Effect of APS flash bond coatings and curvature on TBC performance on rod specimens
The addition of an air plasma sprayed (APS) “flash” bond coating layer on top of a high velocity oxy-fuel (HVOF) bond coating greatly extended the lifetime of APS yttria stabilized zirconia (YSZ) thermal barrier coatings (TBC) on rod specimens of superalloy 247 tested using 100-h cycles in air+10%H2O at 1100 °C. The flash bond coatings of both NiCoCrAlY and NiCoCrAlYHfSi powder were compared to an HVOF-only and a vacuum plasma sprayed (VPS) NiCoCrAlYHfSi bond coating. Here, the flash coatings appear to form a mixed oxide-metal zone, which likely inhibits crack formation and therefore extends lifetime compared to conventional bond coatings. The underlying dense HVOF layer appeared to act as a source of Al for this intermixed zone and prevented the oxide from penetrating deeper into the bond coating. Residual stress in the thermally-grown Al2O3 scale was measured using photo-luminescence piezospectroscopy (PLPS) as a function of time for each coating variation, including a comparison of concave and convex surfaces on a specially designed rod.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE Office of Fossil Energy (FE)
- Grant/Contract Number:
- AC05-00OR22725
- OSTI ID:
- 1561649
- Alternate ID(s):
- OSTI ID: 1561412
- Journal Information:
- Surface and Coatings Technology, Vol. 378, Issue C; ISSN 0257-8972
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Similar Records
Effect of Air Plasma Sprayed Flash Bond Coatings on Furnace Cycle Lifetime of Disks and Rods
Effect of APS flash bond coatings on furnace cycle lifetime of disks and rods