Oxidation/degradation of MCrAlY Coatings

Abstract One of the major reasons coatings are used in internal combustion engines is to enhance the oxidation/corrosion resistance in contaminated corrosive environments. Such atmospheres are often encountered in diesel and utility gas turbines. Aircraft gas turbines are usually subjected to simple oxidation conditions, since the environment is generally cleaner and the operating temperatures higher than in ground‐based engines. The primary source of corrosive species (sulfur, vanadium and even sodium) is in the fuel; but airborne salts are a concern, particularly for those engines operating close to to ocean. Diesel engines in ships may run on fuels containing up to 5% S, 400 ppm V, and 100 ppm Na.