The use of ceramic coatings on gas turbine engine hot section airfoils has the potential for major improvements in engine performance, durability, and fuel economy, for both industrial/utility and flight engine applications. Major improvements in the durability of ceramic thermal barrier coatings for turbine engine application have been made in both hot corrosion resistance and ceramic thermal cycle fatigue. This paper describes the early history, as well as, recent success in the development of mechanically segmented or “microcolumnar” structured coatings that are produced by electro-beam, physical vapor deposition (P. V.D.) of ceramic materials on metallic turbine airfoil components. Due to their columnar structure, these coatings accommodate the thermal cycle stresses that develop between the ceramic coating and the metal substrate due to their very different coefficients of thermal expansion. The hot corrosion, erosion, and thermal fatigue protection properties are also discussed.

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