The Properties of Twinning Dislocations in Alpha-Titanium Simulated With A Many-Body Interatomic Potential

1991 ◽  
Vol 238 ◽  
Author(s):  
David J. Bacon ◽  
Anna Serra
Keyword(s):  
Crystal Structure ◽  
Computer Simulation ◽  
Twin Boundary ◽  
Atomic Structure ◽  
Interatomic Potential ◽  
Many Body ◽  
Twin Boundaries ◽  
Interatomic Spacing ◽  
Alpha Titanium

ABSTRACTComputer simulation of the atomic structure and movement of twinning dislocations in four twin boundaries in the h.c.p. metal α-Ti is described. These dislocations have the form of steps on the twin boundary, and whereas some have cores which are very widely spread over the interface, others are only an interatomic spacing or so across. These configurations are determined mainly by whether or not atomic shuffles are required to restore the h.c.p. crystal structure when the dislocation is introduced. The mobility of the dislocations is also controlled by the same effect, and is found to correlate well with experiment.

Computer simulation of point defect properties in dilute Fe—Cu alloy using a many-body interatomic potential

1997 ◽  
Vol 75 (3) ◽  
pp. 713-732 ◽  
Author(s):  
G. J. Ackland ◽  
D. J. Bacon ◽  
A. F. Calder ◽  
T. Harry
Keyword(s):  
Computer Simulation ◽  
Point Defect ◽  
Interatomic Potential ◽  
Many Body ◽  
Cu Alloy

Characterization of the Structure and Polarity of Twin Boundaries in GaP

1998 ◽  
Vol 510 ◽  
Author(s):  
Dov Cohent ◽  
D.L. Medlin ◽  
C. Barry Carter
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Twin Boundary ◽  
Atomic Structure ◽  
Twin Boundaries ◽  
Planar Defects ◽  
Transmission Electron ◽  
Crystallographic Planes

AbstractThe structure of planar defects in GaP films grown by MBE on Si (110) was investigated by transmission electron microscopy. Growth of GaP films on the (110) surface produced numerous microtwins which formed both first and second order twin boundaries. Using high-resolution transmission electron microscopy, the atomic structure of Σ=3 and Σ=9 twin boundaries were studied. Both the Σ=3 and Σ=9 interfaces were observed to facet along specific crystallographic planes. Geometric models of the Σ=9 {221} twin boundary accounting for different polar bonding configurations were proposed and compared with experimental observations.

Modeling of (121) Twin Boundaries in 2H Martensite

2011 ◽  
Vol 465 ◽  
pp. 65-68 ◽  
Author(s):  
Andriy Ostapovets ◽  
Václav Paidar
Keyword(s):  
Twin Boundary ◽  
Interatomic Potentials ◽  
Type I ◽  
Many Body ◽  
Twin Boundaries

The structures of {121} twin boundary in orthorhombic 2H martensite are modeled using Finnis-Sinclair type many-body interatomic potentials. The boundary corresponds to type-I twinning in 2H martensite of Cu-Al-Ni, Cu-Zn-Al and Au-Cd alloys. Three possible configurations of the {121} boundary are found. The structure with the lowest energy possesses a non-corrugated central {121} plane.

Computer Simulation of the Migration Of Self-Interstitial Atoms in Alpha-Zirconium

1996 ◽  
Vol 439 ◽  
Author(s):  
B. J. Whiting ◽  
D. J. Bacon
Keyword(s):  
Molecular Dynamics ◽  
Computer Simulation ◽  
Low Temperature ◽  
Basal Plane ◽  
Interatomic Potential ◽  
Many Body ◽  
Dynamics Model ◽  
Strong Anisotropy ◽  
Displacement Cascades ◽  
Different Temperatures

AbstractThe migration of single interstitials and small interstitial clusters in ox-zirconium at different temperatures has been analysed using a molecular dynamics model with a many-body interatomic potential. The migration exhibits a strong anisotropy. The defects are very mobile (with Em = 0. 01 eV) along <1120> directions in the basal plane, and this motion is dominant for the single interstitial at low temperature and the di- and tri-interstitials at all temperatures. Above about 500 K, the single interstitial exhibits 2-D and 3-D motion, but Em for non-basal motion is about 0.133 eV. These results point to important consequences for the behaviour of defects formed by displacement cascades in irradiated zirconium.

scholarly journals Свойства движущихся дискретных бризеров в бериллии

2018 ◽  
Vol 60 (5) ◽  
pp. 978
Author(s):  
O.B. Бачурина ◽  
P.T. Мурзаев ◽  
A.C. Семенов ◽  
E.A. Корзникова ◽  
C.B. Дмитриев
Keyword(s):  
Energy Transport ◽  
Interatomic Potential ◽  
Maximum Velocity ◽  
Face Centered Cubic ◽  
Sound Waves ◽  
Many Body ◽  
Hexagonal Close Packed ◽  
Bcc Lattice ◽  
Face Centered ◽  
The Many

AbstractDiscrete breathers (DBs) have been described among pure metals with face-centered cubic (FCC) and body-centered cubic (BCC) lattice, but for hexagonal close-packed (HCP) metals, their properties are little studied. In this paper, the properties of standing and moving DBs in beryllium HCP metal are analyzed by the molecular dynamics method using the many-body interatomic potential. It is shown that the DB is localized in a close-packed atomic row in the basal plane, while oscillations with a large amplitude along the close-packed row are made by two or three atoms, moving in antiphase with the nearest neighbors. Dependences of the DB frequency on the amplitude, as well as the velocity of the DB on its amplitude and on parameter δ, which determines the phase difference of the oscillations of neighboring atoms, are obtained. The maximum velocity of the DB movement in beryllium reaches 4.35 km/s, which is 33.7% of the velocity of longitudinal sound waves. The obtained results supplement our concepts about the mechanisms of localization and energy transport in HCP metals.

Mechanism of Stress-Driven Grain Boundary Migration in Nanotwinned Materials

2018 ◽  
Vol 55 (1) ◽  
pp. 21-25 ◽  
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.

Computer Simulation of Atomic Structure of Fe75P25Amorphous Alloy

1980 ◽  
Vol 19 (6) ◽  
pp. 1033-1037 ◽  
Author(s):  
Shinji Kobayashi ◽  
Koji Maeda ◽  
Shin Takeuchi
Keyword(s):  
Computer Simulation ◽  
Atomic Structure

The Morphology of Grain Boundary Interactions with Twins in YBa2Cu3O7−δ

1993 ◽  
Vol 319 ◽  
Author(s):  
Jenn-Yue Wang ◽  
A. H. King
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Twin Boundary ◽  
Interfacial Energy ◽  
Coincidence Site Lattice ◽  
The Other ◽  
Twin Boundaries ◽  
Site Lattice ◽  
Dislocation Arrays

AbstractVarious morphologies are observed where twins meet grain boundaries in YBa2Cu3O7−δ. Twins may be “correlated” at the boundary (i.e. twin boundaries from one grain may meet a twin boundary from the other grain in a quadruple junction) and the twins may be narrowed or “constricted” at the boundary. These effects are determined by the interfacial energy. We estimate the energy of the various interfaces by determining the dislocation arrays they contain, using the constrained coincidence site lattice (CCSL) model and Bollmann's O2-lattice formalism. Our approach indicates that there are significant changes in the energy of the interfaces and is thus able to explain the variety of observed morphologies.

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