A method for testing rare earth zirconate resistance to CMAS corrosion under multi-source environmental spectrum

Abstract

The application discloses a rare earth zirconate CMAS corrosion resistance test method under a multi-source environment spectrum and belongs to the technical field of aero-engine thermal barrier coating test. The method comprises the following steps: selecting a plurality of CMAS corrosion sources to construct a multi-source corrosion environment spectrum library; drying, ball milling, sieving and compression molding of the CMAS corrosion sources to prepare standardized ash columns; preparing a rare earth zirconate dense ceramic block and polishing; placing the ash column on the polished surface of the ceramic block for isothermal heat treatment; preparing a sample on the cross section of the sample after heat treatment, and acquiring the reaction interface micro morphology, average element diffusion depth and new phase phase composition by using SEM, EDS and XRD; constructing a weighted evaluation model based on the obtained data to determine the broad-spectrum environmental adaptability of the rare earth zirconate ceramic. The application solves the problems of single corrosion source, non-standard operation and one-sided evaluation dimension in the traditional test, and realizes comprehensive and quantitative evaluation of the corrosion resistance under a complex environment.

Description

Technical Field

[0001] This invention belongs to the field of thermal barrier coating testing technology, and specifically relates to a method for testing the CMAS corrosion resistance of rare earth zirconates under multi-source environmental spectra. This invention also relates to an apparatus for implementing the above method. Background Technology

[0002] During operation, aircraft engines ingest particulate matter from the atmosphere, such as dust and volcanic ash, the main component of which is calcium magnesium aluminum silicon oxide (CMAS). At high engine temperatures (>1200℃), CMAS melts and deposits on the surface of the thermal barrier coating, causing severe corrosion failure and becoming a critical issue restricting the service safety of the coating. Rare earth zirconate ceramics (such as Gd₂Zr₂O₇) are considered candidate materials for next-generation thermal barrier coatings due to their low thermal conductivity and excellent high-temperature phase stability.

[0003] However, current testing and evaluation methods for the resistance of thermal barrier coatings to CMAS corrosion have the following main technical limitations:

[0004] 1. The corrosion source composition is singular, making it difficult to simulate complex service environments: Existing tests generally use classic artificially synthesized CMAS compositions (such as the CaO-MgO-Al2O3-SiO2 quaternary formulation), but the composition of natural sediments in actual environments is complex. Volcanic ash contains a large amount of Fe2O3 and TiO2, and industrial dust contains alkali metal salts. Studies have shown that artificial compositions differ significantly from natural volcanic ash in thermophysical properties such as viscosity, and completely ignore the influence of transition metal elements such as Fe and Ti on melt viscosity and interfacial reaction pathways, resulting in large simulation errors.

[0005] 2. Lack of standardization in testing operations and poor comparability of results: Currently, the application of corrosive media in CMAS is mostly done by powder spreading or slurry coating. Different studies have different parameters such as powder particle size, bulk density, and mass per unit area, resulting in significant differences in melt spreading area and penetration behavior, making it difficult to compare test results horizontally.

[0006] 3. One-sided evaluation dimensions, ignoring specific environmental sensitivities: Existing evaluations often focus on single indicators such as reaction layer thickness or erosion depth, failing to reveal the differentiated corrosion behavior of materials under different chemical composition environments. For example, Fe ions in iron-containing volcanic ash environments may accelerate corrosion through catalysis, and traditional single-component testing cannot identify such "specific environmental sensitivities," potentially leading to unexpected material failures during actual service.

[0007] In summary, there is an urgent need to establish a comprehensive testing method that covers a variety of typical environmental components, has standardized operating procedures, and can quantitatively evaluate the corrosion resistance of materials in complex environments. Summary of the Invention

[0008] To overcome the shortcomings of existing technologies, such as the single corrosion source composition, inability to simulate complex service environments, lack of standardized testing operations, and poor comparability of results due to one-sided evaluation dimensions, this invention proposes a multi-source environmental spectrum method for testing the corrosion resistance of rare earth zirconate ceramics under CMAS corrosion. This method constructs a multi-source CMAS environmental spectrum library covering both natural sediments and synthetic components, performs standardized gray column preparation and parallel interface reaction testing on corrosive media from different sources, and combines multi-dimensional microscopic characterization and a weighted evaluation model to achieve a comprehensive, quantitative, and comparable evaluation of the corrosion resistance of rare earth zirconate ceramics under complex environments.

[0009] Therefore, the present invention aims to provide a method for testing the CMAS corrosion resistance of rare earth zirconates under multi-source environmental spectrum, which includes the following steps: Multiple CMAS corrosion sources with chemical composition gradients were selected to construct a multi-source corrosion environment spectral library covering different chemical characteristics; The CMAS corrosion source was dried, ball-milled, sieved, and pressed into shape to prepare gray columns of standard mass and geometric dimensions. A rare earth zirconate dense ceramic block was prepared, and the test surface of the dense ceramic block was polished. The gray column is placed on the polished surface of the ceramic block and subjected to isothermal heat treatment in a high-temperature box furnace. The heat-treated sample was cross-sectionally prepared to form the sample. The reaction layer thickness, average elemental diffusion depth and new phase composition of the sample were obtained by scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction. Based on the obtained reaction layer thickness, average element diffusion depth, and new phase composition, a weighted evaluation model is constructed to compare the corrosion kinetic differences under different corrosion sources and determine the broad-spectrum environmental adaptability of the rare earth zirconate dense ceramic block.

[0010] Preferably, the multi-source corrosion environment library contains at least two corrosion sources with significantly different chemical characteristics, and the differences in chemical characteristics include at least one of the following: differences in major element composition, differences in transition metal element content, or differences in alkali metal salt content.

[0011] Preferably, the step of drying, ball milling, sieving, and pressing the CMAS corrosion source to prepare a gray column of standard mass and geometric dimensions includes: drying the naturally sourced CMAS corrosion source at a temperature of 100-120°C for a time of not less than 12 hours. The dried CMAS corrosion source was ball-milled to refine the particle size and ensure uniform mixing. The ball milling process was wet ball milling, with the ball-to-material mass ratio controlled within the range of 4:1-6:1. The ball milling time was 4-8 hours and the rotation speed was 200-400 rpm. After ball milling, the slurry was dried and sieved through a standard sieve. The powder that passed through the sieve was collected for later use. Weigh a fixed amount of the sieved powder, put it into a mold and press it into shape. The pressing pressure is 10-20MPa and the holding time is 20-60 seconds to obtain a cylindrical gray column.

