A thermal barrier coating thermal-oxygen coupling environmental damage performance detection system and method

Abstract

The present application provides a thermal barrier coating thermal oxygen coupling environment damage performance detection system and method, for solving the technical problems of low temperature rise rate of high temperature furnace heating, complex experimental process and low detection precision existing in the thermal barrier coating nondestructive detection based on high temperature furnace heating and acoustic emission technology. The thermal barrier coating damage performance detection system of the present application simulates the thermal shock effect of a specific heat flow on the thermal barrier coating specimen by laser, applies a bidirectional load to the thermal barrier coating specimen by a bidirectional four-cylinder testing machine, analyzes and judges the damage mode and damage position of the thermal barrier coating specimen by acoustic emission technology, and combines the strain of the surface of the thermal barrier coating specimen in the laser heating process and the real-time temperature of the front and back surfaces of the thermal barrier coating specimen in the laser heating process to realize real-time characterization of the damage degree of the thermal barrier coating specimen, and finally realize the internal crack nondestructive detection of the thermal barrier coating in the thermal oxygen coupling environment.

Description

Technical Field

[0001] This invention relates to thermal barrier coatings, and more particularly to a system and method for detecting thermal barrier coating damage performance in a thermo-oxygen coupled environment. Background Technology

[0002] Thermal barrier coating systems applied to critical components such as turbine blades in aero-engines can develop internal cracks under prolonged exposure to extreme environments such as hot combustion gas, centrifugal force, and film cooling, due to thermal mismatch, interfacial oxidation, and corrosion penetration. Non-destructive testing of crack initiation and propagation within thermal barrier coatings under thermo-mechanical-oxygen coupled environments is a prerequisite for studying the peeling mechanism of thermal barrier coatings under extreme conditions.

[0003] Currently, scholars both domestically and internationally have adopted a method combining high-temperature furnace heating and acoustic emission technology to achieve non-destructive testing of crack initiation and propagation modes in thermal barrier coatings under high-temperature cyclic heating conditions. However, this testing method uses traditional high-temperature furnace heating with a low heating rate, which cannot meet the requirements for high-temperature heating rates. Furthermore, the experiment requires the thermal barrier coating specimen to be repeatedly moved in and out of the high-temperature furnace, making the experimental process cumbersome and prone to generating noise for the acoustic emission testing device, thus affecting the testing accuracy. Summary of the Invention

[0004] The purpose of this invention is to solve the technical problems of low temperature rise rate of high temperature furnace heating, cumbersome experimental procedures, and noise that easily affects the detection accuracy of acoustic emission detection devices in the existing non-destructive testing of thermal barrier coatings based on high temperature furnace heating and acoustic emission technology. In order to provide a thermal barrier coating thermal-oxygen coupled environment damage performance testing system and method.

[0005] To achieve the above objectives, the technical solution provided by this invention is as follows:

[0006] A thermal barrier coating thermal-oxygen coupled environment damage performance testing system, wherein the thermal barrier coating specimen is a cross-shaped thermal barrier coating specimen, including a central region and four loading arms connected in the horizontal and vertical directions of the central region. Its special feature is that it includes a bidirectional four-cylinder testing machine, a laser, an acoustic emission detection unit, a non-contact strain measurement unit, a temperature acquisition unit, and an analysis unit.

[0007] The bidirectional four-cylinder testing machine is used to apply bidirectional prestress to the four loading arms of the thermal barrier coating specimen; the central region of the thermal barrier coating specimen is located in the output light path of the laser, and is used to heat the central region of the thermal barrier coating specimen by laser.

[0008] The acoustic emission detection unit includes four acoustic emission sensors and an acoustic emission instrument; the four acoustic emission sensors are respectively installed on the four loading arms of the thermal barrier coating specimen; the input end of the acoustic emission instrument is connected to the output end of the four acoustic emission sensors respectively, and is used to collect the acoustic emission signal of the thermal barrier coating specimen when the actuator applies prestress.

