A method for preparing SiC composite materials based on cold spraying and silicon infiltration and its application.

Abstract

This invention belongs to the field of ceramic composite material manufacturing technology, specifically relating to a method for preparing SiC composite materials based on cold spraying and silicon infiltration. SiC powder is prepared into a suspension, which is then deposited onto a substrate using a cold gas-powered spraying system to form a porous SiC preform coating. The preform coating undergoes post-curing to enhance its cohesive strength. Finally, melt silicon infiltration is performed, causing silicon to react with carbon in the preform to generate a new SiC phase that fills the pores, resulting in a high-density, high-performance SiC composite component. This method combines the advantages of low-temperature forming in cold spraying with silicon infiltration technology. The relatively low substrate temperature during cold spraying effectively avoids the adverse effects of high temperatures on the material structure, maintaining the stability of the original SiC phase. By adjusting the spraying parameters and matching the silicon infiltration process, the free silicon content and the distribution of the newly generated SiC phase in the composite material can be precisely controlled, further improving the material's density and mechanical properties.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of ceramic composite material manufacturing, and particularly relates to a SiC composite material preparation method based on cold spraying and silicon infiltration and application of the material. BACKGROUND

[0002] SiC ceramics exhibit extremely broad application prospects in multiple important fields such as aerospace, energy field and semiconductor industry due to their excellent high-temperature strength, excellent wear resistance, excellent corrosion resistance and remarkable radiation resistance. However, the high hardness and high brittleness characteristics inherent in SiC materials make them face many challenges in traditional forming processes (such as sintering process, chemical vapor infiltration CVI technology), including complex process flow, long production cycle, high manufacturing cost, and difficulty in manufacturing large-size and complex-shaped components.

[0003] Silicon infiltration method (such as reaction sintering technology) is one of the commonly used technical means for preparing SiC ceramics at present, but its process usually needs to prepare a silicon carbide or carbon-containing preform with a specific pore structure in advance. In the preparation process, liquid silicon or silicon vapor gradually infiltrates into the pore structure of the preform through capillary action, chemically reacts with the internal carbon element, generates new SiC phase, and realizes the densification of the material. However, this method still has some problems that are difficult to overcome in practical application, such as large infiltration resistance of liquid silicon in dense or multi-layer structure preform and short infiltration distance, which easily leads to uneven or incomplete silicon infiltration process, and further affects the performance uniformity of the final component.

[0004] Cold spraying technology as a new low-temperature solid-state deposition technology can effectively avoid phase change or decomposition of materials during spraying process, and is particularly suitable for preparing coatings of heat-sensitive materials. In particular, the suspension cold spraying technology provides a practical and effective solution to the problem of poor flowability of nano-sized SiC powder and difficulty in effective delivery, and can realize the preparation of high-quality SiC coating. However, as of now, there is no related report on the combination of cold spraying technology and silicon infiltration post-processing for directly preparing integral SiC ceramic components.

[0005] Therefore, it is of great significance to develop a new method that can combine the flexibility of cold spraying forming technology with the densification effect of silicon infiltration for promoting the efficient manufacturing of large-size and complex-shaped SiC components. SUMMARY

[0006] In view of the deficiencies of the prior art, the application provides a SiC composite material preparation method based on cold spraying and silicon infiltration. First, SiC is prepared into a suspension, and then the suspension is sprayed and deposited on a substrate by using a cold gas dynamic spraying system to form a porous SiC preform coating. In order to further improve the cohesive strength and overall stability of the coating, the formed porous coating is subjected to post-solidification treatment, which not only enhances the cohesive strength of the coating, but also lays a solid foundation for subsequent processing. Finally, through a molten silicon infiltration treatment process, the molten silicon reacts with the carbon elements in the preform coating to generate new SiC phases, and these newly generated SiC phases effectively fill the pores in the preform, thereby significantly improving the density of the material.