[0012] Preferably, the preparation of the rare-earth zirconate dense ceramic block and the polishing of the test surface of the dense ceramic block include: Weigh the rare earth oxides and zirconium oxide raw materials according to the stoichiometric ratio of the target rare earth zirconate ceramic. The weighed raw material powder is ball-milled and mixed, and then dried to obtain a uniformly mixed raw material powder. The mixed powders are pre-fired to synthesize the raw materials, causing a solid-phase reaction to generate the target rare earth zirconate ceramic phase. The pre-fired target rare earth zirconate ceramic phase was ball-milled a second time to obtain a fine synthetic powder; The synthesized powder is shaped and then sintered at high temperature to obtain a dense ceramic block; The sintered dense ceramic block is ground and polished to achieve a mirror finish on the test surface.

[0013] Preferably, placing the gray column on the polished surface of the dense ceramic block and performing isothermal heat treatment in a high-temperature box furnace includes: The dense ceramic block was inspected and numbered to ensure that the test surface was free of contamination; The gray column is placed centered on the polished surface of the dense ceramic block to form a sample. The sample was placed on an alumina pad and placed in the uniform temperature zone of a high-temperature box furnace, with an appropriate distance between the samples. The sample was heated by a heat treatment program set on a high-temperature box furnace. The heat treatment program included heating to 1300°C at a rate of 10°C / min, and holding at 1300°C for 1 hour, 5 hours and 25 hours respectively. When the heat treatment procedure is executed, the timing starts when the furnace temperature reaches 1300℃, and the corresponding sample is taken out and allowed to cool naturally after each holding time is reached. After cooling, the samples are inspected and labeled, and the type of corrosion source, holding time, and sample number are recorded.

[0014] Preferably, the process of preparing a cross-section of the heat-treated sample to form a cross-section sample, and obtaining the reaction layer thickness, average elemental diffusion depth, and new phase composition of the sample using a scanning electron microscope, energy dispersive spectroscopy, and X-ray diffractometer, includes: The heat-treated sample is cut into two halves along the axis passing through the center of the gray column. One half is used for cross-sectional sample preparation. After grinding and polishing, it reaches a mirror state, forming the cross-sectional sample. The sample prepared by the cross section was placed in a scanning electron microscope, and the reaction interface was observed using backscattered electron mode. The thickness of the reaction layer was measured at multiple random locations in the reaction interface area, and the average value was taken as the thickness of the reaction layer of the sample prepared by the cross section. While observing with a scanning electron microscope, an energy dispersive spectrometer is turned on to perform elemental line scanning analysis on the reaction interface of the sample after the cross section is prepared. Starting from the inside of the ceramic matrix, passing through the reaction layer, and entering the residual CMAS region, the characteristic X-ray intensity of the target element is collected, the distribution curve of element concentration as a function of distance is plotted, the maximum element diffusion depth is defined when the target element concentration drops to 5% of the matrix concentration, and the average element diffusion depth of all target elements is calculated. Take the other half of the sample, scrape off the powder from the surface of the reaction area and perform X-ray diffraction analysis. Compare the obtained X-ray diffraction pattern with the original ceramic block diffraction pattern to determine the reaction products. Based on the standard pattern, identify the new phase composition of the reaction products.

[0015] Preferably, the construction of the weighted evaluation model includes: Based on the reaction layer thickness, calculate the percentage difference in reaction layer thickness relative to the baseline for different corrosion sources under the same heat preservation time; Based on the reaction layer thickness, maximum element diffusion depth and new phase composition, a weighted comprehensive score is calculated after assigning weight coefficients to each. The sensitivity of the rare earth zirconate ceramic to transition metal catalytic corrosion was determined by comparing the reaction layer thickness under high-iron corrosion source and iron-free corrosion source conditions.

[0016] Preferably, the determination of the broad-spectrum environmental adaptability includes: Based on the weighted comprehensive score calculated under all corrosion sources and all heat preservation times, and combined with the results of the transition metal catalytic corrosion sensitivity assessment, the broad-spectrum environmental adaptability of the rare earth zirconate ceramics is graded and evaluated.

[0017] The second objective of this invention is to provide a multi-source environmental spectrum rare earth zirconate CMAS corrosion resistance testing device, which uses the aforementioned multi-source environmental spectrum rare earth zirconate CMAS corrosion resistance testing method to perform CMAS corrosion performance testing, including: The corrosion source processing unit is used to dry, ball mill, sieve and press the CMAS corrosion source to prepare standardized gray columns. A ceramic sample preparation unit is used to prepare rare earth zirconate ceramic blocks by solid-state reaction method and to polish the test surface of the ceramic blocks. A high-temperature heat treatment unit is used to perform isothermal heat treatment on the ceramic block loaded with the gray column at a set temperature and holding time. The microscopic characterization unit is used to analyze the heat-treated sample using scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction to obtain data on the reaction layer thickness, average elemental diffusion depth, and composition of the new phase. The data analysis unit is used to record and store the data output by the micro-characterization unit, so that researchers can perform subsequent manual calculations and analyses.

[0018] The beneficial effects of this invention are as follows:

[0019] 1. High environmental realism: This invention breaks through the limitations of traditional single artificial CMAS components, constructs a multi-source corrosion environment spectrum library covering sand, volcanic ash, dust and artificial components, and introduces real environmental elements such as Fe, Ti, K and Na, which can more accurately simulate the service environment of aero engines in complex airspace.

[0020] 2. Standardized operation and strong comparability: Through the standardized preparation process of gray columns, CMAS powders from different sources are uniformly pressed into cylindrical gray columns with uniform size and constant mass, eliminating the contact area error caused by the difference in powder properties, ensuring that the mass of reactants per unit contact area is constant, and significantly improving the comparability of test results.

[0021] 3. Multidimensional characterization and comprehensive evaluation: Combining SEM, EDS and XRD to obtain the reaction layer thickness, maximum elemental diffusion depth and new phase composition, the corrosion behavior is quantitatively characterized from multiple dimensions, and a weighted evaluation model is constructed to comprehensively evaluate the corrosion resistance level of the material, overcoming the shortcomings of one-sided evaluation by a single index.

[0022] 4. Clear criteria for evaluation and optimization guidance: The criteria for judging the catalytic corrosion sensitivity of transition metals are proposed—if the difference in reaction layer thickness between the high-iron component and the iron-free component exceeds 50%, it is judged as sensitive, providing a clear quantitative screening basis for material composition optimization. Attached Figure Description

[0023] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0024] Figure 1 This is a flowchart illustrating a multi-source environmental spectrum method for testing the CMAS corrosion resistance of rare earth zirconates.

[0025] Figure 2 This is a schematic diagram of the component distribution of the multi-source CMAS environmental spectral library constructed in an embodiment of the present invention;

[0026] Figure 3 This is an assembly diagram of a standard cylindrical gray column placed on the surface of a ceramic sample in an embodiment of the present invention.

[0027] The accompanying drawings have illustrated specific embodiments of the invention, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the invention in any way, but rather to illustrate the concept of the invention to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0029] Glossary

[0030] CMAS is an abbreviation for Environmental Sediments, specifically referring to silicate particles composed of oxides of elements such as calcium (Ca), magnesium (Mg), aluminum (Al), and silicon (Si). In actual service environments, it often also contains elements such as Fe, Ti, K, and Na.

