COMPATIBILITY OF YTTRIA (Y2O3) WITH LIQUID LITHIUM

Compatibility of sintered specimens and plasma sprayed coating specime ns of Y2O3 with liquid lithium was tested at 773 K. No configuration c hange was observed for the sintered specimens with a slight increase o f thickness for 1419 h. Lithium-yttrium complex oxide (LiYO2) was form ed on the surface, and the inner part changed to gray or black nonstoi chiometric Y2O3-x with lower electrical resistivity. The plasma spraye d coating specimens were severely attacked by liquid lithium with or w ithout applied electric field. Lithium penetrated into the coating lay er through small cracks and reacted on Y2O3 to form LiYO2, which has a different density from Y2O3 and is more brittle than Y2O3. It is conc luded that Y2O3 has a possibility as a ceramic coating material for li quid blankets if it can be made into a dense coating on the surface of piping materials.