Study of the high temperature oxidation performance of Thermal Barrier Coatings with HVOF sprayed bond coat and incorporating a PVD ceramic interlayer

The performance of an intermediate Cr₃C₂ ceramic layer applied by PVD between the bond coat and the ceramic top coat in a TBC system was evaluated. The thickness of the transitional layer was kept around 1–2 μm. Two substrate materials and two distinct bond coats were combined in the tests. High Velocity Oxygen Fuel (HVOF) and Atmospheric Plasma Spraying (APS) were used respectively for bond coat and top coat deposition. Isothermal oxidation tests were performed at 1000 °C in static air atmosphere. Thermal grown oxide (TGO) was measured and correlated to the exposition times. Results are discussed in terms of the TGO growth rate and changes in residual stresses. The results suggest an improvement in the oxidation resistance of the bond coat because of the presence of the intermediate layer.