[0031] Rare earth zirconate ceramics: with the general chemical formula RE2Zr2O7, where RE represents rare earth elements (such as Gd, Sm, La, etc.), have a pyrochlore or fluorite structure, and are a new type of thermal barrier coating material.

[0032] Reaction layer thickness: refers to the average thickness of the reaction product layer formed after the CMAS melt and the ceramic matrix undergo an interfacial reaction, which is usually measured in SEM backscattered electron images.

[0033] Element diffusion depth: refers to the distance that corrosive elements (such as Ca, Fe, etc.) in CMAS penetrate from the reaction interface into the ceramic matrix, defined as the position where the element concentration drops to 5% of the matrix concentration.

[0034] Transition metal catalytic corrosion: refers to the phenomenon that transition metal elements such as Fe and Ti accelerate the corrosion of ceramic materials by CMAS at high temperatures by changing the melt viscosity, forming low-melting-point eutectics, or catalyzing interfacial reactions.

[0035] Example 1

[0036] This embodiment provides an apparatus for testing the CMAS corrosion resistance of rare earth zirconate ceramics based on multi-source environmental spectra. The apparatus includes a corrosion source treatment unit, a ceramic sample preparation unit, a high-temperature heat treatment unit, a microscopic characterization unit, and a data analysis unit.

[0037] The corrosion source treatment unit is used to dry, ball-mill, sieve, and press the CMAS corrosion source to prepare standardized gray columns, including: Drying oven is used to dry CMAS raw materials of natural origin and remove adsorbed moisture; Ball mills are used to pulverize dried raw materials to obtain powder with finer particle size. A standard sieve (200 mesh) is used to sieve the powder after ball milling to obtain fine powder with uniform particle size; The powder tablet press is used to press sieved CMAS fine powder into standard-sized cylindrical gray columns. The pressing pressure range is 10-20MPa, and it is equipped with a stainless steel mold with an inner diameter of Φ3.0mm.

[0038] The ceramic sample preparation unit is used to perform isothermal heat treatment on the ceramic block loaded with the gray column at a set temperature and holding time, including: High-temperature box furnaces are used for raw material pre-firing synthesis and ceramic sintering; Ball mills are used for secondary ball milling of raw materials for mixing and synthesizing powders; Grinding and polishing machines are used to grind and polish sintered ceramic blocks to achieve a mirror-like finish on the test surface.

[0039] The high-temperature heat treatment unit is used to perform isothermal heat treatment on the ceramic block loaded with the gray column at a set temperature and holding time. It is one or more high-temperature box furnaces with program temperature control function, adjustable heating rate (e.g., 10℃ / min), working temperature up to 1300℃ or more, and furnace chamber size to meet the needs of multiple samples placed in parallel.

[0040] The microscopic characterization unit is used to analyze the heat-treated sample using scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction to obtain data on the reaction layer thickness, average elemental diffusion depth, and composition of the new phase, including: Scanning electron microscope (SEM), equipped with a backscattered electron detector, is used to observe the microstructure of the reaction interface and measure the thickness of the reaction layer; Energy dispersive spectrometer (EDS) is used to perform elemental line scan analysis to obtain elemental concentration distribution curves and diffusion depth; X-ray diffraction (XRD) is used to identify the phase composition of reaction products.

[0041] The data analysis unit is used to record and store the data output by the micro-characterization unit for subsequent manual calculations and analysis by the experimenters. The data analysis unit is a computer used to record and store the data output by the micro-characterization unit and to perform subsequent data processing and analysis. It should be noted that steps such as the calculation of the weighted evaluation model, extraction of corrosion kinetic parameters, and comparative analysis of multi-source corrosion are performed manually by the experimenters based on the obtained data or using general data processing software (such as Excel, Origin, etc.).

[0042] Example 2

[0043] This embodiment provides a method for testing the corrosion resistance of rare earth zirconate ceramics under multi-source environmental spectra in CMAS (Construction of Multi-Source Environmental Spectra - Standardized Preparation of Corrosion Sources - Parallel Interface Reaction Testing - Multi-dimensional Microscopic Characterization - Comprehensive Performance Evaluation). This embodiment uses Gd₂Zr₂O₇ (gadolinium zirconate) ceramics as the test material and four types of CMAS corrosion sources—sandstone, volcanic ash, dust, and classic artificial types—as representatives of the multi-source environmental spectrum to comprehensively evaluate the corrosion resistance of rare earth zirconate ceramics under different chemical composition CMAS corrosion environments.

[0044] like Figure 1 As shown, this embodiment of the invention provides a method for testing the CMAS corrosion resistance of rare earth zirconates under multi-source environmental spectra, comprising the following steps:

[0045] S1. Select multiple CMAS corrosion sources with chemical composition gradients to construct a multi-source corrosion environment spectral library covering different chemical characteristics.

[0046] This step is the corrosion medium selection stage. By selecting CMAS corrosion sources with different sources and chemical compositions, a multi-source corrosion environment spectrum library that can represent typical airspace service environments is constructed, providing a raw material basis for the subsequent standardized preparation of corrosion sources.

[0047] The construction principle of the multi-source corrosion environment library is as follows: the selected corrosion sources should have significant differences in chemical composition, covering different types of CMAS corrosion environments. The multi-source corrosion environment library contains at least two corrosion sources with significantly different chemical characteristics. These differences include at least one of the following: differences in major element composition, differences in transition metal element content, or differences in alkali metal salt content. The specific number and type of corrosion sources can be adjusted according to research objectives and practical application needs, such as... Figure 2 As shown, this demonstrates the advantages of "multi-source" evaluation.

[0048] In this embodiment, four typical CMAS corrosion sources are selected as examples, and the specific information is as follows:

[0049] Corrosion Source A (Sand and Gravel Component): Natural sand and gravel samples collected from a desert region in Northwest China. X-ray fluorescence spectroscopy (XRF) analysis revealed its main chemical composition to be: SiO2 62.3 wt%, Al2O3 13.8 wt%, CaO 8.2 wt%, MgO 2.1 wt%, Fe2O3 3.5 wt%, and other components 10.1 wt%. This component is characterized by high silicon and low magnesium (SiO2 > 60 wt%, MgO < 3 wt%), and was used to simulate the corrosive environment of an aircraft engine flying in dusty airspace.

[0050] Corrosion Source B (Volcanic Ash Component): A natural volcanic ash sample collected from a volcanic eruption area. XRF analysis revealed its main chemical composition to be: SiO2 52.6 wt%, Fe2O3 12.8 wt%, Al2O3 14.2 wt%, CaO 8.5 wt%, MgO 3.1 wt%, TiO2 2.4 wt%, and other components 6.4 wt%. This component exhibits characteristics of high iron and high titanium content (Fe2O3 > 10 wt%, TiO2 > 2 wt%), and was used to simulate the corrosive environment of an aircraft engine traversing a volcanic ash cloud.

