Deformation of plasma sprayed thermal barrier coatings

The deformation behavior of thermally sprayed partially stabilized zirconia (PSZ) coatings are investigated using Hertzian indentation and four-point bend testing, with in situ acoustic emission monitoring. The experimental d eformation curves, together with the corresponding acoustic emission respon ses and the fracture properties of the material are used in defining the de formation characteristics of the coating (ceramic overlay with metallic bon d coat where applicable) and substrate composite system. Experiments are ai med in examining the influence of the bond coat and the coating properties on the form of deformation. Substrate temperature and pauses during sprayin g are demonstrated to strongly effect the coating properties and the result ing fracture/failure characteristics of the composite system.