An infrared thermometry calibration method and apparatus for CMAS high-temperature corrosion thermal barrier coating

Abstract

This invention discloses an infrared thermometry calibration method and apparatus for thermal barrier coatings (CMAS) subjected to high-temperature corrosion. The method includes: preparing a thermal barrier coating sample coated with CMAS and having side openings; placing the sample in a high-temperature furnace and inserting a high-temperature thermocouple into the sample's temperature measurement hole; adjusting the high-temperature infrared thermometer so that its measurement optical path is aligned with the area to be measured on the sample surface; heating the high-temperature furnace to a predetermined temperature and maintaining that temperature; comparing the thermocouple and infrared thermometry data in real time, adjusting the infrared emissivity so that the difference between the two is within a preset error range, and determining the infrared emissivity parameter of the sample at that temperature. The method provided by this invention can accurately calibrate the infrared thermometry parameters of thermal barrier coatings under different CMAS corrosion conditions, thereby obtaining the corresponding infrared emissivity, providing key technical support for the service life assessment and reliability testing of thermal barrier coatings subjected to high-temperature CMAS corrosion. Furthermore, the apparatus used in this invention has a simple structure, is easy to operate, and provides accurate and effective test results, demonstrating good application value.

Description

Technical Field

[0001] This invention relates to the field of aero-engine technology, specifically to an infrared temperature measurement calibration method and device for CMAS high-temperature corrosion thermal barrier coating. Background Technology

[0002] Thermal barrier coatings, as an important heat insulation technology, are an indispensable key component of aero-engines. The performance of the thermal barrier coating directly determines the service life of the aero-engine. When the thermal barrier coating is damaged and peels off due to external loads, the high-temperature alloy blades of the engine are exposed to a high-temperature environment, which will lead to the entire engine shutting down, resulting in significant safety hazards and economic losses. Therefore, the lifespan of the thermal barrier coating directly determines the operating cycle of the aero-engine.

[0003] Thermal barrier coatings (TBSs) are subject to various physical processes during service, which in turn affect their final service life. Among these processes, CMAS corrosion is currently considered a key factor in TBS failure. Sand, dust, and volcanic ash (primarily composed of CaO, MgO, Al2O3, and SiO2, referred to as CMAS) in the air are easily absorbed into aero-engines and deposited on the surface of the TBS. Under high-temperature conditions, these substances melt and penetrate into the coating's interior, reacting chemically with the TBS, altering its structure and physical properties, and ultimately causing it to peel off and fail.

[0004] Assessing the high-temperature corrosion life of thermal barrier coatings (CBTs) under CMAS (Complex Corrosion Assault System) is crucial for evaluating the CBT's destructive capabilities. Currently, a high-temperature service damage platform for CBTs is an effective means of assessing their service life under high-temperature corrosion conditions. This platform can measure the CBT's service life under high-temperature and CMAS corrosion conditions in a manner relatively close to the coating's actual service conditions. The high-temperature service damage platform requires high-temperature flame impact to the CBT coated with CMAS, thereby simulating the high-temperature service conditions of the CBT. During this process, a high-temperature infrared thermometer is needed to monitor the coating surface temperature in real time, thereby controlling the propane and oxygen flow rates to ensure the coating is tested at the set temperature.

[0005] High-temperature infrared thermometry first requires understanding the material's emissivity. Then, by setting the appropriate emissivity parameters in the infrared device, the true temperature feedback of the material's surface can be obtained. The traditional thermal barrier coating 8YSZ (8 wt% Y₂O₃-Stabilized ZrO₂, yttrium-stabilized zirconium oxide) has an infrared emissivity of 0.75-0.85 at 1200-1500℃. Therefore, setting the emissivity parameter to around 0.80 allows for relatively accurate measurement of the coating surface temperature through high-temperature infrared thermometry. However, the composition and physical properties of different types and regions of CMAS vary greatly. When CMAS is applied to the surface of a thermal barrier coating, the emissivity of the CMAS is unknown, making it impossible to determine the emissivity parameters of the coating surface. This makes it difficult for high-temperature infrared thermometers to reliably measure the coating surface temperature, greatly limiting the effective application of high-temperature service damage platforms for thermal barrier coatings. Therefore, there is an urgent need to develop a high-temperature infrared temperature detection method and device for thermal barrier coatings coated with different CMAS. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide an infrared temperature measurement calibration method and device for CMAS high-temperature corrosion thermal barrier coating. By designing and developing a high-temperature furnace with a specific structure, and combining it with a high-temperature thermocouple and a high-temperature infrared thermometer, the infrared temperature of the thermal barrier coating coated with CMAS is calibrated to obtain the corresponding infrared emissivity, thereby realizing the effective evaluation of the surface temperature of the thermal barrier coating under high-temperature CMAS corrosion conditions.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] This invention proposes an infrared temperature measurement calibration method for CMAS high-temperature corrosion thermal barrier coatings, comprising the following steps:

[0009] S1, Prepare a thermal barrier coating sample with CMAS coating on the surface and temperature measurement holes on the side.

