阅读说明：本技术 一种测试热防护陶瓷涂层隔热性能的方法 (Method for testing heat insulation performance of thermal protection ceramic coating ) 是由 范薇 雷丽军 李斌茂 张磊 张翼 苏铁熊 于 2021-09-29 设计创作，主要内容包括：本发明涉及一种测试热防护陶瓷涂层隔热性能的方法,通过对热防护陶瓷涂层表面快速加热保温同时进行冷却并实时记录陶瓷涂层表面温度和金属基体背面温度；对只有合金粘接层的涂层表面快速预加热保温同时对金属基体背面进行冷却,实时记录合金粘接层的涂层表面温度和金属基体背面温度,通过调节氧气流量使上述两个金属基体背面温度一致,此时合金粘接层的涂层表面温度实际温度即为上述记录温度,稳态条件下的陶瓷涂层表面温度和合金粘接层的涂层表面温度之差即为热防护陶瓷涂层的实际隔热温度。本发明的一种测试热防护陶瓷涂层隔热性能的方法,可以快速、准确地测试热防护陶瓷涂层隔热性能,研究涂层实际服役过程中隔热温度的变化。(The invention relates to a method for testing the heat-insulating property of a thermal protection ceramic coating, which comprises the steps of rapidly heating and preserving the heat of the surface of the thermal protection ceramic coating, simultaneously cooling, and recording the surface temperature of the ceramic coating and the back temperature of a metal matrix in real time; the method comprises the steps of rapidly preheating and preserving heat of the surface of a coating layer only with an alloy bonding layer, simultaneously cooling the back of a metal substrate, recording the temperature of the surface of the coating layer with the temperature of the back of the metal substrate in real time, adjusting the flow of oxygen to enable the temperatures of the backs of the two metal substrates to be consistent, wherein the actual temperature of the surface of the coating layer with the alloy bonding layer is the recorded temperature, and the difference between the temperature of the surface of the ceramic coating layer and the temperature of the surface of the coating layer with the alloy bonding layer under a steady state condition is the actual heat insulation temperature of the thermal protection ceramic coating layer. The method for testing the heat-insulating property of the thermal protection ceramic coating can quickly and accurately test the heat-insulating property of the thermal protection ceramic coating and research the change of the heat-insulating temperature in the actual service process of the coating.)

1. A method for testing the heat-insulating property of a thermal protection ceramic coating is characterized by comprising the following steps of;

the surface of the thermal protection ceramic coating is rapidly heated and insulated, and simultaneously cooled, and the surface temperature of the ceramic coating and the back temperature of the metal matrix are recorded in real time; the method comprises the steps of rapidly preheating the surface of a coating only with an alloy bonding layer, preserving heat, simultaneously cooling the back of a metal substrate, recording the temperature of the surface of the coating of the alloy bonding layer and the temperature of the back of the metal substrate in real time, adjusting the oxygen flow to enable the temperatures of the backs of the two metal substrates to be consistent, wherein the actual temperature of the surface of the coating of the alloy bonding layer is the recorded temperature, and the difference between the surface temperature of the ceramic coating and the surface temperature of the coating of the alloy bonding layer under a steady state condition is the actual heat insulation temperature of the thermal protection ceramic coating.

2. The method for testing the thermal insulation performance of a thermal protective ceramic coating according to claim 1, comprising the following steps:

(1) rapidly heating the surface with the thermal protection ceramic coating to a target temperature of 700-₁And the temperature T of the back surface of the metal substrate₂；

(2) Rapidly preheating the surface of the alloy bonding coating to a target temperature of 500-1300 ℃ by using an oxygen-propane flame gun, preserving the heat for 150-300 seconds, and cooling the back surface of the metal matrix by using compressed air with a certain flow rate while preheating; simultaneously, the non-contact first and second online infrared thermometers are used for respectively recording the surface temperature T of the coating in real time₃And the temperature T of the back surface of the metal substrate₄Adjusting the oxygen flow through an oxygen pressure reducing valve to ensure that the temperature T of the back surface of the metal substrate only with the alloy bonding layer₄The temperature T of the back surface of the metal matrix with the thermal protection ceramic coating₂At the same time, T₃The actual temperature of the surface of the alloy bonding coating is obtained;

(3) the temperature curve data is taken, and the surface temperature T of the ceramic coating under the steady state condition₁And the actual temperature T of the surface of the alloy bonding coating₃The difference is the actual insulation temperature of the thermal protection ceramic coating.

