A kind of Al 2 O 3 -RE 2 O 3 Synergistically modified high-temperature resistant silicon carbide ceramic matrix composite material resistant to water and oxygen erosion and preparation method thereof

Abstract

The present invention relates to an Al2O3-RE2O3 co-modified silicon carbide ceramic matrix composite material with high temperature resistance to water and oxygen erosion and a preparation method thereof. The preparation method of the silicon carbide ceramic matrix composite material includes: (1) mixing SiC powder, RE2O3 powder, Al2O3 powder, carbon black, a binder and a solvent to obtain a mixed slurry; (2) immersing a fiber preform into the mixed slurry, and obtaining a carbon-containing porous preform through drying, curing and pyrolysis; (3) subjecting the carbon-containing porous preform to silicon reaction infiltration treatment to obtain the Al2O3-RE2O3 co-modified silicon carbide ceramic matrix composite material with high temperature resistance to water and oxygen erosion.

Description

Technical Field

[0001] The present invention belongs to the technical field of silicon carbide ceramic matrix composites, and relates to an Al 2 O 3 -RE 2 O 3 co-modified high-temperature resistant silicon carbide ceramic matrix composite material resistant to water and oxygen erosion and a preparation method thereof. Background Technique

[0002] The continuous development of the aviation field has posed higher challenges to the performance of aircraft engines. The hot-end components of aircraft engines need to withstand harsh environments such as high temperature, pressure, gas erosion, and water and oxygen corrosion during service. Continuously reinforced silicon carbide (SiC f / SiC) composites have become the preferred materials for the next-generation hot structural materials of aircraft engines due to their advantages such as high temperature resistance, light weight, high strength, and non-brittle fracture.

[0003] In the actual service environment, the SiO f oxide layer formed by the surface oxidation of SiC 2 / SiC composites reacts with H 2 O in the environment to form volatile Si(OH) 4 . The dense oxide layer gradually becomes loose and even peeled off, thereby accelerating the oxidation erosion of the material, and the service performance of the SiC f / SiC composites rapidly deteriorates. In order to improve the service life of SiC f / SiC composites, it is necessary to introduce a water and oxygen stable phase into the matrix to modify the composites. Rare earth disilicates (RE 2 Si 2 O 7 ) have excellent high-temperature water and oxygen stability and match the thermal expansion coefficient of the SiC matrix. They are a candidate modification material for improving the water and oxygen erosion resistance of SiC f / SiC composites. References [1-2] ([1] Fang He, J Eur Ceram Soc, 2021, 16(41): 93-100; [2] Peng Wang, J Inorg Mater, 2019, 34: 904-908) have both reported directly introducing rare earth silicates into the matrix to improve the water and oxygen erosion resistance of the composites. However, RE 2 Si 2 O 7 has poor fluidity at high temperatures and cannot heal the intrinsic defects of the material and the defects generated by water and oxygen corrosion. The SiC f / SiC composites will still be eroded and damaged by water and oxygen media. Therefore, introducing RE 2 Si 2O 7 Adding self-healing phases for synergistic modification simultaneously is a more promising way to improve the water and oxygen erosion resistance of SiC f / SiC composites.

[0004] Patent No. CN116891384A discloses a SiBCN-RE 2 Si 2 O 7 synergistically modified silicon carbide ceramic matrix composite and its preparation method. By the precursor infiltration and pyrolysis process, RE 2 Si 2 O 7 and SiBCN are directly introduced into the matrix of the silicon carbide ceramic matrix composite. Utilizing the self-healing effect of SiBCN and RE 2 Si 2 O 7 protective layer to improve the water and oxygen erosion resistance of the composite. However, B 2 O 3 formed by the oxidation of SiBCN will volatilize rapidly under high-temperature water and oxygen conditions, which is not conducive to the high-temperature water and oxygen stability of the material.

[0005] Patent No. CN116283318A and Patent No. CN113307660A both directly introduce RE 2 O 3 -Al 2 O 3 -SiO 2 glass phase as the self-healing phase, which has stronger high-temperature water and oxygen stability compared to B 2 O 3 and can play a role in healing cracks and pores. However, directly introducing a large amount of glass phase into the matrix will greatly reduce the high-temperature creep resistance of the composite.

[0006] Patent No. CN117923928A discloses a ceramic matrix composite modified by complex oxides and its preparation method. High-entropy rare-earth disilicates are introduced by slurry impregnation, and then the glass phase is introduced by infiltration to achieve densification, thereby improving the water and oxygen erosion resistance of the material. However, a large amount of glass phase will remain in the material matrix, seriously affecting the high-temperature creep performance of the material. Summary of the Invention

[0007] Aiming at the deficiencies of the prior art, the present invention provides an Al 2 O 3 -RE 2 O 3 synergistically modified silicon carbide ceramic matrix composite with high temperature water and oxygen erosion resistance and its preparation method.

