Method for characterizing thermal barrier coating interfaces based on ct imaging and 3d raman spectroscopy

Abstract

The application relates to a thermal barrier coating interface characterization method based on CT imaging and 3D Raman spectroscopy. The method comprises the following steps: establishing a substrate coordinate plane with the substrate of a target thermal barrier coating; performing imaging analysis on the target thermal barrier coating based on a CT imaging device to obtain a cross-sectional diagram and a three-dimensional reconstruction image based on reconstruction software; determining the positions of a target interface and a target crack of the target thermal barrier coating in the three-dimensional space corresponding to the substrate coordinate plane of the three-dimensional reconstruction image; and scanning the positions of the target interface and the target crack by using a Raman spectroscopy device to obtain first Raman spectroscopy data and second Raman spectroscopy data, and then obtaining the stress distribution of the target interface and the stress distribution of the target crack. Thus, the existing coating interface detection method cannot meet the requirements of nondestructive and comprehensive characterization of the internal structure of the coating, and the effective observation and measurement of the interface morphology and interface strain before and after the thermal cycle of the coating are realized without damaging the coating.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of non-destructive characterization of high-temperature gas turbine and aerospace engine hot-end protective coatings, and particularly relates to a thermal barrier coating interface characterization method based on CT (Computed Tomography) imaging and 3D Raman spectroscopy. BACKGROUND

[0002] Thermal barrier coatings (TBCs) are mainly used in gas turbines and aircraft engines, and can realize a temperature difference of hundreds of degrees Celsius between the inside and the outside by being attached to the surface of a metal substrate, thereby avoiding the erosion of the components by high temperatures and the environment, allowing the components to work normally and improving thermal efficiency. A thermal barrier coating system generally includes the following parts: a metal substrate, a bonding layer (such as NiCoCrAlY, nickel-cobalt-chromium-aluminum-yttrium), a thermal growth oxide (TGO), and a ceramic surface layer, wherein the ceramic surface layer generally has metal oxides as the main component, and the most commonly used one at present is 6-8wt% YSZ (yttrium stabilized zirconia) ceramic.

[0003] During the service of the thermal barrier coating material, the porosity of the coating gradually decreases, and a thermal growth oxide layer appears, the former causes the thermal conductivity of the coating to increase, and the continuous growth of the TGO thickness may eventually cause the coating to peel off. The YSZ coating structure is the most commonly used thermal barrier coating structure, and therefore, it is necessary to adopt a non-destructive testing method to track the changes in the YSZ coating structure, so as to evaluate the service status of the coating and predict the failure of the coating in advance.

[0004] The interfaces in the thermal barrier coating mainly include the TGO layer and the ceramic layer interface, and the interfaces between the layers in the ceramic layer, and these interfaces are the main part of crack generation and expansion, and are also the main reason for the failure of the coating.

[0005] However, the traditional method for detecting the interface of the thermal barrier coating often cannot simultaneously meet the requirements of non-destructive, high precision, and comprehensive characterization of the internal structure of the coating, and needs to be solved urgently. SUMMARY

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

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

[0008] establishing a substrate coordinate plane based on a substrate 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 reconstruction image of the target thermal barrier coating based on the cross-sectional view of the target thermal barrier coating and a preset reconstruction software;

[0009] determining a position of a target interface and a position of a target crack of the target thermal barrier coating based on a three-dimensional space corresponding to the substrate coordinate plane of the three-dimensional reconstruction image;

[0010] scanning 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 scanning the position of the target crack based on the preset Raman spectrum device to obtain second Raman spectrum data corresponding to the position of the target crack, and obtaining a stress distribution of the target interface based on a preset strain formula according to the first Raman spectrum data, or obtaining a stress distribution of the target crack based on the preset strain formula according to the second Raman spectrum data.

[0011] According to an embodiment of the present application, before scanning the position of the target interface based on the preset Raman spectrum device or scanning the position of the target crack based on the preset Raman spectrum device, the method further comprises:

[0012] calibrating the preset Raman spectrum device using a silicon wafer;

[0013] determining a laser wavelength, an objective lens parameter, and a numerical value of a confocal pinhole of the preset Raman spectrum device based on a preset scanning requirement, and setting a scanning range and a data point quantity of the preset Raman spectrum device.

