CMAS coating for thermal barrier coating corrosion experiment and coating method

Abstract

The invention relates to a CMAS coating for a thermal barrier coating corrosion experiment and a coating method, belongs to the technical field of thermal barrier coating high-temperature CMAS corrosion, solves the problem that CMAS coating is uneven in the prior art, and comprises the steps that S1, ethyl cellulose is added into absolute ethyl alcohol to obtain an absolute ethyl alcohol solution containing 2.5 wt%-6.0 wt% of ethyl cellulose, and the mass m0 is recorded; s2, adding sieved CMAS powder into the solution to obtain a CMAS suspension, and recording the addition amount m1 of the CMAS powder; s3, preparing a thermal barrier coating material to be experimented, and recording the mass m2; s4, uniformly applying the CMAS suspension liquid to the to-be-corroded surface of the thermal barrier coating material; s5, ethanol is evaporated to dryness, the coated thermal barrier coating material is obtained, and the mass m3 is recorded; s6, calculating the coating amount of the CMAS: # imgabs0 #, and S7, judging whether the obtained value of the mCMAS meets experimental requirements or not, if not, returning to the step S4, and otherwise, ending and obtaining the final thermal barrier coating material coated with the CMAS.

Description

Technical Field

[0001] The invention relates to the technical field of high-temperature CMAS corrosion of thermal barrier coatings, and in particular to a CMAS coating for thermal barrier coating corrosion experiments and a coating method. Background Art

[0002] Thermal barrier coating (TBC) is a coating that protects the substrate in high temperature environments. It is mainly composed of ceramic materials such as zirconium oxide and aluminum oxide. These materials have high melting points, high thermal conductivity, and excellent anti-oxidation, anti-corrosion, and anti-wear properties. They can effectively isolate the influence of high temperature on the substrate and extend its service life. The application of thermal barrier coatings in aircraft engines is particularly important. It can reduce the surface temperature of components such as combustion chambers and turbine blades, extend their service life, and improve the performance and reliability of the engine. In the aerospace field, thermal barrier coatings can reduce the temperature of the surface of spacecraft, extend its service life, and improve the performance and reliability of spacecraft.

[0003] CMAS (CaO-MgO-Al2O3-SiO2), as an environmental sediment from nature, is mainly composed of calcium oxide, magnesium oxide, aluminum oxide and silicon dioxide. In high temperature environment, CMAS easily reacts with thermal barrier coatings, resulting in degradation of coating performance or even failure. After CMAS reacts with thermal barrier coatings, substances with higher thermal conductivity and lower density, such as calcium feldspar and forsterite, will be formed, resulting in increased thermal conductivity, porosity and thickness of the coating, and decreased thermal insulation performance. At the same time, after CMAS reacts with thermal barrier coatings, it will change the microstructure of the coating, such as grain size, grain boundary morphology, etc., affecting the mechanical and thermal properties of the coating, resulting in decreased coating performance.

[0004] Studying CMAS is crucial to the corrosion of thermal barrier coatings. Through experiments, we can gain a deeper understanding of the corrosion mechanism of CMAS on thermal barrier coatings, thereby optimizing the preparation process of the coatings and improving their corrosion resistance. This will not only help to extend the service life of thermal barrier coatings, but also expand their application range.

[0005] However, the CMAS coating method in the prior art is to directly disperse CMAS in anhydrous ethanol. The low viscosity of anhydrous ethanol causes the sedimentation rate of CMAS in anhydrous ethanol to be too high, which in turn causes uneven CMAS coating and difficulty in adjusting the CMAS coating amount. Summary of the invention

[0006] In view of the above problems, the present invention provides a CMAS coating and a coating method for thermal barrier coating corrosion experiments to adapt to low, medium and high concentration CMAS corrosion conditions.

