Combined effects of nonmetallic impurities and planned metallic dopants on grain boundary energy and strength

Huang, Zhifeng; Shen, Qiang; Zhang, Lianmeng; Rupert, Timothy J.

doi:10.1016/j.actamat.2018.12.031

Cited by 52 publications

(12 citation statements)

References 65 publications

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“…We can see that the mechanical contribution increases with increasing the atomic radius of solutes, indicating that a larger solute will cause a more embrittling effect on grain boundary strength. The mechanical contribution is mainly due to the deformation of grain boundary structure caused by replacing the Cu atom with the solute atom 29 . Therefore, a large solute causing the large structural deformation at the interface will lead to significant embrittlement to the grain boundary.…”

Section: Resultsmentioning

confidence: 99%

“…A negative value of strengthening energy means a strengthening effect on grain boundary strength while a positive value suggests a weakening effect. Furthermore, to understand the grain boundary strengthening/weakening resulting from the local structural deformation and the electronic interactions change after introducing a solute into the boundary, we divided the strengthening energy into mechanical and chemical contributions 29 – 31 .…”

Section: Computational Methods and Detailsmentioning

confidence: 99%

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Understanding solute effect on grain boundary strength based on atomic size and electronic interaction

Huang

Wang

Chen

et al. 2020

Sci Rep

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Solute segregating to grain boundary can stabilize the microstructure of nanocrystalline materials, but a lot of solutes also cause embrittlement effect on interfacial strength. Therefore, uncovering the solute effect on grain boundary strength is very important for nanocrystalline alloys design. In this work, we have systematically studied the effects of various solutes on the strength of a Σ5 (310) grain boundary in Cu by first-principle calculations. The solute effects are closely related to the atomic radius of solutes and electronic interactions between solutes and Cu. The solute with a larger atomic radius is easier to segregate the grain boundary but causes more significant grain boundary embrittlement. The weak electronic interactions between the s- and p-block solutes and Cu play a very limited role in enhancing grain boundary strength. While the strong d-states electronic interactions between transition metallic solutes and Cu can counteract embrittlement caused by size mismatch and significantly improve the grain boundary strength. This work deepens our understanding of solute effects on grain boundary strength based on atomic size and electronic interactions.

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Section: Resultsmentioning

confidence: 99%

Section: Computational Methods and Detailsmentioning

confidence: 99%

Understanding solute effect on grain boundary strength based on atomic size and electronic interaction

Huang

Wang

Chen

et al. 2020

Sci Rep

Self Cite

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show abstract

“…[68] using DFT. We note that our 304-atom cells are considerably larger compared to 76-112-atom cells used in previous similar DFT studies [95][96][97], which allows us to carry out full relaxation of the GB structure as a result of the absorption of vacancies. After the relaxation, both methods show that the vacancy migration from sites 3/9, 4/8 to site 5/7 is accompanied by an energy gain of around 1.0 eV.…”

Section: Interaction Of Mono-vacancy With Grain Boundarymentioning

confidence: 99%

Structure and Migration Mechanisms of Small Vacancy Clusters in Cu: A Combined EAM and DFT Study

Fotopoulos¹,

Mora‐Fonz²,

Kleinbichler³

et al. 2023

Preprint

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Voids in face-centered cubic (fcc) metals are commonly assumed to form by the aggregation of vacancies; however, the mechanisms of vacancy clustering and diffusion are not fully understood. In this study, we use computational modeling to provide a detailed insight into the structures and formation energies of primary vacancy clusters, mechanisms and barriers for their migration in bulk copper, and how these properties are affected at simple grain boundaries. The calculations were carried out using Embedded Atom Method (EAM) potentials and Density Functional Theory (DFT) and employed the Site-Occupation Disorder code (SOD), the Activation Relaxation Technique nouveau (ARTn) and the Knowledge Led Master Code (KLMC). We investigate stable structures and migration paths and barriers for clusters of up to six vacancies. Migration of vacancy clusters occurs via hops of individual constituent vacancies with di-vacancies having a significantly smaller migration barrier than mono-vacancies and other clusters. This barrier is further reduced when di-vacancies interact with grain boundaries. This interaction leads to the formation of self-interstitial atoms and introduces significant changes into the boundary structure. Tetra-, penta-, and hexa-vacancy clusters exhibit increasingly complex migration paths and higher barriers than smaller clusters. Finally, the direct comparison with the DFT results shows that EAM can accurately describe the vacancy-induced relaxation effects in the Cu bulk and in grain boundaries. Significant discrepancies between the two methods were found in structures with a higher number of low-coordinated atoms, such as penta-vacancies and di-vacancy absortion by grain boundary. These results will be useful for modeling the mechanisms of diffusion of complex defect structures and provide further insights into the structural evolution of metal films under thermal and mechanical stress.

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“…[52] using DFT. We note that our 304-atom cells are considerably larger compared to 76-112-atom cells used in previous similar DFT studies [51,78,79], which allows us to carry out full relaxation of the GB structure as a result of the absorption of vacancies. After the relaxation, both methods show that the vacancy migration from sites 3/9, 4/8 to site 5/7 is accompanied by an energy gain of around 1.0 eV.…”

Section: Interaction Of Mono-vacancy With Grain Boundarymentioning

confidence: 99%

Structure and Migration Mechanisms of Small Vacancy Clusters in Cu: A Combined EAM and DFT Study

et al. 2023

View full text Add to dashboard Cite

Voids in face-centered cubic (fcc) metals are commonly assumed to form via the aggregation of vacancies; however, the mechanisms of vacancy clustering and diffusion are not fully understood. In this study, we use computational modeling to provide a detailed insight into the structures and formation energies of primary vacancy clusters, mechanisms and barriers for their migration in bulk copper, and how these properties are affected at simple grain boundaries. The calculations were carried out using embedded atom method (EAM) potentials and density functional theory (DFT) and employed the site-occupation disorder code (SOD), the activation relaxation technique nouveau (ARTn) and the knowledge led master code (KLMC). We investigate stable structures and migration paths and barriers for clusters of up to six vacancies. The migration of vacancy clusters occurs via hops of individual constituent vacancies with di-vacancies having a significantly smaller migration barrier than mono-vacancies and other clusters. This barrier is further reduced when di-vacancies interact with grain boundaries. This interaction leads to the formation of self-interstitial atoms and introduces significant changes into the boundary structure. Tetra-, penta-, and hexa-vacancy clusters exhibit increasingly complex migration paths and higher barriers than smaller clusters. Finally, a direct comparison with the DFT results shows that EAM can accurately describe the vacancy-induced relaxation effects in the Cu bulk and in grain boundaries. Significant discrepancies between the two methods were found in structures with a higher number of low-coordinated atoms, such as penta-vacancies and di-vacancy absortion by grain boundary. These results will be useful for modeling the mechanisms of diffusion of complex defect structures and provide further insights into the structural evolution of metal films under thermal and mechanical stress.

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Combined effects of nonmetallic impurities and planned metallic dopants on grain boundary energy and strength

Abstract: Most research on nanocrystalline alloys has been focused on planned doping of metals with other metallic elements, but nonmetallic impurities are also prevalent in the real world.

Cited by 52 publications

References 65 publications

Understanding solute effect on grain boundary strength based on atomic size and electronic interaction

Understanding solute effect on grain boundary strength based on atomic size and electronic interaction

Structure and Migration Mechanisms of Small Vacancy Clusters in Cu: A Combined EAM and DFT Study

Structure and Migration Mechanisms of Small Vacancy Clusters in Cu: A Combined EAM and DFT Study

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