CMAS-corrosion-resistant high-entropy rare earth monosilicate ceramic material as well as screening method, preparation method and application thereof

Abstract

The invention discloses a CMAS corrosion resistant high-entropy rare earth monosilicate ceramic material as well as a screening method, a preparation method and application thereof. The chemical formula of the composition of the CMAS corroded high-entropy rare earth monosilicate ceramic material is (Nd (1-x) / 3 ErxYb (1-x) / 3 Lu (1-x) / 3) 2SiO5, and in the formula, x is 0.4-0.6. According to the screening method of the CMAS corrosion resistant high-entropy rare earth monosilicate ceramic material, time and labor are saved, the development time and the development cost of the CMAS corrosion resistant high-entropy rare earth monosilicate ceramic material are effectively reduced, and the screened CMAS corrosion resistant high-entropy rare earth monosilicate ceramic material still has excellent CMAS corrosion resistance at 1700 DEG C; the method is suitable for large-scale application in the aerospace field.

Description

Technical Field

[0001] The present invention relates to the technical field of high-entropy ceramics, and in particular to a high-entropy rare earth monosilicate ceramic material resistant to CMAS corrosion, a screening method thereof, a preparation method thereof, and an application thereof. Background Art

[0002] CMAS corrosion refers to the destruction of thermal and environmental barrier coatings by CaO, MgO, Al2O3, and SiO2 (CMAS) at high temperatures. It is a major problem facing hot-end components of aircraft engines, such as turbine blades and combustion chamber walls. As aircraft engine efficiency and thrust-to-weight ratios continue to increase, operating temperatures are also rising, placing increasing demands on hot-end components to resist CMAS corrosion.

[0003] High entropy rare earth monosilicate ceramic materials have the advantages of excellent high temperature phase stability, low thermal conductivity, excellent water and oxygen resistance, and excellent CMAS corrosion resistance. They are considered to be the best candidate materials for the next generation of thermal barrier / environmental barrier coatings and have very broad application prospects in the aerospace field. However, the CMAS corrosion resistance of existing high entropy rare earth monosilicate ceramic materials is still not ideal, and the corrosion temperature is generally below 1300℃. For example, the high entropy rare earth silicate ceramic materials with good CMAS corrosion resistance reported so far are (Ho 1 / 4 Er 1 / 4 Yb 1 / 4 Lu 1 / 4 )2SiO5, which was corroded to a depth of 179μm after CMAS corrosion at 1300℃ for 50h (Composition effects on elastic, thermal and corrosion properties of multiple-RE silicate (Ho 1 / 4 Er 1 / 4 Yb 1 / 4 Lu 1 / 4 )2SiO5 as a promising thermal and environmental barrier coating material, Xiaomin Ren, Jie Zhang, Jingyang Wang. Journal of the European Ceramic Society, 42(2022): 7258-7266), it is difficult to meet the growing service requirements of high thrust-to-weight ratio of aircraft engines, resulting in its application being greatly restricted. In addition, the traditional high-entropy ceramic material screening method is time-consuming and labor-intensive, and it is difficult to quickly find the optimal component in the candidate material library with a huge component space, which limits the development of high-entropy rare earth monosilicate ceramic materials.

[0004] Therefore, it is of great significance to develop a time-saving and labor-saving screening method for high-entropy rare earth monosilicate ceramic materials that are resistant to CMAS corrosion, and to screen out high-entropy rare earth monosilicate ceramic materials with better CMAS corrosion resistance. Summary of the Invention

[0005] The present invention aims to provide a high-entropy rare earth monosilicate ceramic material resistant to CMAS corrosion, and a screening method, a preparation method and an application thereof.

[0006] The technical solution adopted by the present invention is:

[0007] A high entropy rare earth monosilicate ceramic material resistant to CMAS corrosion, the chemical formula of its composition is as follows: (Nd (1-x) / 3 Er x Yb (1-x) / 3 Lu (1-x) / 3 )2SiO5, where x=0.4~0.6.

[0008] Preferably, the corrosion depth of the high-entropy rare earth monosilicate ceramic material resistant to CMAS corrosion is 40 μm to 50 μm after CMAS corrosion for 80 hours at 1400° C., and the corrosion depth of the high-entropy rare earth monosilicate ceramic material after CMAS corrosion for 40 hours at 1700° C. is 30 μm to 40 μm.

