Thermal barrier coating interface characterization method based on CT imaging and 3D Raman spectrum

Abstract

The invention relates to a thermal barrier coating interface characterization method based on CT imaging and 3D Raman spectroscopy, and the method comprises the steps: building a substrate coordinate plane through a substrate of a target thermal barrier coating, carrying out the imaging analysis of the target thermal barrier coating based on CT imaging equipment, obtaining a sectional view, and obtaining a three-dimensional reconstruction image based on reconstruction software; enabling the three-dimensional reconstruction image to correspond to a three-dimensional space of a substrate coordinate plane, and determining a target interface of the target thermal barrier coating and the position of a target crack; respectively scanning the positions of the target interface and the target crack by utilizing Raman spectrum equipment to obtain first Raman spectrum data and second Raman spectrum data, and further obtaining stress distribution of the target interface and stress distribution of the target crack. Therefore, the problem that an existing coating interface detection method cannot meet the requirement for lossless and comprehensive characterization of the internal structure of the coating is solved, and effective observation and measurement of interface morphology and interface strain before and after thermal circulation of the coating are achieved on the premise that the coating is not damaged.

Description

Technical Field

[0001] The present application relates to the technical field of non-destructive characterization of protective coatings at the hot end of high-temperature gas turbines and aerospace engines, and in particular to a method for characterizing the interface of thermal barrier coatings based on CT (Computed Tomography) imaging and 3D Raman spectroscopy. Background Art

[0002] Thermal barrier coatings (TBC) are mainly used in gas turbines and aircraft engines. By adhering to the surface of the metal substrate, a temperature difference of hundreds of degrees Celsius between the inside and the outside is achieved, thereby protecting the components from high temperature and environmental erosion, allowing them to work normally and improve thermal efficiency. Thermal barrier coating systems usually include the following parts: metal substrate, bonding layer (such as NiCoCrAlY, nickel cobalt chromium aluminum yttrium), thermally grown oxide (TGO, Thermal GrownOxidation) and ceramic surface layer, among which the ceramic surface layer is generally composed of metal oxides as the main component, and the most widely used is 6-8wt% YSZ (yttrium stabilized zirconia) ceramics.

[0003] During the service of thermal barrier coating materials, the porosity of the coating will gradually decrease and a thermally grown oxide layer will appear. The former will increase the thermal conductivity of the coating, while the continuous growth of TGO thickness may eventually lead to coating peeling. YSZ coating structure is the most commonly used thermal barrier coating structure. Therefore, it is necessary to adopt a non-destructive testing method to track the changes in the YSZ coating structure, so as to facilitate the evaluation of its service status and predict coating failure in advance.

[0004] The interfaces in thermal barrier coatings mainly include the interface between the TGO layer and the ceramic layer, as well as the interfaces between layers within the ceramic layer. These interfaces are the main parts for crack generation and expansion, and are also the main reasons for coating failure.

[0005] However, traditional methods for detecting interfaces of thermal barrier coatings often fail to meet the requirements of non-destructive, high-precision and comprehensive characterization of the internal structure of the coatings, which urgently needs to be solved. Summary of the invention

[0006] The present application provides a method for characterizing the interface of thermal barrier coatings based on CT imaging and 3D Raman spectroscopy to solve the problem that existing coating interface detection methods cannot meet the requirements of non-destructive and comprehensive characterization of the internal structure of the coating. By combining CT imaging and 3D Raman spectroscopy technology, effective observation and measurement of the interface morphology and interface strain of the coating before and after thermal cycling are achieved without destroying the coating.

[0007] The first embodiment of the present application provides a method for characterizing the interface of a thermal barrier coating based on CT imaging and 3D Raman spectroscopy, comprising the following steps:

[0008] Establishing a base coordinate plane with the base of the target thermal barrier coating, performing imaging analysis on the target thermal barrier coating based on a preset CT imaging device to obtain a cross-sectional view of the target thermal barrier coating, and obtaining a three-dimensional reconstructed image of the target thermal barrier coating based on the cross-sectional view of the target thermal barrier coating and preset reconstruction software;

[0009] Corresponding the three-dimensional reconstructed image to the three-dimensional space of the base coordinate plane, determining the position of the target interface and the position of the target crack of the target thermal barrier coating;

[0010] The position of the target interface is scanned based on a preset Raman spectroscopy device to obtain first Raman spectroscopy data corresponding to the position of the target interface, or the position of the target crack is scanned based on a preset Raman spectroscopy device to obtain second Raman spectroscopy data corresponding to the position of the target crack, and based on a preset strain formula, the stress distribution of the target interface is obtained according to the first Raman spectroscopy data, or based on a preset strain formula, the stress distribution of the target crack is obtained according to the second Raman spectroscopy data.