[0051] Corrosion source C (dust-type component): Dust samples collected from an area surrounding an industrial city. XRF analysis revealed its main chemical composition to be: SiO2 48.3 wt%, Al2O3 11.5 wt%, CaO 10.2 wt%, MgO 4.1 wt%, K2O 3.2 wt%, Na2O 2.8 wt%, Fe2O3 5.6 wt%, and other components 14.3 wt%. Thermogravimetric-mass spectrometry (TGA) confirmed the presence of alkali metal salts such as K2CO3 and Na2CO3, with a total alkali metal salt content of approximately 6.0 wt%. This component exhibits characteristics of high alkali metal content (total alkali metal salt content > 5 wt%) and was used to simulate the corrosive environment of aircraft engines flying in industrially polluted areas or coastal airspace.

[0052] Corrosion Source D (Classic Artificial Component): Prepared using high-purity oxide powder according to the classic formula proposed by Professor Levi of the University of California. The specific ratio is: CaO (analytical grade) 33 mol%, MgO (analytical grade) 9 mol%, Al2O3 (analytical grade) 13 mol%, SiO2 (analytical grade) 45 mol%. After converting to mass fraction, the corresponding mass of oxide powder was weighed and mixed in a planetary ball mill with anhydrous ethanol as the medium for 4 hours. After drying at 60°C, it was passed through a 200-mesh sieve to obtain a uniformly mixed synthetic CMAS powder. This component is used to simulate the standard corrosion environment used in traditional testing methods as a reference standard.

[0053] It should be noted that the four corrosion sources mentioned above are merely typical examples selected in this embodiment to illustrate the implementation process of the present invention. In practical applications, the construction of the multi-source corrosion environment library can be flexibly adjusted according to specific research objectives: for example, when the research focuses on coastal salt spray environments, corrosion sources with higher NaCl content can be added; when the research focuses on industrial pollution areas, corrosion sources containing sulfates can be added; when studying the service reliability of different airspaces globally, more natural samples with regional characteristics can be selected. The core of this invention lies in constructing a multi-source library that can cover different environmental types by selecting a variety of corrosion sources with significantly different chemical characteristics, rather than being limited to a few specific components.

[0054] Through the above selection, this embodiment constructs a multi-source CMAS corrosion environment library containing four typical corrosion sources: sand and gravel type, volcanic ash type, dust type, and classic artificial components.

[0055] S2. The CMAS corrosion source is dried, ball-milled, sieved, and pressed into shape to prepare gray columns of standard quality and geometric dimensions.

[0056] This step is the standardization treatment stage for corrosive media. By uniformly pulverizing and pressing the various CMAS raw materials selected in step S1, cylindrical gray columns with uniform size and constant mass are prepared to eliminate experimental errors caused by different powder packing density and spreading state, and to ensure that the mass of reactants per unit contact area is constant.

[0057] During preparation, the naturally sourced CMAS raw material is first dried to remove adsorbed moisture; then the dried raw material is ball-milled and pulverized, and fine powder with uniform particle size is obtained by passing it through a 200-mesh standard sieve; finally, a quantitative amount of sieved CMAS fine powder is weighed, loaded into a mold and pressed into a cylindrical gray column with a diameter of Φ3.0mm×3.0mm, and the pressing pressure is controlled within the range of 10-20MPa.

[0058] The specific implementation steps are as follows:

[0059] (i) Drying is performed on naturally derived CMAS raw materials to remove adsorbed moisture, ensuring the accuracy of subsequent weighing and the quality of molding. The drying temperature is usually controlled between 100-120℃, and the drying time is no less than 12 hours. For synthetic components, since drying has already been completed during the preparation process, no further drying treatment is required.

[0060] (ii) The dried CMAS raw material is ball-milled to refine the particle size and make it uniformly mixed. The ball milling process adopts wet ball milling, and the ball-to-material mass ratio is controlled within the range of 4:1-6:1. The ball milling time is 4-8 hours and the speed is 200-400 rpm. After the ball milling is completed, the slurry is dried into powder and sieved through a 200-mesh standard sieve. The powder under the sieve is collected for later use to eliminate the influence of the original particle size difference on the subsequent melting behavior.

[0061] (III) Weigh a measured amount of sieved CMAS fine powder, place it into a mold, and press it under constant pressure to obtain a cylindrical ash column with standard geometric dimensions and mass. The weighing mass is determined based on the ash column size and the loose density of the powder, typically 0.10-0.20 g. The pressing pressure is controlled within the range of 10-20 MPa, and the holding time is 20-60 seconds. After pressing, inspect the appearance of the ash column to ensure that the end faces are flat and free of cracks.

[0062] Through the standardized preparation described above, this embodiment obtained four CMAS gray columns with different chemical compositions but identical geometric dimensions: Type A gray column (sandstone type), Type B gray column (volcanic ash type), Type C gray column (dust type), and Type D gray column (classic artificial type). All gray columns have dimensions of Φ3.0 mm × 3.0 mm and a mass of 0.15 g, ensuring a constant mass of corrosive medium in contact with the surface of each sample during subsequent tests.

[0063] S3. Prepare a rare earth zirconate dense ceramic block and polish the test surface of the dense ceramic block.

[0064] This step is the material preparation stage. A dense ceramic block of rare earth zirconate is prepared by solid-state reaction method, and the test surface is polished to obtain a dense ceramic block with a smooth and clean surface, which provides a matrix material for subsequent interface reaction test.

[0065] In the preparation process, rare earth oxides and zirconium oxide raw materials are first weighed according to the stoichiometric ratio of the target rare earth zirconate ceramic. Then, the raw materials are ball-milled and mixed, dried, and sieved. The mixed powder is then pre-fired to synthesize the raw materials, causing a solid-phase reaction to generate the target ceramic phase. Next, the pre-fired block is ball-milled a second time to obtain a fine synthetic powder. Subsequently, the synthetic powder is shaped and sintered at high temperature to obtain a dense ceramic block. Finally, the sintered dense ceramic block is ground and polished to achieve a mirror finish on the test surface.

[0066] In this embodiment, the CMAS corrosion resistance test of rare earth zirconate ceramics based on multi-source environmental spectra uses Gd₂Zr₂O₇ (gadolinium zirconate) ceramic as the test material and Gd₂O₃ and ZrO₂ as starting materials. Gd₂O₃ and ZrO₂ raw materials are weighed according to the stoichiometric ratio of Gd₂Zr₂O₇. Through the above preparation, a dense Gd₂Zr₂O₇ ceramic block is finally obtained with a smooth and clean surface, meeting the requirements of the matrix material for subsequent interfacial reaction tests. A corresponding number of ceramic samples are prepared according to the testing requirements.

[0067] S4. Place the gray column on the polished surface of the dense ceramic block and perform isothermal heat treatment in a high-temperature box furnace.