[0009] A method for screening high-entropy rare earth monosilicate ceramic materials resistant to CMAS corrosion as described above comprises the following steps:

[0010] 1) Preparation of high entropy rare earth apatite Ca2RE8(SiO4)6O2 powder, where RE is a rare earth element;

[0011] 2) Test the dissolution rate of high-entropy rare earth apatite Ca2RE8(SiO4)6O2 powder in CMAS melt, and then determine the type and ratio of rare earth elements based on the high-entropy rare earth apatite Ca2RE8(SiO4)6O2 powder with low dissolution rate, so as to screen out high-entropy rare earth monosilicate ceramic materials that are resistant to CMAS corrosion.

[0012] Preferably, a method for screening high-entropy rare earth monosilicate ceramic materials resistant to CMAS corrosion as described above comprises the following steps:

[0013] 1) CaO powder, rare earth oxide powder and SiO2 powder are weighed according to the stoichiometric ratio, mixed and wet-milled to form a mixed powder slurry, and then dried and calcined to obtain high-entropy rare earth apatite Ca2RE8(SiO4)6O2 powder;

[0014] 2) High-entropy rare earth apatite Ca2RE8(SiO4)6O2 powder and CMAS powder are mixed and wet-milled to form a mixed powder slurry, which is then dried to form a mixed powder slurry, which is then pressed into a green body. The green body is then calcined and cooled to form a glassy block. The volume fraction of apatite in selected areas of the glassy block is then observed and quantitatively tested using a scanning electron microscope. The dissolution rate of high-entropy rare earth apatite Ca2RE8(SiO4)6O2 powder in the CMAS melt is determined based on the volume fraction of apatite. The type and ratio of rare earth elements are then determined based on the high-entropy rare earth apatite Ca2RE8(SiO4)6O2 powder with a low dissolution rate, thereby screening out high-entropy rare earth monosilicate ceramic materials that are resistant to CMAS corrosion.

[0015] Note: The inventors of this patent discovered through research that the CMAS corrosion resistance of the rare earth monosilicate component depends on the dissolution rate of the apatite generated by the reaction in the CMAS melt (Composition engineering of high-entropy rare-earth monosilicates enables remarkable CMAS corrosion resistance, Peng Wei, Hao Bai, Yang Liu, Lei Zhuang, Hulei Yu, Yanhui Chu. Journal of Materiomics, 11(2025):100967). From this, they came up with the idea of reversely screening the CMAS corrosion resistance of the rare earth monosilicate matrix by corresponding to the dissolution rate of the rare earth apatite powder in the CMAS melt, thereby obtaining the screening method of the high-entropy rare earth monosilicate ceramic material resistant to CMAS corrosion of the present invention.

[0016] Preferably, the particle size of the CaO powder in step 1) is 1 μm to 3 μm.

[0017] Preferably, the particle size of the rare earth oxide powder in step 1) is 1 μm to 3 μm, and the purity is ≥99.9%.

[0018] Preferably, the particle size of the SiO2 powder in step 1) is 1 μm to 3 μm, and the purity is ≥99%.

[0019] Preferably, the process parameters of the wet ball milling in step 1) include: the ball milling medium is anhydrous ethanol, the weight ratio of the powder raw material, ZrO2 balls and anhydrous ethanol is 1:1.8~2.2:10~15, and the ball milling time is 6h~10h.

[0020] Preferably, the calcination in step 1) comprises the following operations: first controlling the heating rate to be 6°C / min to 8°C / min from room temperature (25°C±5°C) to 1400°C to 1500°C, keeping the temperature for 2h to 4h, and then cooling to room temperature.

[0021] Preferably, the process parameters of the wet ball milling in step 2) include: the ball milling medium is anhydrous ethanol, the weight ratio of high entropy rare earth apatite Ca2RE8(SiO4)6O2 powder, CMAS powder, ZrO2 balls and anhydrous ethanol is 1:1.2~1.5:1.8~2.2:10~15, and the ball milling time is 20h~24h.

[0022] Preferably, the pressing in step 2) is carried out at a pressure of 10 MPa to 15 MPa, and the holding time is 3 min to 5 min.

[0023] Preferably, the calcination in step 2) comprises the following operations: firstly controlling the heating rate to be 6°C / min to 8°C / min from room temperature to 1350°C to 1450°C, and keeping the temperature for 5min to 10min.

[0024] Preferably, the number of the selected areas in step 2) is 4 to 6, and the volume fraction of apatite is taken as the average value of all the selected areas.

