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Exploring tritium permeation barriers with high permeation reduction factor (PRF) by an industrial scale process is crucial for tritium systems in fusion reactors. Herein, we fabricated a dense Fe-Al/Al 2 O 3 coating by a simple hot-dipping aluminizing (HDA) method and optimized oxidation strategy. The microstructure, chemical composition, and crystallographic characteristic of obtained samples were investigated. And the permeation of deuterium through the sample was determined by gas-driven permeation (GDP) experiments. The results show that the obtained oxide coating mainly consisted of γ-Al 2 O 3 layer and Fe Al gradient transition layer. Notably, the Al 2 O 3 layer formed by the oxidation of FeAl alloy coating possessed a high PRF value of 2394 at 550 °C. Compared with the direct oxidation of HDA sample, the oxide coating prepared by the alloy topcoat oxidation strategy was denser and had less defects. Meanwhile, the effect of Al topcoat and different Fe Al alloy topcoats on the microstructure and performance of the oxide coating were investigated, respectively. And the formation mechanisms of oxide coatings prepared by different oxidation strategies were also analyzed. [Display omitted] • A dense Fe-Al/Al 2 O 3 coating was fabricated on CLAM steel. • The Fe Al topcoat was conducive to the growth of the dense coating. • The coating formed on FeAl topcoat possessed the highest PRF value. [ABSTRACT FROM AUTHOR]

Liquid Lead-Lithium (PbLi) alloys are promising functional material which can act as both neutron multiplier and tritium breeder in liquid blanket of fusion reactors, however, their corrosion behavior on RAFM steel is still a challenge. In this work, the dissolution, diffusion, bonding and charging behavior of steel alloy elements in liquid PbLi were investigated by using the first principles molecular dynamics simulations. The dissolution order of the main alloy elements of RAFM steel dissolved into the liquid PbLi was Cr>Fe>V>Mn>Ta>W>C. O atom tend to bond with Li atom in liquid PbLi and the O dissolution energy had negative value of -3.84 eV. The binding energies of Y-O, Ti-O, Al-O, Si-O, Zr-O, Ta-C, V-C, Ta-N and V-N pairs within liquid PbLi at temperature 500°C show that related oxides/carbides/nitrides in RAFM steel do not likely to decompose and may not affect their dissolution corrosion behavior. These data can provide indispensable information for understanding the dissolution corrosion behavior of advanced RAFM steel in liquid PbLi. [ABSTRACT FROM AUTHOR]

Er 2 O 3 coating is one of the candidate tritium permeation barriers (TPB) to reduce tritium permeation and leakage in fusion reactors. A series of Er 2 O 3 coatings were synthesized on China Low Activation Martensitic (CLAM) steel via sol-gel method, and systematic investigate the influence of synthesis parameters for on microstructure and properties of the Er 2 O 3 coatings. The results showed that no cracks were observed in Er 2 O 3 coatings as chosen 11 vol.% diethanolamine. The best heat treatment temperature could be thought 600 °C, in order to obtain a homogeneous and dense Er 2 O 3 coating with high hardness, good crystallization and strong bonding to the substrate. [ABSTRACT FROM AUTHOR]