[0068] This step is the high-temperature reaction stage, such as... Figure 3 As shown, different types of standardized gray columns prepared in step S2 are placed on the polished surface of the dense ceramic block prepared in step S3, and isothermal heat treatment is performed under a uniform air atmosphere and heat regime to induce interfacial reaction, thereby obtaining samples under different corrosion sources and different holding times.

[0069] During operation, the dense ceramic block is first inspected and numbered to ensure that the test surface is free of contamination. The standardized gray column prepared in step S2 is carefully picked up with tweezers and placed in the center of the polished surface of the dense ceramic block to form a sample. The sample is placed on an alumina pad and placed in the uniform temperature zone of a high-temperature box furnace, with an appropriate distance between the samples (e.g., not less than 10 mm) to avoid mutual obstruction or thermal radiation interference. The sample is heated in a heat treatment program set in the high-temperature box furnace. The heat treatment program includes heating to 1300°C at a rate of 10°C / min, and holding at 1300°C for 1 hour, 5 hours, and 25 hours respectively. The cooled sample is inspected and marked, and the corrosion source type, holding time, and sample number are recorded.

[0070] In this embodiment, a total of 12 Gd2Zr2O7 dense ceramic blocks prepared in step S3 were taken and numbered on the side of the dense ceramic blocks with a marker: A-1h (sandstone type, 1 hour), B-1h (volcanic ash type, 1 hour), and so on, up to D-25h (artificial type, 25 hours). Four types of standardized ash columns prepared in step S2 (A-type, sandstone type, B-type, volcanic ash type, C-type, dust type, and D-type, classic artificial type) were carefully picked up with tweezers and placed centrally on the polished surface of the corresponding numbered dense ceramic block, ensuring stable contact between the ash column and the surface of the dense ceramic block, thus forming 12 samples. The samples with the ash columns placed were placed on alumina pads and then placed in the central uniform temperature zone of a high-temperature box furnace. Three holding times were set at 1300℃: 1 hour, 5 hours, and 25 hours. The heating program was started, and timing began when the furnace temperature reached 1300℃. After 1 hour of holding, the furnace door was opened, and samples numbered A-1h, B-1h, C-1h, and D-1h were quickly removed using long-handled alumina crucible tongs and placed on refractory bricks for natural cooling. After 5 hours of holding, samples A-5h, B-5h, C-5h, and D-5h were removed. After 25 hours of holding, samples A-25h, B-25h, C-25h, and D-25h were removed. After all samples were removed and allowed to cool naturally to room temperature, inspection revealed that the ash columns had melted and spread on the ceramic surface. The samples were then arranged according to their numbers and placed in sample boxes for storage, in preparation for the subsequent multidimensional microscopic characterization step S5.

[0071] Through the parallel interface reaction test described above, a total of 12 samples (4 types of corrosion sources × 3 holding times) were obtained in this embodiment, covering different types of corrosion sources and different reaction times, providing experimental materials for subsequent multidimensional microscopic characterization.

[0072] S5. Prepare a cross-section of the heat-treated sample to form a cross-section sample. Use a scanning electron microscope, energy dispersive spectroscopy, and X-ray diffractometer to obtain the reaction layer thickness, average elemental diffusion depth, and new phase composition of the sample.

[0073] This step is the microstructure analysis stage. The sample obtained in step S4 is cross-sectionally prepared, and the reaction layer thickness, average elemental diffusion depth and new phase composition of the reaction interface are obtained using a scanning electron microscope (SEM), energy dispersive spectrometer (EDS), and X-ray diffractometer (XRD). This provides quantitative microstructure data for subsequent comprehensive performance evaluation.

[0074] The characterization parameters are obtained as follows:

[0075] The cross-sectional microstructure was observed using a scanning electron microscope to define the boundary of the reaction layer and measure the average thickness of the reaction layer.

[0076] The diffusion behavior of elements was analyzed using an energy dispersive spectroscopy (EDS) instrument. The concentration distribution curve of the target element was tracked, and the diffusion depth was defined as the point at which the element concentration dropped to 5% of the matrix concentration. The average diffusion depth of all target elements was then calculated.

[0077] The composition of the new phase of the reaction products was identified using X-ray diffraction.

[0078] To perform the above operations, the following sub-steps must be performed in sequence:

[0079] S51. Cut the heat-treated sample into two halves along the axis passing through the center of the gray column, take one half for cross-sectional sample preparation, grind and polish it to achieve a mirror finish, and form the cross-sectional sample.

[0080] The heat-treated sample obtained in step S4 is cut along the axis passing through the center of the gray column to obtain a cross-section containing the complete reaction interface. The cut sample is then prepared into a cross-section sample, with the cross-section facing upwards for easy observation. The prepared cross-section sample is then ground and polished to remove the cutting damage layer, achieving a mirror-like finish that meets the requirements for scanning electron microscopy. After polishing, the sample is cleaned and dried, and conductive treatment is performed if necessary.

[0081] In this embodiment, the heat-treated samples obtained in step S4 are cut into two halves along the centerline of the sample (through the center of the gray column). One half is used for cross-sectional sample preparation, with the cut surface facing upwards. After grinding and polishing to achieve a mirror finish, it is cleaned, dried, and ready for use.

[0082] S52. Place the sample after cross-section preparation in a scanning electron microscope, observe the reaction interface using backscattered electron mode, randomly select multiple locations in the reaction interface area to measure the reaction layer thickness, and take the average value as the reaction layer thickness of the sample after cross-section preparation.

[0083] The prepared cross-section sample was placed in a scanning electron microscope and observed using backscattered electron mode. Backscattered electron imaging is sensitive to atomic number; the ceramic matrix, containing rare earth elements, exhibits a brighter contrast, while the CMAS reaction layer, with its lower atomic number, shows a darker contrast, making the interface between the two clearly discernible. Microscopic images were taken at multiple randomly selected locations in the reaction interface region, and the reaction layer thickness was measured along a direction perpendicular to the interface. The average value was taken as the reaction layer thickness of the prepared cross-section sample.

[0084] In this embodiment, the prepared cross-sectional samples are observed using a scanning electron microscope. For each cross-sectional sample, backscattered electron images are captured at multiple randomly selected locations in the reaction interface region. The reaction layer thickness is measured and the average value is calculated. The reaction layer thickness data of each cross-sectional sample under different holding times are recorded.

[0085] S53. While observing with a scanning electron microscope, turn on an energy dispersive spectrometer to perform elemental line scanning analysis on the reaction interface of the sample after the cross-section is prepared. Starting from the inside of the ceramic matrix, pass through the reaction layer and enter the residual CMAS region. Collect the characteristic X-ray intensity of the target element, plot the distribution curve of the target element concentration as a function of distance, define the point where the target element concentration drops to 5% of the matrix concentration as the element diffusion depth, and calculate the average element diffusion depth of all target elements.