[0009] The non-contact strain measurement unit includes a camera, a filter, and a strain processing module. The camera is located on the side of the thermal barrier coating specimen away from the laser and is used to acquire speckle images of the thermal barrier coating specimen away from the laser at different heating temperatures. The filter is set at the front end of the camera and is used to filter out interference from high-temperature radiation from the surface of the thermal barrier coating specimen and stray light from the heating laser on the camera imaging. The input end of the strain processing module is connected to the output end of the camera and is used to obtain the strain on the surface of the thermal barrier coating specimen during laser heating based on the acquired speckle images.

[0010] The temperature acquisition unit is used to acquire the temperature of the front and back surfaces of the thermal barrier coating specimen during the laser heating process;

[0011] The input of the analysis unit is connected to the output of the acoustic emission instrument, the strain processing module, and the temperature acquisition unit, respectively. It is used to perform non-destructive testing on the internal cracks of the thermal barrier coating specimen based on the acoustic emission signal of the thermal barrier coating specimen during loading, the strain on the surface of the thermal barrier coating specimen during laser heating, and the temperature change of the front and rear surfaces of the thermal barrier coating specimen during laser heating.

[0012] Furthermore, the bidirectional four-cylinder testing machine includes a horizontal frame, a vertical frame perpendicularly intersecting the horizontal frame, four cylinders, four actuators, and four clamps respectively disposed at both ends of the horizontal frame and both ends of the vertical frame;

[0013] One end of each of the four actuators is connected to one end of each of the four cylinders near the center, and the other end is connected to each of the four clamps. The four clamps hold the ends of the four loading arms of the thermal barrier coating specimen. The four cylinders apply bidirectional prestress to the four loading arms of the thermal barrier coating specimen simultaneously through the four actuators.

[0014] Furthermore, it also includes a first collimating lens, a beam expander lens, and a second collimating lens;

[0015] The first collimating lens, the beam expanding lens, and the second collimating lens are sequentially arranged in the output light path of the laser. The output light of the laser is collimated and expanded by the first collimating lens, the beam expanding lens, and the second collimating lens in sequence to form a flat-top laser.

[0016] The central region of the thermal barrier coating specimen is located in the optical path of the flat-top laser, and is used to heat the central region of the thermal barrier coating specimen by means of the flat-top laser.

[0017] Furthermore, the temperature acquisition unit includes two dual-color thermometers and two infrared thermal imagers;

[0018] A dual-color thermometer and an infrared thermal imager are located on the side of the thermal barrier coating specimen closest to the laser, and another dual-color thermometer and an infrared thermal imager are located on the side of the thermal barrier coating specimen away from the laser. They are used to collect the temperature of the front and back surfaces of the thermal barrier coating specimen during the laser heating process through the infrared thermal imagers on both sides, and to calibrate and standardize the temperature collected by the corresponding infrared thermal imager through the dual-color thermometer.

[0019] The infrared thermal imager has a temperature measurement range of 0℃ to 650℃.

[0020] The measuring range of the dual-color thermometer is 300℃~3000℃.

[0021] Furthermore, reinforcing plates are respectively provided on the outer walls of the four loading arms of the thermal barrier coating specimen, and four clamps hold the ends of the four loading arms of the thermal barrier coating specimen through the reinforcing plates.

[0022] This invention also provides a method for detecting the thermal barrier coating's performance under thermal-oxygen coupled environmental damage, characterized by the following steps:

[0023] 1) Construct a thermal barrier coating thermal-oxygen coupled environmental damage performance testing system as described above;

[0024] 2】A high-temperature speckle pattern is prepared in the central region of the thermal barrier coating specimen on the side away from the laser, and the thermal barrier coating specimen with the prepared high-temperature speckle pattern is held on the four clamps of the testing machine;

[0025] 3】A bidirectional prestress of a certain load is applied to the thermal barrier coating specimen by an actuator, and an acoustic emission instrument is activated to continuously collect the acoustic emission signal of the thermal barrier coating specimen when the actuator applies the prestress; the central area of ​​the thermal barrier coating specimen is heated by a laser, and a tangential airflow is applied to the surface of the thermal barrier coating specimen.

