Corrosion of Si, C, and SiC in molten salt

Xi, Jianqi; Jiang, Hao; Liu, Cheng; Morgan, Dane; Szlufarska, Izabela

doi:10.1016/j.corsci.2018.10.027

Cited by 29 publications

(20 citation statements)

References 47 publications

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“…Even for surfaces that are C-terminated, Si is dissolved first after it has segregated to the surface through a number of swapping reactions. These swapping reactions and Si segregation were previously reported during corrosion of SiC in molten salts [12], which means that this might be a common mechanism for corrosion of multi-component ceramics where one species is significantly more reactive than another.…”

Section: Discussionsupporting

confidence: 69%

“…These results suggest that the observed pitting corrosion on the SiC surface may be a transient phenomenon and the corrosion could eventually move toward more uniform degradation of the surface. It is interesting to point out that the observed dissolution of carbon-rich region in high temperature water is in contrast to corrosion of SiC in molten salt environments, where a carbon-rich layer forms and remains on the surface as a potentially protective layer for continued corrosion [12]. It remains to be determined to what extent the carbon-rich region provides a passive protection to SiC during hydrothermal environment.…”

Section: Introductionmentioning

confidence: 98%

See 1 more Smart Citation

Deciphering Water-Solid Reactions During Hydrothermal Corrosion of SiC

Xi,

Liu,

Morgan

et al. 2020

SSRN Journal

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Water-solid interfacial reactions are critical to understanding corrosion. More specifically, it is notoriously difficult to determine how water and solid interact beyond the initial chemisorption to induce the surface dissolution. Here, we report atomic-scale mechanisms of the elementary steps during SiC hydrothermal corrosion -from the initial surface attack to surface dissolution. We find that hydrogen scission reactions play a vital role in breaking Si-C bonds, regardless of the surface orientations. Stable silica layer does not form on the surface, but the newly identified chemical reactions on SiC are analogous to those observed during the dissolution of silica. SiC is dissolved directly into the water as soluble silicic acid. The rate of hydrothermal corrosion determined based on the calculated reaction activation energies is consistent with available experimental data. Our work sheds new light on understanding and interpreting the experimental observations and it provides foundation for design of materials that are resistant to corrosion in water.

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Section: Discussionsupporting

confidence: 69%

Section: Introductionmentioning

confidence: 98%

Deciphering Water-Solid Reactions During Hydrothermal Corrosion of SiC

Xi,

Liu,

Morgan

et al. 2020

SSRN Journal

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“…In the multilayer samples, all these SiC, TiC, and Ti 3 SiC 2 crystals coexist, and in this case, the chemical potentials of Si, C, and Ti were determined from the following relations: μ SiC = μ Si + μ C , μ TiC = μ Ti + μ C , and μ Ti 3 SiC 2 = 3μ Ti + μ Si + 2μ C . We have taken μ Si = − 5.68 eV, μ Ti = − 9.36 eV, and μ C = − 9.39 eV, following ( 11 , 48 ). Last, the diffusion pathways and migration energy barriers for defects were determined by the climbing-image nudged elastic band (CI-NEB) method ( 49 ) (typically with five images).…”

Section: Methodsmentioning

confidence: 99%

Enhancing the phase stability of ceramics under radiation via multilayer engineering

Zhang

et al. 2021

Sci. Adv.

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In metallic systems, increasing the density of interfaces has been shown to be a promising strategy for annealing defects introduced during irradiation. The role of interfaces during irradiation of ceramics is more unclear because of the complex defect energy landscape that exists in these materials. Here, we report the effects of interfaces on radiation-induced phase transformation and chemical composition changes in SiC-Ti3SiC2-TiCx multilayer materials based on combined transmission electron microscopy (TEM) analysis and first-principles calculations. We found that the undesirable phase transformation of Ti3SiC2 is substantially enhanced near the SiC/Ti3SiC2 interface, and it is suppressed near the Ti3SiC2/TiC interface. The results have been explained by ab initio calculations of trends in defect segregation to the above interfaces. Our finding suggests that the phase stability of Ti3SiC2 under irradiation can be improved by adding TiCx, and it demonstrates that, in ceramics, interfaces are not necessarily beneficial to radiation resistance.

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“…There is limited data on corrosion behavior of SiC in sCO 2 [65][66][67][68][69][70]. Sridharan et al [68] reported minimal mass gain after an initial mass loss for SiC after exposure for 1000h in research grade sCO 2 at 750°C.…”

Section: Corrosion In Scomentioning

confidence: 99%