Thermal Barrier Coatings (TBCs) Produced by Air Plasma Spray: Repair by Grinding and Waterjet (WJ) Processes

TBCs (Thermal Barrier Coatings) are multilayer structures usually consisting of a ceramic layer, known as top coat, arranged on a connecting layer, known as bond coat, which, in turn, is arranged above the substrate to protect. These structures are applied in hot section parts of gas turbine engines for providing thermal protection. During the component life, some oxidation and/or wear phenomena can occur, therefore the TBC is generally removed and then reapplied. To simplify the manufacturing process making it more cost effectiveness, the aim of this work is to study the possibility to repair a TBC system by removing the only damaged layer by using non-conventional processes and analyzing in detail the morphological roughness to ensure a good adhesion between the layers.