Hot corrosion behavior of BaLa₂Ti₃O₁₀ thermal barrier ceramics in V₂O₅ and Na₂SO₄ + V₂O₅ molten salts

BaLa₂Ti₃O₁₀ ceramics for thermal barrier coating (TBC) applications were fabricated, and exposed to V₂O₅ and Na₂SO₄ + V₂O₅ molten salts at 900 °C to investigate the hot corrosion behavior. After 4 h corrosion tests, the main reaction products resulting from V₂O₅ salt corrosion were LaVO₄, TiO₂, and Ba₃V₄O₁₃, whereas those due to Na₂SO₄ + V₂O₅ corrosion consisted of LaVO₄, TiO₂, BaSO₄ and some Ba₃V₄O₁₃. The structures of reaction layers on the surfaces depended on the corrosion medium. In V₂O₅ salt, the layer was dense and had a thickness of 8-10 μm. While in Na₂SO₄ + V₂O₅ salt, it had a ~15 μm porous structure and a dense, thin band at the bottom. Beneath the dense layer or the band, no obvious molten salt was found. The mechanisms by which the reaction layer forms were discussed.