3. The method for testing the thermal insulation performance of a thermal protective ceramic coating according to claim 2, wherein the metal substrate is a nickel-based superalloy, a stainless steel, an aluminum alloy, a magnesium alloy, or the like, and is applicable to a variety of metal substrates.

4. The method for testing the heat-insulating property of the thermal protection ceramic coating according to claim 2, wherein the temperature measuring range of the first infrared thermometer is 250-1650 ℃, and the temperature measuring range of the second infrared thermometer is 250-1400 ℃.

5. The method for testing the thermal insulation performance of the thermal protection ceramic coating according to claim 2, wherein the compressed air flow for cooling the back surface of the metal substrate is 20-60L-min^-1And ensuring that the flow of the compressed air in the steps (1) and (2) is constant in a single measurement.

6. The method for testing the thermal insulation performance of the thermal protective ceramic coating according to claim 2, wherein the steady state condition of the step (3) is a state that the surface temperature change in the heat preservation process of the step (1) and the step (2) is less than 20 ℃ and the heat preservation time is more than or equal to 150 s.

Technical Field

The invention belongs to the technical field of measurement of heat insulation temperature of a thermal protection coating, and particularly relates to a method for testing the heat insulation performance of a thermal protection ceramic coating.

Background

The thermal protection coating system mainly comprises a metal matrix, an alloy bonding layer and a ceramic coating, wherein the thermal protection coating is a low-heat-conduction and anti-oxidation functional coating deposited on the surface of the metal matrix, can be used for reducing the service temperature of a heated part and prolonging the service life of the heated part, and has important application value in core hot-end parts of aircraft engines, high-power diesel engines and the like.

The heat insulation capability is a key index for measuring the performance of the thermal protection coating, and the heat insulation temperature is the difference between the actual surface temperature of the ceramic coating and the interface temperature of the ceramic coating and the alloy bonding layer. The higher the heat insulation temperature of the ceramic coating is, the lower the service temperature of the surface of the metal matrix is correspondingly, and the service life of the metal matrix is prolonged. Therefore, a fast, accurate, non-destructive measurement of the insulation temperature is essential.

The method for testing the heat insulation temperature of the thermal protection coating at present mainly comprises the steps of heating a coated substrate and a non-coated substrate to a target temperature by using a high-temperature furnace, testing the back temperatures of the coated substrate and the non-coated substrate by using a welded thermocouple, and defining the back temperature difference of the coated substrate and the non-coated substrate as the heat insulation temperature of the coating, wherein the method has the defects that the actual service temperature of an adhesive layer cannot be accurately obtained firstly, because a heated surface is tested at the same temperature, but the surface temperature of an alloy adhesive layer is greatly different from the surface temperature of the thermal protection coating in the actual service process, and the heat insulation performance difference of the coating at different service temperatures is large, so the accuracy of the method is relatively low; secondly, the high temperature furnace has longer temperature rise time, great temperature regulation difficulty and lower test efficiency. The patent application No. 201310688002.X, application publication No. CN104713897A discloses a method for testing the surface performance of a thermal protection coating, which comprises heating the surface of the thermal protection coating by using a laser beam with variable intensity, cooling the sample, repeating the steps until the number of cycles reaches a specified number, measuring the temperature value of each temperature measuring point required in the experiment process, obtaining an average difference value, wherein the average difference value is the data of the surface temperature of the thermal protection coating changing along with time obtained by infrared temperature measurement, and the temperature data of a thermocouple at the joint interface of the thermal protection coating and a substrate changing along with time, taking the data of the two as a difference at the same time point, taking the average value to obtain the thermal insulation temperature of the coating when the surface temperature is at a certain value, and obtaining the thermal insulation temperature by taking the difference between the surface temperature of the thermal protection coating and the joint interface temperature of the thermal protection coating and the substrate, the method has the advantages that the temperature of the bonding interface of the alloy bonding layer and the matrix is obtained, the method also has the defect that the actual service temperature of the bonding layer cannot be accurately obtained, because the heated surface is tested at the same temperature, but the surface temperature of the alloy bonding layer and the surface temperature of the thermal protection coating have larger difference in the actual service process, and the heat insulation performance difference of the coating is larger at different service temperatures, so the method has relatively lower accuracy; therefore, it is necessary to develop a method for rapidly and accurately measuring the heat insulation temperature of the thermal protection coating ceramic layer.

