Composition dependence of defect properties in electron-irradiated Fe-Cr-Ni solid solutions

Dimitrov, C.; Dimitrov, O.

doi:10.1088/0305-4608/14/4/005

Cited by 85 publications

(35 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The cumulative effect may also be able to explain the reduction in the experimentally determined vacancy formation energy with increasing Ni content in FeCrNi austenitic alloys. 70 The barrier energies for vacancy migration steps involving solute-vacancy exchange (in Table XIV) show that those for Ni are consistently higher than those for Cr by between 0.25 and 0.43 eV. In the afmD states the migration barrier heights for Fe self-diffusion (Table III) Fig.…”

Section: A Defect-solute Interactionmentioning

confidence: 91%

Defect and solute properties in dilute Fe-Cr-Ni austenitic alloys from first principles

2012

View full text Add to dashboard Cite

We present results of an extensive set of first-principles density functional theory calculations of point defect formation, binding, and clustering energies in austenitic Fe with dilute concentrations of Cr and Ni solutes. A large number of possible collinear magnetic structures were investigated as appropriate reference states for austenite. We found that the antiferromagnetic single-and double-layer structures with tetragonal relaxation of the unit cell were the most suitable reference states and highlighted the inherent instabilities in the ferromagnetic states. Test calculations for the presence and influence of noncollinear magnetism were performed but proved mostly negative. We calculate the vacancy formation energy to be between 1.8 and 1.95 eV. Vacancy cluster binding was initially weak at 0.1 eV for divacancies but rapidly increased with additional vacancies. Clusters of up to six vacancies were studied and a highly stable octahedral cluster and stacking fault tetrahedron were found with total binding energies of 2.5 and 2.3 eV, respectively. The 100 dumbbell was found to be the most stable self-interstitial with a formation energy of between 3.2 and 3.6 eV and was found to form strongly bound clusters, consistent with other fcc metals. Pair interaction models were found to be capable of capturing the trends in the defect cluster binding energy data. Solute-solute interactions were found to be weak in general, with a maximal positive binding of 0.1 eV found for Ni-Ni pairs and maximum repulsion found for Cr-Cr pairs of −0.1 eV. Solute cluster binding was found to be consistent with a pair interaction model, with Ni-rich clusters being the most stable. Solute-defect interactions were consistent with Ni and Cr being modestly oversized and undersized solutes, respectively, which is exactly opposite to the experimentally derived size factors for Ni and Cr solutes in type 316 stainless steel and in the pure materials. Ni was found to bind to the vacancy and to the 100 dumbbell in the tensile site by 0.1 eV and was repelled from mixed and compressive sites. In contrast, Cr showed a preferential binding to interstitials. Calculation of tracer diffusion coefficients found that Ni diffuses significantly more slowly than both Cr and Fe, which is consistent with the standard mechanism used to explain radiation-induced segregation effects in Fe-Cr-Ni austenitic alloys by vacancy-mediated diffusion. Comparison of our results with those for bcc Fe showed strong similarity for pure Fe and no correlation with dilute Ni and Cr.

show abstract

Section: A Defect-solute Interactionmentioning

confidence: 91%

Defect and solute properties in dilute Fe-Cr-Ni austenitic alloys from first principles

2012

View full text Add to dashboard Cite

show abstract

“…Migration energies of point defects were adopted from the evaluation provided by Dimitrov and Dimitrov [5]. Important parameter values used in the numerical calculation are listed in Table 1.…”

Section: Modeling and Calculation Proceduresmentioning

confidence: 99%

Calculation of radiation-induced deformation of SUS 316 in the ITER-relevant condition

Nagakawa

Ueno

2004

Journal of Nuclear Materials

View full text Add to dashboard Cite

“…[2][3][4][5][6] owing to the difficulty in precisely determining atomic quantities 7 such as the formation and migration energies of a single vacancy or that of an interstitial. These physical properties can also be greatly affected by impurities 5 and the influence of the local environment is difficult to properly probe.…”

Section: Introductionmentioning

confidence: 99%

First-principles study of point defects in an fcc Fe-10Ni-20Cr model alloy

Piochaud¹,

Klaver²,

Adjanor³

et al. 2014

Phys. Rev. B

View full text Add to dashboard Cite

The influence of the local environment on vacancy and self-interstitial formation energies has been investigated in a face-centered-cubic (fcc) Fe-10Ni-20Cr model alloy by analyzing an extensive set of first-principle calculations based on density functional theory. Chemical disorder has been considered by designing special quasirandom structures and four different collinear magnetic structures have been investigated in order to determine a relevant reference state to perform point defect calculations at 0 K. Two different convergence methods have also been used to characterize the importance of the method on the results. Although our fcc Fe-10Ni-20Cr would be better represented in terms of applications by the paramagnetic state, we found that the antiferromagnetic single-layer magnetic structure was the most stable at 0 K and we chose it as a reference state to determine the point defect properties. Point defects have been introduced in this reference state, i.e., vacancies and Fe-Fe, Fe-Ni, Fe-Cr, Cr-Cr, Ni-Ni, and Ni-Cr dumbbell interstitials oriented either parallel or perpendicular to the single layer antiferromagnetic planes. Each point defect studied was introduced at different lattice sites to consider a sufficient variety of local environments and analyze its influence on the formation energy values. We have estimated the point defect formation energies with linear regressions using variables which describe the local environment surrounding the point defects. The number and the position of Ni and Cr first nearest neighbors to the point defects were found to drive the evolution of the formation energies. In particular, Ni is found to decrease and Cr to increase the vacancy formation energy of the model alloy, while the opposite trends are found for the dumbbell interstitials. This study suggested that, to a first approximation, the first nearest atoms to point defects can provide reliable estimates of point defect formation energies.

show abstract

Composition dependence of defect properties in electron-irradiated Fe-Cr-Ni solid solutions

Cited by 85 publications

References 24 publications

Defect and solute properties in dilute Fe-Cr-Ni austenitic alloys from first principles

Defect and solute properties in dilute Fe-Cr-Ni austenitic alloys from first principles

Calculation of radiation-induced deformation of SUS 316 in the ITER-relevant condition

First-principles study of point defects in an fcc Fe-10Ni-20Cr model alloy

Contact Info

Product

Resources

About