Degradacja kompozytowych powłok tbc typu la2zr2o7+8ysz podczas utleniania w temperaturze 1100°c

The degradation process of La2Zr2O7 + 8YSZ composite thermal barrier coatings (TBC) was presented in this paper. These systems were deposited by air plasma spraying (APS) on AMS 5599 alloy and on a NiCrAlY bond-coat. A scope of tests consisting of isothermal oxidation in air atmosphere at 1100°C for 500 h was performed. Detailed microstructural tests were carried out after 2, 10, 48, 175 and 500 hours of exposure. These tests included microstructure evaluation of a ceramic layer in all coating types, while particularly taking into account phenomena, which occur in a TGO (thermally growth oxide) zone. Evaluation of TGO zone growth was worked out and obtained results were compared with data for conventional TBC layers, which were deposited from 8YSZ powders and La2Zr2O7 respectively. Keywords: TBC, La zirconates, degradation, TGO zone References.