This article examines the high-temperature oxidation of silica-forming ceramics under constant temperature and cyclic conditions. The effects of water vapor, impurities, and molten salts are discussed. The article describes the oxidation and corrosion of silica-forming composites, oxide ceramics, non-silica forming nitrides, carbides, and borides. The performance of environmental barrier coatings by material type is also discussed. The article also explains the effects of oxidation and corrosion on the mechanical properties of ceramic-matrix composites. It concludes with information on high-temperature applications, wear properties, and the microscopic analyses of advanced ceramics.
Alloys intended for use in high-temperature environments rely on the formation of a continuous, compact, slow-growing oxide layer for oxidation and hot corrosion resistance. This article focuses on the issues related to high-temperature oxidation of superalloys used in gas turbine engine applications. It discusses general methodologies to evaluate oxidation resistance of materials. The article describes the performance characteristics of superalloys, single-crystal superalloys and other high-temperature materials such as refractory metals and ceramics. It discusses hot corrosion of superalloys and airfoil degradation due to deposits resulting from ingested particles or sand. The article concludes with a discussion on the limitations of testing techniques and life prediction.