[0010] S2, the prepared thermal barrier coating sample is placed in a high-temperature furnace, and the temperature measuring end of the high-temperature thermocouple is inserted into the temperature measuring hole of the thermal barrier coating sample.

[0011] S3, adjust and fix the position of the high-temperature infrared thermometer so that the temperature measuring optical path of the high-temperature infrared thermometer is aligned with the area to be measured on the surface of the thermal barrier coating sample.

[0012] S4, control the high-temperature furnace to heat up to the predetermined temperature and maintain the temperature;

[0013] S5. Simultaneously monitor the thermocouple temperature parameters fed back by the high-temperature thermocouple and the infrared temperature parameters fed back by the high-temperature infrared thermometer. Adjust the infrared emissivity setting value of the high-temperature infrared thermometer based on the thermocouple temperature parameters until the difference between the infrared temperature parameters and the thermocouple temperature parameters is within the preset error range. The infrared emissivity setting value at this time is the infrared emissivity of the sample surface.

[0014] Preferably, the thermal barrier coating sample is a regular sheet structure with a preset thickness. The temperature measuring hole starts from one side of the sample in the thickness direction and extends into the sample in a direction parallel to the sample surface, but does not penetrate the sample. The depth of the temperature measuring hole matches the length of the temperature measuring tip to ensure that the temperature measuring tip falls entirely into the temperature measuring hole during operation.

[0015] Preferably, the diameter of the temperature measuring hole is adapted to the outer diameter of the temperature measuring end, so that the temperature measuring end fits snugly against the wall of the temperature measuring hole without rigid contact stress; the distance between the wall of the temperature measuring hole and the upper surface of the sample is set to 0.5-1 mm.

[0016] Preferably, the temperature measuring optical path is aligned with the area to be tested on the surface of the thermal barrier coating sample, including ensuring that the angle between the temperature measuring optical path and the normal of the surface of the area to be tested does not exceed 15°.

[0017] Preferably, the high-temperature furnace is heated to a predetermined temperature of 1200-1500℃ and held for 30-60 minutes.

[0018] Preferably, the preset error range of the difference between the infrared temperature parameter and the thermocouple temperature parameter is less than 10°C.

[0019] In another aspect, this invention also proposes an infrared temperature measurement calibration device for the infrared temperature measurement calibration method of the above-mentioned CMAS high-temperature corrosion thermal barrier coating, comprising at least:

[0020] A high-temperature furnace has an internal furnace chamber for placing and heating the thermal barrier coating sample coated with CMAS; the top of the high-temperature furnace has an infrared detection window, and the side wall has a through hole for a high-temperature thermocouple to pass through the furnace chamber.

[0021] A high-temperature thermocouple, with one end serving as a temperature measuring tip, is inserted into the furnace chamber through the through hole and then fixed in the temperature measuring hole of the thermal barrier coating sample to collect the thermocouple temperature parameters of the thermal barrier coating sample; the other end of the high-temperature thermocouple is connected to a thermocouple temperature controller to realize the transmission, processing and display of temperature signals.

[0022] A high-temperature infrared thermometer is fixedly installed above the high-temperature furnace. Its temperature measuring optical path passes through the infrared detection window and is aimed at the area to be measured on the surface of the thermal barrier coating sample to collect infrared temperature parameters of the thermal barrier coating sample surface.

[0023] Preferably, the high-temperature furnace is a high-temperature resistance furnace with a maximum heating temperature of not less than 1500°C.

[0024] Preferably, the maximum heating temperature of the high-temperature resistance furnace is 1750℃, and the temperature control accuracy is ±1℃.

[0025] Preferably, the high-temperature thermocouple is a precious metal thermocouple with a maximum operating temperature of not less than 1500℃.

[0026] Preferably, the precious metal thermocouple is a type B thermocouple, the maximum temperature of which is 1800℃, and its measurement accuracy in the temperature range of 600-1700℃ is ±3.5℃.

[0027] Preferably, the highest measuring temperature of the high-temperature infrared thermometer is not lower than 1500℃, and the infrared emissivity is adjustable.

