Thick thermal barrier coating with long thermal cycle life and preparation method of thick thermal barrier coating

Abstract

The invention relates to the field of high-temperature functional ceramic coating materials, in particular to a thick thermal barrier coating with a long thermal cycle life. The thick thermal barrier coating sequentially comprises a metal bonding layer and a ceramic layer from bottom to top on the surface of a substrate, the ceramic layer is a nano lanthanum phosphate-8YSZ composite coating, and the mass fraction of lanthanum phosphate in the ceramic layer is 1-10%. According to the thick thermal barrier coating with the high thermal cycle life, the 8YSZ thermal barrier coating is modified by adding nano lanthanum phosphate, and the content of lanthanum phosphate is regulated and controlled, so that the fracture toughness and strain tolerance of the coating are effectively improved, the thermal shock resistance of the coating is effectively improved, the thermal cycle life of the coating is effectively prolonged, and controllable preparation of the thick thermal barrier coating is achieved.

Description

technical field [0001] The invention belongs to the field of high-temperature functional ceramic coating materials, in particular to a thick thermal barrier coating with high thermal cycle life and a preparation method thereof. Background technique [0002] Thermal barrier coating technology is a method of coating the surface of the base alloy with high temperature resistant, high heat insulation and corrosion resistant ceramic materials to improve the high temperature resistance, oxidation resistance and corrosion resistance of the base alloy and reduce the working temperature of the alloy surface. Thermal protection technology, thermal barrier coating is one of the effective ways to improve the performance of advanced aero-engines. Some data show that after the surface of the first-stage turbine blade of an advanced aero-engine is coated with a thermal barrier coating, the cooling air flow rate can be reduced by 50%, the specific fuel consumption can be reduced by 1% to 2%...

AI Technical Summary

Problems solved by technology

However, limited by the thickness of the coating, when the coating surface temperature is 1250 °C, the 500 μm 8YSZ coating can only reduce the metal surface temperature by about 150 °C (A Thibblin, S Jonsson, U Olofsson, Surface and Coatings Technology, 2018, 350 , 1-11; S Xie, C Song, Z Yu, etc., Journal of the European Ceramic Society, 2020, 41, 535-543), and a large amount of cold air must be used to cool down, which will inevitably lead to a decrease in the thrust-to-weight ratio of the engine, Reduced combustion efficiency

The increase in the thickness of the thermal barrier coating results in an increase in the thermal gradient stress across the thickness of the coating, resulting in higher thermal stress inside the coating material, leading to premature failure of the coating

In addition to thermal gradient stress, the higher the thickness, the greater the elastic strain energy stored inside the coating, which may cause cracks and propagation in the coating (S Ahmaniemi, P Vuoristo, T etc., Journal of the European Ceramic Society, 2004, 24(9), 2669-2679), resulting in coating failure

In addition, the main problem of thick thermal barrier coatings is that when subjected to thermal shock, the thermal cycle life of the coating decreases (HD Steffens, Z Babiak, M Gramlich, Journal of thermal spray technology, 1999, 8(4), 517 -522)

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