Abstract
HVOF spraying is used to produce NiCoCrAlYRe deposits that serve as adhesive layers for plasma-sprayed thermal barrier coatings. This paper investigates the influence of HVOF spray parameters on the structure and properties of the adhesion-promoting layers. Spray parameters are optimized to produce high layer densities with low degrees of oxidation and a surface roughness comparable to that of the thermal barrier coatings. A vacuum-sprayed layer with similar composition is also examined. Following the application of the TBC, the oxidized layers are characterized based on microstructure, oxide layer thickness, proportion of the NiAl phase, and imperfections at the boundary layer. It is observed that the less expensive HVOF layer offers the same protective properties as a vacuum plasma sprayed bond coat. Paper includes a German-language abstract.