[0028] Preferably, the temperature measurement range of the high-temperature infrared thermometer is 0-2000℃, the temperature measurement accuracy is ±0.6℃ + (target temperature - ambient temperature) × 0.7%, the infrared emissivity adjustment range is 0.10-1.00, the adjustment step size is 0.01, and the response wavelength is 9.6-11.5 micrometers.

[0029] The beneficial effects of this invention are as follows:

[0030] (1) This invention improves the high-temperature furnace device by designing an infrared detection window above the furnace and providing through holes for high-temperature thermocouples to pass through on the side wall of the furnace. This ensures the light path penetration of the high-temperature infrared thermometer and creates a static, sealed high-temperature heating environment. At the same time, a calibration method that uses simultaneous monitoring of the high-temperature thermocouple and the infrared thermometer is adopted. By dynamically adjusting the infrared emissivity parameter until the temperature difference between the two falls within the preset error range, infrared temperature measurement calibration of thermal barrier coatings with different CMAS coatings is achieved under specific high-temperature conditions. The corresponding infrared emissivity is successfully obtained, overcoming the problem that the surface temperature of different CMAS high-temperature corrosion thermal barrier coatings is difficult to characterize and observe in real time due to the unknown emissivity. This provides key technical support for the reliability evaluation of the surface temperature of high-temperature corrosion of CMAS thermal barrier coatings in aero-engines and promotes the effective application of the high-temperature damage service platform for thermal barrier coatings in the service life assessment of CMAS high-temperature corrosion thermal barrier coatings.

[0031] (2) The present invention places the temperature measuring hole on the side of the sample. On the one hand, it ensures the integrity of the structure and thermal environment of the upper and lower surfaces of the sample, providing a true measurement benchmark for the high-temperature infrared thermometer. On the other hand, since the temperature measuring hole is close to the upper surface of the sample and one end is closed, the temperature measuring end of the high-temperature thermocouple is not directly exposed to the furnace environment. This not only isolates external interferences such as gas convection and furnace wall thermal radiation, but also avoids the loss of heat in the hole. After being kept at high temperature for a long time in the furnace, based on the steady-state heat conduction principle, the temperature measured by the temperature measuring end tends to be consistent with the temperature of the upper surface of the sample, further ensuring the accuracy of the measurement.

[0032] (3) The infrared temperature measurement calibration device provided by the present invention has a simple structure, requires no complicated modification, and is easy to promote; the calibration method provided is easy to operate, has a short test cycle, and the test results are effective and reliable, making it suitable for large-scale application in the field of aerospace high-temperature material testing. Attached Figure Description

[0033] Figure 1 This is a flowchart illustrating the infrared temperature measurement calibration method for CMAS high-temperature corrosion thermal barrier coatings provided in an embodiment of the present invention.

[0034] Figure 2 This is a schematic diagram of an infrared temperature measurement calibration device for CMAS high-temperature corrosion thermal barrier coating provided in an embodiment of the present invention.

[0035] In the diagram: 1. High-temperature furnace; 101. Furnace chamber; 102. Infrared detection window; 103. Adjustable bracket; 2. High-temperature thermocouple; 201. Temperature measuring end; 202. Thermocouple temperature controller; 3. High-temperature infrared thermometer; 301. Infrared lens. Detailed Implementation

[0036] To make the objectives and technical solutions of this invention clearer and more complete, the invention will be further described in detail below with reference to embodiments. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. Modifications or equivalent substitutions made by those skilled in the art based on their understanding of the technical solutions of this invention, without departing from the spirit and scope of the technical solutions of this invention, are all within the scope of protection of this invention.

[0037] See Figure 1 This invention provides an infrared temperature measurement calibration method for CMAS high-temperature corrosion thermal barrier coatings, comprising the following steps:

[0038] S1, Prepare a thermal barrier coating sample with CMAS coating on the surface and temperature measurement holes on the side.

