scholarly journals The shear response of copper bicrystals with Σ11 symmetric and asymmetric tilt grain boundaries by molecular dynamics simulation

Nanoscale ◽  
2015 ◽  
Vol 7 (16) ◽  
pp. 7224-7233 ◽  
Author(s):  
Liang Zhang ◽  
Cheng Lu ◽  
Kiet Tieu ◽  
Xing Zhao ◽  
Linqing Pei
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Shear Deformation ◽  
High Strength ◽  
Stacking Fault ◽  
Boundary Plane ◽  
Dynamics Simulation ◽  
Grain Boundary Plane

The dissociated stacking fault from the grain boundary plane can increase ductility while retaining the high strength of the Cu bicrystal model under shear deformation.

scholarly journals Evaluation of Mechanical Properties of Σ5(210)/[001] Tilt Grain Boundary with Self-Interstitial Atoms by Molecular Dynamics Simulation

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Liang Zhang ◽  
Cheng Lu ◽  
Linqing Pei ◽  
Xing Zhao ◽  
Jie Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Shear Deformation ◽  
Uniaxial Tension ◽  
Dynamics Simulation ◽  
Interstitial Atoms ◽  
Radiation Induced ◽  
Induced Defects

Grain boundary (GB) can serve as an efficient sink for radiation-induced defects, and therefore nanocrystalline materials containing a large fraction of grain boundaries have been shown to have improved radiation resistance compared with their polycrystalline counterparts. However, the mechanical properties of grain boundaries containing radiation-induced defects such as interstitials and vacancies are not well understood. In this study, we carried out molecular dynamics simulations with embedded-atom method (EAM) potential to investigate the interaction of Σ5(210)/[001] symmetric tilt GB in Cu with various amounts of self-interstitial atoms. The mechanical properties of the grain boundary were evaluated using a bicrystal model by applying shear deformation and uniaxial tension. Simulation results showed that GB migration and GB sliding were observed under shear deformation depending on the number of interstitial atoms that segregated on the boundary plane. Under uniaxial tension, the grain boundary became a weak place after absorbing self-interstitial atoms where dislocations and cracks were prone to nucleate.

Molecular Dynamics Simulation of TRIP Steel Residual Austenite Stacking Fault Development

2013 ◽  
Vol 827 ◽  
pp. 8-11
Author(s):  
H.Y. Li ◽  
X.C. Li ◽  
J.H. Li ◽  
J.L. Ma ◽  
Y.J. Zhang
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
High Strength ◽  
Residual Austenite ◽  
Stacking Fault ◽  
Dynamics Simulation ◽  
High Plasticity ◽  
Transformation Induced Plasticity ◽  
Materials Behavior ◽  
Fault Nucleation

TRIP (Transformation induced plasticity) steel has a good combination of high strength and high plasticity which depend on the micro phase transformation and staking fault development greatly. C atom was typical alloying agent of austenite and plays an important role in austenite behavior, especially for staking fault nucleation. As a micro materials behavior, molecular dynamics simulation was carried out to discuss the effect of C atom on the staking fault nucleation. From the simulation result we can find that carbon influence the staking fault nucleation greatly, with the increasing of the number of C atoms, strain for staking fault form decreased, system with 4 C atoms staking fault formed when strain was 7.5% and for system without C atoms there are no staking fault with local tension strain up to 10%. Under the same deformation, stacking fault distribution was uniform for the system with 1 carbon and become uneven with the increasing of the C atom.