[0026] 4】The temperature of the front and back surfaces of the thermal barrier coating specimen during the laser heating process is collected by the temperature acquisition unit. At the same time, the speckle image of the central area of ​​the thermal barrier coating specimen away from the laser is collected by the camera during the heating process. The acquisition results are sent to the strain processing module for processing to obtain the strain on the surface of the thermal barrier coating specimen during the laser heating process.

[0027] 5】The damage mode of the thermal barrier coating specimen is analyzed and judged by the acoustic emission signal collected in step 3; at the same time, the strain on the surface of the thermal barrier coating specimen during the laser heating process and the real-time temperature of the front and back surfaces of the thermal barrier coating specimen during the laser heating process are obtained in step 4 to characterize the degree of damage of the thermal barrier coating under different temperature rise trajectories, and complete the damage performance test of the thermal barrier coating specimen under the thermo-oxygen coupling environment.

[0028] Furthermore, in step 3, heating the central region of the thermal barrier coating specimen using a laser specifically involves:

[0029] Turn on the laser and use a constant power laser to uniformly heat the central area of ​​the thermal barrier coating specimen until the set irradiation time or temperature is reached.

[0030] Furthermore, in step 3, heating the central region of the thermal barrier coating specimen using a laser specifically involves:

[0031] The laser emitted from the laser is used to uniformly heat the central area of ​​the thermal barrier coating specimen. After heating to the set temperature, the laser emission is stopped. Once the temperature drops to room temperature, the central area of ​​the thermal barrier coating specimen is heated to the set temperature again by the emitted laser. This cycle is repeated until the set number of cycles is reached.

[0032] Furthermore, step 5 specifically includes:

[0033] 5.1】Filter out acoustic emission signals with a maximum response time greater than L / v from the acoustic emission signals collected in step 3, where L represents the distance from the acoustic emission sensor to the center of the thermal barrier coating specimen, and v represents the propagation speed of the acoustic emission signal on the thermal barrier coating specimen;

[0034] 5.2】Perform Fourier transform on the filtered acoustic emission signal, and compare the Fourier transformed acoustic emission signal with the cluster signal to determine the failure type of the thermal barrier coating specimen corresponding to the acoustic emission signal and obtain the damage mode of the thermal barrier coating specimen corresponding to the acoustic emission signal.

[0035] 5.3】The degree of thermal barrier coating damage H(t) under different temperature rise histories is obtained by the following formula:

[0036] H(t) = ε0 / ε(t)

[0037] Where ε0 is the strain on the surface of the thermal barrier coating specimen in the initial stage after the load is applied, ε(t) is the strain on the surface of the thermal barrier coating specimen during laser heating, and t is the real-time temperature of the front and back surfaces of the thermal barrier coating specimen during laser heating.

[0038] Furthermore, in step 3, the output power P of the laser... t Calculated using the following formula:

[0039] P t =αP0

[0040] Where P0 represents the simulated heat flux intensity; α represents the absorption coefficient of the laser energy on the surface of the thermal barrier coating specimen;

[0041] The tangential airflow velocity v applied to the surface of the thermal barrier coating specimen t Calculated using the following formula:

[0042] v t =ρ0v0 / ρ t

[0043] Where v0 represents the target airflow velocity to be simulated, ρ0 represents the target airflow density to be simulated, and ρ t This indicates the tangential airflow density applied to the surface of the thermal barrier coating specimen.

