Thermal-Barrier Coatings for Advanced Gas-Turbine Engines

Abstract

Ceramic thermal-barrier coatings (TBCs) have received increasing attention for gasturbine engine applications. The advantages of using TBCs include increased fuel efficiency by allowing higher gas temperatures and improved durability and reliability from lower component temperatures. As illustrated in Figure 1, TBCs can provide effective heat insulation to engine components, thus allowing higher operating temperatures and reduced cooling requirements. Atypical two-layer TBC system consists of a porous ZrO2-Y2O3 ceramic top coat and an oxidation-resistant metallic bond coat. These TBC systems can be applied to the metal substrate either by plasma spray or by electron-beam physical vapor deposition (EB-PVD) techniques.