[0008] On the one hand, the present invention provides an Al 2 O3 -RE 2 O 3 Preparation method of co-modified silicon carbide ceramic matrix composite material resistant to high temperature water and oxygen erosion, comprising:

[0009] (1) Mixing SiC powder, RE 2 O 3 powder, Al 2 O 3 powder, carbon black, binder and solvent to obtain a mixed slurry;

[0010] (2) Immersing the fiber preform into the mixed slurry, and obtaining a carbon-containing porous preform through drying, curing and pyrolysis;

[0011] (3) Subjecting the carbon-containing porous preform to silicon reaction infiltration treatment to obtain the Al 2 O 3 -RE 2 O 3 co-modified silicon carbide ceramic matrix composite material resistant to high temperature water and oxygen erosion.

[0012] The inventor found in the previous R & D process that only introducing RE 2 O 3 in the silicon carbide ceramic matrix composite material will generate RE 2 Si 2 O 7 crystalline phase during the water and oxygen oxidation process. Although it has excellent high temperature water and oxygen stability and can protect the internal matrix from erosion, it cannot repair the defects generated by water and oxygen corrosion and the intrinsic defects of the material. Therefore, in the present invention, by slurry impregnation, RE 2 O 3 and Al 2 O 3 are simultaneously introduced and react with SiO 2 in the oxide layer during the water and oxygen oxidation process to in-situ generate RE 2 Si 2 O 7 crystalline phase and simultaneously in-situ generate Al-Si-O glass phase. Among them, RE 2 Si 2 O 7 crystalline phase has excellent high temperature water and oxygen stability and can protect the internal matrix from erosion. The Al-Si-O glass phase can heal the defects generated by water and oxygen corrosion, improve the density of the oxide layer, and promote the aggregation of RE 2 Si 2 O 7 on the surface of the oxide layer, further slowing down the diffusion of water and oxygen medium to the inside, thereby better improving the water and oxygen erosion resistance of the material. On the other hand, in the present invention, by designing a specific composition of RE 2 O3 -Al 2 O 3 / SiC matrix phase can also avoid the formation of RE-Al-Si-O glass during the oxidation process. Compared with RE-Al-Si-O glass, the water and oxygen erosion resistant phase (RE 2 Si 2 O 7 crystalline phase) and self-healing phase (Al-Si-O glass phase) generated in the present invention act synergistically to better inhibit water and oxygen erosion. In addition, since the Al-Si-O glass phase is only formed in the oxide layer, the matrix still maintains excellent high-temperature creep resistance, thus realizing the integrated design of water and oxygen resistance - structure of the composite material.

[0013] Preferably, in step (1), the RE 2 O 3 powder is selected from one of Y 2 O 3 、Yb 2 O 3 、La 2 O 3 、Lu 2 O 3 、Ce 2 O 3 、Er 2 O 3 、Nd 2 O 3 、Sm 2 O 3 、Eu 2 O 3 、Gd 2 O 3 、Dy 2 O 3 、Ho 2 O 3 。

[0014] Preferably, the binder is at least one of polyvinyl alcohol, polyvinyl butyral or polymethyl methacrylate; the solvent is at least one of ethanol, isopropanol or xylene.

[0015] Preferably, in step (1), the particle size of the SiC powder is 0.01 - 10 μm, preferably 0.5 - 5 μm; the particle size of the RE 2 O 3 powder is 0.01 - 10 μm, preferably 0.5 - 5 μm; the particle size of the Al 2 O 3 powder is 0.01 - 10 μm, preferably 0.5 - 5 μm; the particle size of the carbon black is 0.001 - 1 μm, preferably 0.01 - 0.1 μm.

[0016] Preferably, in step (1), the mass ratio of SiC powder, RE 2 O 3 powder, Al 2 O 3 powder, carbon black, binder and solvent in the mixed slurry is (30-70):(10-30):(5-10):(10-30):(5-10):(35-65).

[0017] Preferably, in step (2), the fiber preform is a silicon carbide fiber preform; preferably, the structure of the silicon carbide fiber preform is at least one of a two-dimensional stitched woven structure, a three-dimensional needle-punched woven structure, a three-dimensional four-directional woven structure, and a three-dimensional five-directional woven structure; more preferably, an interface layer is deposited on the surface of the silicon carbide fiber preform; the interface layer is one of pyrolytic carbon or boron nitride; the thickness of the interface layer is 0.1-1.0 μm.

[0018] Preferably, in step (2), the impregnation method of the slurry is at least one of ultrasonic impregnation, vibration impregnation, and negative pressure impregnation.

[0019] Preferably, in step (2), the curing temperature is 80-300 °C and the curing time is 0.5-2 hours;

[0020] The pyrolysis temperature is 500-1000 °C and the time is 0.5-2 hours.

[0021] Preferably, in step (2), the open porosity of the carbon-containing porous preform is 5%-30%.

[0022] Preferably, in step (3), the temperature of the silicon reactive melt infiltration treatment is 1400-1800 °C and the time is 0.1-5 hours.