[0007] After the above series of processing steps, the finally obtained SiC composite material component not only has a high density, but also has excellent characteristics in terms of mechanical properties, high temperature resistance and corrosion resistance, and is widely used in various high-end industrial fields.

[0008] The application combines the advantages of low-temperature forming of low cold spraying with silicon infiltration technology. The substrate temperature is low during cold spraying, effectively avoiding the adverse effects of high temperature on the material structure and maintaining the stability of the original SiC phase. By adjusting the spraying parameters and matching the silicon infiltration process, the content of free silicon in the composite material and the distribution state of the newly generated SiC phase can be accurately controlled, further improving the density and mechanical properties of the material. The method also has good scalability and is suitable for forming components of various substrate materials and complex geometric surfaces, providing a feasible technical path for the application of high-performance ceramic parts in the fields of aerospace, nuclear energy and the like.

[0009] The technical means adopted by the application to solve the above problems are:

[0010] A SiC composite material preparation method based on cold spraying and silicon infiltration is disclosed. SiC powder is prepared into a suspension, and the suspension is deposited on a substrate by using a cold gas dynamic spraying system to form a porous SiC preform coating. Then, the preform coating is subjected to post-solidification treatment to improve its cohesive strength. Finally, through molten silicon infiltration treatment, silicon reacts with carbon in the preform to generate new SiC phases and fill pores, and finally a SiC composite material component with high density and excellent performance is obtained.

[0011] The SiC composite material preparation method based on cold spraying and silicon infiltration of the application realizes innovative improvement of the SiC composite material preparation process by combining cold spraying technology with silicon infiltration treatment.

[0012] The method first utilizes cold spray technology to deposit SiC suspension on the substrate surface, forming a porous preform coating. This low-temperature deposition process effectively avoids potential damage to material performance at high temperatures, while maintaining the original properties of SiC particles. The cohesive strength of the coating is enhanced through post-solidification treatment, laying the foundation for subsequent silicon infiltration. In the silicon infiltration stage, molten silicon infiltrates the pores of the preform and reacts with carbon to form new SiC phases, not only filling the pores but also significantly improving the material's density. The final SiC composite component exhibits excellent mechanical properties and high-temperature resistance, suitable for aerospace, nuclear energy and other high-end applications. The process is simple and efficient, with significant economic benefits and broad industrial application prospects.

[0013] Further, comprising the following steps:

[0014] S1. Preparation of suspension: SiC powder and solvent are mixed in a mass ratio of 20%-40%:60%-80%, and a uniform and stable suspension is prepared by ultrasonic dispersion or other methods.

[0015] S2. Preparation of SiC preform coating: SiC suspension prepared in step S1 is sprayed onto the substrate surface to form a SiC preform coating; SiC suspension is sprayed onto the pretreated substrate using a suspension cold gas dynamic spraying system to form a porous SiC preform coating.

[0016] S3. Post-solidification treatment: Post-solidification treatment is carried out in a protective atmosphere or air, with a treatment temperature of 40-200°C and a treatment time of 0.5-12h to obtain sufficient initial strength of the coating; The deposited SiC preform is heat treated to remove the solvent and enhance the interparticle bonding. If the preform contains a carbon source, this process may be accompanied by carbonization to form a reactive surface suitable for silicon infiltration.

[0017] S4. Silicon infiltration treatment: Silicon infiltration treatment is carried out on the SiC preform coating after post-solidification treatment, with a silicon infiltration temperature range of 1600-2000°C and a silicon infiltration time of 2-4h; In a high-temperature protective atmosphere, molten silicon is brought into contact with the post-solidified SiC preform and undergoes silicon infiltration reaction, finally obtaining a dense SiC composite material.

[0018] Further, in step S1, the particle size of the SiC powder is 18-45 μm, and the solvent includes one or more of deionized water, isopropyl alcohol, ethanol, and methyl pyrrolidone. In the preparation of the suspension, the SiC powder with a selected particle size range is mixed with deionized water, isopropyl alcohol, or methyl pyrrolidone, etc. according to a specific mass ratio, and sodium dodecyl benzene sulfonate or polyetherimide can be added as a dispersant to improve the flowability and spraying effect of the suspension. The amount of the dispersant is accurately calculated to ensure that the spraying quality is improved while the performance of the final material is not negatively affected.