[0039] Specifically, a certain mass of CMAS is dissolved in anhydrous ethanol, and the mixture is thoroughly stirred with a stirring rod in a cleaned and dried beaker. Then, the CMAS corrosive medium, thoroughly mixed with anhydrous ethanol, is applied to the surface of the sample with the thermal barrier coating using a dropper. Further, a temperature measuring hole is provided on the side of the thermal barrier coating sample. This hole can be opened before or after CMAS coating, for the subsequent insertion of the temperature measuring tip 201 of the high-temperature thermocouple 2. It should be noted that the thermal barrier coating sample prepared in this embodiment is a regular sheet-like sample with a predetermined thickness, comprising, from bottom to top, an alloy substrate layer, an adhesive layer, a thermal barrier coating, and a CMAS layer coated on the surface of the thermal barrier coating (coating concentration in mg / cm³). 2 The sample thickness is at least greater than the diameter of the temperature measuring hole to be opened. The shape can be selected as circular, square, polygonal, etc., according to the testing requirements. Preferably, the temperature measuring hole is opened in the alloy substrate layer of the sample, so the thickness of the alloy substrate layer must be at least greater than the diameter of the temperature measuring hole to be opened. Specifically, the temperature measuring hole starts from one side of the sample thickness direction, preferably from one side of the alloy substrate layer, and extends into the sample in a direction parallel to the upper and lower surfaces of the sample, but does not penetrate the sample. The depth of the temperature measuring hole matches the length of the temperature measuring end 201 of the high-temperature thermocouple 2, ensuring that the temperature measuring end 201 falls entirely into the temperature measuring hole during operation, avoiding the end being exposed and affecting the temperature measurement accuracy. Preferably, when the temperature measuring hole extends into the sample, the extension direction is perpendicular to the sample surface and passes through the central axis of the sample's geometric center, and it must reach or further penetrate the position of the central axis, but does not penetrate the other side of the sample opposite to the opening side. Furthermore, the distance between the hole wall near the upper surface of the sample and the upper surface of the sample is preferably 0.5-1 mm. If the distance is too large, the thermocouple in the temperature measuring hole will be far away from the upper surface of the sample (the object of infrared temperature measurement), resulting in an excessively large difference between the measured temperature and the temperature of the upper surface of the sample, which will affect the accuracy of the calibration correlation. If the distance is too small, it will weaken the strength of the edge structure of the sample, and may even damage the bonding interface between the coating and the substrate, leading to the risk of sample cracking or coating peeling during the test.

[0040] In some embodiments, before coating with the CMAS solution, the surface of the thermal barrier coating needs to be ultrasonically cleaned to remove any contaminants, improve surface cleanliness, and thus ensure the accuracy of subsequent temperature detection of the sample surface, reducing potential external errors. The CMAS corrosive medium includes oxides of calcium, magnesium, aluminum, and / or silicon. The thermal barrier coating can be prepared using electron beam physical vapor deposition (EB-PVD) or plasma spraying (APS) processes. Further, the sample coated with the CMAS solution is placed under a heat lamp for a period of time to allow the CMAS solution to solidify onto the sample surface. The heat lamp temperature is preferably 100-150°C, and the standing time is preferably 2-10 min; more preferably, the heat lamp temperature is 100°C, and the standing time is 2 min.

[0041] S2, the thermal barrier coating sample prepared in step S1 is placed in the high-temperature furnace 1, and the temperature measuring end 201 of the high-temperature thermocouple 2 is inserted into the temperature measuring hole of the sample.

[0042] Specifically, the CMAS-coated thermal barrier coating sample is placed in a high-temperature furnace 1 and fixed with clamps, ensuring the CMAS-coated thermal barrier coating side faces upwards. The temperature-sensing tip 201 of a pre-installed high-temperature thermocouple 2 is inserted into a temperature-sensing hole on the side of the thermal barrier coating sample, ensuring the tip 201 is completely within the hole. The tip 201 is sized to match the temperature-sensing hole, ensuring a stable fit without rigid contact stress, preventing sample cracking or tip deformation. Preferably, the diameter of the temperature-sensing hole is set to 1-5 mm, matching the outer diameter of the currently mainstream temperature-sensing tip 201. It should be understood that in this embodiment, placing the temperature-sensing hole on the side of the sample ensures the integrity of the original structure and thermal environment of the upper and lower surfaces, fully preserving the continuous distribution and surface heat exchange characteristics of the sample surface. This effectively avoids the heat flow distribution disturbances that may occur with other opening methods, such as vertical surface openings, providing a true measurement benchmark for infrared thermometry (using the upper surface of the CMAS-coated sample as the target). Meanwhile, this opening method also ensures the structural load-bearing capacity of the sample, effectively avoiding risks such as coating peeling and sample cracking that may occur with vertical surface openings. It ensures the sample can stably withstand the furnace environment (such as airflow erosion and temperature cycling) during high-temperature testing, guaranteeing the continuity and data validity of the entire measurement process. Furthermore, this opening method ensures that the temperature measuring end 201 of the high-temperature thermocouple 2 is not directly exposed to the furnace environment, preventing the temperature measuring optical path of the high-temperature infrared thermometer 3 from directly irradiating the temperature measuring end 201, thus avoiding the situation where the measured temperature is the thermocouple itself rather than the sample surface temperature. In addition, after the temperature measuring end 201 is inserted into the hole from the side, since the other end of the hole is closed, it completely isolates external interference such as gas convection and furnace wall thermal radiation, while also preventing heat loss from the hole, ensuring measurement accuracy.

