First-principles model for voids decorated by transmutation solutes: Short-range order effects and application to neutron irradiated tungsten

Nguyen-Manh, D.; Wróbel, Jan; Klimenkov, M.; Lloyd, Matthew J.; Messina, Luca; Dudarev, S. L.

doi:10.1103/physrevmaterials.5.065401

Cited by 9 publications

(6 citation statements)

References 125 publications

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“…However, we did not observe the voids in pure W, but in W-3Re alloy. First principles calculations showed that the short-range order (SRO) parameter between Re and vacancy was negative, showing an attractive effect on vacancy [ 46 ]. Neutron irradiation experiments also showed that the voids could be decorated by Re and Os atoms [ 47 , 48 ].…”

Section: Discussionmentioning

confidence: 99%

The Effect of Rhenium Content on Microstructural Changes and Irradiated Hardening in W-Re Alloy under High-Dose Ion Irradiation

Luo

Liu

et al. 2023

Nanomaterials

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An amount of 100 dpa Si2+ irradiation was used to study the effect of transmutation rhenium content on irradiated microscopic defects and hardening in W-xRe (x = 0, 1, 3, 5 and 10 wt.%) alloys at 550 °C. The increase in Re content could significantly refine the grain in the W-xRe alloys, and no obvious surface topography change could be found after high-dose irradiation via the scanning electron microscope (SEM). The micro defects induced by high-dose irradiation in W and W-3Re alloys were observed using a transmission electron microscope (TEM). Dislocation loops with a size larger than 10 nm could be found in both W and W-3Re alloy, but the distribution of them was different. The distribution of the dislocation loops was more uniform in pure W, while they seemed to be clustered around some locations in W-3Re alloy. Voids (~2.4 nm) were observed in W-3Re alloy, while no void was investigated in W. High-dose irradiation induced obvious hardening with the hardening rate between 75% and 155% in all W-xRe alloys, but W-3Re alloy had the lowest hardening rate (75%). The main reasons might be related to the smallest grain size in W-3Re alloy, which suppressed the formation of defect clusters and induced smaller hardening than that in other samples.

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Section: Discussionmentioning

confidence: 99%

The Effect of Rhenium Content on Microstructural Changes and Irradiated Hardening in W-Re Alloy under High-Dose Ion Irradiation

Luo

Liu

et al. 2023

Nanomaterials

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“…The simulations were carried out by quenching alloys from 3000 K down to 100 K with a temperature step of 100 K. Modelling was made for unit cells containing 2000 atoms. The phase stability at a given temperature of considered alloys was specifically analyzed using the enthalpy of mixing derived from the MC simulations [65]. Atomic ordering and segregation within the alloy were analyzed using the MC simulations.…”

Section: Fundamental Research On Smart Systemsmentioning

confidence: 99%

“…Atomic ordering and segregation within the alloy were analyzed using the MC simulations. In the MC calculation the Warren-Cowley short-range order (SRO) parameters [65][66][67] were employed, which describe the nature of chemical interactions between different pairs of atoms. Positive values of the SRO parameter indicate atomic segregation, while negative values suggest the possibility of atomic ordering and, specifically, point out to a possible formation of intermetallic phases.…”