[0044] The advantages of this invention compared to the prior art are as follows:

[0045] 1. This invention provides a thermal barrier coating (TBC) damage performance testing system under thermo-mechanical-oxygen coupling environment. It uses a laser heating source to simulate the thermal shock effect of a specific heat flow on the coating, and a bidirectional four-cylinder testing machine as a mechanical loading device to apply bidirectional loads to the coating. Simultaneously, acoustic emission technology is used to analyze and judge the damage mode of the TBC specimen. Furthermore, by combining the strain on the surface of the TBC specimen during laser heating and the real-time temperature of the front and rear surfaces of the TBC specimen during laser heating, the degree of damage (initiation and evolution of internal cracks) of the TBC specimen is characterized in real time. Ultimately, this system achieves non-destructive testing of internal cracks in TBCs under complex, extreme high-temperature thermo-mechanical-oxygen coupling conditions. It has the advantages of high heating temperature, high temperature rise rate, and efficient acquisition of effect data, and is of great significance for the engineering application of TBCs at high temperatures.

[0046] 2. The present invention provides a thermal barrier coating thermal-oxygen coupled environment damage performance testing system, which can carry out non-destructive testing of internal cracks in thermal barrier coatings under constant heat flux heating experiments and simulated thermal cycling experiments using the same testing system.

[0047] 3. The present invention provides a method for detecting the thermal barrier coating damage performance in a thermo-oxygen coupled environment, which is simple, convenient and highly accurate, and can be widely used in the aerospace industry. Attached Figure Description

[0048] Figure 1 This is a schematic diagram of an embodiment of a thermal barrier coating thermal-oxygen coupled environmental damage performance testing system of the present invention (the cylinder and actuator of the bidirectional four-cylinder testing machine are not shown);

[0049] Figure 2This is a side view of an embodiment of a thermal barrier coating thermal-oxygen coupled environmental damage performance testing system according to the present invention.

[0050] The specific labeling in the attached diagram is as follows:

[0051] 1-Thermal barrier coating specimen; 101-Central region; 102-Loading arm; 103-Reinforcing sheet; 2-Clamp; 3-Laser; 4-First collimating lens; 5-Beam expander lens; 6-Acoustic emission sensor; 7-Acoustic emission instrument; 8-Camera; 9-Filter; 10-Dual-color thermometer; 11-Infrared thermal imager. Detailed Implementation

[0052] To make the advantages and features of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0053] like Figure 1 , Figure 2 As shown, a thermal barrier coating thermal-oxygen coupled environment damage performance testing system includes a bidirectional four-cylinder testing machine, a laser 3, a first collimating lens 4, a beam expander lens 5, a second collimating lens 12, an acoustic emission detection unit, a non-contact strain measurement unit, a temperature acquisition unit, and an analysis unit. The thermal barrier coating specimen 1 to be tested is a cross-shaped specimen, including a central region 101 and four loading arms 102 connected to the central region 101 in the horizontal and vertical directions.

[0054] The bidirectional four-cylinder testing machine includes a horizontal frame, a vertical frame perpendicularly intersecting the horizontal frame, four cylinders respectively located at both ends of the horizontal frame and both ends of the vertical frame, four actuators, and four clamps 2. One end of each actuator is connected to a cylinder near its center, and the other end is connected to each of the four clamps 2. These clamps collectively hold the ends of the four loading arms 102 of the thermal barrier coating specimen 1. The four cylinders, through the four actuators, simultaneously apply bidirectional prestress to the four loading arms 102 of the thermal barrier coating specimen 1. Preferably, reinforcing plates 103 are provided on the outer walls of the ends of the four loading arms 102 of the thermal barrier coating specimen 1. The four clamps 2 hold the ends of the four loading arms 102 of the thermal barrier coating specimen 1 through the reinforcing plates 103, which can effectively improve the clamping stability of the thermal barrier coating specimen 1.

[0055] The first collimating lens 4, the beam expander 5, and the second collimating lens 12 are sequentially arranged in the output light path of the laser 3. The output light of the laser 3 is collimated and expanded sequentially by the first collimating lens 4, the beam expander 5, and the second collimating lens 12 to form a flat-top laser. The central region 101 of the thermal barrier coating specimen 1 is located in the optical path of the flat-top laser and is used to heat the central region 101 of the thermal barrier coating specimen 1 by the flat-top laser.

