Phase-Field Modeling of Chemoelastic Binodal/Spinodal Relations and Solute Segregation to Defects in Binary Alloys
Microscopic phase-field chemomechanics (MPFCM) is employed in the current work to model solute segregation, dislocation-solute interaction, spinodal decomposition, and precipitate formation, at straight dislocations and configurations of these in a model binary solid alloy. In particular, (i) a sing...
Main Authors: | , , , |
---|---|
Format: | Article |
Language: | English |
Published: |
MDPI AG
2021-04-01
|
Series: | Materials |
Subjects: | |
Online Access: | https://www.mdpi.com/1996-1944/14/7/1787 |
id |
doaj-c7ec3de057604d90bb22419b7dd4030f |
---|---|
record_format |
Article |
spelling |
doaj-c7ec3de057604d90bb22419b7dd4030f2021-04-05T23:00:09ZengMDPI AGMaterials1996-19442021-04-01141787178710.3390/ma14071787Phase-Field Modeling of Chemoelastic Binodal/Spinodal Relations and Solute Segregation to Defects in Binary AlloysJaber Rezaei Mianroodi0Pratheek Shanthraj1Bob Svendsen2Dierk Raabe3Microstructure Physics and Alloy Design, Max-Planck-Institut für Eisenforschung GmbH, 40237 Düsseldorf, GermanyThe Department of Materials, The University of Manchester, Manchester M13 9PL, UKMicrostructure Physics and Alloy Design, Max-Planck-Institut für Eisenforschung GmbH, 40237 Düsseldorf, GermanyMicrostructure Physics and Alloy Design, Max-Planck-Institut für Eisenforschung GmbH, 40237 Düsseldorf, GermanyMicroscopic phase-field chemomechanics (MPFCM) is employed in the current work to model solute segregation, dislocation-solute interaction, spinodal decomposition, and precipitate formation, at straight dislocations and configurations of these in a model binary solid alloy. In particular, (i) a single static edge dipole, (ii) arrays of static dipoles forming low-angle tilt (edge) and twist (screw) grain boundaries, as well as at (iii) a moving (gliding) edge dipole, are considered. In the first part of the work, MPFCM is formulated for such an alloy. Central here is the MPFCM model for the alloy free energy, which includes chemical, dislocation, and lattice (elastic), contributions. The solute concentration-dependence of the latter due to solute lattice misfit results in a strong elastic influence on the binodal (i.e., coexistence) and spinodal behavior of the alloy. In addition, MPFCM-based modeling of energy storage couples the thermodynamic forces driving (Cottrell and Suzuki) solute segregation, precipitate formation and dislocation glide. As implied by the simulation results for edge dislocation dipoles and their configurations, there is a competition between (i) Cottrell segregation to dislocations resulting in a uniform solute distribution along the line, and (ii) destabilization of this distribution due to low-dimensional spinodal decomposition when the segregated solute content at the line exceeds the spinodal value locally, i.e., at and along the dislocation line. Due to the completely different stress field of the screw dislocation configuration in the twist boundary, the segregated solute distribution is immediately unstable and decomposes into precipitates from the start.https://www.mdpi.com/1996-1944/14/7/1787phase-field chemomechanicssolute segregationspinodal decompositiondislocation-solute interactionlow angle grain boundary |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Jaber Rezaei Mianroodi Pratheek Shanthraj Bob Svendsen Dierk Raabe |
spellingShingle |
Jaber Rezaei Mianroodi Pratheek Shanthraj Bob Svendsen Dierk Raabe Phase-Field Modeling of Chemoelastic Binodal/Spinodal Relations and Solute Segregation to Defects in Binary Alloys Materials phase-field chemomechanics solute segregation spinodal decomposition dislocation-solute interaction low angle grain boundary |
author_facet |
Jaber Rezaei Mianroodi Pratheek Shanthraj Bob Svendsen Dierk Raabe |
author_sort |
Jaber Rezaei Mianroodi |
title |
Phase-Field Modeling of Chemoelastic Binodal/Spinodal Relations and Solute Segregation to Defects in Binary Alloys |
title_short |
Phase-Field Modeling of Chemoelastic Binodal/Spinodal Relations and Solute Segregation to Defects in Binary Alloys |
title_full |
Phase-Field Modeling of Chemoelastic Binodal/Spinodal Relations and Solute Segregation to Defects in Binary Alloys |
title_fullStr |
Phase-Field Modeling of Chemoelastic Binodal/Spinodal Relations and Solute Segregation to Defects in Binary Alloys |
title_full_unstemmed |
Phase-Field Modeling of Chemoelastic Binodal/Spinodal Relations and Solute Segregation to Defects in Binary Alloys |
title_sort |
phase-field modeling of chemoelastic binodal/spinodal relations and solute segregation to defects in binary alloys |
publisher |
MDPI AG |
series |
Materials |
issn |
1996-1944 |
publishDate |
2021-04-01 |
description |
Microscopic phase-field chemomechanics (MPFCM) is employed in the current work to model solute segregation, dislocation-solute interaction, spinodal decomposition, and precipitate formation, at straight dislocations and configurations of these in a model binary solid alloy. In particular, (i) a single static edge dipole, (ii) arrays of static dipoles forming low-angle tilt (edge) and twist (screw) grain boundaries, as well as at (iii) a moving (gliding) edge dipole, are considered. In the first part of the work, MPFCM is formulated for such an alloy. Central here is the MPFCM model for the alloy free energy, which includes chemical, dislocation, and lattice (elastic), contributions. The solute concentration-dependence of the latter due to solute lattice misfit results in a strong elastic influence on the binodal (i.e., coexistence) and spinodal behavior of the alloy. In addition, MPFCM-based modeling of energy storage couples the thermodynamic forces driving (Cottrell and Suzuki) solute segregation, precipitate formation and dislocation glide. As implied by the simulation results for edge dislocation dipoles and their configurations, there is a competition between (i) Cottrell segregation to dislocations resulting in a uniform solute distribution along the line, and (ii) destabilization of this distribution due to low-dimensional spinodal decomposition when the segregated solute content at the line exceeds the spinodal value locally, i.e., at and along the dislocation line. Due to the completely different stress field of the screw dislocation configuration in the twist boundary, the segregated solute distribution is immediately unstable and decomposes into precipitates from the start. |
topic |
phase-field chemomechanics solute segregation spinodal decomposition dislocation-solute interaction low angle grain boundary |
url |
https://www.mdpi.com/1996-1944/14/7/1787 |
work_keys_str_mv |
AT jaberrezaeimianroodi phasefieldmodelingofchemoelasticbinodalspinodalrelationsandsolutesegregationtodefectsinbinaryalloys AT pratheekshanthraj phasefieldmodelingofchemoelasticbinodalspinodalrelationsandsolutesegregationtodefectsinbinaryalloys AT bobsvendsen phasefieldmodelingofchemoelasticbinodalspinodalrelationsandsolutesegregationtodefectsinbinaryalloys AT dierkraabe phasefieldmodelingofchemoelasticbinodalspinodalrelationsandsolutesegregationtodefectsinbinaryalloys |
_version_ |
1721538960197419008 |