[0011] According to one embodiment of the present application, before scanning the position of the target interface based on a preset Raman spectroscopy device, or scanning the position of the target crack based on a preset Raman spectroscopy device, the method further includes:

[0012] Using a silicon chip to calibrate the preset Raman spectroscopy device;

[0013] Based on the preset scanning requirements, the laser wavelength, objective lens parameters and confocal pinhole values ​​of the preset Raman spectroscopy device are determined, and the scanning range and number of data points of the preset Raman spectroscopy device are set.

[0014] According to one embodiment of the present application, the preset strain formula is:

[0015]

[0016] Among them, ε is the strain inside the coating, ν is the Poisson's ratio inside the coating, Π is the piezoelectric spectral coefficient, E is the elastic modulus of the dense bulk inside the coating, and Δω is the Raman peak offset inside the coating.

[0017] According to one embodiment of the present application, the target interface includes at least one of an interface between a thermally grown oxide layer and a ceramic surface layer and an interface between layers inside the ceramic surface layer.

[0018] According to one embodiment of the present application, the target crack includes at least one of a crack at the interface between the thermally grown oxide layer and the ceramic surface layer and a crack at the interface between layers inside the ceramic surface layer.

[0019] According to the thermal barrier coating interface characterization method based on CT imaging and 3D Raman spectroscopy of the embodiment of the present application, a base coordinate plane is established with the base of the target thermal barrier coating, and the target thermal barrier coating is imaged and analyzed based on the CT imaging device to obtain a cross-sectional view of the target thermal barrier coating, and a three-dimensional reconstructed image of the target thermal barrier coating is obtained based on the reconstruction software; the three-dimensional reconstructed image corresponds to the three-dimensional space of the base coordinate plane to determine the position of the target interface and the position of the target crack of the target thermal barrier coating; the position of the target interface and the position of the target crack are scanned by the Raman spectroscopy device respectively to obtain the first Raman spectroscopy data and the second Raman spectroscopy data, and then the stress distribution of the target interface and the stress distribution of the target crack are obtained. Thus, the existing coating interface detection method cannot meet the requirements of non-destructive and comprehensive characterization of the internal structure of the coating. By combining CT imaging and 3D Raman spectroscopy technology, the effective observation and measurement of the interface morphology and interface strain of the coating before and after thermal cycling are achieved without destroying the coating. At the same time, it can effectively predict and observe the generation and expansion behavior of cracks in the service process of the thermal barrier coating.

[0020] The second aspect of the present application provides a thermal barrier coating interface characterization device based on CT imaging and 3D Raman spectroscopy, comprising:

[0021] A CT imaging and reconstruction module, for establishing a base coordinate plane with a base of a target thermal barrier coating, performing imaging analysis on the target thermal barrier coating based on a preset CT imaging device, obtaining a cross-sectional view of the target thermal barrier coating, and obtaining a three-dimensional reconstructed image of the target thermal barrier coating based on the cross-sectional view of the target thermal barrier coating and preset reconstruction software;

[0022] A determination module, used to correspond the three-dimensional reconstructed image to the three-dimensional space of the base coordinate plane, and determine the position of the target interface and the position of the target crack of the target thermal barrier coating;

[0023] A Raman spectrum analysis module is used to scan the position of the target interface based on a preset Raman spectrum device to obtain first Raman spectrum data corresponding to the position of the target interface, or scan the position of the target crack based on a preset Raman spectrum device to obtain second Raman spectrum data corresponding to the position of the target crack, and obtain the stress distribution of the target interface according to the first Raman spectrum data based on a preset strain formula, or obtain the stress distribution of the target crack according to the second Raman spectrum data based on a preset strain formula.

[0024] According to one embodiment of the present application, before scanning the position of the target interface based on a preset Raman spectroscopy device, or scanning the position of the target crack based on a preset Raman spectroscopy device, the Raman spectroscopy analysis module is further used to:

[0025] Using a silicon chip to calibrate the preset Raman spectroscopy device;

[0026] Based on the preset scanning requirements, the laser wavelength, objective lens parameters and confocal pinhole values ​​of the preset Raman spectroscopy device are determined, and the scanning range and number of data points of the preset Raman spectroscopy device are set.

[0027] According to one embodiment of the present application, the preset strain formula is:

[0028]

[0029] Among them, ε is the strain inside the coating, ν is the Poisson's ratio inside the coating, Π is the piezoelectric spectral coefficient, E is the elastic modulus of the dense bulk inside the coating, and Δω is the Raman peak offset inside the coating.

[0030] According to one embodiment of the present application, the target interface includes at least one of an interface between a thermally grown oxide layer and a ceramic surface layer and an interface between layers inside the ceramic surface layer.

[0031] According to one embodiment of the present application, the target crack includes at least one of a crack at the interface between the thermally grown oxide layer and the ceramic surface layer and a crack at the interface between layers inside the ceramic surface layer.

