Development of Tantalum Pentoxide Coatings by Chemical Vapor Deposition

Thermochemical considerations clearly indicate a need for the protection of SiC and Si 3 N 4 materials from HC1‐ and Na 2 SO 4 ‐induced corrosion. Ta 2 O 5 has been identified as a material which may be suitable for such a protective coating. Thermodynamic calculations have indicated a range of temperatures, pressures, and reactant concentrations under which Ta 2 O 5 coatings may be formed as a single phase by chemical vapor deposition. Ta 2 O 5 coatings exhibiting a range of microstructures were obtained experimentally.