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

[0015]

[0016] wherein ε is a strain size inside the coating, v is a Poisson's ratio inside the coating, Π is a piezoelectric spectrum coefficient, E is an elastic modulus of a dense block inside the coating, and Δω is a Raman peak shift inside the coating.

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

[0018] According to an embodiment of the present application, the target crack comprises at least one of a crack of an interface between the thermal growth oxide layer and the ceramic surface layer, and a crack of an interface between layers inside the ceramic surface layer.

[0019] The method for characterizing a thermal barrier coating interface based on CT imaging and 3D Raman spectroscopy according to the embodiments of the present application establishes a substrate coordinate plane based on the substrate of the target thermal barrier coating, performs imaging analysis on the target thermal barrier coating based on a CT imaging device, obtains a cross-sectional image of the target thermal barrier coating, and obtains a three-dimensional reconstruction image of the target thermal barrier coating based on reconstruction software; determines the position of a target interface and the position of a target crack of the target thermal barrier coating by mapping the three-dimensional reconstruction image to a three-dimensional space corresponding to the substrate coordinate plane; and scans the position of the target interface and the position of the target crack using a Raman spectroscopy device to obtain first Raman spectroscopy data and second Raman spectroscopy data, and further obtain the stress distribution of the target interface and the stress distribution of the target crack. Thus, the existing coating interface detection method cannot meet the requirements of non-destructive and comprehensive characterization of the internal structure of the coating, and by combining CT imaging and 3D Raman spectroscopy technology, the interface morphology and interface strain before and after the thermal cycle of the coating are effectively observed and measured without damaging the coating. At the same time, the generation and expansion behavior of cracks in the thermal barrier coating during service can be effectively predicted and observed.

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

[0021] A CT imaging and reconstruction module is configured to establish a substrate coordinate plane based on the substrate of a target thermal barrier coating, perform imaging analysis on the target thermal barrier coating based on a preset CT imaging device, obtain a cross-sectional image of the target thermal barrier coating, and obtain a three-dimensional reconstruction image of the target thermal barrier coating based on the cross-sectional image of the target thermal barrier coating and a preset reconstruction software.

[0022] A determination module is configured to map the three-dimensional reconstruction image to a three-dimensional space corresponding to the substrate coordinate plane, and determine the position of a target interface and the position of a target crack of the target thermal barrier coating.

[0023] A Raman spectroscopy analysis module is configured to 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, or 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, obtain the stress distribution of the target interface based on a preset strain formula according to the first Raman spectroscopy data, or obtain the stress distribution of the target crack based on a preset strain formula according to the second Raman spectroscopy data.

[0024] According to an 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 configured to:

[0025] calibrating the preset Raman spectrum device using a silicon wafer;

[0026] Based on the preset scanning requirements, the laser wavelength, objective lens parameter and numerical value of the confocal pinhole of the preset Raman spectrum device are determined, and the scanning range and data point quantity of the preset Raman spectrum device are set.

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

[0028]

[0029] wherein ε is the strain size inside the coating, v is the Poisson's ratio inside the coating, Π is the piezoelectric spectrum coefficient, E is the elastic modulus of the dense block inside the coating, and Δω is the Raman peak shift inside the coating.

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

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

[0032] The device for thermal barrier coating interface characterization based on CT imaging and 3D Raman spectrum according to the embodiment of the present application establishes a substrate coordinate plane based on the substrate of the target thermal barrier coating, performs imaging analysis on the target thermal barrier coating based on a CT imaging device, obtains a cross-sectional diagram of the target thermal barrier coating, and obtains a three-dimensional reconstruction image of the target thermal barrier coating based on reconstruction software; determines the position of the target interface and the position of the target crack of the target thermal barrier coating by corresponding the three-dimensional space of the three-dimensional reconstruction image to the substrate coordinate plane; scans the position of the target interface and the position of the target crack by using a Raman spectrum device respectively, obtains first Raman spectrum data and second Raman spectrum data, and further obtains the stress distribution of the target interface and the stress distribution of the target crack. Thus, the existing coating interface detection method cannot meet the requirements of non-destructive and comprehensive characterization of the internal structure of the coating, and by combining the CT imaging and 3D Raman spectrum technology, the interface morphology and interface strain before and after the thermal cycle of the coating are effectively observed and measured without damaging the coating. At the same time, the generation and expansion behavior of the crack of the thermal barrier coating during service can be effectively predicted and observed.