[0023] On the other hand, the present invention provides an Al 2 O 3 -RE 2 O 3 co-synergistically modified high-temperature resistant water and oxygen erosion silicon carbide ceramic matrix composite material. In the Al 2 O 3 -RE 2 O 3 co-synergistically modified high-temperature resistant water and oxygen erosion silicon carbide ceramic matrix composite material, the volume fraction of the silicon carbide fiber preform is 10-40%, the volume fraction of the SiC matrix is 30-60%, and the volume fraction of the RE 2 O 3 phase is 2-10%, and the volume fraction of Al 2 O 3The volume fraction of the phase is 3-6%.

[0024] Preferably, the Al 2 O 3 -RE 2 O 3 The strength retention rate of the co-modified high-temperature water and oxygen erosion-resistant silicon carbide ceramic matrix composite after water and oxygen oxidation at 1400°C for 100 h is 77.0-90.0%, and the thickness of the post-water and oxygen oxidation layer is 10-15 μm.

[0025] Beneficial effects

[0026] (1) In the present invention, the modification components (RE 2 O 3 , Al 2 O 3 ) are introduced into the matrix of the silicon carbide ceramic matrix composite by means of slurry impregnation, and the method is simple and efficient. The introduced RE 2 O 3 -Al 2 O 3 will react with SiO 2 in the oxide layer during the water and oxygen oxidation process to in-situ generate RE 2 Si 2 O 7 crystalline phase and Al-Si-O glass phase. Among them, the RE 2 Si 2 O 7 crystalline phase has excellent high-temperature water and oxygen stability, which can inhibit the damage of water and oxygen media to the material. The Al-Si-O glass phase can heal the defects generated by water and oxygen corrosion, improve the density of the oxide layer, and promote the aggregation of RE 2 Si 2 O 7 on the surface of the oxide layer, further slowing down the diffusion of water and oxygen media to the inside, so as to better improve the water and oxygen erosion resistance of the material;

[0027] (2) In the present invention, by designing a RE 2 O 3 -Al 2 O 3 / SiC matrix phase with a specific composition in the composite material matrix, the formation of RE-Al-Si-O glass is avoided. The water and oxygen erosion-resistant phase (RE 2 Si 2 O 7 crystalline phase) and the self-healing phase (Al-Si-O glass phase) act synergistically to jointly improve the high-temperature water and oxygen erosion resistance of the silicon carbide ceramic matrix composite. In addition, since the Al-Si-O glass phase is only formed in the oxide layer, the matrix still maintains excellent high-temperature creep resistance, thus realizing the integrated design of water and oxygen resistance - structure of the composite material. Brief Description of the Drawings

[0028] Figure 1 For the RE of the present invention 2 O 3 -Al 2 O 3 Preparation route diagram of RE-O-Al co-modified high-temperature resistant silicon carbide ceramic matrix composite material resistant to water and oxygen erosion

[0029] Figure 2 For the RE in Example 1 2 O 3 -Al 2 O 3 Modified SiC f / SiC composite material's microscopic morphology

[0030] Figure 3 For the RE in Example 1 2 O 3 -Al 2 O 3 Modified SiC f / SiC composite material's surface morphology

[0031] Figure 4 For the RE in Example 1 2 O 3 -Al 2 O 3 Modified SiC f Scanning electron microscope image of the RE-O-Al modified SiC / SiC composite material after 100 h of water and oxygen at 1400 °C, where a is the microscopic morphology and b is the oxygen corrosion depth

[0032] Figure 5 For the RE in Example 1 2 O 3 -Al 2 O 3 Modified SiC f / SiC composite material and the unmodified SiC f / SiC composite material's strength retention rate after 100 h of water and oxygen

[0033] Figure 6 For the YE in Comparative Example 3 2 O 3 Modified SiC f / SiC composite material's microscopic morphology after 100 h of water and oxygen at 1400 °C

[0034] Figure 7 For the RE in Comparative Example 6 2 O 3 -Al 2 O 3 Modified SiC fMicroscopic morphology of the / SiC composite after 100 h of water and oxygen at 1400 °C. Detailed implementation manners

[0035] To further illustrate the content, features and actual effects of the present invention, the present invention will be described in detail below with reference to embodiments. It should be noted that the modified methods designed in the present invention are not limited to these specific implementation manners. Without departing from the spirit and connotation of the design of the present invention, equivalent replacements and modifications made by those skilled in the art on the basis of reading the content of the present invention are also within the scope of protection required by the present invention.

