Compatibility of compound oxides with liquid lithium for fusion reactor blanket application

Mixed oxide phases as candidates for a magnethydrodymanics (MHD) coating material in liquid lithium blanket concept were investigated by immersing in liquid lithium. CaZrO3 showed a better compatibility than MgTiO3, MgZrO3 and CaTiO3 with respect to mass and thickness changes and electrical resistance. With increasing density of CaZrO3 sample, better compatibility at 823 K was observed. In case of a low density sample, Li introduced inside of the sample through the opening channel removed the grains itself to increase the corrosion rate to 30 μm/year, while the rate was 11 μm/year in case of high-density sample. CaZrO3 samples containing excess of ZrO2 showed significant decrease of their compatibility at 673 K, for the micro ZrO2 phase, which is unstable in lithium, may be corroded selectively. Thus, the fabrication of high-density coating with Ca to Zr composition ratio being 1 to 1 is considered to be the key ingredient for the corrosion-resistance.