Method for testing heat insulation performance of thermal protection ceramic coating

Abstract

The invention relates to a method for testing the heat insulation performance of a thermal protection ceramic coating. The surface of the thermal protection ceramic coating is rapidly heated and subjected to heat preservation, cooling is conducted at the same time, and the surface temperature of the ceramic coating and the back temperature of a metal matrix are recorded in real time; and the surface of a coating only provided with an alloy bonding layer is rapidly pre-heated and subjected to heat preservation, cooling is conducted on the back surface of the metal matrix, the coating surface temperature of the alloy bonding layer and the back surface temperature of the metal matrix are recorded in real time, and the oxygen flow is adjusted to ensure that the back surface temperatures of the two metal matrixes are consistent, at the moment, the actual coating surface temperature of the alloy bonding layer is the recorded temperature, and the difference between the ceramic coating surface temperature under the steady state condition and the coating surface temperature of the alloy bonding layer is the actual heat insulation temperature of the thermal protection ceramic coating. According to the method for testing the heat insulation performance of the thermal protection ceramic coating, the heat insulation performance of the thermal protection ceramic coating can be rapidly and accurately tested, and the change of the heat insulation temperature in the actual service process of the coating is researched.

Description

technical field [0001] The invention belongs to the technical field of measuring the heat insulation temperature of a heat protection coating, in particular to a method for testing the heat insulation performance of a heat protection ceramic coating. Background technique [0002] The thermal protective coating system mainly includes a metal substrate, an alloy bonding layer and a ceramic coating. The thermal protective coating is a low thermal conductivity and anti-oxidation functional coating deposited on the surface of the metal substrate, which can be used to reduce the service life of heated parts. It has important application value in core hot-end components such as aero-engines and high-power diesel engines. [0003] Heat insulation capability is a key indicator to measure the performance of thermal protective coatings. The heat insulation temperature refers to the difference between the actual temperature of the surface layer of the ceramic coating and the interface t...

AI Technical Summary

Problems solved by technology

[0004] The current method of testing the heat insulation temperature of thermal protective coatings is mainly to use a high-temperature furnace to heat the coated substrate and the uncoated substrate to the target temperature, use a welded thermocouple to measure the backside temperature of the two substrates, and define the temperature difference between the two backsides The first disadvantage of this method is that the actual service temperature of the bonding layer cannot be accurately obtained, because the heating surface is tested at the same temperature, but the surface temperature of the alloy bonding layer is different from that in the actual service process. The surface temperature of the thermal protective coating has a large difference, and the thermal insulation performance of the coating varies greatly under different service temperatures, so the accuracy of this method is relatively low; High difficulty and low test efficiency

The application number is 201310688002.X, and the patent application document with the application publication number CN104713897A is a method for testing the surface performance of thermal protective coatings. Heating the surface of the thermal protective coating, and then cooling the sample, repeating this to the specified number of cycles, measuring the temperature values ​​of each temperature measuring point required during the experiment, and obtaining the average difference, the average difference is The time-varying data of the surface temperature of the thermal protective coating obtained by infrared temperature measurement, and the temperature data of the thermocouple at the bonding interface between the thermal protective coating and the substrate. When the surface temperature reaches a certain value, the thermal insulation temperature of the coating is the thermal insulation temperature obtained by calculating the difference between the surface temperature of the thermal protective coating and the bonding interface temperature between the thermal protective coating and the substrate, that is, the alloy bonding layer and the substrate are obtained Combined with the temperature of the interface, the disadvantage of this method is that it is impossible to accurately obtain the actual service temperature of the bonding layer, because the heating surface is tested at the same temperature, but the surface temperature of the alloy bonding layer is related to the thermal protective coating during actual service. There is a large difference in surface temperature, and the thermal insulation performance of the coating varies greatly under different service temperatures, so the accuracy of this method is relatively low; therefore, it is necessary to develop a method that can quickly and accurately measure the thermal protection coating ceramic layer The method of heat insulation temperature is especially necessary

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