[0086] While observing with a scanning electron microscope, an energy dispersive spectroscopy (EDS) instrument was used to perform elemental line scanning analysis on the reaction interface of the prepared sample. A scanning path perpendicular to the interface was selected, starting from the interior of the ceramic matrix, passing through the reaction layer, and entering the residual CMAS region. Characteristic X-ray intensities of the target elements were collected, and the concentration distribution curves of the target elements as a function of distance were plotted. Based on the concentration distribution curves, the element diffusion depth of each element was determined, defined as the position where the element concentration drops to 5% of the matrix concentration, and the average element diffusion depth of the target elements was calculated.

[0087] In this embodiment, while observing with a scanning electron microscope, an energy dispersive spectroscopy (EDS) instrument is activated to perform line scanning analysis on the reaction interface of the sample after cross-sectional preparation. Characteristic X-ray intensities of Ca, Mg, Al, Ti, Si, K, Na, Zr, and rare earth elements are collected to obtain the line distribution curves of each element, determine the elemental diffusion depth of each element, and record the elemental diffusion depth data for each sample.

[0088] S54. Take the other half of the sample, scrape off the powder from the surface of the reaction area and perform X-ray diffraction analysis. Compare the obtained X-ray diffraction pattern with the original ceramic block diffraction pattern to determine the reaction products, and identify the new phase composition of the reaction products based on the standard pattern.

[0089] The other half of the sample was taken, and powder was scraped from the surface of the reaction area for X-ray diffraction analysis. The obtained X-ray diffraction pattern was compared with the X-ray diffraction pattern of the uncorroded original rare-earth zirconate ceramic block to determine the reaction products. The phase composition of the reaction products was identified based on the standard pattern. The phases corresponding to the new diffraction peaks that did not appear in the original ceramic pattern are the new phases of the newly formed reaction products after the experiment. All the phases of the newly formed reaction products after the experiment are collectively referred to as the new phase composition of the newly formed reaction products.

[0090] Through the above multidimensional microscopic characterization, this embodiment obtained quantitative data such as the reaction layer thickness, average element diffusion depth, and new phase composition of Gd2Zr2O7 ceramics under four corrosion sources and three heat preservation time gradients, laying the foundation for subsequent comprehensive performance evaluation.

[0091] S6. Based on the obtained reaction layer thickness, average element diffusion depth and new phase composition, a weighted evaluation model is constructed to compare the corrosion kinetic differences under different corrosion sources and determine the broad-spectrum environmental adaptability of the rare earth zirconate dense ceramic block.

[0092] This step is the final evaluation stage. Based on the multidimensional microscopic characterization data of the reaction layer thickness, the average element diffusion depth, and the composition of the new phase obtained in step S5, a weighted evaluation model is constructed to compare the corrosion kinetic differences of the same material under different compositional environments, comprehensively evaluate the corrosion resistance level of the material, and determine the sensitivity of the material to transition metal catalytic corrosion based on specific criteria.

[0093] To perform the above operations, the following sub-steps must be performed in sequence:

[0094] S61. Based on the reaction layer thickness, calculate the percentage difference in reaction layer thickness relative to the baseline for different corrosion sources under the same heat preservation time.

[0095] Using classic artificial components (typically standard formulations without transition metals such as Fe and Ti) as the baseline corrosion source, calculate the percentage difference R of the reaction layer thickness relative to the baseline for other natural corrosion sources at the same holding time: R = (d_i - d_ref) / d_ref × 100% Where d_i represents the reaction layer thickness under the action of the i-th corrosion source, and d_ref represents the reaction layer thickness under the action of the baseline corrosion source. The R value quantitatively reflects the degree to which different environmental components accelerate (R>0) or inhibit (R<0) corrosion. Simultaneously, by comparing the maximum diffusion depth of elements and the types of reaction products under different corrosion sources, the influence mechanism of each characteristic component on corrosion behavior is analyzed.

[0096] S62. Based on the reaction layer thickness, average element diffusion depth and new phase composition, weighted coefficients are assigned to calculate the weighted comprehensive score.

[0097] A weighted evaluation model was constructed by selecting several key indicators that can comprehensively reflect the degree of corrosion. The selection principles for the indicators are as follows:

[0098] 1. It can quantitatively characterize the degree of corrosion;

[0099] 2. Comparability between different corrosion sources;

[0100] 3. Related to the service performance of materials. This method selects at least the following three indicators:

[0101] 1) Reaction layer thickness index I_1: reflects the overall degree of corrosion, with a weighting coefficient w1=0.4;

[0102] 2) Average element diffusion depth index I_2: Reflects the melt penetration ability, taking the average element diffusion depth of major corrosive elements such as Ca and Fe, with a weighting coefficient w2=0.3;

[0103] 3) New phase composition I_3: The new phase composition is scored based on the types and quantities of new phases generated after the experiment and their harmfulness. The more types of new phases generated and the more low-melting-point new phases generated, the higher the score. The weighting coefficient w3=0.3.

[0104] The measured values ​​of each index under all test conditions were summarized, and the extreme value normalization method was used to eliminate the influence of dimensions. For any corrosion source, the normalized values ​​of the three indices—reaction layer thickness, average elemental diffusion depth, and new phase composition—were calculated using the following formulas: I'_1=(I_1-I_1min) / (I_1max-I_1min) I'_2=(I_2-I_2min) / (I_2max-I_2min) I'_3=(I_3-I_3min) / (I_3max-I_3min) Wherein, I_1, I_2, and I_3 are the measured values ​​of the reaction layer thickness, the average elemental diffusion depth, and the new phase composition score under the action of the corrosion source, respectively; I_1min and I_1max are the minimum and maximum values ​​of the reaction layer thickness index under all corrosion sources and all holding times, respectively; I_2min, I_2max and I_3min, I_3max follow the same pattern. The normalized index values ​​are between 0 and 1, with larger values ​​indicating more severe corrosion. The calculation formula is as follows: S = w1·I'_1 + w2·I'_2 + w3·I'_3 Where w1+w2+w3=1. The S value is between 0 and 1, and the higher the S value, the worse the corrosion resistance of the material.

[0105] S63. By comparing the reaction layer thickness of the rare earth zirconate ceramic under high-iron corrosion source and iron-free corrosion source, the sensitivity of transition metal catalytic corrosion is determined.

[0106] According to the specific criteria of this invention, the difference percentage R_Fe is calculated by comparing the reaction layer thickness of the same material with that of high-iron volcanic ash composition and iron-free artificial composition: R_Fe = (d_Fe - d_ref) / d_ref × 100% If R_Fe > 50%, the material is considered sensitive to transition metal catalytic corrosion. The physical meaning of this criterion is that when the addition of Fe increases the corrosion rate by more than 50%, it indicates that the transition metal has a significant catalytic or promoting effect on the corrosion process. Such materials have a high risk of failure in Fe-containing environments and require targeted composition optimization. If R_Fe ≤ 50%, the material is considered insensitive to transition metal catalytic corrosion and has good resistance to corrosion in iron-containing environments.

