Suspension Sprayed YSZ Thermal Barrier Coatings on INCONEL®718 Aerospike Manufactured by Laser Powder Bed Fusion

Additive Manufacturing (AM) processes offer geometrical freedom to design complex shaped parts that cannot be manufactured with conventional processes. This leads to new applications including aerospace propulsion systems where the Ni-superalloy based material has to withstand high operating temperatures.

In this contribution the thermo-cycling performance of suspension sprayed YSZ TBC coatings on additively manufactured Inconel^®718 substrates with different surface conditioning state, i.e. as-built, sandblasted and milled was investigated. The TBC coatings were applied using suspension plasma spraying (SPS) with commercially available water- and ethanol-based YSZ suspensions. Furnace cycling tests (FCT) at 1100°C, 1300 °C, and 1500 °C were applied to coating systems until failure occurred. The performance of the coatings was mainly influenced by the coating morphology and FCT test conditions and less by the surface conditioning of the AM substrates. Finally, an aerospike engine demonstrator with a columnar-like thermally sprayed YSZ TBC coating on the spike contour was manufactured and tested in various operating conditions.