Microstructure Characterization of TBC Layers of Gd2Zr2O7 Type

The paper presents microstructural assessment results of thermal barrier coatings deposited by plasma spraying of powders with the formula Gd2Zr2O7. Standard parameters of the air plasma spraying (APS) method were used. A visual assessment of layers and quantitative and qualitative characteristics of an outer ceramic layer with the laser microscopy method were performed. Roughness and other geometric parameters describing the TBC surface were determined. Phase composition analysis of the ceramic layer was also carried out. Microstructural assessment of the layers for meeting the assessment criteria of the ceramic coatings was also carried out. The bondcoat and ceramic layer porosity assessment was performed. The TBC system general quality was assessed for presence of cracks, delamination and massive porosity. It was found that the new type of layers obtained meet the quality requirements used for assessment of the conventional layers obtained by spraying 8YSZ zirconia.