[0043] S3, adjust and fix the position of the high-temperature infrared thermometer 3 so that the temperature measuring optical path of the high-temperature infrared thermometer 3 is aligned with the area to be measured on the surface of the thermal barrier coating sample.

[0044] Specifically, the high-temperature infrared thermometer 3 is fixed above the high-temperature furnace 1 using an adjustable bracket 103, which has both vertical height and horizontal angle adjustment functions. Vertical height adjustment controls the vertical distance between the infrared lens 301 and the sample in the high-temperature furnace 1, ensuring that the field of view of the high-temperature infrared thermometer 3 completely covers the area to be measured and avoiding interference between the infrared lens 301 and the top of the high-temperature furnace 1. Horizontal angle adjustment ensures that the optical axis of the infrared lens 301 coincides with the central axis of the infrared detection window 102, ensuring that the infrared lens 301 is directly facing the infrared detection window 102 above the furnace 101, and that the light-transmitting area of ​​the infrared detection window 102 is completely within the lens's field of view. Further horizontal angle adjustment fine-tunes the tilt angle of the infrared lens 301, ensuring that the temperature-measuring light path of the high-temperature infrared thermometer 3 illuminates the area to be measured on the surface of the thermal barrier coating sample, and that the angle between the temperature-measuring light path and the normal to the surface of the area to be measured does not exceed 15°, minimizing the impact of angular deviation on the reception of infrared radiation energy. It should be noted that the area to be tested is any effective area of ​​the sample surface, with the surface closest to the area where the temperature measuring hole is opened, i.e., the surface where the temperature measuring end 201 is inserted, being the optimal area.

[0045] S4 controls the high-temperature furnace 1 to heat up to the predetermined temperature and maintain the temperature.

[0046] In this step, the high-temperature furnace 1 is heated from room temperature at a rate of 5-10℃ / min. The temperature inside the furnace is monitored in real time using a temperature sensor to ensure a stable heating process and prevent thermal stress or cracking and peeling of the CMAS coating caused by excessively rapid heating. Once the furnace temperature reaches the predetermined range of 1200-1500℃, the furnace is switched to a holding mode for 30-60 minutes. During this period, temperature fluctuations are continuously monitored to ensure the furnace temperature remains within ±5℃ of the predetermined temperature, providing a stable high-temperature static environment for the thermal barrier coating sample.

[0047] S5, synchronously monitor the thermocouple temperature parameters fed back by the high-temperature thermocouple 2 and the infrared temperature parameters fed back by the high-temperature infrared thermometer 3, and adjust the infrared emissivity setting value of the high-temperature infrared thermometer 3 based on the thermocouple temperature parameters until the difference between the infrared temperature parameters and the thermocouple temperature parameters is within the preset error range. At this time, the infrared emissivity setting value is the infrared emissivity of the surface of the sample coated with the thermal barrier coating of CMAS.

[0048] It should be noted that after the temperature inside the high-temperature furnace 1 is maintained at the predetermined temperature for a long period of time, the heat conduction process of the sample has reached a steady state, and a stable temperature field is formed in a certain thickness area near the upper surface of the sample. Since the distance between the wall of the temperature measuring hole and the upper surface of the sample is controlled within the range of 0.5-1mm, when the temperature measuring tip 201 is inserted into the hole from the side and closely attached to the upper surface of the sample, the temperature measuring tip 201 is exactly in this stable temperature region. According to the principle of steady-state heat conduction, the temperature measured by the temperature measuring tip 201 at this time can be consistent with the actual temperature of the upper surface of the sample. Specifically, observe the temperature data displayed on the thermocouple temperature controller 202 connected to the high-temperature thermocouple 2. After the temperature display stabilizes, record the thermocouple temperature parameter at this time as the calibration reference value. Simultaneously observe the infrared temperature parameter displayed by the high-temperature infrared thermometer 3 and compare the differences between the two values. By adjusting the infrared emissivity parameter setting, correct the infrared emissivity and measure the sample surface temperature again. After the temperature of the high-temperature infrared thermometer 3 stabilizes, record the infrared temperature parameter and compare it with the thermocouple temperature reference value again. Repeat the above "adjustment-stabilization-comparison" process until the difference between the infrared temperature parameter displayed by the high-temperature infrared thermometer 3 and the thermocouple temperature parameter fed back by the high-temperature thermocouple 2 is reduced to within the preset error range (≤±10℃). At this point, stop adjusting and record the current infrared emissivity setting value. This value is the infrared emissivity parameter of the surface of the thermal barrier coating sample coated with a specific component CMAS at a predetermined temperature (1200-1500℃).

