High-pressure turbine blade NiCrAlYSi/YSZ thermal barrier coating removal method

Abstract

The invention belongs to the technical field of coatings, and particularly to a high-pressure turbine blade NiCrAlYSi / YSZ thermal barrier coating removal method. According to the high-pressure turbineblade NiCrAlYSi / YSZ thermal barrier coating removal method, the method comprises the following steps of removing a thermal barrier coating of a high-pressure turbine blade by using a dry sand blowing+ chemical solution method, firstly, forming a chemical solution diffusion channel on a YSZ surface layer through dry sand blowing; then reacting with TGO through a chemical solution to remove the YSZ ceramic surface layer, reacting the chemical solution with a NiCrAlYSi anti-oxidation bottom layer, removing the NiCrAlYSi anti-oxidation bottom layer, completely removing the coating, and not causing any corrosion to the blade substrate. According to the high-pressure turbine blade NiCrAlYSi / YSZ thermal barrier coating removal method, the blade thermal barrier coating can be removed multiple times without affecting the mechanical property of the substrate, and the service life of the blade is greatly prolonged.

Description

technical field [0001] The invention belongs to the technical field of coatings, and in particular relates to a method for removing a NiCrAlYSi / YSZ thermal barrier coating of a high-pressure turbine blade. Background technique [0002] Aeroengine and gas turbine blades serve in harsh environments, and their surfaces need to be coated with protective coatings to improve the service life and reliability of parts. The working blade of the high-pressure turbine of a certain type of engine is a hollow air-cooled blade, and the material of the blade body is a directionally solidified superalloy. In order to improve its anti-oxidation and corrosion performance. [0003] With the improvement of the performance of the engine, the working blades of the high-pressure turbine are subjected to higher and higher temperatures. The coated thermal barrier coating is prone to local shedding and blockage under the condition of high temperature and high load. After long-term use, the blades E...

AI Technical Summary

Problems solved by technology

[0003] With the improvement of the performance of the engine, the working blades of the high-pressure turbine are subjected to higher and higher temperatures. The coated thermal barrier coating is prone to local shedding and blockage under the condition of high temperature and high load. After long-term use, the blades Environmental deposits such as CMAS are deposited on the surface, and the heat insulation and oxidation resistance capabilities are significantly reduced, making the blades unusable, resulting in the need to repair or replace the thermal barrier coating of almost all high-pressure turbine working blades after the first turning period

[0004] At present, the commonly used method is to remove the coating by dry sand blowing, but due to the uneven sand blowing force and the uneven thickness of the coating, there are a large number of unremoved or over-removed phenomena in the removal process of the coating, which is seriously serious. Affects recoating and reuse of blade coatings

[0005] The TGO (thermal growth oxide layer, mainly composed of Al2O3) between the NiCrAlYSi anti-oxidation layer and the YSZ ceramic surface layer is difficult to remove by chemical methods, and chemical methods are easy to cause damage to the blade substrate