[0032] According to the thermal barrier coating interface characterization device based on CT imaging and 3D Raman spectroscopy of the embodiment of the present application, a base coordinate plane is established with the base of the target thermal barrier coating, and the target thermal barrier coating is imaged and analyzed based on the CT imaging device to obtain a cross-sectional view of the target thermal barrier coating, and a three-dimensional reconstructed image of the target thermal barrier coating is obtained based on the reconstruction software; the three-dimensional reconstructed image corresponds to the three-dimensional space of the base coordinate plane to determine the position of the target interface and the position of the target crack of the target thermal barrier coating; the position of the target interface and the position of the target crack are scanned by the Raman spectroscopy device respectively to obtain the first Raman spectroscopy data and the second Raman spectroscopy data, and then the stress distribution of the target interface and the stress distribution of the target crack are obtained. Thus, the existing coating interface detection method cannot meet the requirements of non-destructive and comprehensive characterization of the internal structure of the coating. By combining CT imaging and 3D Raman spectroscopy technology, the effective observation and measurement of the interface morphology and interface strain of the coating before and after thermal cycling are achieved without destroying the coating. At the same time, it can effectively predict and observe the generation and expansion behavior of cracks in the service process of the thermal barrier coating.

[0033] The third aspect of the present application provides an electronic device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the thermal barrier coating interface characterization method based on CT imaging and 3D Raman spectroscopy as described in the above embodiment.

[0034] The fourth aspect of the present application provides a computer-readable storage medium having a computer program stored thereon, which is executed by a processor to implement the thermal barrier coating interface characterization method based on CT imaging and 3D Raman spectroscopy as described in the above embodiment.

[0035] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0037] Figure 1 It is a structural schematic diagram of a thermal barrier coating detection system according to an embodiment of the present application;

[0038] Figure 2 A flow chart of a method for characterizing the interface of a thermal barrier coating based on CT imaging and 3D Raman spectroscopy according to an embodiment of the present application;

[0039] Figure 3 A CT cross-sectional view and a three-dimensional reconstruction schematic diagram of a YSZ coating according to an embodiment of the present application;

[0040] Figure 4 A three-dimensional distribution diagram of pores and cracks in a YSZ coating sample according to an embodiment of the present application;

[0041] Figure 5 A schematic diagram of a test interface of a YSZ coating Raman spectrometer according to an embodiment of the present application;

[0042] Figure 6 A schematic diagram of different depths of a YSZ coating according to an embodiment of the present application;

[0043] Figure 7 The stress distribution diagram at different depths and interfaces of a YSZ coating tested by CT imaging and Raman spectroscopy according to one embodiment of the present application;

[0044] Figure 8 It is a schematic block diagram of a thermal barrier coating interface characterization device based on CT imaging and 3D Raman spectroscopy according to an embodiment of the present application;

[0045] Fig. 9 Schematic diagram of the structure of an electronic device according to an embodiment of the present application.

[0046] Figure numerals: 1-thermal barrier coating sample and three-dimensional coordinate system, 2-X-ray microscope CT instrument, 3-computer installed with three-dimensional reconstruction software, 4-3D Raman spectrometer, 5-3D Raman spectrometer combined with computer; 10-thermal barrier coating interface characterization device based on CT imaging and 3D Raman spectroscopy, 100-CT imaging and reconstruction module, 200-determination module, 300-Raman spectroscopy analysis module; 901-memory, 902-processor, 903-communication interface. DETAILED DESCRIPTION

[0047] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0048] The following describes the thermal barrier coating interface characterization method based on CT imaging and 3D Raman spectroscopy according to the embodiment of the present application with reference to the accompanying drawings. In view of the problem mentioned in the above background technology that the requirements for non-destructive and comprehensive characterization of the internal structure of the coating cannot be met, the present application provides a thermal barrier coating interface characterization method based on CT imaging and 3D Raman spectroscopy. The standard coating sample is used as a three-dimensional spatial coordinate system, and a data linkage technology based on the voxel of CT imaging technology and the resolution of Raman spectroscopy is established with the coating sample as the link. After linking CT imaging with 3D Raman spectroscopy, the effective observation and measurement of the interface morphology and interface strain of the coating before and after thermal cycling can be achieved without destroying the coating. At the same time, it can effectively predict and observe the generation and expansion behavior of cracks in the service process of the thermal barrier coating.

[0049] Before introducing the thermal barrier coating interface characterization method based on CT imaging and 3D Raman spectroscopy proposed in this application, the thermal barrier coating detection system involved in the thermal barrier coating interface characterization method based on CT imaging and 3D Raman spectroscopy is first introduced.

[0050] Specifically, if Figure 1 As shown, the thermal barrier coating detection system includes a thermal barrier coating sample and a three-dimensional coordinate system 1, an X-ray microscope CT instrument 2, a computer 3 installed with three-dimensional reconstruction software, a 3D Raman spectrometer 4 and a computer 5 associated with the 3D Raman spectrometer.

