scholarly journals Determinação das características estruturais e mecânicas da liga de alta entropia Hf-Nb-Ta-Zr

2021 ◽  
Vol 30 (2) ◽  
pp. 22-32
Author(s):  
Jhonatan Silva Andrade ◽  
Ivan Napoleão Bastos ◽  
Luis César Rodríguez Aliaga
Keyword(s):  
Embedded Atom Method ◽  
Embedded Atom

Neste artigo, os comportamentos estrutural e mecânico da liga equiatômica de alta entropia Hf-Nb-Ta-Zr foram estudados mediante simulações computacionais de dinâmica molecular. As simulações foram realizadas no código livre LAMMPS, em um sistema composto de 154.000 átomos que interagiram sob o potencial Embedded Atom Method (EAM). O estudo focou na estrutura cúbica de corpo centrado (CCC). Esta estrutura apresenta a maior estabilidade estrutural ou a menor energia potencial a 0 K. A liga foi submetida a ensaios de nanoindentação utilizando um penetrador virtual esférico de diâmetro de 40 Å. Ensaiou-se à temperatura de 10 K para eliminar as contribuições térmicas dos átomos, em três planos cristalográficos (001), (011) e (111), e identificar efeitos de anisotropia. A evolução estrutural da liga foi analisada mediante as funções de distribuição radial parcial (PRDF), funções de distribuição radial total (TRDF) e também por difração de raios-X. As curvas de carregamento-descarregamento mostraram que a nanoindentação na superfície correspondente ao plano (011) requer a maior força de indentação, de cerca de 142 nN, enquanto que o plano (111) conduz à maior deformação elástica antes do início da deformação plástica.

Atomistic Simulation Study of Controlled Nanostructure Patterning

2003 ◽  
Vol 775 ◽  
Author(s):  
Byeongchan Lee ◽  
Kyeongjae Cho
Keyword(s):  
Diffusion Barrier ◽  
Atomistic Simulation ◽  
Degrees Of Freedom ◽  
Embedded Atom Method ◽  
Surface Kinetics ◽  
Bulk Properties ◽  
Embedded Atom ◽  
Kinetics Of ◽  
Dissociation Barrier ◽  
Strain Dependent

AbstractWe investigate the surface kinetics of Pt using the extended embedded-atom method, an extension of the embedded-atom method with additional degrees of freedom to include the nonbulk data from lower-coordinated systems as well as the bulk properties. The surface energies of the clean Pt (111) and Pt (100) surfaces are found to be 0.13 eV and 0.147 eV respectively, in excellent agreement with experiment. The Pt on Pt (111) adatom diffusion barrier is found to be 0.38 eV and predicted to be strongly strain-dependent, indicating that, in the compressive domain, adatoms are unstable and the diffusion barrier is lower; the nucleation occurs in the tensile domain. In addition, the dissociation barrier from the dimer configuration is found to be 0.82 eV. Therefore, we expect that atoms, once coalesced, are unlikely to dissociate into single adatoms. This essentially tells that by changing the applied strain, we can control the patterning of nanostructures on the metal surface.

Modified embedded-atom method potentials for the plasticity and fracture behaviors of unary fcc metals

2021 ◽  
Vol 103 (9) ◽  
Author(s):  
Zachary H. Aitken ◽  
Viacheslav Sorkin ◽  
Zhi Gen Yu ◽  
Shuai Chen ◽  
Zhaoxuan Wu ◽  
...  
Keyword(s):  
Embedded Atom Method ◽  
Fcc Metals ◽  
Embedded Atom ◽  
Fracture Behaviors ◽  
Modified Embedded Atom Method

scholarly journals Fabrication of Magnesium-Aluminum Composites under High-Pressure Torsion: Atomistic Simulation

2021 ◽  
Vol 11 (15) ◽  
pp. 6801
Author(s):  
Polina Viktorovna Polyakova ◽  
Julia Alexandrovna Pukhacheva ◽  
Stepan Aleksandrovich Shcherbinin ◽  
Julia Aidarovna Baimova ◽  
Radik Rafikovich Mulyukov
Keyword(s):  
Atomistic Simulation ◽  
High Pressure Torsion ◽  
Tensile Tests ◽  
Temperature Treatment ◽  
Embedded Atom Method ◽  
Interface Bonding ◽  
Embedded Atom ◽  
Interlayer Region ◽  
Kinetics Of ◽  
Loading Scheme