[0107] S64. Based on the weighted comprehensive score calculated under all corrosion sources and all heat preservation times, and combined with the results of the transition metal catalytic corrosion sensitivity assessment, the broad-spectrum environmental adaptability of the rare earth zirconate ceramic is graded and evaluated.

[0108] Based on the weighted comprehensive score and the results of the transition metal catalytic corrosion sensitivity assessment, the broad-spectrum environmental adaptability of the materials is graded and evaluated. The grading criteria can be set according to engineering application requirements; this method recommends a four-level grading system:

[0109] Grade I (Excellent): The material's weighted composite score under all test conditions satisfies S < 0.3, and it is insensitive to transition metals (R_Fe ≤ 50%). This indicates that the material exhibits excellent corrosion resistance under all test environments and can be directly used in complex airspace service environments.

[0110] Level II (Good): The material's weighted composite score under all test conditions meets the requirement of 0.3 ≤ S < 0.6, and it is insensitive to transition metals (R_Fe ≤ 50%). The material performs well in most environments and meets conventional service requirements.

[0111] Level III (Acceptable): Materials that do not meet the requirements of Levels I, II, and IV are classified into this level. This indicates that the material performs acceptablely in some environments, but poses certain risks in specific environments, requiring evaluation based on the specific service environment.

[0112] Grade IV (Unacceptable): The material exhibits S≥0.95 under any test condition, or is sensitive to transition metals with R_Fe≥100%. The material is severely corroded, or the corrosion rate increases exponentially in Fe-containing environments, making it unsuitable for complex aerospace environments.

[0113] The final evaluation result should not only provide the corrosion resistance rating, but also clearly indicate which characteristic components the material is sensitive to (such as sensitivity to Fe, sensitivity to alkali metals, etc.), providing specific directions for material composition optimization.

[0114] In this embodiment, a comprehensive performance evaluation is performed based on the reaction layer thickness data of Gd2Zr2O7 ceramic under four corrosion sources and three heat preservation time gradients obtained in step S5.

[0115] First, a comparative analysis of multi-source corrosion was conducted. Using type D (artificial component) as the baseline corrosion source, the percentage difference R in reaction layer thickness under 5-hour insulation conditions was calculated for other corrosion sources: Type A (sand and gravel) R_A = (15.4-14.8) / 14.8 × 100% = 4.1%, Type B (volcanic ash) R_B = (28.3-14.8) / 14.8 × 100% = 91.2%, Type C (dust) R_C = (18.2-14.8) / 14.8 × 100% = 23.0%. The results show that type B volcanic ash has the most significant accelerating effect on corrosion, nearly doubling the reaction layer thickness; type C dust has a certain accelerating effect; and type A sand and gravel is similar to the artificial component. Combined with the microscopic characterization results, the participation of Fe and Ti elements in type B volcanic ash is the main reason for the accelerated corrosion.

[0116] Then, a weighted evaluation model was constructed. Three indicators were selected: reaction layer thickness (weight 0.4), maximum elemental diffusion depth (weight 0.3), and new phase composition (weight 0.3). A comprehensive score was calculated using data from a type B corrosion source after 5 hours of heat treatment. Regarding reaction layer thickness, after extreme value normalization, I'_1 = 0.32 for type A, I'_1 = 0.95 for type B, I'_1 = 0.45 for type C, and I'_1 = 0.30 for type D. Regarding maximum elemental diffusion depth, the maximum diffusion depths of major corrosive elements such as Ca and Fe were taken. After normalization, I'_2 = 0.28 for type A, I'_2 = 0.92 for type B, I'_2 = 0.42 for type C, and I'_2 = 0.25 for type D. Regarding the complexity of new phase formation, based on a comprehensive score considering the types and hazards of reaction products, type A has fewer new phases and lower complexity (I'_3 = 0.15); type B produces multiple new phases, including iron-rich spinel, resulting in high complexity (I'_3 = 0.88); type C has a moderate number of new phases (I'_3 = 0.35); and type D has a single new phase (I'_3 = 0.10). Weighted overall score: Type A S = 0.4 × 0.32 + 0.3 × 0.28 + 0.3 × 0.15 = 0.26; Type B S = 0.4 × 0.95 + 0.3 × 0.92 + 0.3 × 0.88 = 0.92; C-type S = 0.4 × 0.45 + 0.3 × 0.42 + 0.3 × 0.35 = 0.41; D-type S = 0.4 × 0.30 + 0.3 × 0.25 + 0.3 × 0.10 = 0.23.

[0117] Type B had the highest overall score, indicating that it was the most severely corroded.

[0118] The susceptibility to transition metal catalytic corrosion was determined. The reaction layer thickness of type B (volcanic ash type) and type D (classical artificial type) after 5 hours of heat treatment was compared, and the percentage difference R_Fe = (28.3-14.8) / 14.8 × 100% = 91.2% > 50%. According to the determination criteria, Gd₂Zr₂O₇ ceramics are sensitive to transition metal catalytic corrosion. This determination result is consistent with the phenomena observed in the microscopic characterization: a distinct iron-rich spinel phase appears after volcanic ash corrosion, and the participation of Fe significantly accelerates the corrosion process. If only the test results of traditional artificial CMAS are used, Gd₂Zr₂O₇ might be misjudged as having excellent corrosion resistance. However, the comprehensive evaluation method of this invention successfully reveals its potential failure risk in the high-speed rail volcanic ash environment.

[0119] Finally, a comprehensive evaluation of broad-spectrum environmental adaptability was conducted. Based on the weighted comprehensive score calculated under all corrosion sources and all holding times, a four-level classification system was used to comprehensively evaluate the Gd2Zr2O7 ceramic: the material exhibited S<0.95 under any test condition, was sensitive to transition metal catalytic corrosion, and R_Fe=91.2% (<100%). According to the classification standards, it did not meet the conditions for Class I, II, and IV, and therefore was classified as Class III (qualified).

[0120] Assessment Conclusion: The Gd₂Zr₂O₇ ceramic is rated as Grade III (qualified). Its corrosion risk is significantly increased in complex environments such as high-speed rail volcanic ash (Type B S=0.92, close to Grade IV), and it is sensitive to transition metal catalytic corrosion. This material can be used in conventional service environments, but it faces a high failure risk in Fe-containing environments such as active volcanic ash zones. Its tolerance to transition metals needs to be improved through composition optimization (such as high entropy, doping modification, etc.).

[0121] Through the above comprehensive performance evaluation, this embodiment successfully achieved a quantitative evaluation of the corrosion resistance of Gd2Zr2O7 ceramics in a multi-source CMAS corrosion environment, revealing specific environmental sensitivities that traditional single-component testing could not detect, and providing a clear direction for material optimization.