[0049] Figure 2A schematic diagram of the apparatus used in the infrared temperature measurement calibration method of the above-described embodiment of the present invention is further shown. As shown in the figure, the infrared temperature measurement calibration apparatus includes at least a high-temperature furnace 1, a high-temperature thermocouple 2, and a high-temperature infrared thermometer 3. The high-temperature furnace 1 has a furnace chamber 101 for accommodating and heating a sample coated with a thermal barrier coating (CMAS). An infrared detection window 102 is provided at the top of the high-temperature furnace 1, above the furnace chamber 101. Its size is adapted to the infrared lens 301 of the high-temperature infrared thermometer 3 to ensure unobstructed transmission of the light path of the high-temperature infrared thermometer 3. The preferred material is high-purity quartz glass with high light transmittance and high temperature resistance. An adjustable bracket 103 is also installed near the infrared detection window 102 to fix the high-temperature infrared thermometer 3, ensuring that the infrared lens 301 can face the infrared detection window 102 and that the temperature measurement light path can be aligned with the area to be measured on the sample surface. Furthermore, a through hole is provided on the left, right, or rear side wall of the high-temperature furnace 1 housing for the temperature measuring end 201 of the high-temperature thermocouple 2 to pass through into the furnace chamber 101, with the through hole preferably located on the rear side wall. After the temperature measuring end 201 is inserted into the furnace chamber 101 and the furnace door in front of the furnace chamber 101 is closed, the entire furnace chamber 101 can form a sealed, static environment suitable for high-temperature heating. The high-temperature furnace 1 is preferably a high-temperature resistance furnace with a maximum heating temperature of not less than 1500℃, and more preferably, the maximum heating temperature of the high-temperature resistance furnace is 1750℃, which is higher than the temperature at which the CMAS thermal barrier coating is corroded, with a temperature control accuracy of ±1℃ and an adjustable heating rate.

[0050] Furthermore, one end of the high-temperature thermocouple 2 is a temperature measuring tip 201, which is inserted and fixed into the temperature measuring hole of the thermal barrier coating sample during testing to collect the thermocouple temperature parameters of the thermal barrier coating sample; the other end is connected to a thermocouple temperature controller 202, which receives, processes, and displays the electrical signal output by the high-temperature thermocouple 2, and converts the electrical signal into an intuitive temperature value. For ease of use, the temperature measuring tip 201 can be inserted through a through hole in the side wall of the high-temperature furnace 1 and left inside the furnace chamber 101, and the inside and outside of the through hole after insertion are sealed to ensure the airtightness of the furnace chamber 101. Preferably, the high-temperature thermocouple 2 is a precious metal thermocouple with a maximum operating temperature of not less than 1500℃; more preferably, it is a type B thermocouple with a maximum measuring temperature of 1800℃ and an accuracy of ±3.5℃ in the range of 600-1700℃, meeting the high-temperature measurement requirements of CMAS corrosion thermal barrier coatings.

[0051] Furthermore, the high-temperature infrared thermometer 3 is fixed above the high-temperature furnace 1 by an adjustable bracket 103. During operation, the infrared lens 301 is positioned directly opposite the infrared detection window 102, and the temperature measurement optical path is close to the test area of ​​the thermal barrier coating sample (the angle between the temperature measurement optical path and the surface normal of the test area does not exceed 15°). This is used to collect infrared temperature parameters of the thermal barrier coating sample surface. Preferably, the maximum measurement temperature of the high-temperature infrared thermometer 3 is not lower than 1500℃, and the infrared emissivity is adjustable. More preferably, its temperature measurement range is 0-2000℃, the temperature resolution is ±0.06℃, the temperature measurement accuracy is ±0.6℃ + (target temperature - ambient temperature) × 0.7%, the infrared emissivity adjustment range is 0.10-1.00, the adjustment step is 0.01, and the response wavelength is 9.6-11.5 micrometers.

[0052] The infrared temperature measurement calibration method for the CMAS high-temperature corrosion thermal barrier coating provided above is further illustrated by specific embodiments below.

[0053] Example 1

[0054] (1) In this embodiment, the 8YSZ thermal barrier coating sample without CMAS coating is used as the test object. Specifically, the 8YSZ thermal barrier coating sample is placed in a high-temperature resistance furnace, and the sample is fixed with a clamp so that the 8YSZ thermal barrier coating surface faces directly upward. The diameter of the temperature measuring hole opened on the side of the sample is 3 mm, and the temperature measuring end 201 of the type B thermocouple is fully inserted into the temperature measuring hole.