[0019] Further, a dispersant is added to the suspension, and the dispersant is one of sodium dodecyl benzene sulfonate and polyetherimide, and the amount of the dispersant is 0.5%-3% of the SiC powder.

[0020] Further, the SiC suspension is sprayed at a gas temperature of 100-600°C, a spraying stress of 1-2.5 MPa, and a spraying distance of 10-60 mm. The prepared SiC suspension is uniformly sprayed onto the surface of the substrate by using a cold gas dynamic spraying system to form a SiC preform coating with a porous structure. In this process, the spraying parameters such as the spraying temperature, speed, and distance are accurately controlled to ensure the quality and uniformity of the coating. The spraying heating temperature is strictly controlled within a certain range to ensure that the SiC powder can be fully deposited and form a stable coating structure.

[0021] Further, when the dispersant is added to the suspension, the post-solidification treatment further includes a carbonization treatment, the carbonization treatment temperature is 600-900°C, and the carbonization time is 1-3 h. The purpose is to carbonize the organic matter attached to the surface of the SiC and in the voids of the preform. The post-solidification treatment can not only significantly improve the cohesive strength of the coating but also lay a solid foundation for the subsequent silicon infiltration treatment. When the dispersant is added to the suspension, the post-solidification treatment can further include a carbonization treatment step to further optimize the structure and performance of the coating.

[0022] Through the molten silicon infiltration treatment process, the molten silicon reacts with the carbon elements in the preform coating to generate new SiC phases and fill the pores. By accurately controlling the silicon infiltration time and temperature, the silicon elements can fully penetrate and fill the pores in the preform, thereby significantly improving the density and performance of the material. The specific operation steps and parameters of the molten silicon infiltration are carefully designed and optimized to ensure the uniformity and completeness of the silicon infiltration process.

[0023] Further, the silicon infiltration treatment is a molten silicon infiltration treatment using silicon powder as the raw material in an inert gas atmosphere.

[0024] Another object of the present application is the use of the material prepared by the method for preparing SiC composite material based on cold spraying and siliconizing described above for aerospace hot end components, nuclear reactor cladding materials, semiconductor device components or wear-resistant devices.

[0025] The present application has the following advantages compared with the prior art:

[0026] The method for preparing SiC composite material based on cold spraying and siliconizing has the advantages of low-temperature forming to maintain the material properties: the temperature during the cold spraying process is at a low level, avoiding the phase transition, oxidation or grain growth of SiC material caused by high temperature, thereby maintaining the intrinsic properties of the material.

[0027] The method for preparing SiC composite material based on cold spraying and siliconizing has the characteristics of near-net-shaping to adapt to complex structures: the cold spraying technology can achieve the deposition of complex shape coatings through program control, and combined with siliconizing densification treatment, it is especially suitable for the manufacturing of large-size and complex shape SiC components which are difficult to process by traditional processes.

[0028] The method for preparing SiC composite material based on cold spraying and siliconizing has the advantage of controllable porosity to help uniform siliconizing: by adjusting the cold spraying process parameters (such as gas pressure, temperature, powder properties, etc.), the porosity structure and distribution of the SiC preform can be precisely controlled, providing ideal conditions for subsequent uniform and complete siliconizing.

[0029] The method for preparing SiC composite material based on cold spraying and siliconizing has the advantages of process integration innovation and considerable potential: the present application innovatively integrates two mature technologies, opening up a new way for the preparation of SiC components, and showing great potential in the manufacturing of high-performance SiC components in the fields of aerospace, nuclear energy, etc. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 The microstructure morphology of the plate-shaped SiC composite material described in Example 1. DETAILED DESCRIPTION

[0031] The present application will be further described below. The specific embodiments are only used for illustrative description, and cannot be understood as limiting the present patent.

