Effects of Cr3+ on the corrosion of SiC in LiF–NaF–KF molten salt

Corrosion of Si, C, and SiC in molten salt

“…3(a) and (c)). Similar results have been experimentally reported for SiC in FLiNaK salt where the Na2SiF6 and K2SiF6 were created due to corrosion [8]. Apart from the most energetically favorable reaction of Si|Si 4+ , according to Fig.…”

“…This result suggests that Si might have been dissolved into the salt, resulting in the formation of a carbon-rich surface [7]. Similar results have also been reported by Xue et al [8] who found that impurities from the salt, such as Cr 3+ , could further accelerate corrosion of SiC. These results suggested that unlike the oxide protected surface formed in oxidizing environment, the SiC surface is corroded in fluoride molten salt via dissolving Si species.…”

“…The integration over the Brillouin zone is performed using the Γ point for AIMD simulations, and the 3×3×1 kpoint mesh is used for the subsequent energy minimization. Motivated by experimental work at high temperatures (around 1000 K) [7,8], the AIMD simulations are performed at 1000 K for the thermodynamics calculations (see Sec. 2.2).…”

Development of an Open-source Alloy Selection and Lifetime Assessment Tool for Structural Components in CSP

“…Studies have shown that intentionally added impurities (such as Ni, Cr ions, etc.) to molten FLiNaK salt, led to a higher mass loss and increased corrosion for SiC [77,78]. Yang et al reported the possibility of Ni reacting with Si in the salt to form NiSi and Ni 31 Si 12 on the surface of Hastelloy N alloy that can drive the dissolution of Si from SiC into salt and alloy.…”

SiC/SiC Composites Technology Gap Analysis for Molten Salt Reactors

“…SiC may be exposed to dissolved metal ions from container alloys such as [70]. For corrosion tests of CVD SiC in purified FLiNaK, cross-sectional line-scanning EDS (energy-dispersive x-ray spectroscopy) spectra showed that corrosion resulted in the loss of elemental silicon and the formation of a C-and O-rich surface.…”