[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 method for characterizing thermal barrier coating interface based on CT imaging and 3D Raman spectroscopy according to the above-mentioned embodiments.

[0034] The fourth aspect of the present application provides a computer readable storage medium, which stores a computer program executable by a processor to implement the method for characterizing thermal barrier coating interface based on CT imaging and 3D Raman spectroscopy according to the above-mentioned embodiments.

[0035] Additional aspects and advantages of the present application will be made apparent by the following description and the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0036] The above and / or additional aspects and advantages of the present application will become apparent and be readily appreciated from the following description, including the accompanying drawings.

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

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

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

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

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

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

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

[0044] Figure 8 Block diagram of a device for characterizing thermal barrier coating interface based on CT imaging and 3D Raman spectroscopy according to an embodiment of the present application;

[0045] Figure 9 Structure schematic diagram of electronic device according to embodiments of the present application.

[0046] Fig. 1 is a structure schematic diagram of the thermal barrier coating sample and a three-dimensional coordinate system; Fig. 2 is a schematic diagram of an X-ray microscope CT instrument; Fig. 3 is a schematic diagram of a computer installed with three-dimensional reconstruction software; Fig. 4 is a schematic diagram of a 3D Raman spectrometer; Fig. 5 is a schematic diagram of a 3D Raman spectrometer associated computer; Fig. 10 is a schematic diagram of a thermal barrier coating interface characterization device based on CT imaging and 3D Raman spectroscopy; Fig. 100 is a CT imaging and reconstruction module; Fig. 200 is a determination module; Fig. 300 is a Raman spectrum analysis module; Fig. 901 is a storage; Fig. 902 is a processor; and Fig. 903 is a communication interface. DETAILED DESCRIPTION

[0047] Embodiments of the present application are described in detail below with reference to the accompanying drawings, wherein the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the accompanying drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0048] A thermal barrier coating interface characterization method based on CT imaging and 3D Raman spectroscopy according to embodiments of the present application is described below with reference to the accompanying drawings. In view of the problem that the coating internal structure cannot be fully and non-destructively characterized mentioned in the background art, the present application provides a thermal barrier coating interface characterization method based on CT imaging and 3D Raman spectroscopy. A standard coating sample is taken 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. After the linkage of CT imaging and 3D Raman spectroscopy, the interface morphology and interface strain before and after the thermal cycle of the coating can be effectively observed and measured without damaging the coating. At the same time, the generation and expansion behavior of cracks in the thermal barrier coating during service can be effectively predicted and observed.

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

[0050] Specifically, as shown in Figure 1 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 installed with three-dimensional reconstruction software 3, a 3D Raman spectrometer 4, and a 3D Raman spectrometer associated computer 5.

[0051] The thermal barrier coating interface characterization method based on CT imaging and 3D Raman spectroscopy using the above thermal barrier coating detection system is introduced below.

[0052] Specifically, Figure 2A flowchart of a thermal barrier coating interface characterization method based on CT imaging and 3D Raman spectroscopy is provided for the embodiments of the present application.

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

[0054] In step S201, a substrate coordinate plane is established based on the substrate of the target thermal barrier coating, a preset CT imaging device is used to analyze the target thermal barrier coating, a cross-sectional image of the target thermal barrier coating is obtained, and a three-dimensional reconstruction image of the target thermal barrier coating is obtained based on the cross-sectional image of the target thermal barrier coating and a preset reconstruction software.

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

[0056] Specifically, the embodiments of the present application can obtain a standard sample with a certain size as a target thermal barrier coating, and a substrate of the target thermal barrier coating is used as a coordinate axis starting plane, that is, a substrate coordinate plane is established based on the substrate of the target thermal barrier coating. A preset CT imaging device (such as an X-ray microscope CT instrument) is used to analyze the target thermal barrier coating, and a plurality of cross-sectional gray scale images of the target thermal barrier coating are obtained.

[0057] Optionally, in order to obtain the highest possible spatial resolution, the voxel size can be set to the highest 1 μm when the preset CT imaging device is used to analyze the target thermal barrier coating, which is not limited here.

[0058] Further, the plurality of cross-sectional gray scale images can be stacked using a preset three-dimensional reconstruction software to obtain a three-dimensional reconstruction image of the target thermal barrier coating. Further analysis of the three-dimensional reconstruction image can obtain information such as the pore distribution in the target thermal barrier coating.

