Compatibility of insulating ceramic materials with liquid breeders

The development of ceramic coating is one of the most important subjects in liquid blanket R and D. The compatibility of candidate ceramic materials (Y2O3, Al2O3, MgO, 3Al2O3-MgO, AlN-BN and BN) with liquid metal breeders such as metallic lithium and lithium-lead alloy (Lil7-Pb83) was investigated at 773 K up to 5 ms with the change in insulating property. Al2O3 and 3Al2O3-MgO were severely corroded and dissolved or broken by lithium, while MgO was corroded uniformly with a moderate rate (e.g. 27 μm for 4.8 ms). The most thermodynamically stable Y2O3 was a little corroded and showed a slight increase in electrical conductivity. On the other hand, all the ceramic materials were not corroded at all by Lil7-Pb83, as predicted from a thermodynamical analysis. AlN-BN and BN corroded by lithium became more fragile because impurities included in the specimens were dissolved in lithium. (orig.)