Evolution of Residual Stresses in PS-PVD Thermal Barrier Coatings on Thermal Cycling
Plasma spray-physical vapor deposition (PS-PVD) is an advanced technique to fabricate quasi-columnar structured thermal barrier coatings (TBCs) with excellent thermal cyclic lifetime. In this study, PS-PVD TBCs were investigated via burner rig test. The residual stresses in both of the topcoat layer and the thermally grown oxide (TGO) scale were measured non-destructively using Raman spectroscopy and Cr3+ photoluminescence piezo-spectroscopy, respectively. Evolution of the microstructures and distribution of residual stresses in such kind structured TBCs before and after thermal cycling test were investigated. The accumulated tensile stress in the as-sprayed ceramic topcoat changed to compressive state after 100 cycles and then gradually increased. In addition, the mapping compressive stresses in the TGO measured through the ceramic topcoat surface decreased rapidly and then essentially maintained at a relatively stable state with further testing. Moreover, the pre-heating of the bondcoat could significantly affect the stress distribution in the TGO, in contrast, no obviously influence on the stresses in the YSZ topcoat.
Keywordsphotoluminescence piezo-spectroscopy (PLPS) plasma spray-physical vapor deposition (PS-PVD) residual stresses thermal barrier coatings (TBCs) thermal cyclic test
This work was jointly supported by the National natural Science Foundation (NSFC) under the Grant No. 51671208, Natural Science Foundation of Shanghai (No. 17ZR141Z200) and Laboratory foundation of Chinese Academy of Sciences (Grant No. 16S084).
- 11.S. Rezanka, G. Mauer, and R. Vaßen, Improved Thermal Cycling Durability of Thermal Barrier Coatings Manufactured by PS-PVD, J. Therm. Spray Technol., 2012, 23(1/2), p 182-189Google Scholar