Thermal barrier coating ( TBC) consisting of a NiCoCrAlY bond coat ( BC) and a ZrO2-8 wt. % Y2O3 topcoat ( TC) was fabricated on the nickel-base superalloy by air plasma spray ( APS) . The BC was treated by supersonic fine particle bombarding ( SFPB) . Thermal cyclic failure and residual stress in thermally grown oxide ( TGO) scale were studied by SEM with EDS and ruby fluorescence spectroscopy ( RFS) . As shown in the results,after treated by SFPB,thickening of TGO was relatively slow,which reduced the level of growth stress. The TBC with SFPB treatment was still remained well undergoing 350 times of thermal cycle. However,after thermal cycle with the same times,the separation of TC was observed in TBC without SFPB treatment. The residual stress analysis by RFS showed that the residual stress of SFPB-treated TBC increased with the increasing number of thermal cycle. The residual stress of conventional TBC reached a value of 650 MPa at 350 times of cycle and that of SFPB-treated TBC only reached 532 MPa at 400 times of cycle. The BC with SFPB treatment after 400 times of cycle was analyzed by RFS,the high stress value was not observed in local thickened region of TGO. Thermal cycling resistance of TBC can be improved by the SFPB technology.
The effect of TGO （ thermally grown oxide ） growth based on typical interface morphology on residual stresses distribution in thermal barrier coatings was analyzed by ABAQUS software. TGO oxidation kinetics, the relationship between TGO thickness and thermal cycles number, and typical morphology including sinusoid , cone and groove were considered in the calculation process. 13 FEM （finite element method） models with different TGO thickness based on uniform interface morphology were established for analysis. The calculation results show that TCC （ top ceramic coating ） /TGO and TGO/BC （bond coating） interface residual stresses are affected significantly by inter）hce morphology and TGO thickness, both of which increase significantly with TGO growth ; the stress level in TCC/TGO interface is greater than that of TGO/BC interface ; each morphology peak exhibits tensile stress while each valley exhibits compressive stress in TCC/TGO interface; stress concentrates in such locations as each morphology center with sharp angle and the stress reaches the maximal value at the tip of each angle.