[0025] A method for preparing the high-entropy rare earth monosilicate ceramic material resistant to CMAS corrosion as described above comprises the following steps:

[0026] a) weighing Nd2O3 powder, Er2O3 powder, Yb2O3 powder, Lu2O3 powder and SiO2 powder according to the stoichiometric ratio, mixing and wet-milling the mixture to obtain a mixed powder slurry;

[0027] b) drying and calcining the mixed powder slurry to obtain high entropy rare earth silicate ceramic powder;

[0028] c) wet-milling the high-entropy rare earth silicate ceramic powder, followed by drying and pressing to obtain a green body;

[0029] d) sintering the green body to obtain a high-entropy rare earth monosilicate ceramic material resistant to CMAS corrosion.

[0030] Preferably, the particle sizes of the Nd2O3 powder, Er2O3 powder, Yb2O3 powder and Lu2O3 powder in step a) are all 1 μm to 3 μm, and the purity is ≥99.9%.

[0031] Preferably, the particle size of the SiO2 powder in step a) is 1 μm to 3 μm, and the purity is ≥99%.

[0032] Preferably, the process parameters of the wet ball milling in step a) include: the ball milling medium is anhydrous ethanol, the weight ratio of the powder raw material, ZrO2 balls and anhydrous ethanol is 1:1.8~2.2:10~15, and the ball milling time is 6h~10h.

[0033] Preferably, the calcination in step b) comprises the following operations: firstly controlling the heating rate to be 6°C / min-8°C / min from room temperature to 1400°C-1500°C, keeping the temperature for 2h-4h, and then cooling to room temperature.

[0034] Preferably, the process parameters of the wet ball milling in step c) include: the ball milling medium is anhydrous ethanol, the weight ratio of the powder raw material, ZrO2 balls and anhydrous ethanol is 1:1.8~2.2:10~15, and the ball milling time is 20h~24h.

[0035] Preferably, the compression molding in step c) comprises the following operations: first placing the powder in a tablet press for pre-compression at a molding pressure of 10 MPa to 15 MPa and a holding time of 3 min to 5 min, and then placing the powder in a cold isostatic press for molding at a molding pressure of 270 MPa to 300 MPa and a holding time of 3 min to 5 min.

[0036] Preferably, the sintering in step d) comprises the following operations: firstly controlling the heating rate to be 6°C / min to 8°C / min from room temperature to 1650°C to 1700°C, keeping the temperature for 10h to 15h, and then cooling to room temperature.

[0037] An aircraft engine, wherein the environmental barrier coating on the hot end component comprises the above-mentioned high-entropy rare earth monosilicate ceramic material resistant to CMAS corrosion.

[0038] The beneficial effects of the present invention are as follows: the screening method of the high-entropy rare earth monosilicate ceramic material resistant to CMAS corrosion of the present invention saves time and labor, effectively reduces the development time and development cost of the high-entropy rare earth monosilicate ceramic material resistant to CMAS corrosion, and the high-entropy rare earth monosilicate ceramic material resistant to CMAS corrosion obtained by screening still has excellent CMAS corrosion resistance at 1700°C, and is suitable for large-scale application in the aerospace field. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is the XRD pattern of the high entropy rare earth apatite powder in Example 1.

[0040] Figure 2 This is the BSE diagram of the glassy block in Example 1.

[0041] Figure 3 This is the XRD pattern of the high entropy rare earth monosilicate ceramic material in Example 2.

[0042] Figure 4 This is the BSE diagram of the high entropy rare earth monosilicate ceramic material in Example 2 after being corroded by CMAS at 1400°C for 80 hours.

[0043] Figure 5 This is the BSE diagram of the high-entropy rare earth monosilicate ceramic material in Example 2 after being corroded by CMAS at 1700°C for 40 hours. DETAILED DESCRIPTION

[0044] The present invention will be further explained and illustrated below with reference to specific embodiments.

[0045] Example 1:

[0046] A method for screening high-entropy rare earth monosilicate ceramic materials resistant to CMAS corrosion (three high-entropy rare earth apatite Ca2RE8(SiO4)6O2 powders are selected as examples), the steps are as follows:

[0047] 1) Preparation of high entropy rare earth apatite powder:

[0048] a) High entropy rare earth apatite powder Ca2(Nd (0.4 / 3) Er 0.6 Yb (0.4 / 3) Lu (0.4 / 3) )8(SiO4)6O2 preparation:

[0049] i) 0.5608 g of CaO powder, 0.8973 g of Nd2O3 powder, 4.5902 g of Er2O3 powder, 1.0509 g of Yb2O3 powder, 1.0612 g of Lu2O3 powder and 1.8025 g of SiO2 powder (the molar ratio of the powders is 1:0.53:2.4:0.53:0.53:3) were added to a planetary ball mill for wet ball milling. The process parameters of the wet ball milling are as follows: The ball milling medium is anhydrous ethanol, the weight ratio of powder raw material, ZrO2 balls and anhydrous ethanol is 1:2:12, and the ball milling time is 6 hours to obtain a mixed powder slurry; the particle size of CaO powder is 1μm to 3μm; the particle size of Nd2O3 powder, Er2O3 powder, Yb2O3 powder and Lu2O3 powder are all 1μm to 3μm, and the purity is ≥99.9%; the particle size of SiO2 powder is 1μm to 3μm, and the purity is ≥99%;

[0050] ii) The mixed powder slurry was placed in an oven at 60°C for 10 h, then placed in a crucible and placed in a muffle furnace. The temperature was then raised from room temperature to 1500°C at a controlled heating rate of 6°C / min, kept at this temperature for 3 h, and cooled to room temperature in the furnace to obtain high entropy rare earth apatite powder Ca2(Nd (0.4 / 3) Er 0.6 Yb (0.4 / 3) Lu (0.4 / 3))8(SiO4)6O2 (denoted as Sample-1);

[0051] b) High entropy rare earth apatite powder Ca2(Y (0.4 / 3) Er 0.6 Yb (0.4 / 3) Lu (0.4 / 3) )8(SiO4)6O2 preparation:

[0052] The preparation method of Sample-1 was exactly the same as that of Sample-2, except that the raw materials in step i) were adjusted to “0.5608 g of CaO powder, 0.6022 g of Y2O3 powder, 4.5902 g of Er2O3 powder, 1.0509 g of Yb2O3 powder, 1.0612 g of Lu2O3 powder, and 1.8025 g of SiO2 powder (the molar ratio of the powders was 1:0.53:2.4:0.53:0.53:3)”.

[0053] c) High entropy rare earth apatite powder Ca2(Nd 0.3 Er 0.1 Yb 0.3 Lu 0.3 )8(SiO4)6O2 preparation:

[0054] The preparation method of Sample-3 was exactly the same as that of Sample-1, except that the raw materials in step i) were adjusted to “0.5608 g of CaO powder, 2.0189 g of Nd2O3 powder, 0.7650 g of Er2O3 powder, 2.3646 g of Yb2O3 powder, 22.3876 g of Lu2O3 powder, and 1.8025 g of SiO2 powder (the molar ratio of the powders was 2:0.3:0.1:0.3:0.3:6)”;

[0055] 2) High-entropy rare earth apatite powder (Sample-1, Sample-2, and Sample-3) and CMAS powder were mixed and added to a planetary ball mill for wet ball milling. The wet ball milling process parameters were as follows: anhydrous ethanol as the ball milling medium, a weight ratio of high-entropy rare earth apatite powder, CMAS powder, ZrO2 balls, and anhydrous ethanol of 1:1.2:2:10, and a ball milling time of 20 h to obtain a mixed powder slurry;

[0056] 3) The mixed powder slurry was placed in an oven at 60°C for 10 hours. 2 g of the dried powder was then pressed into a green body in a tablet press at a molding pressure of 10 MPa and a holding time of 3 minutes. The green body was then placed in a lifting furnace and heated from room temperature to 1400°C at a controlled heating rate of 7°C / min. The temperature was maintained for 5 minutes, and the green body was removed and naturally cooled to obtain a glassy block.

[0057] 4) Scanning electron microscopy was then used to observe and quantitatively measure the volume fraction of apatite in selected areas of the glassy block. Five areas were randomly selected, and the volume fraction of apatite was taken as the average value of all selected areas. The type and ratio of rare earth elements were then determined based on the high-entropy rare earth apatite powder with a low dissolution rate, thereby screening high-entropy rare earth monosilicate ceramic materials that are resistant to CMAS corrosion.

[0058] Note:

[0059] The preparation process of CMAS powder is as follows:

[0060] 1) CaO powder, MgO powder, Al2O3 powder, and SiO2 powder (analytical purity, particle size >100 mesh) were weighed in a stoichiometric ratio of 33CaO-9MgO-13Al2O3-45SiO2, ball-milled for 6 h, heated to 1400°C and held for 3 h to obtain CMAS glass;

[0061] 2) Grind the CMAS glass and pass it through a 100-mesh sieve to obtain CMAS powder.