[0056] The acoustic emission detection unit includes four acoustic emission sensors 6 and an acoustic emission instrument 7. The four acoustic emission sensors 6 are respectively installed on the four loading arms 102 of the thermal barrier coating specimen 1. The input end of the acoustic emission instrument 7 is connected to the output end of the four acoustic emission sensors 6 through waveguide wires, and is used to collect the acoustic emission signal of the thermal barrier coating specimen 1 when the actuator applies prestress.

[0057] The non-contact strain measurement unit includes a camera 8, a filter 9, and a strain processing module. The camera 8 is located on the side of the thermal barrier coating specimen 1 furthest from the laser 3, and is used to acquire speckle images (digital-image signals) of the side of the thermal barrier coating specimen 1 furthest from the laser 3 at different heating temperatures. The filter 9 is positioned at the front of the camera 8 to filter out interference from high-temperature radiation from the surface of the thermal barrier coating specimen 1 and stray light from the heating laser on the imaging of the camera 8. The input of the strain processing module is connected to the output of the camera 8, and is used to obtain the strain on the surface of the thermal barrier coating specimen during laser heating based on the acquired speckle images.

[0058] The temperature acquisition unit includes two dual-color thermometers 10 and two infrared thermal imagers 11. One dual-color thermometer 10 and infrared thermal imager 11 are located on the side of the thermal barrier coating specimen 1 closest to the laser 3, and the other dual-color thermometer 10 and infrared thermal imager 11 are located on the side of the thermal barrier coating specimen 1 furthest from the laser 3. This unit is used to acquire the temperature of the front and rear surfaces of the thermal barrier coating specimen 11 during the laser heating process using the infrared thermal imagers 11 on both sides, and to calibrate and standardize the temperatures acquired by the corresponding infrared thermal imagers 11 using the dual-color thermometers 10. Preferably, the temperature measurement range of the infrared thermal imager 11 is 0℃~650℃, and the measurement range of the dual-color thermometer 10 is 300℃~3000℃. The temperature in the area where their measurement ranges overlap is calibrated and standardized.

[0059] The analysis unit is set in the computer. The output of the acoustic emission instrument 7, the output of the strain processing module, and the output of the infrared thermal imager 11 are all connected to the input of the analysis unit. It is used to perform non-destructive testing on the internal cracks of the thermal barrier coating specimen 1 based on the acoustic emission signal of the thermal barrier coating specimen 1 during the loading process, the strain on the surface of the thermal barrier coating specimen 1 during the laser heating process, and the temperature change of the front and rear surfaces of the thermal barrier coating specimen 1 during the laser heating process.

[0060] This invention also provides a method for detecting the thermal barrier coating's performance under thermal-oxygen coupled environmental damage, specifically including the following steps:

[0061] 1】Build the above-mentioned thermal barrier coating thermal oxygen coupling environmental damage performance testing system.

[0062] 2】A high-temperature speckle pattern is prepared in the central region of the thermal barrier coating specimen 1 on the side away from the laser 3, and the thermal barrier coating specimen 1 with the prepared high-temperature speckle pattern is held on the four clamps 2 of the two-way four-cylinder testing machine.

[0063] 3) A prestress of a certain load is applied to the thermal barrier coating specimen 1 by an actuator, and the acoustic emission instrument 7 is activated to continuously collect the acoustic emission signal of the thermal barrier coating specimen 1 when the prestress is applied by the actuator. The central area of ​​the thermal barrier coating specimen 1 is heated by the laser 3. Specifically, when conducting a constant heat flow heating experiment, the laser heating power is set to a constant output power mode to uniformly heat the central area of ​​the thermal barrier coating specimen 1 until the irradiation time or temperature is reached, and then the laser emission is stopped. When conducting a simulated thermal cycle experiment, the central area of ​​the thermal barrier coating specimen 1 needs to be uniformly heated by the laser emitted by the laser 3. After heating to the set temperature, the laser emission is stopped. After the temperature drops to room temperature, the central area of ​​the thermal barrier coating specimen 1 is heated to the set temperature again by the emitted laser. This cycle is repeated until the set number of cycles is reached, and then the laser emission is stopped.