[0055] (2) Install the high temperature infrared thermometer 3 onto the adjustable bracket 103 above the high temperature resistance furnace, and adjust it so that the infrared lens 301 faces the infrared detection window 102, and the temperature measurement light path is perpendicular to the surface of the sample to be measured.

[0056] (3) Close the furnace door and heat the high temperature resistance furnace to 1300℃ at a heating rate of 10℃ / min. Hold the temperature for 30 min to keep the temperature within the error range of ±5℃.

[0057] (4) After heat preservation, observe the temperature display data on the thermocouple temperature controller 202. After the temperature display stabilizes, record the temperature at this time as the calibration reference value; simultaneously observe the temperature data displayed on the high-temperature infrared thermometer 3, and find that the temperature difference between the two is greater than 10℃. Gradually adjust the infrared emissivity parameter setting, correct the infrared emissivity, and test the sample surface temperature again. After the temperature display of the high-temperature infrared thermometer 3 stabilizes, compare it with the thermocouple temperature parameter again. Repeat the above process until the error between the infrared temperature parameter and the thermocouple temperature parameter is within 10℃.

[0058] (5) After the above steps, the infrared emissivity of the 8YSZ thermal barrier coating surface in an environment of 1300℃ is 0.83, which falls within the known range of 0.75-0.85 for the infrared emissivity of 8YSZ material in this environment, indicating that the infrared temperature measurement calibration method provided by the present invention has high accuracy and effectiveness.

[0059] Example 2

[0060] (1) In this embodiment, CMAS (33CaO-9MgO-13Al2O3-45SiO2 mol%) was dissolved in anhydrous ethanol to prepare the CMAS corrosion medium, which was then applied to the surface of the thermal barrier coating sample made of 8YSZ material using a dropper at a concentration of 10 mg / cm³. 2 Before applying the CMAS solution, a 3 mm circular hole was pre-drilled on the side of the thermal barrier coating sample as a temperature measurement hole, and the surface of the thermal barrier coating was ultrasonically cleaned to remove any contaminants that may be present on the surface and improve the surface cleanliness.

[0061] (2) Place the sample coated with CMAS solution under a 100°C baking lamp for 2 minutes to allow the CMAS solution to solidify onto the sample surface.

[0062] (3) Place the CMAS-cured thermal barrier coating sample into a high-temperature resistance furnace, fix the sample with a clamp, and make the surface of the CMAS-coated thermal barrier coating face directly upward. At the same time, insert the temperature measuring end 201 of the B-type thermocouple reserved in the furnace chamber 101 into the temperature measuring hole of the thermal barrier coating sample, and ensure that the temperature measuring end 201 is completely placed in the hole.

[0063] (4) Install the high temperature infrared thermometer 3 onto the adjustable bracket 103 above the high temperature resistance furnace, and adjust it so that the infrared lens 301 faces the infrared detection window 102, and the temperature measuring light path is perpendicularly irradiated onto the test area on the sample surface.

[0064] (5) Close the furnace door and heat the high temperature resistance furnace to 1300℃ at a heating rate of 10℃ / min. Hold the temperature for 30 min to keep the temperature within the error range of ±5℃.

[0065] (6) After heat preservation, observe the temperature display data on the thermocouple temperature controller 202. After the temperature display stabilizes, record the temperature at this time as the calibration reference value; simultaneously observe the temperature data displayed on the high-temperature infrared thermometer 3, and find that the temperature difference between the two is greater than 10℃. Gradually adjust the infrared emissivity parameter setting, correct the infrared emissivity, and test the sample surface temperature again. After the temperature display of the high-temperature infrared thermometer 3 stabilizes, compare it with the thermocouple temperature parameter again. Repeat the above process until the error between the infrared temperature parameter and the thermocouple temperature parameter is within 10℃.

[0066] (7) After the above steps, the infrared emissivity of the sample surface in an environment of 1300℃ was tested to be 0.95, thus determining that the surface infrared emissivity of the 8YSZ thermal barrier coating coated with the above component CMAS in an environment of 1300℃ was 0.95.