[0051] The following introduces a thermal barrier coating interface characterization method based on CT imaging and 3D Raman spectroscopy using the above-mentioned thermal barrier coating detection system.

[0052] Specifically, Figure 2A schematic flow chart of a method for characterizing the interface of a thermal barrier coating based on CT imaging and 3D Raman spectroscopy provided in an embodiment of the present application.

[0053] like Figure 2 As shown, the thermal barrier coating interface characterization method based on CT imaging and 3D Raman spectroscopy includes the following steps:

[0054] In step S201, a base coordinate plane is established with the base of the target thermal barrier coating, and the target thermal barrier coating is imaged and analyzed based on a preset CT imaging device to obtain a cross-sectional view of the target thermal barrier coating, and a three-dimensional reconstructed image of the target thermal barrier coating is obtained based on the cross-sectional view of the target thermal barrier coating and preset reconstruction software.

[0055] The preset CT imaging device may be an X-ray microscope CT instrument, and the preset reconstruction software may be software with a three-dimensional reconstruction function in the prior art, which is not specifically limited here.

[0056] Specifically, the embodiment of the present application can obtain a standard sample with a certain size as the target thermal barrier coating, and use the substrate of the target thermal barrier coating as the starting plane of the coordinate axis, that is, establish a substrate coordinate plane with the substrate of the target thermal barrier coating, and use a preset CT imaging device (such as an X-ray microscope CT instrument) to perform imaging analysis on the target thermal barrier coating to obtain multiple cross-sectional grayscale images of the target thermal barrier coating.

[0057] Optionally, in order to obtain the highest possible spatial resolution, when the target thermal barrier coating is imaged using a preset CT imaging device in the embodiment of the present application, the voxel size can be set to a maximum of 1 μm, which is not specifically limited herein.

[0058] Furthermore, by stacking multiple cross-sectional grayscale images using a preset three-dimensional reconstruction software, a three-dimensional reconstructed image of the target thermal barrier coating can be obtained. Further analysis of the three-dimensional reconstructed image can obtain information such as the pore distribution in the target thermal barrier coating.

[0059] In step S202, the three-dimensional reconstructed image is mapped to the three-dimensional space of the base coordinate plane to determine the position of the target interface and the position of the target crack of the target thermal barrier coating.

[0060] Specifically, the 3D reconstructed image corresponds to the 3D space of the base coordinate plane, and different material layers are identified by the difference in grayscale values ​​and morphological features. For example, the interface between the thermally grown oxide layer and the ceramic layer usually has specific grayscale value changes and morphological features. Similarly, cracks will also appear as sudden changes in grayscale values ​​and discontinuities in morphology in the 3D reconstructed image. By carefully observing and analyzing these features, the location and direction of the crack can be determined.

[0061] In step S203, the position of the target interface is scanned based on a preset Raman spectroscopy device to obtain first Raman spectroscopy data corresponding to the position of the target interface, or the position of the target crack is scanned based on a preset Raman spectroscopy device to obtain second Raman spectroscopy data corresponding to the position of the target crack, and based on a preset strain formula, the stress distribution of the target interface is obtained according to the first Raman spectroscopy data, or based on the preset strain formula, the stress distribution of the target crack is obtained according to the second Raman spectroscopy data.

[0062] Optionally, the preset Raman spectroscopy device may be a Raman spectrometer in the prior art.

[0063] In some embodiments, the target interface includes at least one of an interface between a thermally grown oxide layer and a ceramic surface layer, and an interface between layers inside the ceramic surface layer. The target crack includes at least one of a crack at the interface between a thermally grown oxide layer and a ceramic surface layer, and a crack at the interface between layers inside the ceramic surface layer.

[0064] Specifically, the embodiment of the present application can place the target thermal barrier coating sample on the stage of a preset Raman spectroscopic device, and accurately adjust the position of the target thermal barrier coating sample according to the substrate coordinate plane previously obtained by X-ray CT imaging and three-dimensional reconstruction, so that the target interface or target crack is located within the focused spot of the preset Raman spectroscopic device.

[0065] Furthermore, the scanning range and number of data points required by the Raman spectroscopy equipment are set according to the actual situation of the target thermal barrier coating to ensure that the target interface or crack area can be fully covered. For example, a 100μm×100μm area is set in the microscope field of view, and multiple data points (such as 3×3=9 data points) are scanned in this area to obtain more detailed spectral information.

[0066] Furthermore, the embodiment of the present application can scan the position of the target interface based on a preset Raman spectroscopy device to obtain first Raman spectroscopy data corresponding to the position of the target interface, and then output a first peak position imaging image as needed, and further convert it into the stress distribution of the target interface through calculation by a preset strain formula.