Disclosure of Invention

The invention aims to provide a method for testing the heat insulation performance of a thermal protection ceramic coating, in order to test the heat insulation performance of the surface layer of the thermal protection ceramic coating more quickly and accurately and research the change of the heat insulation temperature in the actual service process of the coating.

In order to achieve the purpose, the invention adopts the following technical scheme:

a method for testing the heat-insulating property of a thermal protection ceramic coating is characterized by comprising the following steps of;

the surface of the thermal protection ceramic coating is rapidly heated and insulated, and simultaneously cooled, and the surface temperature of the ceramic coating and the back temperature of the metal matrix are recorded in real time; the method comprises the steps of rapidly preheating and preserving heat of the surface of a coating layer only with an alloy bonding layer, simultaneously cooling the back of a metal substrate, recording the temperature of the surface of the coating layer with the temperature of the back of the metal substrate in real time, adjusting the flow of oxygen to enable the temperatures of the backs of the two metal substrates to be consistent, wherein the actual temperature of the surface of the coating layer with the alloy bonding layer is the recorded temperature, and the difference between the surface temperature of the ceramic coating layer and the surface temperature of the coating layer with the alloy bonding layer under a steady state condition is the actual heat insulation temperature of the thermal protection ceramic coating layer.

The method for testing the heat insulation performance of the thermal protection ceramic coating specifically comprises the following steps:

(1) rapidly heating the surface with the thermal protection ceramic coating to the target temperature of 700-₁And the temperature T of the back surface of the metal substrate₂；

(2) Rapidly preheating the surface of the alloy bonding coating to a target temperature of 500-1300 ℃ by using an oxygen-propane flame gun, preserving the heat for 150-300 seconds, and cooling the back surface of the metal matrix by using compressed air with a certain flow rate while preheating; simultaneously, the non-contact first and second online infrared thermometers are used for respectively recording the surface temperature T of the coating in real time₃And the temperature T of the back surface of the metal substrate₄Adjusting the oxygen flow through an oxygen pressure reducing valve to ensure that the temperature T of the back surface of the metal substrate only with the alloy bonding layer₄The temperature T of the back surface of the metal matrix with the thermal protection ceramic coating₂At the same time, T₃The actual temperature of the surface of the alloy bonding coating is obtained;

(3) the temperature curve data is taken, and the surface temperature T of the ceramic coating under the steady state condition₁And the actual temperature T of the surface of the alloy bonding coating₃The difference is the actual insulation temperature of the thermal protection ceramic coating.

Preferably, the metal matrix can be nickel-based high-temperature alloy, stainless steel, aluminum alloy, magnesium alloy and the like, and is suitable for various metal matrixes.

Preferably, the temperature measuring range of the first infrared thermometer is 250-1650 ℃, and the temperature measuring range of the second infrared thermometer is 250-1400 ℃.

Preferably, the flow rate of the compressed air for cooling the back surface of the metal substrate is 20-60 L.min^-1And ensuring that the flow of the compressed air in the steps (1) and (2) is constant in a single measurement.

Preferably, the steady state condition of step (3) is a state that the surface temperature change is less than 20 ℃ and the holding time is more than or equal to 150s in the holding process of step (1) and step (2).

The invention has the following beneficial effects:

(1) according to the method, the real service working condition of the thermal protection ceramic coating is simulated through the operation of heat preservation and heating and simultaneous cooling, the surface temperature is enabled to reach a stable state, the test heat insulation temperature is relatively accurate, and the heat insulation temperature is the temperature difference in the heat preservation process.