[0007] According to one embodiment of the present invention, a CMAS coating method for thermal barrier coating corrosion experiment is provided, comprising the following steps:

[0008] Step S1, solvent preparation: adding ethyl cellulose to anhydrous ethanol, stirring for 12 to 15 hours to fully dissolve the ethyl cellulose in the anhydrous ethanol, obtaining an anhydrous ethanol solution having 2.5 wt% to 6.0 wt% of ethyl cellulose, and recording the amount of ethyl cellulose added in the solution m0;

[0009] Step S2, preparation of CMAS suspension: sieve the ground CMAS powder, and add the sieved CMAS powder to the above-mentioned anhydrous ethanol solution having 2.5 wt% to 6.0 wt% of ethyl cellulose, stir for 6 to 12 hours to evenly disperse the CMAS powder in the solution to obtain a CMAS suspension, and record the amount of CMAS powder added m1;

[0010] Step S3, preparation of thermal barrier coating material: placing the thermal barrier coating material to be tested with flat upper and lower surfaces in an analytical balance, and recording the mass m2;

[0011] Step S4, CMAS coating: taking a CMAS suspension, evenly dripping it on the surface to be etched of the thermal barrier coating material, placing the thermal barrier coating material on a spin coater for spin coating, so that the CMAS suspension is evenly spread on the surface of the thermal barrier coating material;

[0012] Step S5, CMAS solution treatment: placing the thermal barrier coating material coated with the CMAS suspension on a hot stage, slowly evaporating excess ethanol to obtain the coated thermal barrier coating material, and recording the mass of the coated thermal barrier coating material as m3;

[0013] Step S6, calculating the coating amount of CMAS of the thermal barrier coating material after coating:

[0014]

[0015] Step S7, determine the obtained m C,AS The value of meets the set experimental requirements. If not, return to step S4 to adjust the coating amount of CMAS. Otherwise, the process ends and obtains a thermal barrier coating material coated with CMAS that meets the experimental requirements.

[0016] Optionally, in step S2, the ground CMAS powder is sieved through a sieve with a mesh size of 200 or above.

[0017] Optionally, in step S1, 0.2 g to 0.5 g of ethyl cellulose is added to 10 ml of anhydrous ethanol to obtain an anhydrous ethanol solution having 2.5 wt% to 6.0 wt% of ethyl cellulose; in step S2, 0.1 g to 2 g of sieved CMAS powder is added to the anhydrous ethanol solution having 2.5 wt% to 6.0 wt% of ethyl cellulose.

[0018] Optionally, in step S4, the thermal barrier coating material is placed on a spin coater for spin coating, which is to place the thermal barrier coating material on a spin coater and perform spin coating at 200 rpm to 400 rpm.

[0019] Optionally, the temperature of the hot plate in step S5 is set to 40° C. to 50° C.

[0020] According to another embodiment of the present invention, a CMAS coating for thermal barrier coating corrosion test is provided, which includes ethyl cellulose dissolved in anhydrous ethanol and a CMAS suspension obtained by mixing CMAS powder.

[0021] Optionally, the proportion of ethyl cellulose dissolved in the CMAS suspension is 2.5 wt% to 6.0 wt%.

[0022] Compared with the prior art, a CMAS coating and coating method for thermal barrier coating corrosion testing provided according to an embodiment of the present invention has at least the following beneficial effects:

[0023] 1) The obtained CMAS coating suspension will not be delaminated.

[0024] 2) The concentration difference of CMAS in the middle area and the edge area of ​​the CMAS coating is smaller.

[0025] 3) It is easy to adjust the coating amount of CMAS coating, which can greatly improve the uniformity of coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. The features and advantages of the present invention can be more clearly understood by referring to the drawings. The drawings are schematic and should not be understood as limiting the present invention in any way. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 The pictures are of the CMAS suspension dispersed in ethanol obtained by comparative example 1 of the prior art, and the pictures of the CMAS coating obtained by example 1 of a CMAS coating method for thermal barrier coating corrosion experiment according to the present invention.

[0028] Figure 2 The figures are coating effect diagrams of the ethanol-dispersed CMAS suspension obtained in Comparative Example 1 of the prior art, and effect diagrams of the CMAS coating obtained in Example 1 of the CMAS coating method for thermal barrier coating corrosion experiment according to the present invention. DETAILED DESCRIPTION

[0029] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0030] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0031] A CMAS coating method for thermal barrier coating corrosion experiment provided according to an embodiment of the present invention is described in detail below with reference to the accompanying drawings.