[0064] In order to simulate the cooling process of thermal barrier coating specimen 1 under strong convection conditions during the heating process, a tangential airflow was applied to the surface of thermal barrier coating specimen 1.

[0065] Among them, the output power P of laser 3 t Calculated using the following formula:

[0066] P t =αP0

[0067] Where P0 represents the simulated heat flux intensity; α represents the absorption coefficient of the thermal barrier coating specimen surface to laser energy, which can be obtained by looking up a table.

[0068] The tangential airflow velocity v applied to the surface of thermal barrier coating specimen 1 t Calculated using the following formula:

[0069] v t =ρ0v0 / ρ t

[0070] Where v0 represents the target airflow velocity to be simulated, ρ0 represents the target airflow density to be simulated, and ρ t This indicates the tangential airflow density applied to the surface of thermal barrier coating specimen 1.

[0071] 4) The temperatures of the front and rear surfaces of the thermal barrier coating specimen 1 during the laser heating process are collected by two infrared thermal imagers 11. At the same time, the speckle image of the central area of ​​the thermal barrier coating specimen 1 away from the laser 3 is collected by the camera 8 during the heating process, and the collected results are sent to the strain processing module for processing to obtain the strain on the surface of the thermal barrier coating specimen 1 during the laser heating process.

[0072] 5. Damage performance testing of thermal barrier coating specimen 1 under a thermo-oxygen coupling environment.

[0073] 5.1】Filter out acoustic emission signals with a maximum response time greater than L / v from the acoustic emission signals collected in step 3, where L represents the distance from the acoustic emission sensor 6 to the center of the thermal barrier coating specimen 1, and v represents the propagation speed of the acoustic emission signal on the thermal barrier coating specimen 1.

[0074] 5.2】The filtered acoustic emission signal is subjected to Fourier transform, and the clustering signal of the acoustic emission signal is obtained by existing technology. The Fourier transformed acoustic emission signal is then compared with the clustering signal to determine the failure type of the thermal barrier coating specimen 1 corresponding to the acoustic emission signal, and thus obtain the damage mode of the thermal barrier coating specimen 1.

[0075] 5.3】The degree of thermal barrier coating damage H(t) under different temperature rise histories is obtained by the following formula:

[0076] H(t) = ε0 / ε(t)

[0077] Where ε0 is the strain on the surface of thermal barrier coating specimen 1 in the initial stage after the load is applied, ε(t) is the strain on the surface of thermal barrier coating specimen 1 during laser heating, and t is the real-time temperature of the front and rear surfaces of thermal barrier coating specimen 1 during laser heating.

[0078] The above description is only used to illustrate the technical solutions of the present invention, and is not intended to limit them. For those skilled in the art, modifications can be made to the specific technical solutions described in the above embodiments, or equivalent substitutions can be made to some of the technical features. However, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions protected by the present invention.

