{"id":4120,"date":"2024-09-23T11:29:58","date_gmt":"2024-09-23T03:29:58","guid":{"rendered":"https:\/\/turbineblade.net\/?p=4120"},"modified":"2025-05-19T11:37:22","modified_gmt":"2025-05-19T03:37:22","slug":"analysis-of-the-causes-of-thermal-barrier-coating-peeling-off-aero-engine-turbine-blades","status":"publish","type":"post","link":"https:\/\/turbineblade.net\/id\/analysis-of-the-causes-of-thermal-barrier-coating-peeling-off-aero-engine-turbine-blades\/","title":{"rendered":"Analysis of the causes of thermal barrier coating peeling off aero engine turbine blades"},"content":{"rendered":"

Aiming at the phenomenon of thermal barrier coating peeling of engine working turbine blades<\/a> during test run, this study found out the root cause of coating peeling during the use of the product through macroscopic observation, scanning electron microscope morphology analysis and energy spectrum microcomponent analysis, combined with the investigation results of the whole process process, and put forward suggestions for improvement of the processing technology of subsequent parts.<\/p>

Electron beam physical vapor deposition (EB-PVD) thermal barrier coating has been widely used in aero engine blades, and has become an indispensable key technology for aero engine blades. EB-PVD technology is a technology that uses a high energy density electron beam to heat the material to be vaporized into a water-cooled crucible in a vacuum environment, so that it reaches a molten gasification state, and evaporates to the substrate under the action of a deflecting magnetic field to condense into a coating. There are many kinds of EB-PVD thermal barrier coating structures, including double layer structure, gradient structure and multilayer structure, of which the most widely used is the double layer thermal barrier coating. The double-layer thermal barrier coating is composed of a ceramic top layer and a metal bonding layer. The ceramic layer mainly plays the role of heat insulation, and the metal bonding layer mainly plays the role of alleviating the thermal expansion mismatch between the matrix and the ceramic layer, and improving the resistance of the matrix to high temperature oxidation corrosion. In the actual working environment, the interface between the bond layer and the ceramic layer will form an oxide layer, the main component of which is \u03b1-Al2O3, thus inhibiting the further diffusion of O elements into the coating . The main challenge facing the application of thermal barrier coatings is the durability of the coating, especially the coating resistance to spalling, which is influenced by many factors, such as the stress state in the ceramic layer, the microstructure of the bond layer, the thickness and stress state of the TGO layer, and the fracture resistance of the various interfaces between the bond layer and TGO. At present, it is recognized that the oxidation of the bond layer is the key factor to determine the life of the thermal barrier coating.<\/p>

1. Test process and results<\/strong><\/p>

1.1 Macroscopic observation of coating spalling morphology<\/strong><\/p>

9 h after the engine test, it was found that the coating on the surface of the working blade was spalling, and the spalling area exceeded the standard requirements. Its macro morphology is shown in Figure 1.<\/p>

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1.2 Comparative analysis of coating before and after use<\/strong><\/p>

In order to further analyze the causes of leaf coating peeling, the service leaves were compared with the new leaves of the same batch, and the coating components and microstructure of the blade tips and middle parts of each leaf were compared and analyzed according to the leaf positions shown in Figure 2.<\/p>

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