Atomistic simulation of nanoindentation response of dual-phase nanocrystalline CoCrFeMnNi high-entropy alloy

Qiu, Yuhang; Qi, Yuming; Zheng, Huayong; He, Tengwu; Feng, Miaolin

doi:10.1063/5.0057591

Cited by 19 publications

(4 citation statements)

References 37 publications

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“…The Shockley dislocations appear the most and dominate other dislocations types in the CuCrFeNiCo HEA samples. This result is completely similar to the results reported in many previous studies [49,52,[54][55][56]. Overall, the dislocations network formed in the SC CuCrFeNiCo HEA samples is significantly sparser than that in the NC and TN CuCrFeNiCo HEA samples.…”

Section: The Influences Of Boundary Conditionssupporting

confidence: 91%

Crack growth and fracture mechanics of CuCrFeNiCo high-entropy alloy during tension testing

Tran,

Chu,

Trinh

et al. 2024

Phys. Scr.

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In this work, the crack growth and fracture mechanics of CuCrFeNiCo high-entropy alloy (HEA) during tension process are studied through molecular dynamics simulation method. The single-crystalline, nanocrystalline, and twinned-nanocrystalline CuCrFeNiCo HEA samples with an initial crack are prepared. The influences of boundary conditions, crack length and crystallographic orientation are considered in detail. The results indicate that the phase transition from face-centered cubic (FCC) structure into hexagonal close-packed (HCP) structure and the appearance of Shockley dislocations are the majority in all samples. The dislocations appear most densely in the twinned-nanocrstalline sample and most sparsely in the single-crystalline sample. The growth of the initial crack combined with the formation and expansion of new cracks along the grain boundaries (GBs) is the determining factor in the fracture mechanics of the CuCrFeNiCo HEA samples. The deformation capacity of the samples with free boundary conditions along the y-axis is better and the plastic deformation process is longer than the samples with periodic boundary conditions along the y-axis. The tensile strength values of the CuCrFeNiCo HEA samples change significantly in the range from 2.61 GPa to 7.75 GPa when changing the simulation conditions. The von Mises stress in the grains is markedly lower than that in the GBs.

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Section: The Influences Of Boundary Conditionssupporting

confidence: 91%

Crack growth and fracture mechanics of CuCrFeNiCo high-entropy alloy during tension testing

Tran,

Chu,

Trinh

et al. 2024

Phys. Scr.

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“…The pile-up symmetry related to a given crystallographic orientation appears naturally not only in MD but also in CP simulations. On the other hand, the pile-up around an indent in the case of chemically complex materials appears to be almost circular which is typical for an isotropic material, as observed for polycrystalline Cantor alloys [24]. The four-fold crystallographic symmetry is however still present too.…”

Section: Introductionmentioning

confidence: 86%

Multiscale nanoindentation modeling of concentrated solid solutions: A continuum plasticity model

Frydrych¹,

Domínguez-Gutiérrez²,

Alava³

et al. 2022

Preprint

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Recently developed single-phase concentrated solid-solution alloys (CSAs) contain multiple elemental species in high concentrations with different elements randomly arranged on a crystalline lattice. These chemically disordered materials present excellent physical properties, including hightemperature thermal stability and hardness, with promising applications to industries at extreme operating environments. The aim of this paper is to present a continuum plasticity model accounting for the first time for the behaviour of a equiatomic five-element CSA, that forms a face-centered cubic lattice. The inherent disorder associated with the lattice distortions caused by an almost equiatomic distribution of atoms, is captured by a single parameter α that quantifies the relative importance of an isotropic plastic contribution to the model. This results in multiple plasticity mechanisms that go beyond crystallographic symmetry-based ones, common in the case of conventional single element metals. We perform molecular dynamics simulations of equiatomic CSAs: NiFe, NiFeCr, NiFeCrCo, and Cantor alloys to validate the proposed continuum model which is implemented in the finite element method and applied to model nanoindentation tests for three different crystallographic orientations. We obtain the representative volume element model by tracking the combined model yield surface.

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“…MD simulations are performed with LAMMPS, and the well-validated MEAM potential is used. This potential has been widely adopted in describing the physical and mechanical properties of the FCC-phased CoCrFeMnNi alloy system , and is also used in FCC/HCP DP CoCrFeMnNi alloy systems. ,, In addition, to further verify the reliability of the potential function, we calculate the lattice constant, cohesive energy, elastic properties, and stacking fault energy of the HCP-phased CoCrFeMnNi HEA by means of MD simulations and compare the results with those of first-principles calculations (see Supporting Information for more details). The atomistic models are first optimized by the conjugate gradient algorithm and then annealed at 600 K for reaching the thermodynamic steady state.…”

Section: Atomistic Simulation Approachmentioning

confidence: 99%

Phase Volume Fraction-Dependent Strengthening in a Nano-Laminated Dual-Phase High-Entropy Alloy

2022

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A recently synthesized FCC/HCP nano-laminated dual-phase (NLDP) CoCrFeMnNi high entropy alloy (HEA) exhibits excellent strength–ductility synergy. However, the underlying strengthening mechanisms of such a novel material is far from being understood. In this work, large-scale atomistic simulations of in-plane tension of the NLDP HEA are carried out in order to explore the HCP phase volume fraction-dependent strengthening. It is found that the dual-phase (DP) structure can significantly enhance the strength of the material, and the strength shows apparent phase volume fraction dependence. The yield stress increases monotonously with the increase of phase volume fraction, resulting from the increased inhibition effect of interphase boundary (IPB) on the nucleation of partial dislocations in the FCC lamella. There exists a critical phase volume fraction, where the flow stress is the largest. The mechanisms for the volume fraction-dependent flow stress include volume fraction-dependent phase strengthening effect, volume fraction-dependent IPB strengthening effect, and volume fraction-dependent IPB softening effect, that is, IPB migration and dislocation nucleation from the dislocation–IPB reaction sites. This work can provide a fundamental understanding for the physical mechanisms of strengthening effects in face-centered cubic HEAs with a nanoscale NLDP structure.

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Atomistic simulation of nanoindentation response of dual-phase nanocrystalline CoCrFeMnNi high-entropy alloy

Cited by 19 publications

References 37 publications

Crack growth and fracture mechanics of CuCrFeNiCo high-entropy alloy during tension testing

Crack growth and fracture mechanics of CuCrFeNiCo high-entropy alloy during tension testing

Multiscale nanoindentation modeling of concentrated solid solutions: A continuum plasticity model

Phase Volume Fraction-Dependent Strengthening in a Nano-Laminated Dual-Phase High-Entropy Alloy

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