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

[0060] Specifically, the three-dimensional space corresponding to the substrate coordinate plane of the three-dimensional reconstruction image is used to identify different material layers through the difference in gray value and morphological characteristics. For example, the interface between the thermal growth oxide layer and the ceramic layer usually has a specific gray value change and morphological characteristics. Similarly, the crack in the three-dimensional reconstruction image also shows a sudden change in gray value and discontinuity in morphology. By carefully observing and analyzing these characteristics, the position and direction of the crack can be determined.

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

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

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

[0064] Specifically, the target thermal barrier coating sample can be placed on the object stage of the preset Raman spectrum device, and the position of the target thermal barrier coating sample is accurately adjusted according to the substrate coordinate plane obtained by X-ray CT imaging and three-dimensional reconstruction in advance, so that the target interface or the target crack is located in the focusing spot of the preset Raman spectrum device.

[0065] Further, the scanning range and the number of data points required by the Raman spectrum device 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 100 μm x 100 μm area is set in the field of view of the microscope, and a plurality of data points (such as 3 x 3 = 9 data points) are scanned in the area to obtain more detailed spectrum information.

[0066] Further, the preset Raman spectrum device can be used to scan the position of the target interface to obtain first Raman spectrum data corresponding to the position of the target interface, and then the first peak position imaging map can be output as needed, and the stress distribution of the target interface can be further converted through the preset strain formula calculation.

[0067] For example, the interface between the thermal growth oxide layer and the ceramic surface layer is scanned and tested by using a 3D Raman spectrometer to obtain Raman spectrum data corresponding to the interface between the thermal growth oxide layer and the ceramic layer, and the stress distribution of the interface between the thermal growth oxide layer and the ceramic layer is obtained based on a preset strain formula, and then the strain state of the interface between the thermal growth oxide layer and the ceramic layer is analyzed.

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

[0069] For example, the 3D Raman spectrometer is used to scan and test the cracks between the internal layers of the ceramic surface layer, obtain the Raman spectrum data of the cracks between the internal layers of the ceramic surface layer and its vicinity, and obtain the stress distribution of the cracks between the internal layers of the ceramic surface layer and its vicinity based on the preset strain formula, and then analyze the strain state near the cracks between the internal layers of the ceramic surface layer.

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

[0071]

[0072] Wherein, ε is the strain size inside the coating, v is the Poisson's ratio inside the coating, Π is the piezoelectric spectrum coefficient, and the value can be 2.01 cm -1 / GPa. E is the elastic modulus of the dense block inside the coating, and Δω is the Raman peak shift inside the coating. For YSZ coating, the elastic modulus can be 205 GPa, the stress can be obtained by testing the elastic modulus of the coating, and the standard peak position used in the analysis can be 465 cm -1 .

[0073] Further, in some embodiments, before scanning the position of the target interface based on the preset Raman spectrum device or scanning the position of the target crack based on the preset Raman spectrum device, the preset Raman spectrum device is calibrated using a silicon wafer; based on the preset scanning requirements, the laser wavelength, objective lens parameter and the value of the confocal pinhole of the preset Raman spectrum device are determined, and the scanning range and data point quantity of the preset Raman spectrum device are set.

[0074] For example, the embodiment of the present application can use a silicon wafer to calibrate the Raman spectrometer, and use the characteristic peak at 520.7 cm -1 to eliminate instrument errors. In addition, according to specific scanning requirements, the laser wavelength of the Raman spectrometer can be selected as 532 nm or 633 nm, while ensuring no fluorescent background signal.

[0075] Further, the objective parameters of the present application include magnification, working distance and numerical aperture (NA), and in the present application, a 50x LWD objective is usually selected, the numerical aperture NA=0.5, the grating is 600 gr / mm, and the detector is a CCD (silicon-based multi-channel array) detector. The numerical value of the confocal pinhole reflects the blocking ability of the system to signals outside the focal point, and can be 50-200.

[0076] Further, after the calibration of the Raman spectrometer and the setting of the device parameters of the Raman spectrometer are completed, the present application embodiment sets the required scanning range and the number of data points according to the actual scanning requirements, and performs scanning test.