(2) The tested heat insulation temperature is accurate, and the testing method can directly obtain the real temperature of the surface of the alloy bonding coating.

(3) The testing method is simple, the temperature adjusting speed is high, the response of the testing temperature change on the surface of the coating and the back of the metal matrix is high, and the testing efficiency is high.

(4) The method has no damage to the sample, and belongs to non-contact measurement, so that the requirements on the thickness, the diameter and other dimensions of the matrix sample are low; the temperature test response is fast, and is different from the traditional test method, and the application does not need to weld a thermocouple, does not need to process samples such as punching, and eliminates the influence of pores in a matrix and the like on the heat insulation temperature.

Drawings

FIG. 1 is a schematic diagram of the thermal insulation performance test of a thermal protective ceramic coating used in the present invention;

FIG. 2 is a graph showing the results of two kinds of samples with respect to the heat insulating temperature curve.

In the figure: 1-a first online infrared thermometer; 2-a second on-line infrared thermometer, 3-a sample with a thermal protection ceramic coating, 4-an oxygen-propane flame gun, 5-a compressed air nozzle and 6-an alloy bonding coating sample.

Detailed Description

The invention is explained in further detail below with reference to the examples and the figures, the steps are as follows:

as shown in fig. 1, the method for testing the thermal insulation performance of the thermal protection ceramic coating specifically comprises the following steps: (1) rapidly heating the sample 3 with the thermal protection ceramic coating to a target temperature by adopting an oxygen-propane flame gun 4 and ensuringThe temperature is kept for a certain time, and the back of the metal matrix is cooled by compressed air sprayed by a compressed air nozzle 5 with a certain flow rate in the heating process; simultaneously respectively recording the surface temperature T of the ceramic coating with thermal protection in real time by using a first online infrared thermometer 1 and a second online infrared thermometer 2 which are in non-contact₁And the temperature T of the back surface of the metal substrate₂；

(2) Rapidly preheating the surface of a sample 6 only with the alloy bonding coating to a target temperature by using an oxygen-propane flame gun, preserving heat, and cooling the back of the metal matrix by using compressed air sprayed by a compressed air nozzle 5 with a certain flow rate while preheating; simultaneously, the non-contact first online infrared thermometer 1 and the second online infrared thermometer 2 are utilized to respectively record the surface temperature T of the alloy bonding coating in real time₃And the temperature T of the back surface of the metal substrate₄Adjusting the oxygen flow through an oxygen pressure reducing valve to ensure that the temperature T of the back surface of the metal matrix with the alloy bonding coating₄The temperature T of the back surface of the metal matrix with the thermal protection ceramic coating₂At the same time, T₃The actual temperature of the surface of the alloy bonding coating is obtained;

(3) finally, the temperature curve data is taken, and T under the steady state condition₁And T₃The difference is the actual insulation temperature of the thermal protection ceramic coating.

Further, the metal substrate may be a nickel-based superalloy, stainless steel, aluminum alloy, magnesium alloy, or the like.

Further, the target temperature in the step (1) is 700-.

Further, the temperature measuring range of the first online infrared thermometer is 250-1650 ℃, and the temperature measuring range of the second online infrared thermometer is 250-1400 ℃.

Further, the compressed air flow for cooling the back surface of the metal matrix in the steps (1) and (2) is 20-60 L.min^-1And the flow of the compressed air is ensured to be constant in a single measurement.

Further, the steady state condition of the step (3) refers to a state that the surface temperature change is less than 20 ℃ and the heat preservation time is more than or equal to 150s in the heat preservation process of the step (1) and the step (2).

