A study of irradiated FeCr alloys: deviations from Matthiessen's rule and interstitial migration

Maury, F.; Lucasson, P.; Lucasson, A.; Faudot, F.; Bigot, J.

doi:10.1088/0305-4608/17/5/014

Cited by 63 publications

(88 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The predictions of mixed Fe-Cr dumbbells are in agreement with experiments. 66,67 V is an interesting element since it is largely transparent to vacancies and also to the ͗111͘ type interstitials while it does, however, repulse rather strongly the ͗110͘ interstitials. Thus, one can expect to see differences for dilute Fe-V alloys in the singleinterstitial diffusion pattern but not in that of interstitial loops, with respect to that in pure Fe.…”

Section: Discussionmentioning

confidence: 99%

Ab initiostudy of solute transition-metal interactions with point defects in bcc Fe

Olsson

Klaver²,

Domain³

2010

Phys. Rev. B

205

150

View full text Add to dashboard Cite

The properties of 3d, 4d, and 5d transition-metal elements in ␣-Fe have been studied using ab initio density-functional theory. The intrinsic properties of the solutes have been characterized as well as their interaction with point defects. Vacancies and interstitials of ͗110͘ and ͗111͘ orientations have been considered in order to discern trends that may explain experimental evidence of solute influences on radiation response and possibly aid future material design regarding the choice of alloy composition. Depending on the solute element, the different interactions are governed by the chemical interactions and the solute size factor. It is shown that magnetic interactions play an important role for the properties of the center series 3d elements, especially so for the antiferromagnetically coupling V, Cr, and Mn. For the 4d, 5d, and remaining 3d elements the interaction with point defects is mainly governed by the solute size factor. The solute-solute interaction is mostly repulsive with a few exceptions. The interactions with vacancies are in most cases binding; but the second nearest neighbor configurations exhibit strong repulsion for the early transition metals. Cr and Mn interact strongly binding with interstitial defects. The trends of the solute defect interactions have been determined to depend on the characteristic local deformation. Early transition metals interact stronger with defects than late ones of equal size factor.

show abstract

Section: Discussionmentioning

confidence: 99%

Ab initiostudy of solute transition-metal interactions with point defects in bcc Fe

Olsson

Klaver²,

Domain³

2010

Phys. Rev. B

205

150

View full text Add to dashboard Cite

show abstract

“…Concurrently to materials engineering, many efforts are dedicated to the understanding of the physical processes responsible for the radiation degradation processes [31][32][33][34], based on multiscale modeling, together with validation experiments. In this regard, RR experiments are used as validation experiments to monitor the changes in defect populations, which can also be reproduced by modeling simulations [13,[35][36][37][38][39]. The well-known work of Fu et al [38] demonstrated that overall agreement can be achieved between modeling [ab initio and kinetic Monte Carlo (KMC)] and experiments (RR and positron annihilation [13,40]) in the case of electron-irradiated ultrapure Fe.…”

mentioning

confidence: 97%

“…A recent work [39] which combines molecular dynamics (MD), atomistic KMC (AKMC) coupled to a neural network, and rate theory (RT) succeeded in reproducing several experimental results of RR in dilute [35,36] and concentrated electron-irradiated Fe-Cr alloys [37]. That work reproduces well the recovery stages due to correlated recombinations but has a limited range of application given that it only simulates a single recombination process in stage II and is not able to accurately reproduce the amplitude of stage III.…”

mentioning

confidence: 99%

“…The pre-Irr+classic RR sample shows a residual resistivity value that is two times lower than the classic RR one. The small amount of residual resistivity still observed could be due to some clusters that are not yet annealed or to deviations induced by the residual concentration of defects (two current model deviations [35,47]). Above 400 K we no longer have information on the SRO.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Decoupling of defect and short-range order contributions to resistivity recovery measurements in binary alloys