[0062] Performance testing:

[0063] 1) The X-ray diffraction (XRD) patterns of the high entropy rare earth apatite powders (Sample-1, Sample-2, and Sample-3) in this example are shown in FIG. Figure 1 shown.

[0064] Depend on Figure 1 It can be seen that: Ca2(Nd (0.4 / 3) Er 0.6 Yb (0.4 / 3) Lu (0.4 / 3) )8(SiO4)6O2 powder (Sample-1), Ca2(Y (0.4 / 3) Er 0.6 Yb (0.4 / 3) Lu (0.4 / 3) )8(SiO4)6O2 powder (Sample-2) and Ca2(Nd 0.3 Er 0.1 Yb 0.3 Lu 0.3 )8(SiO4)6O2 powders (Sample-3) are all uniform single-phase apatite, and no other impurity phases are found.

[0065] 2) The backscattered scanning electron microscope (BSE) image of the glassy block in this embodiment is as follows: Figure 2 (a is Sample-1, b is Sample-2, and c is Sample-3).

[0066] Depend on Figure 2 It can be seen that:

[0067] a)Ca2(Nd (0.4 / 3) Er 0.6 Yb (0.4 / 3) Lu (0.4 / 3) After the )8(SiO4)6O2 powder (Sample-1) was dissolved in CMAS at 1400℃, the volume fraction of the residual apatite powder was 65.08%, indicating that the apatite generated by the reaction of this component has a low dissolution rate in CMAS;

[0068] b)Ca2(Y (0.4 / 3) Er 0.6 Yb (0.4 / 3) Lu (0.4 / 3) After the )8(SiO4)6O2 powder (Sample-2) was dissolved in CMAS at 1400℃, the volume fraction of the residual apatite powder was 36.93%, indicating that the apatite generated by the reaction of this component has a high dissolution rate in CMAS, and the apatite generated by the reaction of the selected elements dissolves faster;

[0069] c)Ca2(Nd 0.3 Er 0.1 Yb 0.3 Lu 0.3 After the )8(SiO4)6O2 powder (Sample-3) was dissolved in CMAS at 1400℃, the volume fraction of the residual apatite powder was 35.14%, indicating that the apatite generated by the reaction of this component has a high dissolution rate in CMAS, and the apatite generated by the reaction of the selected elements dissolves faster;

[0070] Based on the above results, the chemical formula of the components can be obtained as (Nd (0.4 / 3) Er 0.6 Yb (0.4 / 3) Lu (0.4 / 3) )2SiO5 high entropy rare earth monosilicate ceramic material has excellent resistance to CMAS corrosion.

[0071] Example 2:

[0072] A high-entropy rare earth monosilicate ceramic material (a high-entropy rare earth monosilicate ceramic material corresponding to the three high-entropy rare earth apatite powders in Example 1) is prepared as follows:

[0073] Ca2(Nd (0.4 / 3) Er 0.6 Yb (0.4 / 3) Lu (0.4 / 3) )8(SiO4)6O2 powder corresponding to the high entropy rare earth monosilicate ceramic material (the chemical formula of the composition is (Nd (0.4 / 3) Er 0.6 Yb (0.4 / 3) Lu(0.4 / 3) Preparation of )2SiO5):

[0074] 1) 1.3459 g of Nd2O3 powder, 6.8853 g of Er2O3 powder, 1.5764 g of Yb2O3 powder, 1.5917 g of Lu2O3 powder and 1.8025 g of SiO2 powder (the molar ratio of the powders is 2.12:9.6:2.12:42.12:1) are added to a planetary ball mill for wet ball milling. The process parameters of wet ball milling are as follows: Below: The ball milling medium is anhydrous ethanol, the weight ratio of powder raw material, ZrO2 balls and anhydrous ethanol is 1:2:12, and the ball milling time is 8 hours to obtain a mixed powder slurry; the particle size of Nd2O3 powder, Er2O3 powder, Yb2O3 powder and Lu2O3 powder are all 1μm to 3μm, and the purity is ≥99.9%; the particle size of SiO2 powder is 1μm to 3μm, and the purity is ≥99%;

[0075] 2) drying the mixed powder slurry in an oven, placing it into a crucible, and placing it in a muffle furnace. The temperature was then raised from room temperature to 1450° C. at a heating rate of 8° C. / min, held for 3 hours, and then cooled to room temperature in the furnace to obtain a high-entropy rare earth silicate ceramic powder.