[0032] A CMAS coating method for thermal barrier coating corrosion experiment provided according to an embodiment of the present invention includes the following steps.

[0033] Step S1, solvent preparation: add 0.2g-0.5g ethyl cellulose (49.6%+(ethoxy), 270-330mPa·s) to 10ml anhydrous ethanol, stir for 12 to 15 hours to fully dissolve the ethyl cellulose in the anhydrous ethanol, and obtain an anhydrous ethanol solution with 2.5wt%-6.0wt% ethyl cellulose. Record the amount of ethyl cellulose added in the solution m0. In the anhydrous ethanol solution of the ethyl cellulose, the proportion of ethyl cellulose can be selected according to the physicochemical properties of the CMAS. For example, a CMAS with a large particle size uses a solution with a high ethyl cellulose concentration, and a CMAS with a small particle size uses a solution with a low ethyl cellulose concentration.

[0034] Step S2, preparation of CMAS suspension: sieve the ground CMAS powder. Add 0.1g to 2g of sieved CMAS powder to the above-mentioned 2.5wt% to 6.0wt% anhydrous ethanol solution of ethyl cellulose, stir for 6 to 12 hours to evenly disperse the CMAS powder in the solution to obtain a CMAS suspension. Record the amount of CMAS powder added m1. Sieve the ground CMAS powder through a sieve of 200 mesh or above. Optionally, sieve it through a 200 mesh sieve. The obtained CMAS suspension is a CMAS coating provided according to an embodiment of the present invention.

[0035] Step S3, preparation of thermal barrier coating materials: Place a round or square block of thermal barrier coating material with flat upper and lower surfaces to be tested in an analytical balance, and record the mass m2.

[0036] Step S4, CMAS coating: Take an appropriate amount of CMAS suspension and evenly drop it on the surface of the thermal barrier coating material to be etched. Then, place the thermal barrier coating material on a spin coater and spin coat it at 200 rpm to 400 rpm to evenly spread the CMAS suspension on the surface of the thermal barrier coating material.

[0037] Step S5, CMAS solution treatment: Place the thermal barrier coating material coated with the CMAS suspension on a hot plate at 40°C to 50°C to slowly evaporate excess ethanol to obtain the coated thermal barrier coating material. The mass of the coated thermal barrier coating material is recorded as m3.

[0038] Step S6, calculating the coating amount of CMAS of the thermal barrier coating material after coating:

[0039]

[0040] Step S7, adjusting the coating amount of CMAS: judging the obtained m CMAS The value of meets the set experimental requirements. If not, return to step S4, otherwise end and obtain a thermal barrier coating material coated with CMAS that meets the experimental requirements. That is, steps S4 to S6 can be repeated until the CMAS coating amount required by the experiment is reached.

[0041] The actual application effect of the CMAS coating method for thermal barrier coating corrosion experiment provided according to the embodiment of the present invention is described below with reference to Example 1 of the present invention and Comparative Example 1 of the prior art.

[0042] In Comparative Example 1, 1.0 g of CMAS was dispersed in 10 mL of ethanol to obtain a suspension.

[0043] Example 1 is an example of applying the CMAS coating method for thermal barrier coating corrosion test provided according to an embodiment of the present invention, wherein a suspension prepared by dispersing 1.0 g of CMAS in 10 mL of 3 wt % ethyl cellulose ethanol solution.

[0044] like Figure 1 As shown, the left side is the CMAS suspension dispersed in ethanol obtained by using the comparative example 1 of the prior art, and the right side is the CMAS coating obtained by using the embodiment 1 of the CMAS coating method for thermal barrier coating corrosion experiment according to the present invention. As shown in the figure, the suspension obtained in comparative example 1 and the suspension obtained in embodiment 1 show obvious differences after being precipitated at the same time for 1 minute. The CMAS suspension dispersed in ethanol of comparative example 1 shows obvious stratification. However, the CMAS suspension dispersed in ethyl cellulose solution of embodiment 1 does not show stratification, which greatly improves the accuracy of coating.