Molecular Dynamics Simulation of Stress Induced Grain Boundary Migration during Nanoindentation Experiments

2004 ◽  
Vol 449-452 ◽  
pp. 89-92 ◽  
Author(s):  
Jang Hyuk Yoon ◽  
Seong Jin Kim ◽  
Ho Jang
Keyword(s):  
Molecular Dynamics ◽  
Grain Boundary ◽  
Boundary Migration ◽  
Boundary Plane ◽  
Dynamics Simulation ◽  
Geometric Feature ◽  
Grain Boundary Migration ◽  
Grain Boundary Plane ◽  
Diamond Indenter ◽  
Slip Planes

Molecular dynamics (MD) simulation was performed to study the stress induced grain boundary migration caused by the interaction of dislocations with a grain boundary. The simulation was carried out in a Ni block (295020 atoms) with a Σ = 5 (210) grain boundary and an embedded atom potential for Ni was used for the MD calculation. Stress was provided by indenting a diamond indenter and the interaction between Ni surface and diamond indenter was assumed to have a fully repulsive force to emulate a traction free surface. Results showed that the indentation nucleated perfect dislocations and the dislocations produced stacking faults in the form of a parallelepiped tube. The parallelepiped tube was comprised of four {111} slip planes and it contained two pairs of parallel dislocations with Shockley partials. The dislocations propagated along the parallelepiped slip planes and fully merged onto the Σ = 5 (210) grain boundary without emitting a dislocation on the other grain. The interaction of the dislocations with the grain boundary induced the migration of the grain boundary plane in the direction normal to the boundary plane and the migration continued as long as the successive dislocations merged onto the grain boundary plane. The detailed mechanism of the conservative motion of atoms at the grain boundary was associated with the geometric feature of the Σ = 5 (210) grain boundary.

scholarly journals Molecular Dynamics Simulation on Σ5 Grain Boundaries of Copper Bicrystal under Tensile and Shear Deformation

2014 ◽  
Vol 1651 ◽  
Author(s):  
Liang. Zhang ◽  
Cheng. Lu ◽  
Kiet. Tieu
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Grain Boundaries ◽  
Shear Deformation ◽  
Structural Unit ◽  
Maximum Tensile Stress ◽  
Dynamics Simulation ◽  
Deformation Simulation ◽  
Simulation Results ◽  
Related Process

ABSTRACTMolecular Dynamics simulation are employed to investigate the structures and mechanical behavior of both symmetric and asymmetric Σ5[0 0 1] tilt grain boundaries (GBs) of copper bicrystal under uniaxial tension and shear deformation. Simulation results indicate that the Σ5 asymmetric GBs can facet into their corresponding symmetric GB structures. The maximum tensile stress of symmetric GBs is higher than the asymmetric ones at both 10 K and 300 K, which suggests the symmetric GBs may have a more stable boundary structures. All the Σ5 GBs investigate in this study can migrate under the shear deformation with different velocity. The migration of Σ5 symmetric GBs is realized by uniform displacement of local atoms and rotation of the atomic group in “E” structural unit, while for the asymmetric GBs, the migration is identified to be a diffusion-related process result from local atoms shuffling.

scholarly journals Recrystallization from a Three-Grain Crystalline Iron

2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Bo Zhao ◽  
Shanshan Chen ◽  
Jinfan Huang ◽  
Lawrence S. Bartell
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Solid State ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Misorientation Angle ◽  
Dynamics Simulation ◽  
Iron Nanoparticle ◽  
Critical Nuclei ◽  
Solid State Recrystallization

The solid state recrystallization and grain boundary migrations in an iron nanoparticle Fe2616 with three grains were studied by a molecular dynamics simulation. It was found that nucleation rates could be determined as the smaller grains were consumed by the larger ones. Moreover, the grain disorder was more important than the misorientation angle in governing the rates. Suggestions about the critical nuclei for the recrystallization are proposed. No obvious interaction between the grain boundaries was observed in the example studied in this report.

Molecular dynamics simulation of crack propagation behaviors at the Ni/Ni3Al grain boundary

RSC Advances ◽  
2014 ◽  
Vol 4 (62) ◽  
pp. 32749 ◽  
Author(s):  
Jingui Yu ◽  
Qiaoxin Zhang ◽  
Rong Liu ◽  
Zhufeng Yue ◽  
Mingkai Tang ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Grain Boundary ◽  
Crack Propagation ◽  
Dynamics Simulation
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