Thermodynamic trapping and diffusion model for multiple species in systems with multiple sorts of traps

Leitner, Silvia; Ecker, Werner; Fischer, Franz Dieter; Svoboda, Jiřı́

doi:10.1016/j.actamat.2022.117940

Cited by 7 publications

(2 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Macroscopic rate theory is commonly used for H migration behavior in materials [9,[40][41][42][43][44][45][46][47]. Typically, the classical model identifies the behavior of single-component HIs in materials into three processes: diffusion, trapping, and detrapping.…”

Section: Introductionmentioning

confidence: 99%

Mechanism of hydrogen isotope exchange for tritium removal in plasma-facing materials: a multi-scale investigation

Sun,

Hao,

Chen

et al. 2024

Nucl. Fusion

View full text Add to dashboard Cite

The safety of future fusion reactors is critically dependent on the tritium (T) retention in plasma-facing materials. Hydrogen isotope exchange offers a method to redistribute hydrogen isotopes within solid materials, presenting a feasible approach for removing T from bulk materials and trapped by strong trapping sites. Nonetheless, unraveling the intricate mechanism behind hydrogen isotope exchange remains an urgent yet formidable challenge. This study undertakes a comprehensive investigation into the mechanism of hydrogen isotope exchange in tungsten materials across multiple scales. First, we developed a multi-component hydrogen isotope transport and exchange model (HIDTX) based on classical rate theory. The model validation was further carried out, demonstrating good consistency with the well-controlled laboratory experiments. From the results of different comparative models in HIDTX, it is found that the reduction in deuterium retention due to hydrogen isotope exchange was primarily driven by three synergistic effects: competitive re-trapping, collision, and swapping effects. Through molecular dynamics and first-principles calculations, the microscopic mechanism of hydrogen isotope exchange was revealed to be that the presence of hydrogen atoms in the interstitial sites surrounding a vacancy in tungsten decreased the binding energy between the vacancy and hydrogen. Meanwhile, we discovered that the combination of thermal desorption and hydrogen isotope exchange can significantly lower the temperature required for the hydrogen removal and enhance the removal rate. Particularly, the hydrogen removal time can be shortened by approximately 95% with simultaneous hydrogen isotope exchange compared to that with only thermal desorption. This work provides a practical guideline for comprehending and subsequently designing for efficient T removal in future nuclear fusion materials.

show abstract

Section: Introductionmentioning

confidence: 99%

Mechanism of hydrogen isotope exchange for tritium removal in plasma-facing materials: a multi-scale investigation

Sun,

Hao,

Chen

et al. 2024

Nucl. Fusion

View full text Add to dashboard Cite

show abstract

“…The abovementioned modeling, which is not completely compatible with the thermodynamic mechanism of the hydrogen trapping in secondary phases, could not really capture the physical process of the hydrogen trapping and might miss some details that can motivate the design of the new hydrogen storage scheme. In addition, Leitner et al [18] physically modeled the trapping and diffusion of multiple solute atoms in systems with multiple traps based on irreversible thermodynamics and the representative volume element technique (RVE), covering effectively any kinetics of exchange between the lattice and traps as well as site competition effects within A massive effort has been devoted to the development of solid-state hydrogen storage. Besides the active investigations on hydrides [10,11], the latest study [12] indicates that the secondary phases within aluminum alloys are capable of trapping large amounts of hydrogens (Figure 2c), which implies a potential new type of hydrogen storage scheme.…”

Section: Introductionmentioning

confidence: 99%

Phase-Field Insights into Hydrogen Trapping by Secondary Phases in Alloys

Bai

Liu

et al. 2023

Materials

View full text Add to dashboard Cite

Solid-state hydrogen storage is the best choice for balancing economy and safety among various hydrogen storage technologies, and hydrogen storage in the secondary phase might be a promising solid-state hydrogen storage scheme. In the current study, to unmask its physical mechanisms and details, a thermodynamically consistent phase-field framework is built for the first time to model hydrogen trapping, enrichment, and storage in the secondary phases of alloys. The hydrogen trapping processes, together with hydrogen charging, are numerically simulated using the implicit iterative algorithm of the self-defined finite elements. Some important results are attained: 1. Hydrogen can overcome the energy barrier under the assistance of the local elastic driving force and then spontaneously enter the trap site from the lattice site. The high binding energy makes it difficult for the trapped hydrogens to escape. 2. The secondary phase geometry stress concentration significantly induces the hydrogen to overcome the energy barrier. 3. The manipulation of the geometry, volume fraction, dimension, and type of the secondary phases is capable of dictating the tradeoff between the hydrogen storage capacity and the hydrogen charging rate. The new hydrogen storage scheme, together with the material design ideology, promises a viable path toward the optimization of critical hydrogen storage and transport for the hydrogen economy.

show abstract