[0036] In the present invention, RE introduced by slurry impregnation 2 O 3 -Al 2 O 3 will react with SiO in the oxide layer during the water and oxygen oxidation process 2 to in-situ generate RE 2 Si 2 O 7 crystalline phase and Al-Si-O glass phase. Among them, RE 2 Si 2 O 7 crystalline phase has excellent high-temperature water and oxygen stability, can protect the internal matrix from erosion, and the generated Al-Si-O glass phase can heal the defects caused by water and oxygen corrosion, improve the density of the oxide layer, and promote the aggregation of RE 2 Si 2 O 7 on the surface of the oxide layer, further slowing down the diffusion of water and oxygen media to the inside, thereby better improving the water and oxygen erosion resistance of the material. By designing a RE 2 O 3 -Al 2 O 3 / SiC matrix phase with a specific composition in the composite material matrix, the formation of RE-Al-Si-O glass during the oxidation process is avoided. Compared with RE-Al-Si-O glass, the water and oxygen erosion resistant phase (RE 2 Si 2 O 7 crystalline phase) and the self-healing phase (Al-Si-O glass phase) work together to play a better role in inhibiting water and oxygen erosion. In addition, since the Al-Si-O glass phase is only formed in the oxide layer, the matrix still maintains excellent high-temperature creep resistance, thereby realizing the integrated design of water and oxygen resistance - structure of the composite material.

[0037] Specifically, the present invention controls RE 2 O 3 and Al 2 O 3The mass ratio is in the range of 1 to 6, so that RE is formed in situ in the oxide layer 2 Si 2 O 7 crystalline phase and Al-Si-O glass phase, without directly forming RE-Al-Si-O glass. If the mass ratio of RE 2 O 3 :Al 2 O 3 is greater than 6, too little Al 2 O 3 is not conducive to the formation of Al-Si-O glass and affects the self-healing performance of the material. If the mass ratio of RE 2 O 3 :Al 2 O 3 is less than 1, too much Al 2 O 3 results in a greater tendency to directly form RE-Al-Si-O glass during the oxidation process. The water and oxygen erosion resistance of RE-Al-Si-O glass is inferior to that of RE 2 Si 2 O 7 crystalline phase, and the water and oxygen erosion resistance of the material will also decrease significantly.

[0038] The following exemplarily illustrates the preparation method of the Al 2 O 3 -RE 2 O 3 synergistically modified silicon carbide ceramic matrix composite with high temperature water and oxygen erosion resistance (as shown in Figure 1 ).

[0039] Mix SiC powder, RE 2 O 3 powder (RE = Y, Yb, La, Lu, etc.), Al 2 O 3 powder, carbon black, binder and solvent to obtain a mixed slurry. The particle size of the SiC powder is 0.01 to 10 μm, preferably 0.5 to 5 μm; the particle size of the RE 2 O 3 powder is 0.01 to 10 μm, preferably 0.5 to 5 μm; the particle size of the Al 2 O 3 powder is 0.01 to 10 μm, preferably 0.5 to 5 μm; the particle size of the carbon black is 0.001 to 1 μm, preferably 0.01 to 0.1 μm. The binder is at least one of polyvinyl alcohol, polyvinyl butyral or polymethyl methacrylate; the solvent is at least one of ethanol, isopropanol or xylene.

[0040] In an alternative embodiment, the RE 2 O 3 powder is selected from Y 2 O 3 , Yb 2 O 3 , La 2 O 3 , Lu 2 O 3 , Ce 2 O 3 , Er 2 O 3 , Nd 2 O 3 , Sm 2 O 3 , Eu 2 O 3 , Gd 2 O 3 , Dy 2 O 3 , Ho 2 O 3 or one of the following.

[0041] In an alternative embodiment, the mass ratio of SiC powder, RE 2 O 3 powder, Al 2 O 3 powder, carbon black, binder and solvent in the mixed slurry is (30-70):(10-30):(5-10):(10-30):(5-10):(35-65).

[0042] The fiber preform is immersed in the mixed slurry, dried, cured and pyrolyzed to obtain a carbon-containing porous preform. The open porosity of the obtained carbon-containing porous preform is 5%-30%.

[0043] In an alternative embodiment, the fiber preform is a silicon carbide fiber preform; preferably, the structure of the silicon carbide fiber preform is at least one of a two-dimensional stitched woven structure, a three-dimensional needle-punched woven structure, a three-dimensional four-directional woven structure, and a three-dimensional five-directional woven structure; more preferably, an interface layer is deposited on the surface of the silicon carbide fiber preform; the interface layer is one of pyrolytic carbon or boron nitride.

[0044] In an alternative embodiment, the impregnation method of the slurry is at least one of ultrasonic impregnation, vibration impregnation, and negative pressure impregnation.

[0045] In an alternative embodiment, the curing temperature is 80-300 °C and the curing time is 0.5-2 hours. The pyrolysis temperature is 500-1000 °C and the time is 0.5-2 hours.

[0046] The carbon-containing porous preform is subjected to silicon reaction infiltration treatment to obtain the Al 2 O 3 -RE 2 O 3 co-modified high-temperature resistant silicon carbide ceramic matrix composite resistant to water and oxygen erosion.

[0047] In an optional embodiment, the temperature of the silicon reaction infiltration treatment is 1400-1800 °C, and the time is 0.1-5 hours.