[0067] For example, a 3D Raman spectrometer is used to scan and test the interface between the thermally grown oxide layer and the ceramic surface layer to obtain Raman spectrum data corresponding to the interface between the thermally grown oxide layer and the ceramic layer, and based on a preset strain formula, the stress distribution at the interface between the thermally grown oxide layer and the ceramic layer is obtained, thereby analyzing the strain state of the interface between the thermally grown oxide layer and the ceramic layer.

[0068] In addition, the embodiment of the present application can also scan the position of the target crack based on a preset Raman spectroscopy device to obtain second Raman spectroscopy data corresponding to the position of the target crack, and then output a second peak position imaging map as needed, and further convert it into the stress distribution of the target crack through calculation of a preset strain formula.

[0069] For example, a 3D Raman spectrometer is used to scan and test cracks at the interface between layers inside the ceramic surface layer, and Raman spectrum data of the cracks at the interface between layers inside the ceramic surface layer and its vicinity is obtained. Based on a preset strain formula, the stress distribution of the cracks at the interface between layers inside the ceramic surface layer and its vicinity is obtained, and then the strain state near the cracks at the interface between layers inside the ceramic surface layer is analyzed.

[0070] In some embodiments, the preset strain formula is:

[0071]

[0072] Among them, ε is the strain inside the coating, ν is the Poisson's ratio inside the coating, and Π is the piezoelectric spectral coefficient, which can be 2.01cm -1 / GPa. E is the elastic modulus of the dense block inside the coating, and Δω is the Raman peak offset inside the coating. For the YSZ coating, the elastic modulus can be 205GPa, and the stress can be obtained by testing the elastic modulus of the coating. The standard peak position used in the analysis can be 465cm -1 .

[0073] Furthermore, in some embodiments, before scanning the position of the target interface based on the preset Raman spectroscopy device, or scanning the position of the target crack based on the preset Raman spectroscopy device, it also includes: calibrating the preset Raman spectroscopy device using a silicon wafer; based on the preset scanning requirements, determining the laser wavelength, objective lens parameters and confocal pinhole values ​​of the preset Raman spectroscopy device, and setting the scanning range and number of data points of the preset Raman spectroscopy device.

[0074] For example, the present application embodiment can use a silicon wafer to calibrate the Raman spectrometer, using its 520.7 cm -1 In addition, according to the specific scanning requirements, the laser wavelength of the Raman spectrometer can be selected as 532nm or 633nm, and at the same time, it is necessary to ensure that there is no fluorescent background signal.

[0075] Further, the objective lens parameters of the present application include magnification, working distance and numerical aperture (NA). Under the conditions of the present application embodiment, a 50x LWD objective lens is usually selected, with a numerical aperture NA=0.5, a grating of 600gr / mm, and a CCD (silicon-based multi-channel array) detector. The value of the confocal pinhole reflects the system's ability to block out-of-focus signals, which can be 50 to 200.

[0076] Furthermore, after the Raman spectrometer is calibrated and the device parameters of the Raman spectrometer are set, the required scanning range and number of data points are set according to actual scanning requirements, and a scanning test is performed.

[0077] Therefore, by innovatively combining X-ray CT technology and confocal Raman spectroscopy, non-destructive testing of changes in morphology and strain evolution near the interface is carried out to obtain visualized internal structure information of the thermal barrier coating, including the surface layer, bonding layer and substrate, especially the interfaces between layers and within the layers. The strain distribution in specific areas is characterized based on this, and the evolution of the strain state of the coating during service is monitored. This can evaluate the service state of the coating, determine the failure mode of the coating, and provide an experimental and theoretical basis for further optimizing the coating preparation process.

[0078] In order to help those skilled in the art to more clearly and intuitively understand the thermal barrier coating interface characterization method based on CT imaging and 3D Raman spectroscopy proposed in the present application, it is described in detail below in conjunction with specific embodiments.

[0079] The detection system used in the thermal barrier coating interface characterization method based on CT imaging and 3D Raman spectroscopy in the embodiment of the present application includes an X-ray microscope CT instrument, a computer installed with three-dimensional reconstruction software, a 3D Raman spectrometer and a connected computer, wherein the computer installed with the three-dimensional reconstruction software is used to perform three-dimensional reconstruction of the coating interface morphology and nearby structures, and ultimately determine the specific position of the internal interface of the coating; the 3D Raman spectrometer and the connected computer are used to characterize the Raman spectral information near the interface, so as to facilitate the subsequent calculation of the coating interface strain size through the Raman peak offset.

[0080] Specifically, firstly, the thermal barrier coating sample of the embodiment of the present application is a YSZ coating obtained by atmospheric plasma spraying, and the complete structure of the coating is a YSZ ceramic surface layer, a metal bonding layer and a high-temperature alloy substrate.