Claims

1. A method for detecting the thermal barrier coating's performance under thermal-oxygen coupled environmental damage, characterized in that, Includes the following steps: 1】A thermal barrier coating thermal-oxygen coupled environment damage performance testing system is built for testing the thermal barrier coating specimen (1) thermal-oxygen coupled environment damage performance; the thermal barrier coating specimen (1) includes a central region (101) and four loading arms (102) connected in the horizontal and vertical directions of the central region (101). The thermal barrier coating thermal-oxygen coupling environment damage performance testing system includes a two-way four-cylinder testing machine, a laser (3), and an acoustic emission testing unit; the two-way four-cylinder testing machine includes a horizontal frame, a vertical frame perpendicularly intersecting the horizontal frame, four cylinders respectively set at both ends of the horizontal frame and both ends of the vertical frame, four actuators, and four clamps (2); one end of each of the four actuators is connected to one end of the four cylinders near the center, and the other end is connected to the four clamps (2); the acoustic emission testing unit includes four acoustic emission sensors (6) and an acoustic emission instrument (7); the four acoustic emission sensors (6) are respectively set on the four loading arms (102) of the thermal barrier coating specimen (1); 2】A high-temperature speckle is prepared in the central region of the thermal barrier coating specimen (1) on the side away from the laser (3), and the thermal barrier coating specimen (1) with the high-temperature speckle is clamped on the four clamps (2) of the two-way four-cylinder testing machine. 3】A bidirectional prestress is applied to the thermal barrier coating specimen (1) by an actuator, and the acoustic emission instrument (7) is activated to continuously collect the acoustic emission signal of the thermal barrier coating specimen (1) when the actuator applies the prestress; the central region (101) of the thermal barrier coating specimen (1) is heated by a laser (3), and a tangential airflow is applied to the surface of the thermal barrier coating specimen (1); the output power of the laser (3) is... Calculated using the following formula: ； Where P0 represents the simulated heat flux intensity; α represents the absorption coefficient of the laser energy on the surface of the thermal barrier coating specimen; The tangential airflow velocity v applied to the surface of the thermal barrier coating specimen (1) t Calculated using the following formula: ； Where v0 represents the target airflow velocity to be simulated. This represents the target airflow density to be simulated. This indicates the tangential airflow density applied to the surface of the thermal barrier coating specimen; 4】The temperature acquisition unit collects the real-time temperature of the front and back surfaces of the thermal barrier coating specimen (1) during the laser heating process. At the same time, the camera (8) collects the speckle image of the central area of ​​the thermal barrier coating specimen (1) away from the laser (3) during the heating process. The acquisition results are sent to the strain processing module for processing to obtain the strain on the surface of the thermal barrier coating specimen (1) during the laser heating process. 5】Complete the damage performance test of the thermal barrier coating specimen (1) under a thermo-oxygen coupling environment; 5.1】Filter out the acoustic emission signals with a maximum response time greater than L / v from the acoustic emission signals collected in step 3, where L represents the distance from the acoustic emission sensor (6) to the center of the thermal barrier coating specimen (1), and v represents the propagation speed of the acoustic emission signal on the thermal barrier coating specimen (1); 5.2】The filtered acoustic emission signal is subjected to Fourier transform, and the Fourier transformed acoustic emission signal is compared with the cluster signal to obtain the damage mode of the thermal barrier coating specimen (1) corresponding to the acoustic emission signal; 5.3】The degree of thermal barrier coating damage H(t) under different temperature rise histories is obtained by the following formula: H(t) = ε0 / ε(t); Where ε0 is the strain on the surface of the thermal barrier coating specimen (1) in the initial stage after the load is applied, ε(t) is the strain on the surface of the thermal barrier coating specimen (1) during the laser heating process, and t is the real-time temperature of the front and back surfaces of the thermal barrier coating specimen (1) during the laser heating process.

2. The method for detecting the thermal barrier coating's performance under thermal-oxygen coupled environmental damage according to claim 1, characterized in that: In step 3, heating the central area of ​​the thermal barrier coating specimen (1) using a laser (3) specifically involves: Turn on the laser (3) and use a constant power laser to uniformly heat the central area of ​​the thermal barrier coating specimen (1) until the set irradiation time or temperature is reached.