[0077] Thus, by innovatively combining X-ray CT technology and confocal Raman spectroscopy, the changes in the morphology near the interface and the evolution of the strain are non-destructively detected to obtain visualized internal structure information of the thermal barrier coating, including the surface layer, the bonding layer and the substrate, especially the interface information between and within the layers, and the strain distribution in a specific region is characterized according to the interface information, the evolution of the strain state in the coating during service is monitored, the service state of the coating can be evaluated, the failure mode of the coating is judged, and experimental and theoretical basis for further optimizing the preparation process of the coating is provided.

[0078] In order to make the person skilled in the art more clearly and intuitively understand the thermal barrier coating interface characterization method based on CT imaging and 3D Raman spectroscopy proposed by the present application, specific embodiments will be described in detail below.

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

[0080] Specifically, first, the thermal barrier coating sample of the present application embodiment 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 region of 1mmx1mmx1mm is selected for analysis, and the region includes each layer and the surface to obtain more comprehensive information. Figure 3 The CT cross-sectional diagram and the three-dimensional reconstruction diagram of the thermal barrier coating sample of the present application embodiment are shown. Figure 3 (a) and Figure 3(b)YSZ layer, bonding layer and superalloy substrate can be distinguished clearly, and each layer has a certain roughness at the interface. The thickness of YSZ coating is about 350 μm, and the dark area in YSZ layer is a pore; the thickness of bonding layer is about 100 μm. Figure 3 (c) is a cross-sectional view at the interface between YSZ and bonding layer, and the two are staggered due to the interface roughness. As shown in Figure 3 (d), the layer and pore condition can be observed intuitively by three-dimensional reconstruction.

[0082] The CT technology used in the embodiments of the present application has the advantage of obtaining internal information of the material. A cuboid is taken from the YSZ layer, and the gray value of the pore is obviously greater than the gray value of YSZ, so the pore can be identified and the three-dimensional distribution of the pore can be obtained, Figure 4 the image processing process is shown, Figure 4 (a) is the process of selecting a cuboid region from the YSZ layer, Figure 4 (b) is the process of marking the pore position in the cuboid region according to the gray value, Figure 4 (c) is the process of extracting the pore and obtaining the three-dimensional distribution of the pore. As shown in the pore distribution map, the pores are uniformly distributed in the YSZ layer.

[0083] Further, before the Raman spectrum test of the YSZ coating is performed by using the Raman spectrometer, the area in the field of view of the microscope of the Raman spectrometer is tested first, and the field of view range is set to 100 μm×100 μm, 3×3=9 data points are scanned in the area, as shown in Figure 5 the spectrum of each data point and the summary are shown, and the characteristic peak position is imaged, as shown in Figure 5 the right lower part, the imaging map is further processed to obtain the stress value corresponding to each point. In addition, a larger planar region can be selected, or a plurality of regions of the above size can be selected on the YSZ coating according to the experimental needs, and the test is performed respectively to obtain the average stress size of the whole coating. As shown in Figure 6 a larger range (6000 μm×6000 μm) of the sample is scanned, and a range of 200 μm in the vertical direction (depth) is selected in the selected area, the 200 μm depth is divided into three different layers, and the surface scanning is performed at different depths (i.e. Figure 6 1, 2, 3 and 4 in Figure 7 ), and finally the imaging is converted into stress distribution, in which the stress distribution results at different depths and interfaces are shown in Figure 7 , so that the test can be performed at any depth position. According to the results of the CT, the specific depth and data point distribution can be selected to realize the stress characterization near the interface between the surface layer and the bonding layer.

[0084] Therefore, by the thermal barrier coating interface characterization method based on CT imaging and 3D Raman spectrum provided in the application, after the CT imaging and 3D Raman spectrum are linked, the interface morphology and interface strain before and after the coating thermal cycle are successfully characterized and measured, and the method has good practicability.

[0085] According to the thermal barrier coating interface characterization method based on CT imaging and 3D Raman spectrum provided in the embodiments of the application, the substrate coordinate plane is established based on the substrate of the target thermal barrier coating, the target thermal barrier coating is analyzed based on the CT imaging device, the cross-sectional view of the target thermal barrier coating is obtained, and the three-dimensional reconstruction image of the target thermal barrier coating is obtained based on the reconstruction software; the three-dimensional space corresponding to the substrate coordinate plane of the three-dimensional reconstruction image is determined to determine the position of the target interface and the position of the target crack of the target thermal barrier coating; the Raman spectrum device is used to scan the position of the target interface and the position of the target crack, respectively, to obtain the first Raman spectrum data and the second Raman spectrum data, and then the stress distribution of the target interface and the stress distribution of the target crack are obtained. Therefore, the existing coating interface detection method cannot meet the requirements of nondestructive and comprehensive characterization of the internal structure of the coating, and by combining the CT imaging and 3D Raman spectrum technology, the effective observation and measurement of the interface morphology and interface strain before and after the coating thermal cycle are realized without damaging the coating. At the same time, the generation and expansion behavior of the crack in the thermal barrier coating during the service process can be effectively predicted and observed.

