Defective structures in FeCrAl alloys from first principles calculations

Abstract

The FeCrAl alloy system is well known as a potential candidate material for the accident tolerant fuel (ATF) cladding in the nuclear power industry owing to its high oxidation resistance under irradiation and high-temperature environment. The mechanical properties of FeCrAl alloys with various defects degrade under irradiation condition. In the present work, the structures of FeCrAl alloys with 10 ∼ 15Cr wt% and 5 ∼ 6Al wt% were simulated from the first principles calculations. Mechanical properties were predicted for FeCrAl alloys with different defects and components. Calculated results showed that doping Cr into alloys may improve its mechanical properties. On the other hand, Al was predicted to downgrade the mechanical properties by replacing the Fe atom. The mechanical anisotropies of FeCrAl were researched through Zener’s index and 3D Young’s modulus sketches. Additionally, the investigation on electronic characteristics indicated that an attenuated Fe–Fe interaction and strengthened Fe–Al interactions occur with the addition of Al.

The electronic and mechanical properties of (U, Th)O2 compounds: a first-principles study

“…To further understand the changes in the mechanical anisotropy of the compound after the addition of Th atoms, we use the three-dimensional Young's modulus diagram to more intuitively show the anisotropic changes in elasticity. For cubic crystal form and orthorhombic crystal form, the calculation formula of the three-dimensional Young's modulus diagram is as follows: 32 E o = 1/( l 1 4 S 11 +2 l 1 2 l 2 2 S 12 +2 l 1 2 l 3 2 S 13 + l 2 4 S 22 +2 l 2 2 l 3 2 S 23 + l 3 4 S 33 + l 2 2 l 3 2 S 44 + l 1 2 l 3 2 S 55 + l 1 2 l 2 2 S 66 )…”

Modeling phase separation and composition patterning in FeCrAl alloys at neutron irradiation

“…By considering point defect subsystem we introduce concentration of point defects as c d = N d /N, where N d is the number of the corresponding defects of d = {i, v}-type (i/v stands for interstitials/vacancies). Here one should stress out that all interstitials in FeCrAl alloys are Fe-Cr dumbbells as the most stable ones [38,39]. These dumbbells can be of both 〈110〉 and 〈111〉 type.…”

AisNet: A Universal Interatomic Potential Neural Network with Encoded Local Environment Features

“…The FeCrAl data set was constructed by ourselves according to the procedures of VASP. 30 Here, 4 × 4 × 4 supercells of the BCC structure were randomly initialized with the content of Fe102−Cr13−Al13. The k-point was set to 2 × 2 × 2 for atomic force calculation, and the cutoff energy in the electronic structure calculation was 350 eV.…”

“…The FeCrAl data set was constructed by ourselves according to the procedures of VASP . Here, 4 × 4 × 4 supercells of the BCC structure were randomly initialized with the content of Fe102–Cr13–Al13.…”

“…However, in many materials, data are difficult to obtain and do not cover a wide range of compositions, such as FeCrAl alloys. In fact, the FeCrAl alloy is one of the most popular candidates for nuclear fuel cladding materials. − At the same time, multiscale researches rely heavily on high-precision MLFFs, but the FNN architecture is limited in terms of accuracy and efficiency gains from descriptors with scarce data volume. , …”