Al2O3 /Al2O3 ceramic matrix composites (CMC) are candidate materials for high-temperature applications like in gas turbine blades. As water vapor corrosion of Al2O3 /Al2O3 CMC is a major issue, the application of suitable environmental barrier coatings (EBC) is inevitable. Besides the density a good adhesion of the EBC is a crucial aspect for providing an effective barrier against the combustion atmosphere.
This work examines the suitability of different EBC materials (e.g. Y2O3, Y3Al5O12, zirconates) for use by air plasma spraying (APS) on an Al2O3/Al2O3-CMC. The effects of different spraying parameters (temperature, distance, power) on the resulting coating properties were studied as well as the chemical compatibility of these coating-substrate-systems at the interface. Moreover various substrate surface treatments were tested to increase the adhesion. The adhesion was then characterized by different methods, like indentation tests and thermal cycling.