The influence of feedstock powders on the CGS deposition efficiency of bond coats for TBCs

Thermal barrier coatings (TBCs) are ceramic coatings used to isolate turbine blades from the hot gas coming from the engine. A bond coat (BC) is placed between the ceramic top coat and the vane so as to improve adhesion and extend TBCs' lifetime. This study is focused on BC production using CGS. It is well-known that the particle size distribution of powders used for cold gas spray (CGS) deposition is one of the most important parameters to take into account in order to achieve a well-deposited and well-bonded coating. Because of this, three CoNiCrAlY powders were analyzed, two of which were experimental (AE10086/AE10087) while the other was commercial (AMDRY 9951). The powders were sprayed under the same spray conditions using CGS technology and the resultant coatings compared. The results reveal that feedstock powders characteristics greatly influence the capacity to obtain a thick, homogeneous, non-porous coating, in an efficient way. (C) 2014 Elsevier B.V. All rights reserved.