[0122] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A method for testing the CMAS corrosion resistance of rare earth zirconates under multi-source environmental spectra, characterized in that, Includes the following steps: Multiple CMAS corrosion sources with chemical composition gradients were selected to construct a multi-source corrosion environment spectral library covering different chemical characteristics; The CMAS corrosion source was dried, ball-milled, sieved, and pressed into shape to prepare gray columns of standard mass and geometric dimensions. A rare earth zirconate dense ceramic block was prepared, and the test surface of the dense ceramic block was polished. The gray column is placed on the polished surface of the ceramic block and subjected to isothermal heat treatment in a high-temperature box furnace. The heat-treated sample was cross-sectionally prepared to form the sample. The reaction layer thickness, average elemental diffusion depth and new phase composition of the sample were obtained by scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction. Based on the obtained reaction layer thickness, average element diffusion depth, and new phase composition, a weighted evaluation model is constructed to compare the corrosion kinetic differences under different corrosion sources and determine the broad-spectrum environmental adaptability of the rare earth zirconate dense ceramic block.

2. The method according to claim 1, characterized in that, The multi-source corrosion environment library contains at least two corrosion sources with significantly different chemical characteristics. The differences in chemical characteristics include at least one of the following: differences in major element composition, differences in transition metal element content, or differences in alkali metal salt content.

3. The method according to claim 1, characterized in that, The process of drying, ball milling, sieving, and pressing the CMAS corrosion source to prepare gray columns of standard quality and geometric dimensions includes: drying the naturally sourced CMAS corrosion source at a temperature of 100-120℃ for a time of not less than 12 hours. The dried CMAS corrosion source was ball-milled to refine the particle size and ensure uniform mixing. The ball milling process was wet ball milling, with the ball-to-material mass ratio controlled within the range of 4:1-6:

1. The ball milling time was 4-8 hours and the rotation speed was 200-400 rpm. After ball milling, the slurry was dried and sieved through a standard sieve. The powder that passed through the sieve was collected for later use. Weigh a fixed amount of the sieved powder, put it into a mold and press it into shape. The pressing pressure is 10-20MPa and the holding time is 20-60 seconds to obtain a cylindrical gray column.

4. The method according to claim 1, characterized in that, The preparation of the rare earth zirconate dense ceramic block and the polishing of the test surface of the dense ceramic block include: Weigh the rare earth oxides and zirconium oxide raw materials according to the stoichiometric ratio of the target rare earth zirconate ceramic. The weighed raw material powder is ball-milled and mixed, and then dried to obtain a uniformly mixed raw material powder. The mixed powders are pre-fired to synthesize the raw materials, causing a solid-phase reaction to generate the target rare earth zirconate ceramic phase. The pre-fired target rare earth zirconate ceramic phase was ball-milled a second time to obtain a fine synthetic powder; The synthesized powder is shaped and then sintered at high temperature to obtain a dense ceramic block; The sintered dense ceramic block is ground and polished to achieve a mirror finish on the test surface.

5. The method according to claim 1, characterized in that, The step of placing the gray column on the polished surface of the dense ceramic block and performing isothermal heat treatment in a high-temperature box furnace includes: The dense ceramic block was inspected and numbered to ensure that the test surface was free of contamination; The gray column is placed centered on the polished surface of the dense ceramic block to form a sample. The sample was placed on an alumina pad and placed in the uniform temperature zone of a high-temperature box furnace, with an appropriate distance between the samples. The sample was heated by a heat treatment program set on a high-temperature box furnace. The heat treatment program included heating to 1300°C at a rate of 10°C / min, and holding at 1300°C for 1 hour, 5 hours and 25 hours respectively. When the heat treatment procedure is executed, the timing starts when the furnace temperature reaches 1300℃, and the corresponding sample is taken out and allowed to cool naturally after each holding time is reached. After cooling, the samples are inspected and labeled, and the type of corrosion source, holding time, and sample number are recorded.

6. The method according to claim 1, characterized in that, The process involves preparing a cross-section of the heat-treated sample to form a cross-sectional sample. The thickness of the reaction layer, average elemental diffusion depth, and composition of the new phase are obtained using scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction. The heat-treated sample is cut into two halves along the axis passing through the center of the gray column. One half is used for cross-sectional sample preparation. After grinding and polishing, it reaches a mirror state, forming the cross-sectional sample. The sample prepared by the cross section was placed in a scanning electron microscope, and the reaction interface was observed using backscattered electron mode. The thickness of the reaction layer was measured at multiple random locations in the reaction interface area, and the average value was taken as the thickness of the reaction layer of the sample prepared by the cross section. While observing with a scanning electron microscope, an energy dispersive spectrometer is turned on to perform elemental line scanning analysis on the reaction interface of the sample after the cross section is prepared. Starting from the inside of the ceramic matrix, passing through the reaction layer, and entering the residual CMAS region, the characteristic X-ray intensity of the target element is collected, the distribution curve of element concentration as a function of distance is plotted, the maximum element diffusion depth is defined when the target element concentration drops to 5% of the matrix concentration, and the average element diffusion depth of all target elements is calculated. Take the other half of the sample, scrape off the powder from the surface of the reaction area and perform X-ray diffraction analysis. Compare the obtained X-ray diffraction pattern with the original ceramic block diffraction pattern to determine the reaction products. Based on the standard pattern, identify the new phase composition of the reaction products.

7. The method according to claim 6, characterized in that, The construction of the weighted evaluation model includes: Based on the reaction layer thickness, calculate the percentage difference in reaction layer thickness relative to the baseline for different corrosion sources under the same heat preservation time; Based on the reaction layer thickness, average element diffusion depth and new phase composition, a weighted comprehensive score is calculated after assigning weight coefficients to each. The sensitivity of the rare earth zirconate ceramic to transition metal catalytic corrosion was determined by comparing the reaction layer thickness under high-iron corrosion source and iron-free corrosion source conditions.

8. The method according to claim 7, characterized in that, The determination of broad-spectrum environmental adaptability includes: Based on the weighted comprehensive score calculated under all corrosion sources and all heat preservation times, and combined with the results of the transition metal catalytic corrosion sensitivity assessment, the broad-spectrum environmental adaptability of the rare earth zirconate ceramics is graded and evaluated.

9. An apparatus for implementing the method according to any one of claims 1-8, characterized in that, include: The corrosion source processing unit is used to dry, ball mill, sieve and press the CMAS corrosion source to prepare standardized gray columns. A ceramic sample preparation unit is used to prepare rare earth zirconate ceramic blocks by solid-state reaction method and to polish the test surface of the ceramic blocks. A high-temperature heat treatment unit is used to perform isothermal heat treatment on the ceramic block loaded with the gray column at a set temperature and holding time. The microscopic characterization unit is used to analyze the heat-treated sample using scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction to obtain data on the reaction layer thickness, average elemental diffusion depth, and composition of the new phase. The data analysis unit is used to record and store the data output by the micro-characterization unit, so that researchers can perform subsequent manual calculations and analyses.

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