Effect of composition on antiphase boundary energy in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Ni</mml:mi><mml:mn>3</mml:mn></mml:msub><mml:mi>Al</mml:mi></mml:mrow></mml:math>based alloys:<i>Ab initio</i>calculations

Gorbatov, Oleg I.; Lomaev, I. L.; Gornostyrev, Yu. N.; Ruban, Andrei V.; Furrer, David; Venkatesh, V.C.; Novikov, D.L.; Burlatsky, S. F.

doi:10.1103/physrevb.93.224106

Cited by 68 publications

(19 citation statements)

References 56 publications

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“…We first note that {100} APBs in Cu 3 Au exhibit strong faceting at equilibrium, thus suggesting that these APBs carry very low excess free energy. While it is problematic to calculate APB energies from standard first principles techniques [46,47] in Cu 3 Au, mean-field models provide simple expressions for the energy of an L1 2 ordered state and its APBs as linear combination of the pairwise interaction parameters J 1 , J 2 , J 3 [48]. It is commonly assumed (and observed) that the strength of these pairwise interactions decrease with the interaction range, so that Further work is needed, however, to test this hypothesis for Cu 3 Au, especially since nonequilibrium point defects play an important role in ordering and disordering kinetics under irradiation [49].…”

Section: Discussionmentioning

confidence: 99%

Novel mechanism for order patterning in alloys driven by irradiation

2017

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Abstract:Kinetic Monte Carlo simulations have been performed to investigate the evolution of ordered domains in model alloys under irradiation. The alloys investigated were equiatomic binary alloys on a simple square lattice with first and second nearest-neighbor interactions, chosen so that a 2×2 ordered structure is the equilibrium phase below a critical order-disorder transition temperature, T c . The ratio of second to first nearest neighbor interactions, R was varied from 0 to 0.45 to explore the effect of the thermodynamic frustrations induced by the proximity of the 2×1 phase boundary, which occurs at R = 0.5 for T = 0. The atomic mixing produced by nuclear collisions was modeled by forcing the ballistic exchange of pairs of atoms at a controlled rate, Γ b . This disordering process competed with thermodynamic re-ordering, resulting in nonequilibrium steady states. Two trivial steady states were found, a disordered state at high

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Section: Discussionmentioning

confidence: 99%

Novel mechanism for order patterning in alloys driven by irradiation

2017

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“…where 110 is the Burgers vector of superdislocations in {111} and {010} planes which will be dissociated into two 110 /2 partials with an APB between them [19][20][21][22][23]. There may be other dissociation types like CSF (complex stacking fault) and SISF (superlattice intrinsic stacking fault).…”

Section: Introductionmentioning

confidence: 99%

Effects of Alloying Atoms on Antiphase Boundary Energy and Yield Stress Anomaly of L12 Intermetallics: First-Principles Study

Gao

Wang

et al. 2018

Crystals

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Abstract:The antiphase boundary energies of {111} and {010} planes in L1 2 intermetallics (Ni 3 Ge, Ni 3 Si, Al 3 Sc, Ni 3 Al, Ni 3 Ga and Al 3 Ti) under different pressure are presented using first-principle methods. The yield stress anomaly is predicted by the energy criterion p-factor based on the anisotropy of antiphase boundary energies and elasticity. These L1 2 intermetallics exhibit anomalous yield stress behavior except Al 3 Sc. It is found that pressure cannot introduce the transition between anomalous and normal behavior. In order to investigate the transition, Al 3 Sc, Ni 3 Si and Ni 3 Ge with substituting atoms are investigated in detail due to p-factors of them are close to the critical value p c = √ 3. Al 3 Sc can change to anomalous when Sc atoms in {010} planes are substituted by Ti with plane concentration 25%. When Li substitutes Al in {111} planes, anomalous Al 3 Sc will change to normal. Ni 3 Si and Ni 3 Ge can exhibit normal yield stress behavior when Ge and Si in {111} planes are substituted by alloying atoms with plane concentrations 12.5% and 25%. When Ga and Al substitute in {010} planes, normal Ni 3 Si and Ni 3 Ge will revert to anomalous behavior. Therefore, transparent transition between normal and anomalous yield stress behavior in L1 2 intermetallics can be introduced by alloying atoms.

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“…However, ternary additions can strongly affect the APB energy and enhance strengthening by increasing the APB energy. Recently, the effect of off-stoichiometry [4] and that of transition-metal additions [5,6] on the APB energy of Ni 3 Al have been investigated from computational approaches.…”

Section: Introductionmentioning

confidence: 99%

First-principles study on Ni3Al (111) antiphase boundary with Ti and Hf impurities

2017

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The effect of Ti and Hf impurities on the (111) antiphase boundary (APB) energy of Ni 3 Al is investigated via ab initio calculations. Cluster expansion is performed to predict supercell total energies sampled in a Monte Carlo approach that accounts for nondilute point defects at finite temperature, obtaining APB energies as a function of impurity concentration and temperature. Of the two ternary elements, Hf is more effective in increasing the APB energy. While the (111) APB energy of a pure L1 2 material requires at least second-nearest-neighbor interactions, we observe a strong correlation between impurity-induced APB energy enhancement and formation of first-nearest-neighbor Ni-Ni bonds across the APB due to symmetry breaking. Using a linear-chain model and effective bond energies derived from effective cluster interactions, we propose a mechanism that explains why Hf is more effective than Ti.

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Effect of composition on antiphase boundary energy inNi3Albased alloys:Ab initiocalculations

Cited by 68 publications

References 56 publications

Novel mechanism for order patterning in alloys driven by irradiation

Novel mechanism for order patterning in alloys driven by irradiation

Effects of Alloying Atoms on Antiphase Boundary Energy and Yield Stress Anomaly of L12 Intermetallics: First-Principles Study

First-principles study on Ni3Al (111) antiphase boundary with Ti and Hf impurities

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