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2024--Nitol-M-S-Echeverria-M-J-Dang-K-et-al--V-Nb-Ta-Ti-Zr

Citation: M.S. Nitol, M.J. Echeverria, K. Dang, M.I. Baskes, and S.J. Fensin (2024), "New modified embedded-atom method interatomic potential to understand deformation behavior in VNbTaTiZr refractory high entropy alloy", Computational Materials Science, 237, 112886. DOI: 10.1016/j.commatsci.2024.112886.

Abstract: High Entropy Alloys (HEAs) have attracted much interest over the past 20 years because of their remarkable mechanical properties. Recent works on BCC refractory HEAs have demonstrated high strength even at extreme temperatures with an unusual mix of strength and ductility. They also show excellent strain-hardening behavior. This study focuses on the VNbTaTiZr alloy, which stands out for its favorable qualities including relatively low density, impressive yield strength, and ductility at room temperature. To better understand the atomic behavior and microstructural features inherent to this alloy, a Modified Embedded Atom Method (MEAM) potential is developed, based on first-principles computations. Through accurate modeling of lattice constants, elastic constants, and formation enthalpies, a hybrid Molecular Dynamics/Monte Carlo (MD/MC) simulation of an equimolar VNbTaTiZr refractory HEA was performed to explore the role of local chemical compositions to its mechanical response. The current MEAM potential aligns closely with recent experimental work, validating its effectiveness. Adding Zr to the VNbTaTi alloy induces more lattice distortion, matching recent experimental observations. The potential also predicts that for RHEAs, deformation behavior is dominated by edge dislocations, unlike in pure BCC elements where screw dislocations prevail. Overall, this potential will be useful for unraveling the intricate atomic-level processes that give this alloy its remarkable mechanical performance.

LAMMPS pair_style meam (2024--Nitol-M-S--V-Nb-Ta-Ti-Zr--LAMMPS--ipr1)

See Computed Properties
Notes: This file was provided by Mashroor Nitol on February 28, 2024.
File(s):

VNbTaTiZr.parameter
VNbTaTiZr.library

Implementation Information

This page displays computed properties for the 2024--Nitol-M-S--V-Nb-Ta-Ti-Zr--LAMMPS--ipr1 implementation of the 2024--Nitol-M-S-Echeverria-M-J-Dang-K-et-al--V-Nb-Ta-Ti-Zr potential. Computed values for other implementations can be seen by clicking on the links below:

2024--Nitol-M-S--V-Nb-Ta-Ti-Zr--LAMMPS--ipr1

Diatom Energy vs. Interatomic Spacing

Plots of the potential energy vs interatomic spacing, r, are shown below for all diatom sets associated with the interatomic potential. This calculation provides insights into the functional form of the potential's two-body interactions. A system consisting of only two atoms is created, and the potential energy is evaluated for the atoms separated by 0.02 Å <= r <= 6.0> Å in intervals of 0.02 Å. Two plots are shown: one for the "standard" interaction distance range, and one for small values of r. The small r plot is useful for determining whether the potential is suitable for radiation studies.

The calculation method used is available as the iprPy diatom_scan calculation method.

Clicking on the image of a plot will open an interactive version of it in a new tab. The underlying data for the plots can be downloaded by clicking on the links above each plot.

Notes and Disclaimers:

These values are meant to be guidelines for comparing potentials, not the absolute values for any potential's properties. Values listed here may change if the calculation methods are updated due to improvements/corrections. Variations in the values may occur for variations in calculation methods, simulation software and implementations of the interatomic potentials.
As this calculation only involves two atoms, it neglects any multi-body interactions that may be important in molecules, liquids and crystals.
NIST disclaimer

Version Information:

2019-11-14. Maximum value range on the shortrange plots are now limited to "expected" levels as details are otherwise lost.
2019-08-07. Plots added.

Download data

Click on plot to load interactive version

2024--Nitol-M-S--V-Nb-Ta-Ti-Zr--LAMMPS--ipr1/diatom

Click on plot to load interactive version

2024--Nitol-M-S--V-Nb-Ta-Ti-Zr--LAMMPS--ipr1/diatom_short

Cohesive Energy vs. Interatomic Spacing

Plots of potential energy vs interatomic spacing, r, are shown below for a number of crystal structures. The structures are generated based on the ideal atomic positions and b/a and c/a lattice parameter ratios for a given crystal prototype. The size of the system is then uniformly scaled, and the energy calculated without relaxing the system. To obtain these plots, values of r are evaluated every 0.02 Å up to 6 Å.

The calculation method used is available as the iprPy E_vs_r_scan calculation method.

Clicking on the image of a plot will open an interactive version of it in a new tab. The underlying data for the plots can be downloaded by clicking on the links above each plot.

Notes and Disclaimers:

These values are meant to be guidelines for comparing potentials, not the absolute values for any potential's properties. Values listed here may change if the calculation methods are updated due to improvements/corrections. Variations in the values may occur for variations in calculation methods, simulation software and implementations of the interatomic potentials.
The minima identified by this calculation do not guarantee that the associated crystal structures will be stable since no relaxation is performed.
NIST disclaimer

Version Information:

2020-12-18. Descriptions, tables and plots updated to reflect that the energy values are the measuredper atom potential energy rather than cohesive energy as some potentials have non-zero isolated atom energies.
2019-02-04. Values regenerated with even r spacings of 0.02 Å, and now include values less than 2 Å when possible. Updated calculation method and parameters enhance compatibility with more potential styles.
2019-04-26. Results for hcp, double hcp, α-As and L1₀ prototypes regenerated from different unit cell representations. Only α-As results show noticable (>1e-5 eV) difference due to using a different coordinate for Wykoff site c position.
2018-06-13. Values for MEAM potentials corrected. Dynamic versions of the plots moved to separate pages to improve page loading. Cosmetic changes to how data is shown and updates to the documentation.
2017-01-11. Replaced png pictures with interactive Bokeh plots. Data regenerated with 200 values of r instead of 300.
2016-09-28. Plots for binary structures added. Data and plots for elemental structures regenerated. Data values match the values of the previous version. Data table formatting slightly changed to increase precision and ensure spaces between large values. Composition added to plot title and structure names made longer.
2016-04-07. Plots for elemental structures added.

Select a composition:

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2024--Nitol-M-S--V-Nb-Ta-Ti-Zr--LAMMPS--ipr1/EvsR.Nb