Thermal barrier coatings for turbine airfoils

Thermal barrier coatings (TBCs) for turbine airfoils in high performance engines represent an advanced materials technology that has both performance and durability benefits. Foremost of the benefits of TBCs is the reduction of heat transferred into air-cooled components. Other potential benefits include increased resistance to hot corrosion, erosion and oxidation. To achieve these benefits, however, the TBC system must be reliable. Process-microstructure relationships are considered to be key factors in the achievement of TBC durability. Microstructural requirements for strain tolerance for both plasma-sprayed and electron beam physically vapor-deposited TBC systems are discussed. The effect of processing on bond coating oxidation and durability is also reviewed.