Oxide coating fabrication by metal organic decomposition method for liquid blanket systems

Performance tests and process improvement for ceramic coatings fabricated by the metal organic decomposition (MOD) method have been conducted to obtain tritium permeation barrier and MHD insulator in liquid cooled blanket systems. In the present study, fabrication of MOD Er2O3 coating on a low activation ferritic steel substrate has been tested under reduced pressure condition. Measured hydrogen permeation reduction factors of >100 indicate that MOD coating fabrication under reduced pressure would be effective for suppression oxidation of a substrate and achieving superior coating performances. While crystallinities of MOD coating layers are significantly lower compared with sintered bulk materials, results of electrical conductivity and breakdown voltage measurements indicate that MOD Er2O3 coatings would have sufficient performances as an MHD insulation coating in a Li/V-alloy blanket system. Cathodoluminescence measurement using scanning electron microscope (SEM) is successfully applied to microscopic characterization of MOD coating layers.