The aerospace industry is increasingly using the Additive Manufacturing (AM) to produce Nickel-based superalloy components with complex geometries. The use of this manufacturing technology is particularly focused on the development of hot-section components for gas turbine engines, which require increased efficiency. An increase in their operating temperatures could be achieved by developing cooling channels components using AM processes such as Electron Beam – Powder Bed Fusion (EB-PBF) and protecting them with Thermal Barrier Coatings (TBCs). Thermal Barrier Coatings have been used for several decades in the gas turbine industry to protect conventionally manufactured components from the high-temperature environment. The objective of this work is to evaluate the surface, the microstructure, and the functional properties of TBCs deposited on EB-PBF additive manufactured substrates.

In this study, Thermal Barrier Coatings were sprayed onto HAYNES®282® superalloy AM substrates manufactured by the EB-PBF process. For reference, Thermal Barrier Coatings sprayed onto HAYNES®282® forged substrates have also been prepared. The TBC bondcoats were sprayed by the High Velocity Air-Fuel (HVAF) process using NiCoCrAlY powder feedstock. Seven different spray runs were performed to deposit the TBC top-coats by the Suspension Plasma Spraying (SPS) process using different parameters and two different suspensions of 8wt.% Yttria-Stabilized Zirconia (8YSZ). Characterizations were then carried out on the samples.

The results obtained showed that the deposition of the bond-coats reduces the roughness and asperities of the AM substrates caused by the EB-PBF manufacturing method. The Thermal Barrier Coatings exhibit vertically cracked and columnar microstructures depending on the suspensions and spray parameters used. The TCF lifetimes obtained for the Thermal Barrier Coatings on the AM substrates were not lower than those achieved for the Thermal Barrier Coatings on the standard substrates. The deposition of Thermal Barrier Coatings on substrates made by Additive Manufacturing process results in microstructures similar to what could be obtained on conventional substrates.