Tensile deformation behavior of twist grain boundaries in CoCrFeMnNi high entropy alloy bicrystals

Lee, Hyunsoo; Shabani, Mitra; Pataky, Garrett J.; Abdeljawad, Fadi F.

doi:10.1038/s41598-020-77487-z

Cited by 10 publications

(4 citation statements)

References 87 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…After verification by Choi et al The lattice constant calculated by this potential for the equi-atomic percentage CoCrFeMnNi alloy is 3.595 Å, which is close to the experimental value of 3.59 Å. This potential has been used by other authors to calculate the deformation mechanism and mechanical properties of CoCrFeMnNi alloy with the effects of GB considered [48][49][50][51]. Consequently the potential is acceptable as a parameter reasonably to describe those GBs in this work.…”

Section: Calculation Details 21 Potential and Diffusion Coefficientssupporting

confidence: 75%

Simulation of bulk and grain boundary diffusion phenomena in a high entropy CoCrFeMnNi alloy by molecular dynamics

Fan

Zhang²

2023

Phys. Scr.

View full text Add to dashboard Cite

A series of calculations on the self-diffusion behavior of high entropy CoCrFeMnNi alloy were carried out using molecular dynamics methods. By computing both vacancy formation energy and atomic migration energy of the constituent elements in the alloy, the diffusional activation energy of each element is obtained, and the self-diffusion coefficients for bulk diffusion were calculated, with the values exhibiting close to of experiments. A model for structures of symmetrically tilted grain boundary is established, with Σ9 and Σ27 grain boundaries studied based on the coincidence site lattice theory. Measured by the full width at half maxima of the radial distribution function, it is found that the grain boundaries with low index are more ordered than those with high plane index, and the atom fluctuation occurred in the low-indexed grain boundaries is less intensively and sensitively to temperature change. Meanwhile, the diffusion coefficients of ordered grain boundaries are generally smaller than those of disordered grain boundaries. Compared with the experimental values of grain boundary diffusion, the diffusion activation energy of configured grain boundaries from coincidence site lattice is smaller than that of normal large-angle grain boundaries.

show abstract

Section: Calculation Details 21 Potential and Diffusion Coefficientssupporting

confidence: 75%

Simulation of bulk and grain boundary diffusion phenomena in a high entropy CoCrFeMnNi alloy by molecular dynamics

Fan

Zhang²

2023

Phys. Scr.

View full text Add to dashboard Cite

show abstract

“…The second nearest-neighbor modified embedded-atom method (2NN MEAM) potential and the parameters developed by Choi et al (2018) are employed to describe the interaction between the atoms, which have been widely used in the MD simulation of mechanical behaviors of CoCrFeNiMn HEA (Fang et al, 2019;Lee et al, 2021;Wang et al, 2021;Zhou et al, 2021). The stacking fault energy of CoCrFeNiMn calculated using these potential parameters is negative, consistent with firstprinciples calculation results (Zhao et al, 2017), which further demonstrates the validity of the potential.…”

Section: Simulation Detailssupporting

confidence: 60%

Formation and Anisotropic Mechanical Behavior of Stacking Fault Tetrahedron in Ni and CoCrFeNiMn High-Entropy Alloy

Liang

et al. 2022

Front. Mater.

View full text Add to dashboard Cite

Stacking fault tetrahedron (SFT) is a kind of detrimental three-dimensional defect in conventional face-centered cubic (FCC) structural metals; however, its formation and anisotropic mechanical behavior in a CoCrFeNiMn high-entropy alloy (HEA) remain unclear. In this work, we first performed molecular dynamics simulations to verify the applicability of the Silcox-Hirsch mechanism in the CoCrFeNiMn HEA. The mechanical responses of the SFT to shear stress in different directions and that of the pure Ni counterpart were simulated, and the evolutions of the atomic structures of the SFTs during shear were analyzed in detail. Our results revealed that the evolution of the SFT has different patterns, including the annihilation of stacking faults, the formation and expansion of new stacking faults, and insignificant changes in stacking faults. It was found that the effects of SFT on the elastic properties of Ni and HEA are negligible. However, the introduction of SFT would reduce the critical stress, while the critical stress of the CoCrFeNiMn HEA is much less sensitive to SFT than that of Ni.

show abstract

“…In addition, a system with a ∑3 {111} coherent twin GB is constructed, as this GB exhibits one of the lowest GB energies . Ni bicrystal geometries with planar GBs are generated using the γ-surface method. , A fully periodic atomistic system is created from two half-crystals, each of which is rotated about the [001] tilt axis by an equal and opposite angle θ/2, where θ defines the tilt angle. Figure b is a schematic illustration of the atomistic bicrystal geometry used in this work.…”

Section: Methodsmentioning

confidence: 99%

Unraveling the Role of Grain Boundary Anisotropy in Sintering: Implications for Nanoscale Manufacturing

Hussein

Alghalayini

Dillon

et al. 2021

ACS Appl. Nano Mater.

Self Cite

View full text Add to dashboard Cite

Sintering is a thermal processing technique used to consolidate particle compacts into structures broadly used in optical, catalytic, electronic, and structural applications. Of particular interest is the sintering of nanocrystalline particles, as it leads to reduced sintering temperatures and faster processing times and it enables the fabrication of bulk nanostructured or nanoporous materials. However, the lack of knowledge of the role of grain boundary (GB) geometry in sintering rates limits our ability to manipulate densification and coarsening processes. Herein, we leverage atomistic simulations to investigate the sintering behavior of a series of [001] tilt GBs in Ni over 200 ns using the two-particle geometry. The energy and self-diffusion for these GBs are calculated, and several geometric features describing the morphological evolution are tracked over time. Particle rotation, resulting in the temporal evolution of GB misorientation, is observed in several systems. Our results show large variations in particle neck growth and shrinkage rates as a function of GB type and suggest faster sintering rates with increased GB misorientation angle. Further, it is found that nanoparticles sinter at a much slower rate than predicted from GB-based sintering models, suggesting that the process is not dominated by a single mechanism. As a measure of sintering stress, we track the temporal evolution of particle neck curvatures, which are shown to decrease over time at a rate dependent on GB geometry. In broad terms, our simulation results provide future avenues to employ particle orientations and resultant GB types as a strategy to fabricate sintered materials with controlled nanostructured features.

show abstract

Tensile deformation behavior of twist grain boundaries in CoCrFeMnNi high entropy alloy bicrystals

Cited by 10 publications

References 87 publications

Simulation of bulk and grain boundary diffusion phenomena in a high entropy CoCrFeMnNi alloy by molecular dynamics

Simulation of bulk and grain boundary diffusion phenomena in a high entropy CoCrFeMnNi alloy by molecular dynamics

Formation and Anisotropic Mechanical Behavior of Stacking Fault Tetrahedron in Ni and CoCrFeNiMn High-Entropy Alloy

Unraveling the Role of Grain Boundary Anisotropy in Sintering: Implications for Nanoscale Manufacturing

Contact Info

Product

Resources

About