Thermal barrier coating with thermal radiation property as well and preparation method of thermal barrier coating

Abstract

The invention discloses a thermal barrier coating with thermal radiation property. The thermal barrier coating is a SiO2 plugging surface layer which is prepared by on the surface of a ZrO2 coating after sol-gel by using a dipping-pull method and is high in finishing degree and low in roughness. On one hand, a function of increasing the thermal radiation rate of the surface of the coating is achieved, on the other hand, a function of filling pores of the thermal resisting coating is achieved, and the pores in the surface of the coating are made up. The composite coating of a novel structure can be used for improving the thermal protection property of the surface of a titanium alloy at high temperature, and has important values on protection of high-speed aircraft shells.

Description

technical field [0001] The invention belongs to the technical field of thermal spraying, and relates to a thermal barrier coating with thermal radiation performance and a preparation method thereof. Background technique [0002] When a high-speed aircraft flies at high speed for a long time, the outer surface of the cavity and the atmosphere undergo intense friction to generate heat, which brings about a serious aerodynamic heating effect. The surface temperature of hyper-vehicle cavity can reach over 800°C for a short time. On the one hand, the mechanical properties of the metal-based structural materials that constitute the main load-bearing components of the cavity will decline rapidly. On the other hand, this type of aircraft has strict requirements on the structural weight and effective loading volume, and the thickness and weight of the thermal protection layer must be reduced as much as possible. A large-area, thin-thick thermal protective coating is prepared on the ...

AI Technical Summary

Problems solved by technology

However, although the traditional thermal barrier coating has low thermal conductivity, due to the low blackness of the zirconia layer on the coating surface, it is in a thermally translucent state (the so-called translucent state means that part of the heat is absorbed by the ceramic coating and conducted inward, and the other Part of it convects with the external environment and radiates to the atmosphere), the external thermal radiation is very small (the thermal radiation rate is only 0.3-0.6), and most of the heat will be conducted to the substrate along the direction perpendicular to the coating, and in the ceramic layer attenuation is absorbed (see figure 2 )

After reaching a steady state after a certain period of time, the temperature at the junction of the thermal barrier coating and the substrate is only 0-40°C lower than that of the coating surface, resulting in the heat resistance performance of conventional thermal barrier coatings failing to meet the requirements of the titanium alloy material on the outer surface of the super aircraft cavity. protection needs

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