of any integrity concerns explicitly by way of full field modeling.
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spelling doaj.art-5aea00023dbf443ca7da04c97efe5ead2023-11-22T07:17:56ZengMDPI AGCrystals2073-43522021-08-0111899410.3390/cryst11080994Crystal Plasticity with Micromorphic Regularization in Assessing Scale Dependent Deformation of Polycrystalline Doped Copper AlloysMatti Lindroos0Tom Andersson1Jarkko Metsäjoki2Anssi Laukkanen3Integrated Computational Materials Engineering, VTT Technical Research Centre of Finland Ltd., 02044 Espoo, FinlandIntegrated Computational Materials Engineering, VTT Technical Research Centre of Finland Ltd., 02044 Espoo, FinlandIntegrated Computational Materials Engineering, VTT Technical Research Centre of Finland Ltd., 02044 Espoo, FinlandIntegrated Computational Materials Engineering, VTT Technical Research Centre of Finland Ltd., 02044 Espoo, FinlandIt is planned that doped copper overpacks will be utilized in the spent nuclear fuel repositories in Finland and in Sweden. The assessment of long-term integrity of the material is a matter of importance. Grain structure variations, segregation and any possible manufacturing defects in microstructure are relevant in terms of susceptibility to creep and damage from the loading evolution imposed by its operating environment. This work focuses on studying the microstructure level length-scale dependent deformation behavior of the material, of particular significance with respect to accumulation of plasticity over the extensive operational period of the overpacks. The reduced micromorphic crystal plasticity model, which is similar to strain gradient models, is used in this investigation. Firstly, the model’s size dependent plasticity effects are evaluated. Secondly, different microstructural aggregates presenting overpack sections are analyzed. Grain size dependent hardening responses, i.e., Hall-Petch like behavior, can be achieved with the enhanced hardening associated with the micromorphic model at polycrystalline level. It was found that the nominally large grain size in the base material of the overpack shows lower strain hardening potential than the fine grained region of the welded microstructure with stronger strain gradient related hardening effects. Size dependent regularization of strain localization networks is indicated as a desired characteristic of the model. The findings can be utilized to provide an improved basis for modeling the viscoplastic deformation behavior of the studied copper alloy and to assess the microstructural origins of any integrity concerns explicitly by way of full field modeling.https://www.mdpi.com/2073-4352/11/8/994micromechanicscrystal plasticitymicromorphicHall-Petchcopper alloys
spellingShingle Matti Lindroos
Tom Andersson
Jarkko Metsäjoki
Anssi Laukkanen
Crystal Plasticity with Micromorphic Regularization in Assessing Scale Dependent Deformation of Polycrystalline Doped Copper Alloys
Crystals
micromechanics
crystal plasticity
micromorphic
Hall-Petch
copper alloys
title Crystal Plasticity with Micromorphic Regularization in Assessing Scale Dependent Deformation of Polycrystalline Doped Copper Alloys
title_full Crystal Plasticity with Micromorphic Regularization in Assessing Scale Dependent Deformation of Polycrystalline Doped Copper Alloys
title_fullStr Crystal Plasticity with Micromorphic Regularization in Assessing Scale Dependent Deformation of Polycrystalline Doped Copper Alloys
title_full_unstemmed Crystal Plasticity with Micromorphic Regularization in Assessing Scale Dependent Deformation of Polycrystalline Doped Copper Alloys
title_short Crystal Plasticity with Micromorphic Regularization in Assessing Scale Dependent Deformation of Polycrystalline Doped Copper Alloys
title_sort crystal plasticity with micromorphic regularization in assessing scale dependent deformation of polycrystalline doped copper alloys
topic micromechanics
crystal plasticity
micromorphic
Hall-Petch
copper alloys
url https://www.mdpi.com/2073-4352/11/8/994
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AT jarkkometsajoki crystalplasticitywithmicromorphicregularizationinassessingscaledependentdeformationofpolycrystallinedopedcopperalloys
AT anssilaukkanen crystalplasticitywithmicromorphicregularizationinassessingscaledependentdeformationofpolycrystallinedopedcopperalloys