Inelastic deformation behavior of thermal barrier coatings exposed at a high-temperature environment

¹ Materials Science Research Lab., Central Research Institute of Electric Power Industry, 2-6-1 Nagasaka, Yokosuka-shi, Kanagawa-ken, Japan
² School of Aerospace, Xi’an Jiaotong University, Xi’an 710049, China

^a e-mail : marai@criepi.denken.or.jp

Abstract

Thermal barrier coatings (TBCs) are usually deposited onto the surface of the high-temperature component such as gas turbine, in order to protect it from a hightemperature environment. Coating stress generated by such a high-temperature brings serious damages in TBCs in service. For predicting numerically it, it is necessary to develop the constitutive equation suite to plasam-sprayed TBCs. Previous studies have made clear that the freestanding ceramic coat peeled from TBC coated substrate deforms nonlinearly with a mechanical loading, however the results there have been restricted to the test done using as-sprayed sample. In this study, effect of deposition parameter and high-temperature exposure condition on stress-strain curve of the freestanding ceramic coating sample was examined. The associated deformation process was discussed with the microstructure changes observed after performing a bending test for the exposed sample.