Anisotropic Behavior of Water Vapor Corrosion of Rutile TiO2 at High Temperature

Water vapor corrosion behavior of rutile TiO2 was examined at 1773 K in 30 mass% H2O environment. The corrosion rate for this sample was 2.2 × 10−4 kg·m−2·h under this experimental conditions. Anisotropic corrosion behavior was recognized in the planes that are parallel to c-axis. Many rectangular shaped etch-pits were generated at the grain surfaces. The corrosion proceeded from the side wall of the etch-pits and then, terrace fields were grown on the grain surface. Ridge-shaped microstructure was observed on the side wall of the terrace owing to the anisotropic corrosion.