Thermal corrosion behavior of Yb4Hf3O12 exposed to Na2SO4+V2O5 molten salt

The thermal corrosion behavior and corrosion mechanism of Yb 4 Hf 3 O 12 ceramics in Na 2 SO 4 +V 2 O 5 molten salt corrosion environment were investigated. The results show that the corrosion behavior of Yb 4 Hf 3 O 12 in Na 2 SO 4 +V 2 O 5 corrosive environment at 900 °C, 1000 °C and 1100 °C is not obvious, and the new phases of (Yb, Hf)VO 4 and t-HfO 2 are generated after the thermal corrosion, in which (Yb, Hf)VO 4 exhibits both rod-like and cubic morphology. Meanwhile, a reaction layer consisting of (Yb, Hf)VO 4 solid solution and t-HfO 2 was formed inside the ceramic, which effectively blocked the penetration of molten salt . Furthermore, the thickness of the reaction layer increases with the corrosion temperature owing to the fact that the rate of penetration of the molten salt is greater than the rate of filling of the pores.