Section: Fundamental Research On Smart Systemsmentioning

confidence: 99%

Advanced Self-Passivating Alloys for an Application under Extreme Conditions

Litnovsky

Klein

Tan

et al. 2021

Metals

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Self-passivating Metal Alloys with Reduced Thermo-oxidation (SMART) are under development for the primary application as plasma-facing materials for the first wall in a fusion DEMOnstration power plant (DEMO). SMART materials must combine suppressed oxidation in case of an accident and an acceptable plasma performance during the regular operation of the future power plant. Modern SMART materials contain chromium as a passivating element, yttrium as an active element and a tungsten base matrix. An overview of the research and development program on SMART materials is presented and all major areas of the structured R&D are explained. Attaining desired performance under accident and regular plasma conditions are vital elements of an R&D program addressing the viability of the entire concept. An impressive more than 104-fold suppression of oxidation, accompanied with more than 40-fold suppression of sublimation of tungsten oxide, was attained during an experimentally reproduced accident event with a duration of 10 days. The sputtering resistance under DEMO-relevant plasma conditions of SMART materials and pure tungsten was identical for conditions corresponding to nearly 20 days of continuous DEMO operation. Fundamental understanding of physics processes undergone in the SMART material is gained via fundamental studies comprising dedicated modeling and experiments. The important role of yttrium, stabilizing the SMART alloy microstructure and improving self-passivating behavior, is under investigation. Activities toward industrial up-scale have begun, comprising the first mechanical alloying with an industrial partner and the sintering of a bulk SMART alloy sample with dimensions of 100 mm × 100 mm × 7 mm using an industrial facility. These achievements open the way to further expansion of the SMART technology toward its application in fusion and potentially in other renewable energy sources such as concentrated solar power stations.

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“…The DFT calculations used for fitting enthalpy of mixing [36,37] in this study were performed with the Vienna ab initio simulation package (VASP) [38][39][40]. The interaction among ions and electrons is described by using the projector augmented waves (PAWs) method [41].…”

Section: Dft Calculationsmentioning

confidence: 99%

“…Besides the data obtained from the large supercell structures for random configurations, the DFT calculations were also performed for 2 ×2× 2 supercell structures generated from decoration of one vacancy and other W, Re, Os atoms from 58 bcc-like ordered structures originally used for binary system [44,45]. In addition, special quasi-random structures, created from alloy theoretic automated toolkit code [36,37,45,46], for configurations with one vacancy and different W and solute atoms were also employed. More detailed information about the DFT energy data used in figures 1-4 and 6 of the present work can be found from recent publications [13,36,37,[47][48][49].…”

Section: Dft Calculationsmentioning

confidence: 99%

Development of a solute and defect concentration dependant Ising model for the study of transmutation induced segregation in neutron irradiated W–(Re, Os) systems

Lloyd

Martínez

Messina

et al. 2021

J. Phys.: Condens. Matter

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In this study, radiation-induced precipitation of transmutation products is addressed via the development of a new solute and vacancy concentration dependant Ising model for the W–Re–Os system. This new model includes interactions between both Os and Re atoms with vacancies, thus facilitating more representative simulations of transmutation in fusion reactor components. Local solute concentration dependencies are introduced for the W–Re, W–Os and Re–Os pair interactions. The model correctly accounts for the repulsion between small clusters of vacancies and the attraction between larger clusters/voids, via the introduction of local vacancy concentration dependant interaction coefficients between pairs of atoms and vacancies. To parameterise the pair interactions between atoms and/or vacancies, the enthalpy of mixing, ΔH mix, for various configurations and solute/defect concentrations, was calculated using density functional theory, within 6 binary systems: W–Re, W–Os, Re–Os, W–vacancy, Re–vacancy and Os–vacancy. The new energy model was implemented into the SPPARKS Monte Carlo code, and successfully used to predict the formation of voids decorated with Re and Os solute atoms. Analysis suggests that there is a strong thermodynamic tendency for Os to bind to these voids with a comparatively weaker binding from Re atoms. The binding energies of various solute/vacancy clusters were calculated and showed that Re and Os solute atoms tend to stabilise small clusters of vacancies, increasing the attractive binding energy between the constituents.

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First-principles model for voids decorated by transmutation solutes: Short-range order effects and application to neutron irradiated tungsten

Cited by 9 publications

References 125 publications

The Effect of Rhenium Content on Microstructural Changes and Irradiated Hardening in W-Re Alloy under High-Dose Ion Irradiation

The Effect of Rhenium Content on Microstructural Changes and Irradiated Hardening in W-Re Alloy under High-Dose Ion Irradiation

Advanced Self-Passivating Alloys for an Application under Extreme Conditions

Development of a solute and defect concentration dependant Ising model for the study of transmutation induced segregation in neutron irradiated W–(Re, Os) systems

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