[0086] Secondly, the thermal barrier coating interface characterization device based on CT imaging and 3D Raman spectrum provided in the embodiments of the application is described with reference to the accompanying drawings.

[0087] Figure 8 is the block schematic diagram of the thermal barrier coating interface characterization device based on CT imaging and 3D Raman spectrum in the embodiments of the application.

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

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

[0090] Further, in some embodiments, before the scanning of the position of the target interface based on the preset Raman spectrum device or the scanning of the position of the target crack based on the preset Raman spectrum device, the Raman spectrum analysis module 300 is further configured to calibrate the preset Raman spectrum device by using a silicon wafer; determine a laser wavelength, an objective lens parameter and a numerical value of a confocal pinhole of the preset Raman spectrum device based on a preset scanning requirement, and set a scanning range and a data point quantity of the preset Raman spectrum device.

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

[0092]

[0093] wherein ε is a strain size inside the coating, v is a Poisson's ratio inside the coating, Π is a piezoelectric spectrum coefficient, E is an elastic modulus of a dense block inside the coating, and Δω is a Raman peak shift inside the coating.

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

[0096] It should be noted that the foregoing explanation and description of the embodiment of the method for characterizing a thermal barrier coating interface based on CT imaging and 3D Raman spectrum also apply to the embodiment of the device for characterizing a thermal barrier coating interface based on CT imaging and 3D Raman spectrum, which will not be described herein again.

[0097] The device for characterizing thermal barrier coating interface based on CT imaging and 3D Raman spectrum according to the embodiment of the application establishes a substrate coordinate plane based on the substrate of the target thermal barrier coating, performs imaging analysis on the target thermal barrier coating based on a CT imaging device, obtains a cross-sectional view of the target thermal barrier coating, and obtains a three-dimensional reconstruction image of the target thermal barrier coating based on reconstruction software; determines the position of the target interface and the position of the target crack of the target thermal barrier coating by corresponding the three-dimensional space of the three-dimensional reconstruction image to the substrate coordinate plane; scans the position of the target interface and the position of the target crack by using a Raman spectrum device to obtain first Raman spectrum data and second Raman spectrum data, and further obtains the stress distribution of the target interface and the stress distribution of the target crack. Thus, the existing coating interface detection method cannot meet the requirement of nondestructive and comprehensive characterization of the internal structure of the coating, and by combining the CT imaging and 3D Raman spectrum technology, the effective observation and measurement of the interface morphology and interface strain of the coating before and after thermal cycling are realized without damaging the coating. Meanwhile, the generation and expansion behavior of the crack of the thermal barrier coating during service can be effectively predicted and observed.

[0098] Figure 9 The structure schematic diagram of the electronic device provided by the embodiment of the application is provided. The electronic device can include:

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

[0100] The processor 902 implements the method for characterizing thermal barrier coating interface based on CT imaging and 3D Raman spectrum provided in the above embodiment when executing the program.

[0101] Further, the electronic device further includes:

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

[0103] The memory 901 is used for storing the computer program executable on the processor 902.

[0104] The memory 901 can include a high-speed RAM memory, and can also include a non-volatile memory, for example, 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 with each other through a bus and complete communication between 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, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For convenience of representation, Figure 9 Only one thick line is used to represent the bus in the figure, but it 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 complete communication between each other through an internal interface.

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

[0108] The embodiment of the present application also provides a computer readable storage medium, which stores a computer program, and the program is executed by a processor to implement the method for characterizing a thermal barrier coating interface based on CT imaging and 3D Raman spectroscopy.

[0109] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example" or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or N embodiments or examples in a suitable manner. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the present specification and the features of the different embodiments or examples without contradiction.

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

[0111] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary and should not be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above-described embodiments within the scope of the present application.