[0048] The Al 2 O 3 -RE 2 O 3 co-modified high-temperature resistant silicon carbide ceramic matrix composite resistant to water and oxygen erosion prepared by the preparation method of the present invention, the volume fraction of the silicon carbide fiber preform in the Al 2 O 3 -RE 2 O 3 co-modified high-temperature resistant silicon carbide ceramic matrix composite resistant to water and oxygen erosion is 10-40%, the volume fraction of the SiC matrix is 30-60%, and the volume fraction of the RE 2 O 3 phase is 2-10%, and the volume fraction of the Al 2 O 3 phase is 3-6%.

[0049] The following further gives examples to illustrate the present invention in detail. It should be understood that the following examples are only used to further illustrate the present invention and cannot be construed as limiting the protection scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention all fall within the protection scope of the present invention. The specific process parameters and the like in the following examples are also only an example within a suitable range, that is, those skilled in the art can make selections within a suitable range through the description herein, rather than being limited to the specific values in the following examples. The parameters of high-temperature water and oxygen are: the heating and cooling rates are controlled at 1-10 °C / min, and the gas flow rate is controlled at 100-1000 ml / min (oxygen: steam molar ratio = 0.3-15).

[0050] Example 1

[0051] (1) SiC powder, Y 2 O 3 powder, Al 2 O 3 powder, carbon black, polyvinyl alcohol (binder) and ethanol (solvent) are ball-milled and mixed to obtain a stable slurry; wherein, SiC powder, Y 2 O 3 powder, Al 2O 3 The mass ratio of the powder, carbon black, polyvinyl alcohol (binder), and ethanol is 40:15:5:10:5:55; the average particle size of the SiC powder is 2 μm, Y 2 O 3 The average particle size of the powder is 2 μm, Al 2 O 3 The average particle size of the powder is 2 μm, and the average particle size of the carbon black is 0.1 μm;

[0052] (2) The slurry is introduced into the silicon carbide fiber preform (three-dimensional needle-punched woven structure) by vibration impregnation. Before impregnation, a BN interface phase is deposited on the surface of the fiber preform, and the thickness of the BN interface layer is 0.5 μm. After impregnation, a carbon-containing porous preform is obtained through drying, curing, and pyrolysis. The curing temperature is 200 °C and the time is 1 hour; the pyrolysis temperature is 700 °C and the time is 1 hour; the open porosity of the obtained porous preform is 20%;

[0053] (3) The porous preform is subjected to silicon reaction infiltration treatment to obtain Al 2 O 3 -RE 2 O 3 Co-synergistically modified high-temperature resistant water and oxygen erosion silicon carbide ceramic matrix composite; wherein, the temperature of the reaction infiltration is 1600 °C and the time is 2 hours.

[0054] After testing, the strength retention rate of the Al 2 O 3 -RE 2 O 3 Co-synergistically modified high-temperature resistant water and oxygen erosion silicon carbide ceramic matrix composite after water and oxygen oxidation at 1400 °C for 100 h is 85.2% (as Figure 5 shown), and the thickness of the post-water and oxygen oxidation layer is 10.8 μm (as Figure 4 shown in a).

[0055] Example 2

[0056] In this Example 2, the preparation process of the Al 2 O 3 -RE 2 O 3 Co-synergistically modified high-temperature resistant water and oxygen erosion silicon carbide ceramic matrix composite refers to Example 1, with the only difference being that: in step (1), the average particle size of the SiC powder is 5 μm.

[0057] After testing, the Al 2 O 3 -RE 2 O 3The strength retention rate of the co-modified silicon carbide ceramic matrix composite resistant to high-temperature water and oxygen erosion is 80.6% after water and oxygen oxidation at 1400 °C for 100 h, and the thickness of the post-water and oxygen oxidation layer is 13.5 μm.

[0058] Example 3

[0059] In this Example 3, Al 2 O 3 -RE 2 O 3 The preparation process of the co-modified silicon carbide ceramic matrix composite resistant to high-temperature water and oxygen erosion refers to Example 1, with the only difference being that in step (1), the mass ratio of SiC powder, Y 2 O 3 powder, Al 2 O 3 powder, carbon black, polyvinyl alcohol (binder) and ethanol is 45: 15: 5: 10: 5: 55.

[0060] After testing, the Al 2 O 3 -RE 2 O 3 The strength retention rate of the co-modified silicon carbide ceramic matrix composite resistant to high-temperature water and oxygen erosion is 83.5% after water and oxygen oxidation at 1400 °C for 100 h, and the thickness of the post-water and oxygen oxidation layer is 11.3 μm.

[0061] Example 4

[0062] In this Example 4, Al 2 O 3 -RE 2 O 3 The preparation process of the co-modified silicon carbide ceramic matrix composite resistant to high-temperature water and oxygen erosion refers to Example 1, with the only difference being that in step (1), the Y 2 O 3 powder is replaced by Yb 2 O 3 powder.

[0063] After testing, the Al 2 O 3 -RE 2 O 3 The strength retention rate of the co-modified silicon carbide ceramic matrix composite resistant to high-temperature water and oxygen erosion is 82.6% after water and oxygen oxidation at 1400 °C for 100 h, and the thickness of the post-water and oxygen oxidation layer is 11.7 μm.