[0076] 3) adding high entropy rare earth silicate ceramic powder to a planetary ball mill for wet ball milling. The process parameters of the wet ball milling are as follows: the ball milling medium is anhydrous ethanol, the weight ratio of the powder raw material, ZrO2 balls and anhydrous ethanol is 1:2:12, the ball milling time is 22 hours, and then the powder is placed in an oven for drying. The powder is then placed in a tablet press for pre-pressing at a molding pressure of 12 MPa and a holding time of 4 minutes. The powder is then placed in a cold isostatic press for molding at a molding pressure of 285 MPa and a holding time of 4 minutes to obtain a green body.

[0077] 4) The green body was placed in a muffle furnace and heated from room temperature to 1650°C at a controlled heating rate of 7°C / min, held at that temperature for 12 h, and then cooled to room temperature in the furnace to obtain a high-entropy rare earth monosilicate ceramic material (block; denoted as Sample-4).

[0078] Ca2(Y (0.4 / 3) Er 0.6 Yb (0.4 / 3) Lu (0.4 / 3) )8(SiO4)6O2 powder corresponding to the high entropy rare earth monosilicate ceramic material (the chemical formula of the composition is (Y (0.4 / 3) Er 0.6 Yb (0.4 / 3) Lu (0.4 / 3) Preparation of )2SiO5):

[0079] Except for adjusting the raw materials in step 1) to "3.9140g of Y2O3 powder, 29.8363g of Er2O3 powder, 6.8310g of Yb2O3 powder, 6.8976g of Lu2O3 powder and 7.8108g of SiO2 powder (the molar ratio of the powders is 0.27:1.2:0.27:0.27:1)", the rest is exactly the same as the preparation method of Sample-4 (denoted as Sample-5).

[0080] Ca2(Nd 0.3 Er 0.1 Yb 0.3 Lu 0.3 )8(SiO4)6O2 powder corresponding to the high entropy rare earth monosilicate ceramic material (the chemical formula of the composition is (Nd 0.3 Er 0.1 Yb 0.3 Lu 0.3 Preparation of )2SiO5):

[0081] Except for adjusting the raw materials in step 1) to "13.1228g of Nd2O3 powder, 4.9727g of Er2O3 powder, 15.3698g of Yb2O3 powder, 15.5195g of Lu2O3 powder and 7.8108g of SiO2 powder (the molar ratio of the powders is 3:1:3:3:5)", the rest is exactly the same as the preparation method of Sample-4 (denoted as Sample-6).

[0082] Performance testing:

[0083] 1) The X-ray diffraction (XRD) patterns of the high entropy rare earth monosilicate ceramic materials (Sample-4, Sample-5, and Sample-6) in this embodiment are shown in FIG. Figure 3 shown.

[0084] Depend on Figure 3 It can be seen that the chemical formula of Sample-4 (components is (Nd (0.4 / 3) Er 0.6 Yb (0.4 / 3) Lu (0.4 / 3) )2SiO5), Sample-5 (the chemical formula of the composition is (Y (0.4 / 3) Er 0.6 Yb (0.4 / 3) Lu (0.4 / 3) )2SiO5) and Sample-6 (the chemical formula of the composition is (Nd 0.3 Er 0.1 Yb 0.3 Lu 0.3 )2SiO5) are all uniform single phase X2-RE2SiO5, and no other impurity phases are found.

[0085] 2) The BSE images of the high entropy rare earth monosilicate ceramic materials (Sample-4, Sample-5 and Sample-6) in this embodiment after CMAS corrosion at 1400°C for 80 hours are shown in FIG. Figure 4 (a is Sample-4, b is Sample-5, c is Sample-6).

[0086] The specific operation of the anti-CMAS test is as follows:

[0087] 1) First, CaO powder, MgO powder, Al2O3 powder, and SiO2 powder (purity: analytical grade, particle size >100 mesh) were weighed according to the stoichiometric ratio of 33CaO-9MgO-13Al2O3-45SiO2, ball-milled for 6 h, heated to 1400°C and kept warm for 3 h to obtain CMAS glass;

[0088] 2) Grind the CMAS glass and pass it through a 100-mesh sieve to obtain CMAS powder, which is then coated on the surface of the high-entropy rare earth monosilicate ceramic material at a coating amount of 50 mg / cm 2 The sample was then heated to 1400°C and kept warm for 80 hours to evaluate its resistance to CMAS corrosion. The corroded sample was then cut with a wire cutting machine, and its corrosion depth was observed under a scanning electron microscope (the corrosion depth refers to the depth to which the CMAS melt penetrates into the matrix with the uncorroded surface of the sample as the initial interface).