Example 1

Firstly, an oxygen-propane flame gun is adopted to quickly heat a thermal protection ceramic coating sample with the thickness of 2.5 mm and the diameter of 25.4 mm, the metal matrix of which is magnesium alloy, to 700 ℃, and the temperature is kept for 240S, and the utilization flow of the back of the metal matrix is 40 L.min in the heating process^-1The compressed air is cooled, and simultaneously the non-contact first online infrared thermometer 1 and the non-contact second online infrared thermometer 2 are used for respectively recording the surface temperature T of the thermal protection ceramic coating in real time₁And the temperature T of the back surface of the metal substrate₂；

Then, an oxygen-propane flame gun is used for quickly preheating the surface of a magnesium alloy sample only provided with the alloy bonding coating to about 500 ℃, the temperature is kept for 250S, and the utilization flow rate of the back surface of the metal matrix in the preheating process is 40L-min^-1Cooling the compressed air; simultaneously, the non-contact first online infrared thermometer 1 and the second online infrared thermometer 2 are utilized to respectively record the surface temperature T of the alloy bonding coating in real time₃And the temperature T of the back surface of the metal substrate₄Adjusting the oxygen flow through an oxygen pressure reducing valve to ensure that the temperature T of the back surface of the metal substrate only with the alloy bonding coating₄The temperature T of the back surface of the metal matrix with the thermal protection ceramic coating₂At the same time, T₃The actual temperature of the surface of the alloy bonding layer is obtained;

finally, the temperature curve data is taken, and T under the steady state condition₁(707. + -. 8 ℃ C.) and T₃The difference (399 +/-10 ℃) is the actual heat insulation temperature of the thermal protection ceramic coating and is 308 +/-9 ℃.

Example 2

Firstly, an oxygen-propane flame gun is adopted to quickly heat a thermal protection ceramic coating sample with the thickness of 3mm and the diameter of 50 mm, the substrate of which is aluminum alloy, to 900 ℃, and the temperature is kept for 150 seconds, and 60 L.min is utilized for the back of the metal substrate in the heating process^-1The compressed air is cooled, and simultaneously the non-contact first online infrared thermometer 1 and the non-contact second online infrared thermometer 2 are used for respectively recording the thermal protection ceramic in real timeTemperature T of the coating surface₁And the temperature T of the back surface of the metal substrate₂；

Then, an oxygen-propane flame gun is used for quickly preheating the surface of the aluminum alloy sample only provided with the alloy bonding coating to 700 ℃, the temperature is kept for 150 seconds, and the back of the metal matrix is heated for 60L-min in the preheating process^-1Cooling the compressed air; simultaneously, the non-contact first online infrared thermometer 1 and the second online infrared thermometer 2 are utilized to respectively record the surface temperature T of the alloy bonding coating in real time₃And the temperature T of the back surface of the metal substrate₄Adjusting the oxygen flow through an oxygen pressure reducing valve to ensure that the temperature T of the back surface of the metal substrate only with the alloy bonding coating₄The temperature T of the back surface of the metal matrix with the protective ceramic coating₂At the same time, T₃The actual temperature of the surface of the alloy bonding coating is obtained;

by taking the tested sample heat insulation temperature curve, T under the steady state condition₁(903. + -. 12 ℃ C.) and T₃The difference of (583 +/-8 ℃) is the actual heat insulation temperature of the thermal protection ceramic coating, and is 320 +/-10 ℃.

Example 3

Firstly, an oxygen-propane flame gun is adopted to quickly heat a thermal protection ceramic coating sample with the metal matrix of stainless steel, the thickness of the sample is 1.1 mm, the diameter of the sample is 30mm, the sample is heated to 1000 ℃, the temperature is kept for 300s, and the utilization flow rate of the back of the metal matrix is 20 L.min in the heating process^-1The compressed air is cooled, and simultaneously the non-contact first online infrared thermometer 1 and the non-contact second online infrared thermometer 2 are used for respectively recording the surface temperature T of the thermal protection ceramic coating in real time₁And the temperature T of the back surface of the metal substrate₂；

Then, an oxygen-propane flame gun is used for quickly preheating the surface of a stainless steel sample only provided with the alloy bonding coating to 700 ℃, the temperature is kept for 250S, and the utilization flow rate of the back surface of the metal matrix in the preheating process is 20 L.min^-1Cooling the compressed air; simultaneously respectively recording the surface temperature T of the coating in real time by using a first online infrared thermometer 1 and a second online infrared thermometer 2 which are in non-contact₃And the temperature T of the back surface of the metal substrate₄Adjusting oxygen flow rate by oxygen pressure reducing valve to make only alloy stickTemperature T of back surface of coated metal substrate₄The temperature T of the back surface of the substrate with the protective ceramic coating₂At the same time, T₃The actual temperature of the surface of the alloy bonding coating is obtained;

finally, the temperature curve data is taken, and T under the steady state condition₁(1011. + -. 9 ℃ C.) and T₃The difference of (775 +/-7 ℃) is the actual heat insulation temperature of the thermal protection ceramic coating, and is 236 +/-8 ℃.

