Abstract:Cyclic and discontinuous high-temperature oxidation behavior and the residual stress of thermal growth oxide (TGO) of modified aluminide bond coating with different Pt contents in nickel base superalloys for TBC (thermal barrier coating) application were studied in air at 1100 °C. It was found that the continuous and compact α-Al2O3 layers formed over Pt modified aluminide bond coating in the process of the cyclic oxidation, and the two Pt-modified aluminide coatings with different Pt contents had similar morphology and thickness. Thermal growth stress of α-Al2O3 layers increased quickly during initial discontinuous oxidation and a peak value of the residual stress appeared when the coating oxidation was prolonged to 100 h; at the same time, the high content of Pt promoted the diffusion of element Al, resulting in changing the mechanical property of the coating, and exhibiting a relatively great residual stress in the coating with high content of Pt, but the high content of Pt had no influence upon the change trend of the residual stress curve of α-Al2O3 layers. In addition, γ′-Ni3Al phase usually grew along β-NiAl grain boundary, while the high content of Pt would refine coating grains, resulting in γ′-Ni3Al growth in the way of dispersion distribution, and thus a net-like high velocity diffusion channel for element Al would form