[0064] Example 5

[0065] In this Example 5, Al 2 O 3 -RE2 O 3 The preparation process of the co-modified high-temperature resistant silicon carbide ceramic matrix composite material resistant to water and oxygen erosion refers to Example 1, with the only difference being that in step (2), two-dimensional silicon carbide fiber cloth is selected, and after impregnation, the fiber cloth is laminated and then cured.

[0066] After testing, the Al prepared in this Example 5 2 O 3 -RE 2 O 3 The strength retention rate of the co-modified high-temperature resistant silicon carbide ceramic matrix composite material resistant to water and oxygen erosion after water and oxygen oxidation at 1400 °C for 100 h is 78.9%, and the thickness of the post-water and oxygen oxidation layer is 13.8 μm. Compared with Example 1, Al 2 O 3 -RE 2 O 3 The strength retention rate of the co-modified high-temperature resistant silicon carbide ceramic matrix composite material resistant to water and oxygen erosion decreases significantly after water and oxygen oxidation at 1400 °C for 100 h. This is because some pores are likely to remain between layers during the lamination process of the two-dimensional fiber cloth, and these pores will cause some oxidation media to erode into the material interior faster, so the strength retention rate decreases more significantly.

[0067] Example 6

[0068] In this Example 6, Al 2 O 3 -RE 2 O 3 The preparation process of the co-modified high-temperature resistant silicon carbide ceramic matrix composite material resistant to water and oxygen erosion refers to Example 1, with the only difference being that in step (2), the curing temperature is 100 °C.

[0069] After testing, the Al prepared in this Example 6 2 O 3 -RE 2 O 3 The strength retention rate of the co-modified high-temperature resistant silicon carbide ceramic matrix composite material resistant to water and oxygen erosion after water and oxygen oxidation at 1400 °C for 100 h is 81.9%, and the thickness of the post-water and oxygen oxidation layer is 12.3 μm.

[0070] Example 7

[0071] In this Example 7, Al 2 O 3 -RE 2 O 3 The preparation process of the co-modified high-temperature resistant silicon carbide ceramic matrix composite material resistant to water and oxygen erosion refers to Example 1, with the only difference being that in step (2), the pyrolysis temperature is 800 °C.

[0072] After testing, the Al prepared in this Example 72 O 3 -RE 2 O 3 The strength retention rate of the co-modified high-temperature resistant silicon carbide ceramic matrix composite material resistant to water and oxygen erosion is 84.2% after being oxidized by water and oxygen at 1400 °C for 100 h, and the thickness of the post-water and oxygen oxidation layer is 11.4 μm.

[0073] Example 8

[0074] In this Example 8, Al 2 O 3 -RE 2 O 3 The preparation process of the co-modified high-temperature resistant silicon carbide ceramic matrix composite material resistant to water and oxygen erosion refers to Example 1, with the only difference being that: in step (3), the reaction infiltration temperature is 1700 °C.

[0075] After testing, the Al 2 O 3 -RE 2 O 3 The strength retention rate of the co-modified high-temperature resistant silicon carbide ceramic matrix composite material resistant to water and oxygen erosion is 82.6% after being oxidized by water and oxygen at 1400 °C for 100 h, and the thickness of the post-water and oxygen oxidation layer is 12.1 μm.

[0076] Example 9

[0077] In this Example 9, Al 2 O 3 -RE 2 O 3 The preparation process of the co-modified high-temperature resistant silicon carbide ceramic matrix composite material resistant to water and oxygen erosion refers to Example 1, with the only difference being that: in step (3), the reaction infiltration time is 1 h.

[0078] After testing, the Al 2 O 3 -RE 2 O 3 The strength retention rate of the co-modified high-temperature resistant silicon carbide ceramic matrix composite material resistant to water and oxygen erosion is 80.3% after being oxidized by water and oxygen at 1400 °C for 100 h, and the thickness of the post-water and oxygen oxidation layer is 13.2 μm.

[0079] Comparative Example 1

[0080] The preparation process of the silicon ceramic matrix composite material in this Comparative Example 1 refers to Example 1, with the only difference being that: in step (1), Y 2 O 3 powder and Al 2 O 3 powder were not introduced.

[0081] After testing, the strength retention rate of the silicon carbide ceramic matrix composite prepared in Comparative Example 1 was 57.6% after 100 h of hydrothermal oxidation at 1400 °C, and the thickness of the hydrothermal post-oxidation layer was 32.5 μm.

[0082] Comparative Example 2

[0083] The preparation process of the silicon ceramic matrix composite in this Comparative Example 2 refers to Example 1, with the only difference being that in step (1), only Al 2 O 3 powder was introduced.

[0084] After testing, the strength retention rate of the silicon carbide ceramic matrix composite prepared in this Comparative Example 2 was 65.9% after 100 h of hydrothermal oxidation at 1400 °C, and the thickness of the hydrothermal post-oxidation layer was 25.9 μm.