[0089] Depend on Figure 4 It can be seen that:

[0090] a) Sample-4 (chemical formula of the composition is (Nd (0.4 / 3) Er 0.6 Yb (0.4 / 3) Lu (0.4 / 3) The corrosion depth of )2SiO5) after CMAS corrosion at 1400℃ for 80h is only 50μm. The reason is that a very dense apatite layer is formed, and the dissolution rate of apatite in CMAS is low, which effectively blocks the further penetration of CMAS.

[0091] b) Sample-5 (the chemical formula of the composition is (Y (0.4 / 3) Er 0.6 Yb (0.4 / 3) Lu (0.4 / 3) The corrosion depth of )2SiO5) after CMAS corrosion at 1400℃ for 40h is 85μm, which is significantly greater than that of Sample-4. The reason is that the dissolution rate of apatite in CMAS is much higher than that of Sample-4, and it cannot effectively block the further penetration of CMAS.

[0092] Combining the results of a) and b), we can see that when the rare earth element composition of the high-entropy rare earth monosilicate ceramic material is Nd, Er, Yb, and Lu, the dissolution rate of high-entropy rare earth apatite in CMAS is low, and the high-entropy rare earth silicate ceramic material has excellent resistance to high-temperature CMAS corrosion. This shows that the type of rare earth element has a great influence on the resistance to high-temperature CMAS corrosion, mainly due to the synergistic effect between the rare earth elements.

[0093] c) Sample-6 (chemical formula of the composition is (Nd 0.3 Er 0.1 Yb 0.3 Lu 0.3 The corrosion depth of )2SiO5) after CMAS corrosion at 1400℃ for 40h is 92μm, which is significantly greater than that of Sample-4. The reason is that the dissolution rate of apatite in CMAS is much higher than that of Sample-4, and it cannot effectively block the further penetration of CMAS.

[0094] Combining the results of a) and c), we can know that the composition of high entropy rare earth monosilicate ceramic material is (Nd (0.4 / 3) Er 0.6 Yb (0.4 / 3) Lu (0.4 / 3) )2SiO5, the dissolution rate of high-entropy rare earth apatite in CMAS is low, and high-entropy rare earth silicate ceramic materials have excellent CMAS corrosion resistance at 1400℃~1700℃, which shows that the content of rare earth elements has a great influence on the resistance to high-temperature CMAS corrosion, mainly due to the synergistic effect between different rare earth element ratios.

[0095] 3) The BSE image of the high entropy rare earth monosilicate ceramic material (Sample-4) in this embodiment after CMAS corrosion at 1700°C for 40 hours is as follows: Figure 5 shown.

[0096] Depend on Figure 5 It can be seen that the corrosion depth of the high-entropy rare earth monosilicate ceramic material (Sample-4) after CMAS corrosion at 1700℃ for 40h is only 37μm. The reason is that a denser apatite layer is generated after high-temperature corrosion, which effectively blocks the further penetration of CMAS.

[0097] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A high-entropy rare earth monosilicate ceramic material resistant to CMAS corrosion, characterized in that: The chemical formula of the components is as follows: (Nd (1-x) / 3 Er x Yb (1-x) / 3 Lu (1-x) / 3 )2SiO5, where x=0.4~0.

6.

2. The high-entropy rare earth monosilicate ceramic material resistant to CMAS corrosion according to claim 1, characterized in that: The corrosion depth of the high-entropy rare earth monosilicate ceramic material resistant to CMAS corrosion is 40 μm to 50 μm after CMAS corrosion for 80 hours at 1400° C., and the corrosion depth of the high-entropy rare earth monosilicate ceramic material after CMAS corrosion for 40 hours at 1700° C. is 30 μm to 40 μm.

3. A method for screening high-entropy rare earth monosilicate ceramic materials resistant to CMAS corrosion according to claim 1 or 2, characterized in that: The following steps are involved: 1) Preparation of high entropy rare earth apatite Ca2RE8(SiO4)6O2 powder, where RE is a rare earth element; 2) Test the dissolution rate of high-entropy rare earth apatite Ca2RE8(SiO4)6O2 powder in CMAS melt, and then determine the type and ratio of rare earth elements based on the high-entropy rare earth apatite Ca2RE8(SiO4)6O2 powder with low dissolution rate, so as to screen out high-entropy rare earth monosilicate ceramic materials that are resistant to CMAS corrosion.