Claims

1. An infrared temperature measurement calibration method for a CMAS high-temperature corrosion thermal barrier coating, characterized in that, The method comprises the following steps: S1, preparing a thermal barrier coating sample coated with CMAS on the surface and provided with a temperature measuring hole on the side surface; the thermal barrier coating sample has a regular sheet structure with a preset thickness, the temperature measuring hole starts from one side surface of the sample thickness direction and extends to the inside of the sample in a direction parallel to the sample surface without penetrating the sample; the distance between the hole wall of the temperature measuring hole and the upper surface of the sample is 0.5-1 mm; S2, placing the prepared thermal barrier coating sample in a high-temperature furnace to build a static and closed high-temperature heating environment, and inserting a temperature measuring end of a high-temperature thermocouple into the temperature measuring hole of the thermal barrier coating sample; S3, adjusting and fixing the position of a high-temperature infrared temperature measuring instrument so that the temperature measuring light path of the high-temperature infrared temperature measuring instrument is aligned with the to-be-measured area on the surface of the thermal barrier coating sample; S4, controlling the high-temperature furnace to heat to a predetermined temperature and keep warm; S5, based on the principle of steady-state heat conduction, synchronously monitoring the thermocouple temperature parameter fed back by the high-temperature thermocouple and the infrared temperature parameter fed back by the high-temperature infrared temperature measuring instrument, adjusting the infrared emissivity set value of the high-temperature infrared temperature measuring instrument based on the thermocouple temperature parameter, until the difference between the infrared temperature parameter and the thermocouple temperature parameter is within a preset error range, and the infrared emissivity set value at this time is the infrared emissivity of the sample surface.

2. The method of calibrating the infrared temperature measurement of a CMAS high-temperature corrosion thermal barrier coating according to claim 1, characterized in that The depth of the temperature measuring hole matches the length of the temperature measuring end, so that the temperature measuring end falls into the temperature measuring hole during work.

3. The method of calibrating the infrared temperature measurement of a CMAS high-temperature corrosion thermal barrier coating according to claim 2, characterized in that The diameter of the temperature measuring hole is matched with the outer diameter of the temperature measuring end, so that the temperature measuring end is attached to the hole wall of the temperature measuring hole without rigid contact stress.

4. The method of calibrating the infrared temperature measurement of a CMAS high-temperature corrosion thermal barrier coating according to claim 1, characterized in that, The temperature measuring light path is aligned with the to-be-measured area on the surface of the thermal barrier coating sample, including that the included angle between the temperature measuring light path and the surface normal of the to-be-measured area is not more than 15°.

5. The method of calibrating the infrared temperature measurement of a CMAS high-temperature corrosion thermal barrier coating according to claim 1, characterized in that, The predetermined temperature to which the high-temperature furnace is heated is 1200-1500℃, and the keeping warm time is 30-60 min.

6. The method of calibrating the infrared temperature measurement of a CMAS high-temperature corrosion thermal barrier coating according to claim 1, characterized in that The preset error range of the difference between the infrared temperature parameter and the thermocouple temperature parameter is less than 10℃.

7. The infrared temperature calibration method for the CMAS high-temperature corrosion thermal barrier coating according to any one of claims 1-6, wherein the infrared temperature calibration device used in the method is characterized in that, At least comprising: A high-temperature furnace provided with a hearth inside for placing and heating the thermal barrier coating sample coated with CMAS; an infrared detection window is arranged on the top of the high-temperature furnace, and a through hole is arranged on the side wall for the high-temperature thermocouple to pass into the hearth; the material of the infrared detection window is high-purity quartz glass, and the through hole is sealed after the high-temperature thermocouple passes through; A high-temperature thermocouple with a temperature measuring end, which is inserted and fixed into the temperature measuring hole of the thermal barrier coating sample after passing through the through hole into the hearth, for collecting the thermocouple temperature parameter of the thermal barrier coating sample; the other end of the high-temperature thermocouple is connected to a thermocouple temperature controller to realize the transmission, processing and display of the temperature signal; A high-temperature infrared temperature measuring instrument fixedly arranged above the high-temperature furnace, whose temperature measuring light path passes through the infrared detection window to align with the to-be-measured area on the surface of the thermal barrier coating sample, for collecting the infrared temperature parameter of the surface of the thermal barrier coating sample.

8. The infrared temperature measurement calibration device of claim 7, wherein, The high-temperature furnace is a high-temperature resistance furnace with a maximum heating temperature not less than 1500℃.

9. The infrared temperature measurement calibration device of claim 7, wherein, The high-temperature thermocouple is a precious metal thermocouple with a maximum use temperature not less than 1500℃.

10. The infrared temperature measurement calibration device of claim 7, wherein, The highest measuring temperature of the high-temperature infrared temperature measuring instrument is not less than 1500 DEG C, and the infrared emissivity is adjustable.

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