Measurement of Young's modulus and Poisson's ratio of thermal barrier coatings

In gas turbines, thermal barrier coatings (TBCs) applied by air plasma spraying are widely used to lower the temperature of hot components. To analyze the characteristics of TBCs such as residual stress, bond strength, fracture toughness, and crack propagation ratio, the Young's modulus and Poisson's ratio are important parameters. For TBC is a brittle and thin film, it is desirable to evaluate those properties while the coatings are bonded to a substrate. An atmospheric plasma spray MCrAlY bond coat and Yttria stabilized zirconia (YSZ) top coat are deposited onto a nickel-base superalloy GH150 substrate. The Young's modulus and Poisson's ratio are measured by cantilever beam bending with NDI. The method will be developed to test the Young's modulus and Poisson ratio of other multilayer systems.