[0081] Secondly, when using X-ray CT imaging, a 1mm×1mm×1mm area is selected for analysis, and the area includes all layers and the surface to obtain more comprehensive information. Figure 3 The CT cross-sectional view and three-dimensional reconstruction image of the thermal barrier coating sample of the embodiment of the present application are shown. Figure 3 (a) and Figure 3(b) The YSZ layer, bonding layer and high-temperature alloy substrate can be clearly distinguished, and the interfaces of each layer have a certain degree of roughness. The thickness of the YSZ coating is about 350μm, and the dark area in the YSZ layer is the pore; the thickness of the bonding layer is about 100μm. Figure 3 (c) is a cross-sectional view of the interface between YSZ and the bonding layer. Due to the roughness of the interface, the two are staggered. Figure 3 As shown in (d), through three-dimensional reconstruction, the conditions of each layer and pores can be intuitively observed.

[0082] The advantage of the CT technology used in the embodiment of the present application is that the internal information of the material can be obtained. A cuboid is cut in the YSZ layer, and the gray value of the pore is significantly greater than the YSZ gray value. Based on this, the pore can be identified and a three-dimensional distribution map of the pore can be obtained. Figure 4 The image processing process is shown. Figure 4 (a) is the process of selecting a rectangular region from the YSZ layer. Figure 4 (b) is the process of marking the pore positions in the rectangular area according to the grayscale. Figure 4 (c) The process of extracting pores and obtaining the three-dimensional distribution of pores. It can be seen from the pore distribution diagram that the pores are evenly distributed in the YSZ layer.

[0083] Furthermore, before using the Raman spectrometer to perform Raman spectrum testing on the YSZ coating, the area within the microscope field of view of the Raman spectrometer is tested first, and the field of view range is set to 100 μm×100 μm, and 3×3=9 data points are scanned in this area, such as Figure 5 As shown, the spectrum and summary of each data point are reflected, and the characteristic peak position is imaged, such as Figure 5 As shown in the lower right, further data processing of this image can obtain the stress value corresponding to each point. In addition, a larger plane area can be selected, or multiple areas of the above size can be selected on the YSZ coating according to experimental needs, and tested separately to obtain the average stress of the entire coating. Figure 6 As shown in the figure, a large range of the sample (6000 μm × 6000 μm) was scanned, and a range of 200 μm was further selected in the vertical direction (depth) within the selected area, and the 200 μm depth was divided into three different layers at different depths (i.e. Figure 6 1, 2, 3 and 4) in the figure are used to perform surface scanning, and finally the imaging is converted into stress distribution. The stress distribution results at different depths and interfaces are as follows: Figure 7 As shown, any depth position can be tested. By selecting a specific depth and data point distribution based on the CT results, the stress characterization near the interface between the surface layer and the bonding layer can be achieved.

[0084] Therefore, through the thermal barrier coating interface characterization method based on CT imaging and 3D Raman spectroscopy proposed in this application, after linking CT imaging with 3D Raman spectroscopy, the characterization and measurement of the interface morphology and interface strain of the coating before and after thermal cycling are successfully achieved, which has good practicality.

[0085] According to the thermal barrier coating interface characterization method based on CT imaging and 3D Raman spectroscopy of the embodiment of the present application, a base coordinate plane is established with the base of the target thermal barrier coating, and the target thermal barrier coating is imaged and analyzed based on the CT imaging device to obtain a cross-sectional view of the target thermal barrier coating, and a three-dimensional reconstructed image of the target thermal barrier coating is obtained based on the reconstruction software; the three-dimensional reconstructed image corresponds to the three-dimensional space of the base coordinate plane to determine the position of the target interface and the position of the target crack of the target thermal barrier coating; the position of the target interface and the position of the target crack are scanned by the Raman spectroscopy device respectively to obtain the first Raman spectroscopy data and the second Raman spectroscopy data, and then the stress distribution of the target interface and the stress distribution of the target crack are obtained. Thus, the existing coating interface detection method cannot meet the requirements of non-destructive and comprehensive characterization of the internal structure of the coating. By combining CT imaging and 3D Raman spectroscopy technology, the effective observation and measurement of the interface morphology and interface strain of the coating before and after thermal cycling are achieved without destroying the coating. At the same time, it can effectively predict and observe the generation and expansion behavior of cracks in the service process of the thermal barrier coating.

[0086] Next, a thermal barrier coating interface characterization device based on CT imaging and 3D Raman spectroscopy proposed in accordance with an embodiment of the present application will be described with reference to the accompanying drawings.

[0087] Figure 8 It is a block diagram of a thermal barrier coating interface characterization device based on CT imaging and 3D Raman spectroscopy according to an embodiment of the present application.

[0088] like Figure 8 As shown, the thermal barrier coating interface characterization device 10 based on CT imaging and 3D Raman spectroscopy includes: a CT imaging and reconstruction module 100 , a determination module 200 and a Raman spectroscopy analysis module 300 .

