204 Influence of stress on growth of an oxide at an interface between a thermal barrier coating and a bond coating on a gas turbine blade
Details
In order to investigate the influence of stress on growth of an oxide at an interface between a thermal barrier coating (TBC) and a bond coating, a creep test was carried out. The TBC of 300-μm thick Yttria stabilized Zirconia (YSZ) and 100-μm thick CoNiCrAlY was plasma sprayed on the surface of the Ni base superalloy substrate. The creep test was performed under various conditions of temperature and axial stress. It was found that the TGO grew following a parabolic law and it consisted of an Al_2O_3 layer. Both the composition and the shape of the oxide did not change regardless of the applied stress at temperatures below 950℃. However, the thickness of the TGO clearly increased with increases of the applied stress and temperature. It was about 23% when the applied stress was increased from 0MPa to 205MPa at 900℃ and was about 29% when the stress was increased from 0MPa to 150MPa at 950℃.
