Hot corrosion behavior of Y ₃ NbO ₇ as thermal barrier coating material

Y ₃ NbO ₇ , a simple ternary oxide, has shown excellent high-temperature stability lately. The growing need for more durable thermal barrier coatings in extreme conditions underscores the importance of exploring materials that can resist challenges like hot corrosion. This study examines the thermal barrier properties and hot corrosion characteristics of Y ₃ NbO ₇ . Thermal diffusivity and the coefficient of thermal expansion were measured using laser flash technique and dilatometry respectively. The interaction with the thermally grown oxide (TGO) was evaluated by exposing the Y ₃ NbO ₇ powder to Al ₂ O ₃ at high temperatures. To demonstrate the viability of the as-synthesized powder for coating deposition, a plasma sprayed TBC architecture was developed using the Y ₃ NbO ₇ powder. The behavior of as-deposited coating under thermal shock was studied using thermal cycling test. Hot corrosion study was performed on Y ₃ NbO ₇ pellets in a species composed of 32 wt% Na ₂ SO ₄ and 68 wt% V ₂ O ₅ at 900°C. The corrosion products were examined with X-ray Diffraction and Scanning Electron Microscopy. The corrosion phenomenon was found to align with the Lewis acid-base theory, where Y ₂ O ₃ was preferred over Nb ₂ O ₅ for the acidic activity of V ₂ O ₅ .