4. The method for screening high-entropy rare earth monosilicate ceramic materials resistant to CMAS corrosion according to claim 3, characterized in that: The following steps are involved: 1) CaO powder, rare earth oxide powder and SiO2 powder are weighed according to the stoichiometric ratio, mixed and wet-milled to form a mixed powder slurry, and then dried and calcined to obtain high-entropy rare earth apatite Ca2RE8(SiO4)6O2 powder; 2) High-entropy rare earth apatite Ca2RE8(SiO4)6O2 powder and CMAS powder are mixed and wet-milled to form a mixed powder slurry, which is then dried to form a mixed powder slurry, which is then pressed into a green body. The green body is then calcined and cooled to form a glassy block. The volume fraction of apatite in selected areas of the glassy block is then observed and quantitatively tested using a scanning electron microscope. The dissolution rate of high-entropy rare earth apatite Ca2RE8(SiO4)6O2 powder in the CMAS melt is determined based on the volume fraction of apatite. The type and ratio of rare earth elements are then determined based on the high-entropy rare earth apatite Ca2RE8(SiO4)6O2 powder with a low dissolution rate, thereby screening out high-entropy rare earth monosilicate ceramic materials that are resistant to CMAS corrosion.

5. The method for screening high-entropy rare earth monosilicate ceramic materials resistant to CMAS corrosion according to claim 4, characterized in that: The particle size of the CaO powder in step 1) is 1 μm to 3 μm; the particle size of the rare earth oxide powder in step 1) is 1 μm to 3 μm, and the purity is ≥99.9%; the particle size of the SiO2 powder in step 1) is 1 μm to 3 μm, and the purity is ≥99%; the calcination in step 1) includes the following operations: first controlling the heating rate to be 6°C / min to 8°C / min from room temperature to 1400°C to 1500°C, keeping the temperature for 2h to 4h, and then cooling to room temperature.

6. The method for screening high-entropy rare earth monosilicate ceramic materials resistant to CMAS corrosion according to claim 4 or 5, characterized in that: The pressing in step 2) is carried out under a pressure of 10 MPa to 15 MPa, and the holding time is 3 min to 5 min; the calcination in step 2) comprises the following operations: first controlling the heating rate to be 6°C / min to 8°C / min from room temperature to 1350°C to 1450°C, and holding the temperature for 5 min to 10 min; the number of selected areas in step 2) is 4 to 6, and the volume fraction of apatite is taken as the average value of all selected areas.

7. A method for preparing a high-entropy rare earth monosilicate ceramic material resistant to CMAS corrosion as claimed in claim 1 or 2, characterized in that: The following steps are involved: a) weighing Nd2O3 powder, Er2O3 powder, Yb2O3 powder, Lu2O3 powder and SiO2 powder according to the stoichiometric ratio, mixing and wet ball milling to obtain a mixed powder slurry; b) drying and calcining the mixed powder slurry to obtain high entropy rare earth silicate ceramic powder; c) wet-milling the high-entropy rare earth silicate ceramic powder, followed by drying and pressing to obtain a green body; d) sintering the green body to obtain a high-entropy rare earth monosilicate ceramic material resistant to CMAS corrosion.

8. The method for preparing a high-entropy rare earth monosilicate ceramic material resistant to CMAS corrosion according to claim 7, characterized in that: The particle sizes of the Nd2O3 powder, Er2O3 powder, Yb2O3 powder and Lu2O3 powder in step a) are all 1μm to 3μm, and the purity is ≥99.9%; the particle size of the SiO2 powder in step a) is 1μm to 3μm, and the purity is ≥99%; the calcination in step b) includes the following operations: first controlling the heating rate to 6℃ / min~8℃ / min from room temperature to 1400℃~1500℃, keeping warm for 2h~4h, and then cooling to room temperature.

9. The method for preparing a high-entropy rare earth monosilicate ceramic material resistant to CMAS corrosion according to claim 7 or 8, characterized in that: The compression molding in step c) comprises the following operations: firstly placing the powder in a tablet press for pre-compression at a molding pressure of 10 MPa to 15 MPa and a holding time of 3 to 5 minutes, and then placing the powder in a cold isostatic press for molding at a molding pressure of 270 MPa to 300 MPa and a holding time of 3 to 5 minutes; and the sintering in step d) comprises the following operations: firstly controlling the heating rate to be 6°C / min to 8°C / min from room temperature to 1650°C to 1700°C, holding the temperature for 10 to 15 hours, and then cooling to room temperature.

10. An aircraft engine, characterized in that: The environmental barrier coating on the hot end component comprises the high-entropy rare earth monosilicate ceramic material resistant to CMAS corrosion according to claim 1 or 2.

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