Atomic simulations of dislocation emission from Cu/Cu and Co/Cu grain boundaries

Yuasa, Motohiro; Nakazawa, Takumi; Mabuchi, Mamoru

doi:10.1016/j.msea.2010.09.040

Cited by 13 publications

(4 citation statements)

References 41 publications

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“…The meso-and macro-scale properties of materials are determined to a large extent by the complicated topological and geometric defects [1], such as vacancies, voids, dislocations, grain boundaries and microcracks. These defects are derived from the sophisticated nonequilibrium dynamic processes in the atomic scale [2]. For the multi-scale simulation methods used currently, it is a major challenge to model and simulate the real time evolution of these microstructures.…”

Section: Introductionmentioning

confidence: 99%

Phase field crystal study of nano-crack growth and branch in materials

Ying-jun

Luo

Huang

et al. 2016

Modelling Simul. Mater. Sci. Eng.

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The phase field crystal (PFC) method is a new multiscale method, which can reproduce physical phenomena on an atomic level and on a diffusion time scale for the microstructure evolution of materials. The morphology of microcrack propagation and the branch of single crystal materials under tensile strain with a fixed grip condition are simulated by using PFC coupling with an external field method. The results show that microcrack propagation depends a lot on the applied strain. The crack starts to grow and branch when the strain reaches a critical value for biaxial tension. The temperature parameter may also have an effect on crack propagation and the branch. In order to indicate the connection between the PFC results and materials behavior, the energy balance approach is used to analyze the mechanism of crack extension, and also the critical value of the strain for crack extension is obtained. The simulated results are in good agreement with other simulation results and experimental results.

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Section: Introductionmentioning

confidence: 99%

Phase field crystal study of nano-crack growth and branch in materials

Ying-jun

Luo

Huang

et al. 2016

Modelling Simul. Mater. Sci. Eng.

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“…Disorders such as disconnections and steps are formed at boundaries between different phases [54]. Yuasa et al [55,56] showed that disorders affect atomic shuffling and dislocation nucleation at fcc/hcp boundaries of Cu/Co bicrystals. The HRTEM observations revealed that significant disorders were generated at the grain boundaries of the as-deposited specimen.…”

Section: Discussionmentioning

confidence: 99%

Softening due to disordered grain boundaries in nanocrystalline Co

Yuasa

Hakamada

Nakano

et al. 2013

J. Phys.: Condens. Matter

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Nanocrystalline Co consisting of fcc and hcp phases was processed by electrodeposition, and its mechanical properties were investigated by hardness tests. In addition, high-resolution transmission electron microscopy observations and molecular dynamics (MD) simulations were performed to investigate the grain boundary structure and dislocation nucleation from the grain boundaries. A large amount of disorders existed at the grain boundaries and stacking faults were formed from the grain boundaries in the as-deposited Co specimen. The as-deposited specimen showed a lower hardness than did the annealed specimen, although the grain size of the former was smaller than that of the latter. The activation volume of the as-deposited specimen (=1.5b(3)) was lower than that of the annealed specimen (=50b(3)), thus indicating that nucleation of dislocations from grain boundaries is more active in the as-deposited specimen than in the annealed specimens. The MD simulations showed that dislocation nucleation was closely related to a change in the defect structures at the boundary. Therefore, it is suggested that a significant amount of defects enhance changes in the defect structures at the boundary, resulting in softening of the as-deposited specimen.

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“…To ensure the stable grain boundary structure, a relaxation calculation without an applied stress was carried out for 10 ps at 5 K and a constant pressure of 1 atm with an NPT ensemble [29]. The temperature and pressure were fixed using the Nose-Hoover thermostat [30] and the Parrinello-Rahman constant-stress techniques [31], respectively.…”

Section: Pure Grain Boundary Modelsmentioning

confidence: 99%

Grain boundary sliding in pure and segregated bicrystals: a molecular dynamics and first principles study

Yuasa

Nakazawa²,

Mabuchi³

2012

J. Phys.: Condens. Matter

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Sliding behaviors of Σ9(221) grain boundary bicrystals have been investigated in pure metals (Al, Ag, Au, Cu, Pt and Co) and in segregated metals (Cu segregated by Al, Ag, Au, Pt and Co) by molecular dynamics simulations and first-principles calculations. The grain boundary energy, the atomic size and the electronegativity of the segregated elements were not critical for the occurrence of grain boundary sliding. On the other hand, the sliding rate increased as the minimum charge density decreased at the bond critical point. This was the case for both pure grain boundary models and segregated grain boundary models. Therefore, it seems that the sliding rate depends on atomic movement at sites with minimum charge density, irrespective of the elements involved and of the presence of segregated atoms.

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Atomic simulations of dislocation emission from Cu/Cu and Co/Cu grain boundaries

Cited by 13 publications

References 41 publications

Phase field crystal study of nano-crack growth and branch in materials

Phase field crystal study of nano-crack growth and branch in materials

Softening due to disordered grain boundaries in nanocrystalline Co

Grain boundary sliding in pure and segregated bicrystals: a molecular dynamics and first principles study

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