Applied Surface Science, Vol.257, No.15, 6837-6842, 2011
Preparation and characteristics of three-layer YSZ-(YSZ/Al2O3)-YSZ TBCs
Novel three-layer YSZ-(YSZ/Al2O3)-YSZ (6 wt.% Y2O3 partially stabilized ZrO2) thermal barrier coatings (TBCs) were successfully prepared on Ni-based superalloy substrate using composite sol-gel and pressure filtration microwave sintering (PFMS) techniques. The coatings were evaluated for the cyclic oxidation resistance, thermal barrier effect and the presences of phases and microstructures. FE-SEM results indicate that the coatings were dense and crack-free. The coatings maintained their structural integrity when they were exposed at 1100 for 100 h. They exhibited superior oxidation resistance, spallation resistance and thermal insulation property compared with single-layer YSZ coatings. Moreover, the detailed mechanisms were discussed in order to understand the improved performance of the three-layer TBCs. (C) 2011 Elsevier B. V. All rights reserved.
Keywords:Laminated TBCs;Composite sol-gel;Cyclic oxidation resistance;Spallation resistance;Thermal barrier effect