Ab initiostudy of symmetrical tilt grain boundaries in bcc Fe: structural units, magnetic moments, interfacial bonding, local energy and local stress

The preferential sites for vacancies on a series of symmetric tilt grain boundaries in copper have been investigated by molecular dynamics simulation. The regularity of preferential sites for vacancies on these boundaries can be described by the structural unit model. This is essential because of the correspondence between the geometries of the structural units and the local stress field. The vacancies are energetically preferred at the sites with relatively large tensile stress, and these sites are the corner sites of the structural units. Moreover, these preferential sites are mainly related to the structural unit types irrespective of which grain boundary that the structure units locate in. Therefore, the preferential sites for vacancies on various grain boundaries formed by combinations of certain structural units can be readily described and predicted by the structural unit model.

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Failure mode in first-principles computational tensile tests of grain boundaries: effects of a bulk-region size, dominant factors, and local-energy and local-stress analysis

Journal of Physics Condensed Matter ◽

10.1088/1361-648x/aaf7f2 ◽

2019 ◽

Vol 31 (9) ◽

pp. 095001 ◽

Cited By ~ 4

Author(s):

Hao Wang ◽

Masanori Kohyama ◽

Shingo Tanaka ◽

JinKai Wang ◽

Ying Chen

Keyword(s):

Stress Analysis ◽

Grain Boundaries ◽

Failure Mode ◽

First Principles ◽

Local Stress ◽

Tensile Tests ◽

Local Energy ◽

Bulk Region ◽

Region Size

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Structure and Stability of Grain Boundaries in Molybdenum with Segregated Carbon Impurities

MRS Proceedings ◽

10.1557/proc-578-405 ◽

1999 ◽

Vol 578 ◽

Cited By ~ 1

Author(s):

R. Janisch ◽

T. Ochs ◽

A. Merkle ◽

C. Elsässer

Keyword(s):

Ab Initio ◽

Grain Boundaries ◽

Density Functional ◽

Local Density ◽

Structural Parameters ◽

Carbide Phases ◽

Carbon Impurities ◽

Transmission Electron ◽

Local Density Functional Theory ◽

Symmetrical Tilt

AbstractThe segregation of interstitial impurities to symmetrical tilt grain boundaries (STGB) in bodycentered cubic transition metals is studied by means of ab-initio electronic-structure calculations based on the local density functional theory (LDFT). Segregation energies as well as changes in atomic and electronic structures at the ΣE5 (310) [001] STGB in Mo caused by segregated interstitial C atoms are investigated. The results are compared to LDFT data obtained previously for the pure Σ5 (310) [001] STGB in Mo. Energetic stabilities and structural parameters calculated ab initio for several crystalline Molybdenum Carbide phases with cubic, tetragonal or hexagonal symmetries and different compositions, MoCx, are reported and compared to recent high-resolution transmission electron microscopy (HRTEM) observations of MoCx, intergranular films and precipitates formed by C segregation to a Σ5 (310) [001] STGB in a Mo bicrystal.

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On the Periodicity of ⟨001⟩ Symmetrical Tilt Grain Boundaries

MATERIALS TRANSACTIONS ◽

10.2320/matertrans.m2014394 ◽

2015 ◽

Vol 56 (3) ◽

pp. 281-287 ◽

Cited By ~ 10

Author(s):

Kazutoshi Inoue ◽

Mitsuhiro Saito ◽

Zhongchang Wang ◽

Motoko Kotani ◽

Yuichi Ikuhara

Keyword(s):

Grain Boundaries ◽

Symmetrical Tilt

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Image Simulations of Ge Twin Boundaries.

MRS Proceedings ◽

10.1557/proc-295-173 ◽

1992 ◽

Vol 295 ◽

Cited By ~ 1

Author(s):

Stuart Mckernan ◽

C. Barry Carter

Keyword(s):

Grain Boundary ◽

Grain Boundaries ◽

High Angle ◽

Structural Units ◽

Twin Boundaries ◽

Large Unit ◽

Unit Cells ◽

The Individual ◽

Image Simulations

AbstractGeneral high-angle tilt grain boundaries may be described by an arrangement of repeating structural units. Some grain-boundary defects may also be modeled by the incorporation of structural units of related boundary structures into the boundary. The simulation of these structures requires the use of prohibitively large unit cells. The possibility of modeling these boundaries by the superposition of image simulations of the individual structural units isinvestigated.

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