The aluminum–magnesium (Al–Mg) composite materials possess a large potential value in practical application due to their excellent properties. Molecular dynamics with the embedded atom method potentials is applied to study Al–Mg interface bonding during deformation-temperature treatment. The study of fabrication techniques to obtain composites with improved mechanical properties, and dynamics and kinetics of atom mixture are of high importance. The loading scheme used in the present work is the simplification of the scenario, experimentally observed previously to obtain Al–Cu and Al–Nb composites. It is shown that shear strain has a crucial role in the mixture process. The results indicated that the symmetrical atomic movement occurred in the Mg–Al interface during deformation. Tensile tests showed that fracture occurred in the Mg part of the final composite sample, which means that the interlayer region where the mixing of Mg, and Al atoms observed is much stronger than the pure Mg part.

scholarly journals An interatomic potential for saturated hydrocarbons based on the modified embedded-atom method

2014 ◽  
Vol 16 (13) ◽  
pp. 6233-6249 ◽  
Author(s):  
S. Nouranian ◽  
M. A. Tschopp ◽  
S. R. Gwaltney ◽  
M. I. Baskes ◽  
M. F. Horstemeyer
Keyword(s):  
Interatomic Potential ◽  
Embedded Atom Method ◽  
Computationally Efficient ◽  
Saturated Hydrocarbons ◽  
Embedded Atom ◽  
Modified Embedded Atom Method

Extension of the computationally efficient modified embedded-atom method to hydrocarbons and polymers.

Modified embedded-atom method interatomic potential for theFe−Cualloy system and cascade simulations on pure Fe andFe−Cualloys

2005 ◽  
Vol 71 (18) ◽  
Author(s):  
Byeong-Joo Lee ◽  
Brian D. Wirth ◽  
Jae-Hyeok Shim ◽  
Junhyun Kwon ◽  
Sang Chul Kwon ◽  
...  
Keyword(s):  
Interatomic Potential ◽  
Embedded Atom Method ◽  
Embedded Atom ◽  
Modified Embedded Atom Method

An embedded-atom method interatomic potential for Pd–H alloys

2008 ◽  
Vol 23 (3) ◽  
pp. 704-718 ◽  
Author(s):  
X.W. Zhou ◽  
J.A. Zimmerman ◽  
B.M. Wong ◽  
J.J. Hoyt
Keyword(s):  
Computational Models ◽  
Mechanical Response ◽  
Hydrogen Diffusion ◽  
Interatomic Potential ◽  
Diffusion Mechanism ◽  
Miscibility Gap ◽  
Embedded Atom Method ◽  
Embedded Atom ◽  
Formidable Challenge ◽  
Embedded Atom Method Potential

Palladium hydrides have important applications. However, the complex Pd–H alloy system presents a formidable challenge to developing accurate computational models. In particular, the separation of a Pd–H system to dilute (α) and concentrated (β) phases is a central phenomenon, but the capability of interatomic potentials to display this phase miscibility gap has been lacking. We have extended an existing palladium embedded-atom method potential to construct a new Pd–H embedded-atom method potential by normalizing the elemental embedding energy and electron density functions. The developed Pd–H potential reasonably well predicts the lattice constants, cohesive energies, and elastic constants for palladium, hydrogen, and PdHx phases with a variety of compositions. It ensures the correct hydrogen interstitial sites within the hydrides and predicts the phase miscibility gap. Preliminary molecular dynamics simulations using this potential show the correct phase stability, hydrogen diffusion mechanism, and mechanical response of the Pd–H system.

scholarly journals Structural, elastic, and thermal properties of cementite (Fe3C) calculated using a modified embedded atom method

2014 ◽  
Vol 89 (9) ◽  
Author(s):  
Laalitha S. I. Liyanage ◽  
Seong-Gon Kim ◽  
Jeff Houze ◽  
Sungho Kim ◽  
Mark A. Tschopp ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Embedded Atom Method ◽  
Embedded Atom ◽  
Modified Embedded Atom Method
Sign in / Sign up

Export Citation Format

Share Document