Claims

1. A method for thermal barrier coating interface characterization based on CT imaging and 3D Raman spectroscopy, characterized in that, The method comprises the following steps: a substrate coordinate plane is established based on a substrate of a target thermal barrier coating, imaging analysis is performed on the target thermal barrier coating based on a preset CT imaging device, a cross-sectional view of the target thermal barrier coating is obtained, and a three-dimensional reconstruction image of the target thermal barrier coating is obtained based on the cross-sectional view of the target thermal barrier coating and a preset reconstruction software; the position of a target interface and the position of a target crack of the target thermal barrier coating are determined based on the three-dimensional space corresponding to the substrate coordinate plane of the three-dimensional reconstruction image; first Raman spectrum data corresponding to the position of the target interface is obtained by scanning the position of the target interface based on a preset Raman spectrum device, or second Raman spectrum data corresponding to the position of the target crack is obtained by scanning the position of the target crack based on the preset Raman spectrum device, and the stress distribution of the target interface is obtained according to the first Raman spectrum data based on a preset strain formula, or the stress distribution of the target crack is obtained according to the second Raman spectrum data based on the preset strain formula; wherein, before scanning the position of the target interface based on the preset Raman spectrum device or scanning the position of the target crack based on the preset Raman spectrum device, the preset Raman spectrum device is calibrated using a silicon wafer, the laser wavelength, the objective lens parameter and the numerical value of the confocal pinhole of the preset Raman spectrum device are determined based on a preset scanning requirement, and the scanning range and the number of data points of the preset Raman spectrum device are set; the preset strain formula is: ； wherein, ε is the strain size inside the coating, v is the Poisson's ratio inside the coating, Π is the piezoelectric optical spectrum coefficient, E is the elastic modulus of the compact block inside the coating, Δ ω is the Raman peak shift inside the coating; the target interface comprises at least one of an interface between a thermal growth oxide layer and a ceramic surface layer and an interface between internal layers of the ceramic surface layer; the target crack comprises at least one of a crack of the interface between the thermal growth oxide layer and the ceramic surface layer and a crack of the interface between the internal layers of the ceramic surface layer.

2. A device for thermal barrier coating interface characterization based on CT imaging and 3D Raman spectroscopy, characterized in that, The method for characterizing a thermal barrier coating interface based on CT imaging and 3D Raman spectrum according to claim 1, wherein the device comprises: a CT imaging and reconstruction module for establishing a substrate coordinate plane based on a substrate 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 reconstruction image of the target thermal barrier coating based on the cross-sectional view of the target thermal barrier coating and a preset reconstruction software; a determination module for determining the position of a target interface and the position of a target crack of the target thermal barrier coating based on the three-dimensional space corresponding to the substrate coordinate plane of the three-dimensional reconstruction image; a Raman spectrum analysis module for obtaining first Raman spectrum data corresponding to the position of the target interface by scanning the position of the target interface based on a preset Raman spectrum device, or obtaining second Raman spectrum data corresponding to the position of the target crack by scanning the position of the target crack based on the preset Raman spectrum device, obtaining the stress distribution of the target interface according to the first Raman spectrum data based on a preset strain formula, or obtaining the stress distribution of the target crack according to the second Raman spectrum data based on the preset strain formula.

3. The apparatus of claim 2, wherein, Before scanning the position of the target interface based on the preset Raman spectrum device or scanning the position of the target crack based on the preset Raman spectrum device, the Raman spectrum analysis module is further configured to: Calibrate the preset Raman spectrum device using a silicon wafer; Determine a laser wavelength, an objective lens parameter, and a numerical value of a confocal pinhole of the preset Raman spectrum device based on a preset scanning requirement, and set a scanning range and a data point quantity of the preset Raman spectrum device.

4. The apparatus of claim 2, wherein, The preset strain formula is: ； wherein, ε is the size of the strain inside the coating, v is the Poisson's ratio inside the coating, Π is the piezoelectric optical spectrum coefficient, E is the elastic modulus of the compact mass inside the coating, Δ ω is the Raman peak shift inside the coating.

5. An electronic device, comprising: comprise: 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 method for characterizing a thermal barrier coating interface based on CT imaging and 3D Raman spectrum.

6. A computer-readable storage medium having stored thereon a computer program, characterized in that, The program is executed by the processor to implement the method for characterizing a thermal barrier coating interface based on CT imaging and 3D Raman spectrum.

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