[0045] like Figure 2As shown, the left side is a coating effect diagram of the CMAS suspension dispersed in ethanol obtained by comparative example 1 of the prior art, and the right side is a CMAS coating obtained by applying Example 1 of a CMAS coating method for thermal barrier coating corrosion experiment according to the present invention. As shown in the figure, the CMAS suspension dispersed in ethanol of comparative example 1 is prone to CMAS concentration differences between the middle area and the edge area when coated at a low concentration. The excellent film-forming property of the ethyl cellulose solution of Example 1 can make the coating of CMAS at a low concentration more uniform.

[0046] All the above optional technical solutions can be arbitrarily combined to form optional embodiments of the present application, which will not be described one by one here.

[0047] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0048] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A CMAS coating method for thermal barrier coating corrosion experiment, characterized in that: The following steps are involved: Step S1, solvent preparation: adding ethyl cellulose to anhydrous ethanol, stirring for 12 to 15 hours to fully dissolve the ethyl cellulose in the anhydrous ethanol, obtaining an anhydrous ethanol solution having 2.5 wt% to 6.0 wt% of ethyl cellulose, and recording the amount of ethyl cellulose added in the solution m0; Step S2, preparation of CMAS suspension: sieve the ground CMAS powder, and add the sieved CMAS powder to the above-mentioned anhydrous ethanol solution having 2.5 wt% to 6.0 wt% of ethyl cellulose, stir for 6 to 12 hours to evenly disperse the CMAS powder in the solution to obtain a CMAS suspension, and record the amount of CMAS powder added m1; Step S3, preparation of thermal barrier coating material: placing the thermal barrier coating material to be tested with flat upper and lower surfaces in an analytical balance, and recording the mass m2; Step S4, CMAS coating: taking a CMAS suspension and evenly dropping it on the surface to be etched of the thermal barrier coating material, placing the thermal barrier coating material on a spin coater for spin coating, so that the CMAS suspension is evenly spread on the surface of the thermal barrier coating material; Step S5, CMAS solution treatment: placing the thermal barrier coating material coated with the CMAS suspension on a hot stage, slowly evaporating excess ethanol to obtain the coated thermal barrier coating material, and recording the mass of the coated thermal barrier coating material as m3; Step S6, calculating the coating amount of CMAS of the thermal barrier coating material after coating: Step S7, determine the obtained m C,AS The value of meets the set experimental requirements. If not, return to step S4 to adjust the coating amount of CMAS. Otherwise, the process ends and obtains a thermal barrier coating material coated with CMAS that meets the experimental requirements.

2. The CMAS coating method for thermal barrier coating corrosion experiment according to claim 1, characterized in that: In step S2, the ground CMAS powder is sieved using a sieve with a mesh size of 200 or more.

3. The CMAS coating method for thermal barrier coating corrosion experiment according to claim 1, characterized in that: In step S1, 0.2 g to 0.5 g of ethyl cellulose is added to 10 ml of anhydrous ethanol to obtain an anhydrous ethanol solution having 2.5 wt % to 6.0 wt % of ethyl cellulose; In step S2, 0.1 g to 2 g of sieved CMAS powder is added to an anhydrous ethanol solution containing 2.5 wt% to 6.0 wt% of ethyl cellulose.

4. The CMAS coating method for thermal barrier coating corrosion experiment according to claim 1, characterized in that: In step S4, the thermal barrier coating material is placed on a spin coater for spin coating, and the thermal barrier coating material is placed on the spin coater for spin coating at 200 rpm to 400 rpm.

5. The CMAS coating method for thermal barrier coating corrosion experiment according to claim 1, characterized in that: In step S5, the temperature of the heating stage is set to 40°C to 50°C.

6. A CMAS coating for thermal barrier coating corrosion testing, characterized in that: The method comprises dissolving ethyl cellulose in anhydrous ethanol and mixing the CMAS powder to obtain a CMAS suspension.

7. The CMAS coating for thermal barrier coating corrosion test according to claim 6, characterized in that: The proportion of ethyl cellulose dissolved in the CMAS suspension is 2.5 wt % to 6.0 wt %.

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