Electrical resistivity and hydrogen permeation of dip-coated Er2O3 on JLF-1

Liquid blanket systems are very promising directions for future fusion reactors. A ceramic coating on the ducts would solve issues for the liquid blankets such as MHD pressure drop and tritium permeation through structure materials. In this study, an Er2O3 coating was fabricated on JLF-1 (Fe–9Cr–2W based reduced activation ferritic/martensitic steel), SUS430 (18Cr based commercial ferritic steel) by dip-coating method with metal organic decomposition (MOD) liquid followed by baking in air. XRD patterns indicated that good crystallinity of the Er2O3 coating was obtained for the baking temperature of 600 °C. The highest electrical resistivity was about 1011 Ω m. Below the coating, a substrate oxidation layer was also formed according to a XPS elemental depth profile. Hydrogen permeability of the coated sample was decreased only by 1/15 compared with bare JLF-1 sample. The reason might be oxidation of the substrate surface for degrading the coating barrier performance.