Example 4

Firstly, an oxygen-propane flame gun is adopted to quickly heat a thermal protection ceramic coating sample with a substrate of nickel-based superalloy, the thickness of the sample is 0.5 mm, the diameter of the sample is 45mm to 1500 ℃, the temperature is kept for 280 s, and the utilization flow of the back of the metal substrate is 30 L.min in the heating process^-1The compressed air is cooled, and simultaneously the non-contact first online infrared thermometer 1 and the non-contact second online infrared thermometer 2 are used for respectively recording the surface temperature T of the thermal protection ceramic coating in real time₁And the temperature T of the back surface of the metal substrate₂；

Then, an oxygen-propane flame gun is used for quickly preheating the surface of a nickel-based high-temperature alloy sample only provided with the alloy bonding coating to 1300 ℃, the temperature is kept for 300 seconds, and the flow rate of the oxygen-propane flame gun is 30L-min^-1Cooling the compressed air; simultaneously, the first online infrared thermometer 1 and the second online infrared thermometer 2 are utilized to respectively record the surface temperature T of the thermal protection ceramic coating in real time₃And the temperature T of the back surface of the metal substrate₄Adjusting the oxygen flow through an oxygen pressure reducing valve to ensure that the temperature T of the back surface of the substrate with the alloy bonding coating is only₄The temperature T of the back surface of the substrate with the protective ceramic coating₂At the same time, T₃The actual temperature of the surface of the alloy bonding coating is obtained;

finally, the temperature curve data is taken, and T under the steady state condition₁(1512. + -. 11 ℃ C.) and T₃The difference of (1290 +/-13 ℃) is the actual heat insulation temperature of the thermal protection ceramic coating, and is 222 +/-12 ℃.

Example 5

Firstly, an oxygen-propane flame gun is adopted to ensure that the thickness of a substrate made of nickel-based superalloy is 0.4mm,Rapidly heating the sample with the thermal protection ceramic coating with the diameter of 60mm to 1350 ℃, preserving the heat for 230 s, and utilizing the flow of 45L-min on the back surface of the metal matrix in the heating process^-1The compressed air is cooled, and simultaneously the non-contact first online infrared thermometer 1 and the non-contact second online infrared thermometer 2 are used for respectively recording the surface temperature T of the thermal protection ceramic coating in real time₁And the temperature T of the back surface of the metal substrate₂；

Then, an oxygen-propane flame gun is used for quickly preheating the surface of a nickel-based high-temperature alloy sample only provided with the alloy bonding coating to 1150 ℃, the temperature is kept for 240S, and the utilization flow rate of the back of the metal matrix in the preheating process is 45L-min^-1Cooling the compressed air; simultaneously, the first online infrared thermometer 1 and the second online infrared thermometer 2 are utilized to respectively record the surface temperature T of the thermal protection ceramic coating in real time₃And the temperature T of the back surface of the metal substrate₄Adjusting the oxygen flow through an oxygen pressure reducing valve to ensure that the temperature T of the back surface of the substrate with the alloy bonding coating is only₄The temperature T of the back surface of the substrate with the protective ceramic coating₂At the same time, T₃The actual temperature of the surface of the alloy bonding coating is obtained;

finally, the temperature curve data is taken, and T under the steady state condition₁(1362. + -. 11 ℃ C.) and T₃The difference of (1140 +/-13 ℃) is the actual heat insulation temperature of the thermal protection ceramic coating, and is 222 +/-12 ℃.

The above description is only an example of the present invention, and not intended to limit the scope of the invention, and all equivalent changes and modifications made in the claims and the specification should be included within the scope of the present invention.