[0085] Comparative Example 3

[0086] The preparation process of the silicon ceramic matrix composite in this Comparative Example 3 refers to Example 1, with the only difference being that in step (1), only Y 2 O 3 powder was introduced.

[0087] After testing, the strength retention rate of the silicon carbide ceramic matrix composite prepared in this Comparative Example 3 was 74.6% after 100 h of hydrothermal oxidation at 1400 °C, and the thickness of the hydrothermal post-oxidation layer was 18.8 μm (as Figure 6 shown), which was significantly greater than the oxidation layer thickness after hydrothermal treatment in Example 1. This is because although the introduction of Y 2 O 3 enabled the in-situ formation of RE 2 Si 2 O 7 crystalline phase, which could protect the internal matrix from erosion, it could not repair the defects generated by hydrothermal corrosion and the intrinsic defects of the material. The hydrothermal medium could diffuse rapidly into the material through these defects, accelerating the hydrothermal corrosion of the material and making the oxidation layer thicker.

[0088] Comparative Example 4

[0089] In this Comparative Example 4, the preparation process of the Al 2 O 3 -RE 2 O 3 co-modified high-temperature hydrothermal erosion-resistant silicon carbide ceramic matrix composite refers to Example 1, with the only difference being that in step (1), SiC powder, Y 2 O 3 powder, Al 2 O 3The mass ratio of the powder, carbon black, polyvinyl alcohol (binder), and ethanol is 25: 35: 20: 5: 4: 70.

[0090] After testing, the Al prepared in Comparative Example 4 2 O 3 -RE 2 O 3 The strength retention rate of the co-modified high-temperature water and oxygen erosion-resistant silicon carbide ceramic matrix composite after water and oxygen oxidation at 1400 °C for 100 h is only 60.5%. This is because the introduction of too much Y 2 O 3 and Al 2 O 3 will consume too much SiO 2 , which is not conducive to the formation of a dense oxide layer, allowing the oxidation medium to easily erode into the material interior. The thickness of the post-water and oxygen oxidation layer is 28.4 μm.

[0091] Comparative Example 5

[0092] In this Comparative Example 5, the preparation process of the Al 2 O 3 -RE 2 O 3 co-modified high-temperature water and oxygen erosion-resistant silicon carbide ceramic matrix composite refers to Example 1, with the only difference being that in step (1), the mass ratio of SiC powder, Y 2 O 3 powder, Al 2 O 3 powder, carbon black, polyvinyl alcohol (binder), and ethanol is 45: 18: 2: 10: 5: 55.

[0093] After testing, the Al 2 O 3 -RE 2 O 3 co-modified high-temperature water and oxygen erosion-resistant silicon carbide ceramic matrix composite has a strength retention rate of 76.7% after water and oxygen oxidation at 1400 °C for 100 h, and the thickness of the post-water and oxygen oxidation layer is 16.4 μm.

[0094] Comparative Example 6

[0095] In this Comparative Example 6, the Al 2 O 3 -RE 2 O 3 co-modified high-temperature water and oxygen erosion-resistant silicon carbide ceramic matrix composite refers to Example 1, with the only difference being that in step (1), the SiC powder, Y 2 O 3 powder, Al 2 O3 The mass ratio of powder, carbon black, polyvinyl alcohol (binder), and ethanol is 45:5:15:10:5:55.

[0096] After testing, the Al prepared in Comparative Example 6 2 O 3 -RE 2 O 3 The strength retention rate of the co-modified high-temperature water and oxygen erosion-resistant silicon carbide ceramic matrix composite is only 68.3% after water and oxygen oxidation at 1400 °C for 100 h, and the thickness of the post-water and oxygen oxidation layer is 15.7 μm.

[0097] Figure 2 For the RE in Example 1 2 O 3 -Al 2 O 3 modified SiC f / SiC composite microstructure. As can be seen from the figure, the white phase (RE 2 O 3 +Al 2 O 3 ) is uniformly and dispersedly distributed in the composite matrix.

[0098] Figure 3 For the RE in Example 1 2 O 3 -Al 2 O 3 modified SiC f / SiC composite surface morphology. As can be seen from the figure, a large number of crystalline phases are aggregated on the surface of the oxide layer, isolating the water and oxygen medium, and it is determined by EDS results that this crystalline phase is Y 2 Si 2 O 7 .

[0099] Figure 4 For the RE in Example 1 2 O 3 -Al 2 O 3 modified SiC f / SiC composite SEM image after water and oxygen at 1400 °C for 100 h, where a is the microstructure and b is the oxygen corrosion depth. As can be seen from the figure, the oxide layer on the material surface is thin and dense, and oxygen is inhibited in the surface area of the material.

[0100] Figure 5 For the RE in Example 1 2 O 3 -Al 2 O 3 modified SiC f / SiC composite and unmodified SiC in Comparative Example 1f Strength retention rate of unmodified SiC / SiC composites after 100 h of water and oxygen exposure. As can be seen from the figure, with the increase of water and oxygen temperature, the bending strength retention rate of unmodified SiC / SiC materials decreases significantly, while that of REO-Al2O3-SiC / SiC composites is significantly higher after water and oxygen erosion. f / SiC materials decreases significantly, while RE 2 O 3 -Al 2 O 3 SiC f / SiC composites is significantly higher after water and oxygen erosion.

