Topological grain boundary segregation transitions

Fuente: arXiv
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Main Authors: Devulapalli, Vivek, Chen, Enze, Brink, Tobias, Frolov, Timofey, Liebscher, Christian H.
Format: Preprint
Published: 2024
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author Devulapalli, Vivek
Chen, Enze
Brink, Tobias
Frolov, Timofey
Liebscher, Christian H.
author_facet Devulapalli, Vivek
Chen, Enze
Brink, Tobias
Frolov, Timofey
Liebscher, Christian H.
contents Engineering structure of grain boundaries (GBs) by solute segregation is a promising strategy to tailor the properties of polycrystalline materials. Theoretically it has been suggested that solute segregation can trigger phase transitions at GBs offering novel pathways to design interfaces. However, an understanding of their intrinsic atomistic nature is missing. Here, we combine atomic resolution electron microscopy atomistic simulations to discover that iron segregation to GBs in titanium stabilizes icosahedral units (cages) that form robust building blocks of distinct GB phases. Due to their five-fold symmetry, the Fe cages cluster and assemble into hierarchical GB phases characterised by a different number and arrangement of the constituent icosahedral units. Our advanced GB structure prediction algorithms and atomistic simulations validate the stability of these observed phases and the high excess of Fe at the GB that is accommodated by the phase transitions.
format Preprint
id arxiv_https___arxiv_org_abs_2405_08193
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Topological grain boundary segregation transitions
Devulapalli, Vivek
Chen, Enze
Brink, Tobias
Frolov, Timofey
Liebscher, Christian H.
Materials Science
Engineering structure of grain boundaries (GBs) by solute segregation is a promising strategy to tailor the properties of polycrystalline materials. Theoretically it has been suggested that solute segregation can trigger phase transitions at GBs offering novel pathways to design interfaces. However, an understanding of their intrinsic atomistic nature is missing. Here, we combine atomic resolution electron microscopy atomistic simulations to discover that iron segregation to GBs in titanium stabilizes icosahedral units (cages) that form robust building blocks of distinct GB phases. Due to their five-fold symmetry, the Fe cages cluster and assemble into hierarchical GB phases characterised by a different number and arrangement of the constituent icosahedral units. Our advanced GB structure prediction algorithms and atomistic simulations validate the stability of these observed phases and the high excess of Fe at the GB that is accommodated by the phase transitions.
title Topological grain boundary segregation transitions
topic Materials Science
url https://arxiv.org/abs/2405.08193