[0089] Among them, the CT imaging and reconstruction module 100 is used to establish a substrate coordinate plane with the substrate of the target thermal barrier coating, perform imaging analysis on the target thermal barrier coating based on a preset CT imaging device, obtain a cross-sectional view of the target thermal barrier coating, and obtain a three-dimensional reconstructed image of the target thermal barrier coating based on the cross-sectional view of the target thermal barrier coating and a preset reconstruction software; the determination module 200 is used to correspond the three-dimensional reconstructed image to the three-dimensional space of the substrate coordinate plane, and determine the position of the target interface and the position of the target crack of the target thermal barrier coating; the Raman spectrum analysis module 300 is used to scan the position of the target interface based on a preset Raman spectrum device to obtain first Raman spectrum data corresponding to the position of the target interface, or scan the position of the target crack based on a preset Raman spectrum device to obtain second Raman spectrum data corresponding to the position of the target crack, obtain the stress distribution of the target interface according to the first Raman spectrum data based on a preset strain formula, or obtain the stress distribution of the target crack according to the second Raman spectrum data based on a preset strain formula.

[0090] Furthermore, in some embodiments, before scanning the position of the target interface based on the preset Raman spectroscopy device, or scanning the position of the target crack based on the preset Raman spectroscopy device, the Raman spectroscopy analysis module 300 is also used to: calibrate the preset Raman spectroscopy device using a silicon wafer; determine the laser wavelength, objective lens parameters and confocal pinhole values ​​of the preset Raman spectroscopy device based on preset scanning requirements, and set the scanning range and number of data points of the preset Raman spectroscopy device.

[0091] Furthermore, in some embodiments, the preset strain formula is:

[0092]

[0093] Among them, ε is the strain inside the coating, ν is the Poisson's ratio inside the coating, Π is the piezoelectric spectral coefficient, E is the elastic modulus of the dense bulk inside the coating, and Δω is the Raman peak offset inside the coating.

[0094] Further, in some embodiments, the target interface includes at least one of an interface between a thermally grown oxide layer and a ceramic surface layer, and an interface between layers inside the ceramic surface layer.

[0095] Further, in some embodiments, the target crack includes at least one of a crack at an interface between the thermally grown oxide layer and the ceramic surface layer, and a crack at an interface between layers inside the ceramic surface layer.

[0096] It should be noted that the aforementioned explanation of the embodiment of the thermal barrier coating interface characterization method based on CT imaging and 3D Raman spectroscopy is also applicable to the thermal barrier coating interface characterization device based on CT imaging and 3D Raman spectroscopy in this embodiment, and will not be repeated here.

[0097] According to the thermal barrier coating interface characterization device based on CT imaging and 3D Raman spectroscopy of the embodiment of the present application, a base coordinate plane is established with the base of the target thermal barrier coating, and the target thermal barrier coating is imaged and analyzed based on the CT imaging device to obtain a cross-sectional view of the target thermal barrier coating, and a three-dimensional reconstructed image of the target thermal barrier coating is obtained based on the reconstruction software; the three-dimensional reconstructed image corresponds to the three-dimensional space of the base coordinate plane to determine the position of the target interface and the position of the target crack of the target thermal barrier coating; the position of the target interface and the position of the target crack are scanned by the Raman spectroscopy device respectively to obtain the first Raman spectroscopy data and the second Raman spectroscopy data, and then the stress distribution of the target interface and the stress distribution of the target crack are obtained. Thus, the existing coating interface detection method cannot meet the requirements of non-destructive and comprehensive characterization of the internal structure of the coating. By combining CT imaging and 3D Raman spectroscopy technology, the effective observation and measurement of the interface morphology and interface strain of the coating before and after thermal cycling are achieved without destroying the coating. At the same time, it can effectively predict and observe the generation and expansion behavior of cracks in the service process of the thermal barrier coating.

[0098] Fig. 9 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. The electronic device may include:

[0099] A memory 901 , a processor 902 , and a computer program stored in the memory 901 and executable on the processor 902 .

[0100] When the processor 902 executes the program, the thermal barrier coating interface characterization method based on CT imaging and 3D Raman spectroscopy provided in the above embodiment is implemented.

[0101] Furthermore, the electronic device further comprises:

[0102] The communication interface 903 is used for communication between the memory 901 and the processor 902 .

[0103] The memory 901 is used to store computer programs that can be executed on the processor 902 .

[0104] The memory 901 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0105] If the memory 901, the processor 902 and the communication interface 903 are implemented independently, the communication interface 903, the memory 901 and the processor 902 can be connected to each other through a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Fig. 9 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0106] Optionally, in a specific implementation, if the memory 901, the processor 902 and the communication interface 903 are integrated on a chip, the memory 901, the processor 902 and the communication interface 903 can communicate with each other through an internal interface.

