High-temperature materials such as MCrAlY, aluminide, silicon-base environmental barrier, and
thermal barrier coatings, as well as nickel- and cobalt-based superalloys, ceramic matrix composites,
and ceramics are used in various corrosive environments. Materials that may be resistant to one
environment may be susceptible in other environments. The interaction of the protective oxide of the
given material changes as a function of a number of factors. The increasing desire to raise
temperatures in different high-temperature applications requires a thorough understanding of those
factors influencing passivity in order to develop and implement alternative, more corrosion-resistant
materials.
This paper will examine some of the factors that influence the interaction of high-temperature
materials with several corrosive species and offers observations and recommendations improve the
service life of these materials.