[0101] Figure 6 For the YE-modified SiC / SiC composite in Comparative Example 3, the micro-morphology after 100 h of water and oxygen exposure at 1400 °C. As can be seen from the figure, although there are a large number of Y2SiO5 crystalline phases aggregated in the oxide layer, there are many pores and cracks under the oxide layer. 2 O 3 modified SiC f / SiC composites after 100 h of water and oxygen exposure at 1400 °C. As can be seen from the figure, although there are a large number of Y2SiO5 crystalline phases aggregated in the oxide layer, there are many pores and cracks under the oxide layer. 2 Si 2 O 7 crystalline phases aggregated, there are many pores and cracks under the oxide layer.

[0102] Figure 7 For the REO-Al2O3-modified SiC / SiC composite in Comparative Example 6, the micro-morphology after 100 h of water and oxygen exposure at 1400 °C. As can be seen from the figure, a large amount of glass phase aggregates on the surface of the oxide layer, and there are a large number of pores on the surface of the oxide layer. It is determined by EDS results that the glass phase is Y-Al-Si-O glass. 2 O 3 -Al 2 O 3 modified SiC f / SiC composites after 100 h of water and oxygen exposure at 1400 °C. As can be seen from the figure, a large amount of glass phase aggregates on the surface of the oxide layer, and there are a large number of pores on the surface of the oxide layer. It is determined by EDS results that the glass phase is Y-Al-Si-O glass.

Claims

1. A method for preparing an Al2O3-RE2O3 synergistically modified high temperature water and oxygen corrosion resistant silicon carbide ceramic matrix composite material, characterized in that: include: (1) SiC powder, RE2O3 powder, Al2O3 powder, carbon black, a binder and a solvent are mixed to obtain a mixed slurry; the mass ratio of SiC powder, RE2O3 powder, Al2O3 powder, carbon black, a binder and a solvent in the mixed slurry is (30-70): (10-30): (5-10): (10-30): (5-10): (35-65); (2) immersing the fiber preform in the mixed slurry, drying, curing, and pyrolyzing to obtain a carbon-containing porous preform; the fiber preform is a silicon carbide fiber preform; (3) The carbon-containing porous preform is subjected to silicon reactive infiltration treatment to obtain the Al2O3-RE2O3 synergistically modified high temperature water and oxygen corrosion resistant silicon carbide ceramic matrix composite material.

2. The preparation method according to claim 1, characterized in that: In step (1), the RE2O3 powder is selected from one of Y2O3, Yb2O3, La2O3, Lu2O3, Ce2O3, Er2O3, Nd2O3, Sm2O3, Eu2O3, Gd2O3, Dy2O3, and Ho2O3.

3. The preparation method according to claim 1, characterized in that In step (1), the particle size of the SiC powder is 0.01 to 10 μm; the particle size of the RE2O3 powder is 0.01 to 10 μm; the particle size of the Al2O3 powder is 0.01 to 10 μm; and the particle size of the carbon black is 0.001 to 1 μm.

4. The preparation method according to claim 1, characterized in that: In step (2), the structure of the silicon carbide fiber preform is at least one of a two-dimensional stitched braided structure, a three-dimensional needle-punched braided structure, a three-dimensional four-way braided structure, and a three-dimensional five-way braided structure; an interface layer is deposited on the surface of the silicon carbide fiber preform; the interface layer is one of pyrolytic carbon or boron nitride; and the thickness of the interface layer is 0.1 to 1.0 μm.

5. The preparation method according to claim 1, characterized in that: In step (2), the slurry is impregnated by at least one of ultrasonic impregnation, vibration impregnation, and negative pressure impregnation.

6. The preparation method according to claim 1, characterized in that In step (2), the curing temperature is 80 to 300°C and the curing time is 0.5 to 2 hours; The pyrolysis temperature is 500-1000°C and the time is 0.5-2 hours.

7. The preparation method according to claim 1, characterized in that In step (2), the open porosity of the carbon-containing porous preform is 5% to 30%.

8. The preparation method according to claim 1, characterized in that In step (3), the temperature of the silicon reactive infiltration treatment is 1400-1800° C., and the time is 0.1-5 hours.

9. An Al2O3-RE2O3 synergistically modified high temperature water and oxygen corrosion resistant silicon carbide ceramic matrix composite material prepared by the preparation method according to any one of claims 1 to 8, characterized in that: In the Al2O3-RE2O3 synergistically modified high temperature water and oxygen corrosion resistant silicon carbide ceramic matrix composite material, the volume fraction of the silicon carbide fiber preform is 10-40%, the volume fraction of the SiC matrix is ​​30-60%, the volume fraction of the RE2O3 phase is 2-10%, and the volume fraction of the Al2O3 phase is 3-6%.

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