3. The method for detecting the thermal barrier coating's performance under thermal-oxygen coupled environmental damage according to claim 2, characterized in that: In step 3, heating the central area of ​​the thermal barrier coating specimen (1) using a laser (3) specifically involves: The laser emitted by the laser (3) uniformly heats the central area of ​​the thermal barrier coating specimen (1). After heating to the set temperature, the laser emission is stopped. After the temperature drops to room temperature, the central area of ​​the thermal barrier coating specimen (1) is heated to the set temperature again by the emitted laser. This cycle is repeated until the set number of times is reached.

4. The method for detecting thermal barrier coating damage performance in a thermo-oxygen coupled environment according to claim 3, characterized in that: The thermal barrier coating thermal-oxygen coupled environment damage performance detection system also includes a non-contact strain measurement unit, a temperature acquisition unit, and an analysis unit. The non-contact strain measurement unit includes a camera (8), a filter (9), and a strain processing module. The camera (8) is located on the side of the thermal barrier coating specimen (1) away from the laser (3) and is used to acquire speckle images of the side of the thermal barrier coating specimen (1) away from the laser (3) at different heating temperatures. The filter (9) is set at the front end of the camera (8) and is used to filter out the interference of high-temperature radiation and stray light from the heating laser on the imaging of the camera (8) from the surface of the thermal barrier coating specimen (1). The input end of the strain processing module is connected to the output end of the camera (8) and is used to obtain the strain on the surface of the thermal barrier coating specimen (1) during laser heating based on the acquired speckle images. The temperature acquisition unit is used to acquire the temperature of the front and back surfaces of the thermal barrier coating specimen (1) during the laser heating process; The input end of the analysis unit is connected to the output end of the acoustic emission instrument (7), the strain processing module and the temperature acquisition unit, respectively. It is used to perform non-destructive testing on the internal cracks of the thermal barrier coating specimen (1) based on the acoustic emission signal of the thermal barrier coating specimen (1) during loading, the strain of the surface of the thermal barrier coating specimen (1) during laser heating and the temperature change of the front and back surfaces of the thermal barrier coating specimen (1) during laser heating.

5. The method for detecting the thermal barrier coating's performance under thermal-oxygen coupled environmental damage according to claim 4, characterized in that: The thermal barrier coating thermal oxygen coupling environment damage performance detection system also includes a first collimating lens (4), a beam expander lens (5), and a second collimating lens (12). The first collimating lens (4), the beam expander (5) and the second collimating lens (12) are sequentially arranged in the output light path of the laser (3). The output light of the laser (3) is collimated and expanded by the first collimating lens (4), the beam expander (5) and the second collimating lens (12) in sequence to form a flat-top laser. The central region (101) of the thermal barrier coating specimen (1) is located in the optical path of the flat-top laser, and is used to heat the central region (101) of the thermal barrier coating specimen (1) by the flat-top laser.

6. The method for detecting the thermal barrier coating's performance under thermal-oxygen coupled environmental damage according to claim 5, characterized in that: The temperature acquisition unit includes two dual-color thermometers (10) and two infrared thermal imagers (11). A dual-color thermometer (10) and an infrared thermal imager (11) are located on the side of the thermal barrier coating specimen (1) close to the laser (3), and another dual-color thermometer (10) and an infrared thermal imager (11) are located on the side of the thermal barrier coating specimen (1) away from the laser (3). The thermometers (11) on both sides are used to collect the temperature of the front and back surfaces of the thermal barrier coating specimen (1) during the laser heating process, and the dual-color thermometer (10) is used to calibrate and standardize the temperature collected by the corresponding infrared thermal imager (11). The infrared thermal imager (11) has a temperature measurement range of 0℃ to 650℃; The range of the dual-color thermometer (10) is 300℃~3000℃.

7. The method for detecting the thermal barrier coating's performance under thermal-oxygen coupled environmental damage according to claim 6, characterized in that: The outer walls of the four loading arms (102) of the thermal barrier coating specimen (1) are respectively provided with reinforcing plates (103), and the four clamps (2) clamp the ends of the four loading arms (102) of the thermal barrier coating specimen (1) through the reinforcing plates (103).

Images