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.

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 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.

The Structure, Role and Flexibility of Grain Boundaries

2008 ◽  
Vol 1125 ◽  
Author(s):  
M. Samaras ◽  
M. Victoria ◽  
W. Hoffelner
Keyword(s):  
Molecular Dynamics ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Boundary Movement ◽  
Displacement Cascade ◽  
Interstitial Atoms ◽  
Atomic Analysis ◽  
Grain Boundary Movement

ABSTRACTThe structure and role of grain boundaries is investigated using an atomic analysis of the grain boundary movement during Molecular Dynamics displacement cascade simulations of bcc Fe. The results show the grain boundary to be a flexible entity. Local restructuring of the GB accommodates the incoming self interstitial atoms with local kinks, or small movements of a few atomic spacings occurring when the grain boundary is engulfed in the displacement cascade. The damage created is investigated using two potentials: the Ackland (non-magnetic) and the Dudarev- Derlet (magnetic) to study the role and influence of magnetism on the results obtained.

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.

scholarly journals Effects of grain boundaries on the radiation-induced defects evolution in BCC Fe–Cr alloy: A molecular dynamics study

2020 ◽  
Vol 22 ◽  
pp. 100726
Author(s):  
Jiahui Zhang ◽  
Huan He ◽  
Wenbo Liu ◽  
Long Kang ◽  
Di Yun ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Grain Boundaries ◽  
Radiation Induced ◽  
Induced Defects

scholarly journals The Influence of Grain Boundaries on Crystal Structure and Tensile Mechanical Properties of Al0.1CoCrFeNi High-Entropy Alloys Studied by Molecular Dynamics Method

Crystals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 48
Author(s):  
Cuixia Liu ◽  
Rui Wang ◽  
Zengyun Jian
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Molecular Dynamics Method ◽  
High Entropy Alloy ◽  
High Entropy Alloys ◽  
Face Centered Cubic ◽  
High Entropy ◽  
Dynamics Method

The mechanical properties of high-entropy alloys are superior to those of traditional alloys. However, the key problem of finding a strengthening mechanism is still challenging. In this work, the molecular dynamics method is used to calculate the tensile properties of face-centered cubic Al0.1CoCrFeNi high-entropy alloys containing Σ3 grain boundaries and without grain boundary. The atomic model was established by the melting rapid cooling method, then stretched by the static drawing method. The common neighbor analysis and dislocation extraction algorithm are used to analyze the crystal evolution mechanism of Σ3 grain boundaries to improve the material properties of high-entropy alloys during the tensile test. The results show that compared with the mechanical properties Al0.1CoCrFeNi high-entropy alloys without grain boundary, the yield strength and Young’s modulus of a high-entropy alloy containing Σ3 grain boundary are obviously larger than that of high-entropy alloys without grain boundary. Dislocation type includes mainly 1/6<112> Shockley partial dislocations, a small account of 1/6<110> Stair-rod, 1/2<110>perfect dislocation, and 1/3<111> Hirth dislocations. The mechanical properties of high-entropy alloys are improved by dislocation entanglement and accumulation near the grain boundary.

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