et al. 2014

View full text Add to dashboard Cite

We report a new and improved approach that uses low-temperature resistivity recovery measurements to study the defect kinetics in metallic binary alloys. This method is able to decouple the effect related to the irradiation defect contribution to the resistivity from that of the short-range order, which is enhanced by the free migration of defects. This approach can provide reliable experimental data which are more suitable for comparisons with current computational models. Furthermore, the difference in this method with respect to the classical one is that our method gives information concerning the role of vacancies and interstitials on short-range order. The method is applied to a model alloy Fe-5%Cr, of interest for fusion applications, where short-range order effects have been previously found to play a role. In general, concentrated alloys have enough solute concentration to perturb the electronic structure and the phonon spectrum. Typically this composition range starts at 1%-2% of the solute concentration. These perturbations lead to an atomic configuration which is never fully random; there are certain atomic correlations that can be described as short-range order (SRO). The SRO parameters (α i ) are defined as the correlation between first-and next-nearest neighbors (NN) of an atom [1]. Every alloy has different SRO equilibrium configurations for every solute concentration and temperature [2], which also depend on the thermomechanical process experienced [3,4]. Quenching experiments have been widely used to study the kinetics of ordering [2][3][4][5][6][7][8] given the linear relation of the resistivity (ρ) with α i (cf. Refs. [1,8]). Concurrently, resistivity recovery (RR) experiments have been commonly used to investigate radiation effects in pure metals, based on the recovery of the residual resistivity up to its original value after low-temperature irradiation and subsequent isochronal annealing [9][10][11][12][13][14][15][16][17]. However, in the case of concentrated alloys, the presence of migrating defects allows solute rearrangements and changes in the SRO, which in turn affect the residual resistivity of the alloy. This effect might thus significantly alter the RR results and their interpretation, as it has been discussed in the case of Fe-Cr [18,19].In the field of energy advanced materials development there is specific interest in the study of Cr effects on nuclear alloys [20,21], given that Cr concentrations (C Cr ) close to 9% reduce swelling [22,23], reduce the radiation-induced ductile-brittle transition temperature (DBTT) [24], and increase protection against corrosion [25]. The physics of these effects is not yet well understood though it is believed that the minimum of the SRO parameters might play a role in affecting the kinetics of radiation defects in a concentrated Fe-Cr system. Indeed, it has been proven that α i change their sign at C Cr close to 10% [26][27][28]. At C Cr < 11% the SRO becomes negative, i.e., Cr tends to distribute as far * begona.gomez-ferrer@externos.ciemat.es...

show abstract

“…The binding energy between a Cr atom and the cluster, if any, is sometimes mere hundredths of eV and usually does not exceed 0.2 eV. For clusters of two or three parallel dumbbells or the ring-like tri-interstitial the weak binding is not surprising, as all these configurations consist of multiple <110> dumbbells and the binding of Cr to a single <110> dumbbell is usually weak [30][31][32] and could be somewhat stronger in concentrated alloys [33][34][35]. The interaction of one or two Cr atoms with a <110> dumbbell that is a part of a cluster is rather similar to the interaction with a single dumbbell, i.e.…”

Section: Dft Results Of the Interaction Between Cr And Di-and Tri-intmentioning

confidence: 99%

Benchmarking FeCr empirical potentials against density functional theory data

Klaver¹,

Bonny²,

Olsson³

et al. 2010

Modelling Simul. Mater. Sci. Eng.

View full text Add to dashboard Cite

Three semi-empirical force field FeCr potentials, two within the formalism of the Two Band model and one within the formalism of the Concentration Dependent model, have been benchmarked against a wide variety of Density Functional Theory structures. The benchmarking allows an assessment of how reliable empirical potential results are in different areas relevant to radiation damage modeling. The Density Functional Theory data consists of defect-free structures, structures with single interstitials and structures with small di-and tri-interstitial clusters. All three potentials reproduce the general trend of the heat of formation quite well. The most important shortcomings of the original Two Band model potential are the low or even negative heat of formation for Cr-rich structures and the lack of a strong repulsion when moving two solute Cr atoms from being second-nearest neighbours to nearest neighbours. The newer Two Band model potential partly solves the first problem. The most important shortcoming in the Concentration Dependent model potential is the magnitude of the Cr-Cr repulsion, being too strong at short distances and mostly absent at longer distances. Both Two Band model potentials do reproduce long range Cr-Cr repulsion. For interstitials the Two Band model potentials reproduce a number of Cr-interstitial binding energies surprisingly well, in contrast to the Concentration Dependent model potential. For Cr interacting with clusters, the result can sometimes be directly extrapolated from Cr interacting with single interstitials, both according to Density Functional Theory and the three empirical potentials.

show abstract

A study of irradiated FeCr alloys: deviations from Matthiessen's rule and interstitial migration

Cited by 63 publications

References 22 publications

Ab initiostudy of solute transition-metal interactions with point defects in bcc Fe

Ab initiostudy of solute transition-metal interactions with point defects in bcc Fe

Decoupling of defect and short-range order contributions to resistivity recovery measurements in binary alloys

Benchmarking FeCr empirical potentials against density functional theory data

Contact Info

Product

Resources

About