[0107] The processor 902 may be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0108] An embodiment of the present application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-mentioned thermal barrier coating interface characterization method based on CT imaging and 3D Raman spectroscopy.

[0109] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0110] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0111] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for characterizing the interface of thermal barrier coatings based on CT imaging and 3D Raman spectroscopy, characterized in that: The following steps are involved: Establishing a base coordinate plane with the base of the target thermal barrier coating, performing imaging analysis on the target thermal barrier coating based on a preset CT imaging device to obtain a cross-sectional view of the target thermal barrier coating, and obtaining a three-dimensional reconstructed image of the target thermal barrier coating based on the cross-sectional view of the target thermal barrier coating and preset reconstruction software; Corresponding the three-dimensional reconstructed image to the three-dimensional space of the base coordinate plane, determining the position of the target interface and the position of the target crack of the target thermal barrier coating; The position of the target interface is scanned based on a preset Raman spectroscopy device to obtain first Raman spectroscopy data corresponding to the position of the target interface, or the position of the target crack is scanned based on a preset Raman spectroscopy device to obtain second Raman spectroscopy data corresponding to the position of the target crack, and based on a preset strain formula, the stress distribution of the target interface is obtained according to the first Raman spectroscopy data, or based on a preset strain formula, the stress distribution of the target crack is obtained according to the second Raman spectroscopy data.

2. The method according to claim 1, characterized in that Before scanning the position of the target interface based on a preset Raman spectroscopy device, or scanning the position of the target crack based on a preset Raman spectroscopy device, the method further includes: Using a silicon chip to calibrate the preset Raman spectroscopy device; Based on the preset scanning requirements, the laser wavelength, objective lens parameters and confocal pinhole values ​​of the preset Raman spectroscopy device are determined, and the scanning range and number of data points of the preset Raman spectroscopy device are set.

3. The method according to claim 1, characterized in that The preset strain formula is: Among them, ε is the strain inside the coating, ν is the Poisson's ratio inside the coating, Π is the piezoelectric spectral coefficient, E is the elastic modulus of the dense bulk inside the coating, and Δω is the Raman peak offset inside the coating.

4. The method according to claim 1, characterized in that: The target interface includes at least one of an interface between a thermally grown oxide layer and a ceramic surface layer and an interface between layers inside the ceramic surface layer.

5. The method according to claim 1, characterized in that The target cracks include at least one of cracks at the interface between the thermally grown oxide layer and the ceramic surface layer and cracks at the interface between layers inside the ceramic surface layer.

6. A thermal barrier coating interface characterization device based on CT imaging and 3D Raman spectroscopy, characterized in that: include: A CT imaging and reconstruction module, for establishing a base coordinate plane with a base of a target thermal barrier coating, performing imaging analysis on the target thermal barrier coating based on a preset CT imaging device, obtaining a cross-sectional view of the target thermal barrier coating, and obtaining a three-dimensional reconstructed image of the target thermal barrier coating based on the cross-sectional view of the target thermal barrier coating and preset reconstruction software; A determination module, used to correspond the three-dimensional reconstructed image to the three-dimensional space of the base coordinate plane, and determine the position of the target interface and the position of the target crack of the target thermal barrier coating; A Raman spectrum analysis module is used to scan the position of the target interface based on a preset Raman spectrum device to obtain first Raman spectrum data corresponding to the position of the target interface, or scan the position of the target crack based on a preset Raman spectrum device to obtain second Raman spectrum data corresponding to the position of the target crack, and obtain the stress distribution of the target interface according to the first Raman spectrum data based on a preset strain formula, or obtain the stress distribution of the target crack according to the second Raman spectrum data based on a preset strain formula.

7. The device according to claim 6, characterized in that Before scanning the position of the target interface based on a preset Raman spectroscopy device, or scanning the position of the target crack based on a preset Raman spectroscopy device, the Raman spectroscopy analysis module is further used to: Using a silicon chip to calibrate the preset Raman spectroscopy device; Based on the preset scanning requirements, the laser wavelength, objective lens parameters and confocal pinhole values ​​of the preset Raman spectroscopy device are determined, and the scanning range and number of data points of the preset Raman spectroscopy device are set.

8. The device according to claim 6, characterized in that The preset strain formula is: Among them, ε is the strain inside the coating, ν is the Poisson's ratio inside the coating, Π is the piezoelectric spectral coefficient, E is the elastic modulus of the dense bulk inside the coating, and Δω is the Raman peak offset inside the coating.

9. An electronic device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the thermal barrier coating interface characterization method based on CT imaging and 3D Raman spectroscopy as described in any one of claims 1 to 5.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: The program is executed by a processor to implement the thermal barrier coating interface characterization method based on CT imaging and 3D Raman spectroscopy as described in any one of claims 1 to 5.

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