Hot corrosion of (Sm _1-xYb _x) ₂Zr ₂O ₇ (x=0, 0.5, 1.0) ceramics against V ₂O ₅ Molten salt in air at 800°C

(Sm _1-xYb _x) ₂Zr ₂O ₇ (x=0, 0.5, 1.0) powders synthesized by chemical-coprecipitation and calcination method were pressureless-sintered at 1700°C for 10 h in air. Molten V ₂O ₅ reacts with (Sm _1-xYb _x) ₂Zr ₂O ₇ to form m-ZrO ₂ and rare-earth vanadates at 800°C. The thickness of corrosion scales was investigated to evaluate the hot corrosion resistance of (Sm _1-xYb _x) ₂Zr ₂O ₇. The hot corrosion resistance of (Sm _1-xYb _x) ₂Zr ₂O ₇ against molten V ₂O ₅ increases with increasing Yb content. The hot corrosion mechanisms were proposed based on phase diagrams and the difference in hot corrosion resistance was discussed on terms of basicity of (Sm _1-xYb _x) ₂Zr ₂O ₇ ceramics.