Lithium/yttrium cluster effect on {101¯1} twin boundary migration in magnesium

AbstractAt the nanoscale, elastic strain and crystal defects largely influence the properties and functionalities of materials. The ability to predict the structural evolution of catalytic nanocrystals during the reaction is of primary importance for catalyst design. However, to date, imaging and characterising the structure of defects inside a nanocrystal in three-dimensions and in situ during reaction has remained a challenge. We report here an unusual twin boundary migration process in a single platinum nanoparticle during CO oxidation using Bragg coherent diffraction imaging as the characterisation tool. Density functional theory calculations show that twin migration can be correlated with the relative change in the interfacial energies of the free surfaces exposed to CO. The x-ray technique also reveals particle reshaping during the reaction. In situ and non-invasive structural characterisation of defects during reaction opens new avenues for understanding defect behaviour in confined crystals and paves the way for strain and defect engineering.

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Twin boundary migration creating zero shear strain: In-situ TEM observations and atomistic simulations

Magnesium Technology 2013 ◽

10.1007/978-3-319-48150-0_18 ◽

2013 ◽

pp. 107-111 ◽

Cited By ~ 2

Author(s):

B. Y. Liu ◽

B. Li ◽

Z. W. Shan

Keyword(s):

Shear Strain ◽

Twin Boundary ◽

Boundary Migration ◽

Atomistic Simulations ◽

In Situ Tem

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The diffusive character of extension twin boundary migration in magnesium

Materialia ◽

10.1016/j.mtla.2018.07.017 ◽

2018 ◽

Vol 2 ◽

pp. 208-213 ◽

Cited By ~ 6

Author(s):

Xiao-Zhi Tang ◽

Qun Zu ◽

Ya-Fang Guo

Keyword(s):

Twin Boundary ◽

Boundary Migration

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Observation of twin boundary migration in copper during deformation

Materials Science and Engineering A ◽

10.1016/j.msea.2003.12.044 ◽

2004 ◽

Vol 372 (1-2) ◽

pp. 173-179 ◽

Cited By ~ 52

Author(s):

D.P. Field ◽

B.W. True ◽

T.M. Lillo ◽

J.E. Flinn

Keyword(s):

Twin Boundary ◽

Boundary Migration

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Mechanism of Stress-Driven Grain Boundary Migration in Nanotwinned Materials

REVIEWS ON ADVANCED MATERIALS SCIENCE ◽

10.1515/rams-2018-0024 ◽

2018 ◽

Vol 55 (1) ◽

pp. 21-25 ◽

Cited By ~ 1

Author(s):

N.V. Skiba

Keyword(s):

Theoretical Model ◽

Grain Boundary ◽

Twin Boundary ◽

Boundary Migration ◽

Grain Boundary Migration ◽

High Angle ◽

Twin Boundaries ◽

Critical Stresses ◽

Ultrafine Grained ◽

Ultrafine Grained Materials

Abstract Stress-driven grain boundary (GB) migration in ultrafine-grained materials with nanotwinned structure is theoretically described. In the framework of the theoretical model, the stress-driven high-angle GB migration is accompanied by migration of twin boundaries which adjoin this GB. Energetic characteristics and critical stresses of the GB migration accompanied by the twin boundary migration are calculated.

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Plastic Deformation Behavior of Bi-Crystal Magnesium Nanopillars with a { 10 1 ¯ 2 } Twin Boundary under Compression: Molecular Dynamics Simulations

Materials ◽

10.3390/ma12050750 ◽

2019 ◽

Vol 12 (5) ◽

pp. 750

Author(s):

Xiaoyue Yang ◽

Shuang Xu ◽

Qingjia Chi

Keyword(s):

Molecular Dynamics ◽

Plastic Deformation ◽

Molecular Dynamics Simulations ◽

Twin Boundary ◽

Basal Slip ◽

Boundary Migration ◽

Plastic Deformation Process ◽

Plastic Deformation Behavior ◽

Schmid Factor ◽

Dynamics Simulations

In this study, molecular dynamics simulations were performed to study the uniaxial compression deformation of bi-crystal magnesium nanopillars with a { 10 1 ¯ 2 } twin boundary (TB). The generation and evolution process of internal defects of magnesium nanopillars were analyzed in detail. Simulation results showed that the initial deformation mechanism was mainly caused by the migration of the twin boundary, and the transformation of TB into (basal/prismatic) B/P interface was observed. After that, basal slip as well as pyramidal slip nucleated during the plastic deformation process. Moreover, a competition mechanism between twin boundary migration and basal slip was found. Basal slip can inhibit the migration of the twin boundary, and { 10 1 ¯ 1 } ⟨ 10 1 ¯ 2 ⟩ twins appear at a certain high strain level ( ε = 0.104). In addition, Schmid factor (SF) analysis was conducted to understand the activations of deformation modes.

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