[0032] The method for preparing SiC composite material based on cold spraying and siliconizing of the present application prepares SiC powder into a suspension, uses a cold gas dynamic spraying system to deposit the suspension on a substrate to form a porous SiC preform coating; then performs post-solidification treatment on the preform coating to improve its cohesive strength; finally, through molten siliconizing treatment, silicon reacts with carbon in the preform to generate new SiC phase and fill the pores, finally obtaining a SiC composite material component with high density and excellent performance.

[0033] Example 1: This example takes the preparation of a flat plate-shaped SiC composite material as an example, and its preparation method comprises the following steps:

[0034] S1. Preparation of suspension: mix SiC powder with solvent, the ratio of SiC powder to solvent is 20%:80% by mass; take SiC powder with an average particle size of 18-25 μm, use deionized water as the solvent, and add a small amount of sodium dodecyl benzene sulfonate as a dispersant, wherein the amount of the dispersant added is 0.5% of the SiC powder; configure into a suspension, and uniformly and stably disperse for 4 h through ultrasonic dispersion.

[0035] S2. Preparation of SiC preform coating: spray the SiC suspension prepared in step S1 onto the surface of the substrate to form a SiC preform coating. A suspension cold gas dynamic spraying system mentioned in patent CN112090609B is used. This system generally includes a control device, a feeding system, an atomizing device, a spray gun (such as a Laval nozzle), a gas heating and supply system, etc. In this example, the above suspension is fed into the system, nitrogen gas is used as the main gas, heated to 500-600℃, the spraying pressure is 1-1.5 MPa, and the spraying distance is 10-30 mm; under the operation of a mechanical arm, a porous SiC preform coating with a thickness of about 1 mm is deposited on the carbon ceramic substrate.

[0036] S3. Post-curing treatment: carried out in a protective atmosphere or air, the treatment temperature is 40-80℃, and the treatment time is 10-12 h, so that the coating obtains sufficient initial strength; specifically, the substrate with the coating is placed in an atmosphere furnace and heat treated at 80℃ for 12 h under nitrogen protection, to further enhance the cohesive strength of the coating.

[0037] S4. Silicon infiltration treatment: the SiC preform coating after the post-curing treatment is subjected to silicon infiltration treatment, and the silicon infiltration temperature ranges from 1600℃ to 1800℃; specifically, a solid silicon infiltration method is adopted, the preform coating is placed in a melting furnace and subjected to silicon infiltration by being heated to 1800℃ and kept for 2 h under argon protection, to obtain a dense SiC composite material.

[0038] Using silicon powder as the raw material, the silicon in the molten state gradually infiltrates into the pores of the preform coating under the protection of inert gas, chemically reacts with the carbon elements in the coating, generates new SiC phases, and these newly generated SiC phases fill the pores in the preform, thereby significantly improving the density of the material.

[0039] The microstructure morphology of the flat plate-shaped SiC composite material prepared is shown in Figure 1 . From Figure 1It can be seen that the prepared flat plate-shaped SiC composite material structure is dense, the newly generated SiC phase is uniformly distributed in the material, effectively filling the pores in the preform, so that the overall performance of the material is significantly improved. This microstructure feature is a direct manifestation of the advantages of the preparation method of the application. By accurately controlling the parameters of cold spraying and siliconizing treatment, high density and performance optimization of the material are successfully achieved.

[0040] Embodiment 2: This embodiment takes the preparation of flat plate-shaped SiC composite material as an example, and the preparation method comprises the following steps:

[0041] S1. Preparation of suspension: mix SiC powder with solvent, the ratio of SiC powder to solvent is 40%:60% according to mass ratio; take SiC powder with an average particle size of 40-45 μm, isopropanol as solvent, and add a small amount of polyetherimide as dispersant, wherein the addition amount of dispersant is 3% of SiC powder; configure into suspension, and uniformly and stably disperse for 4 h by ultrasonic dispersion.

[0042] S2. Preparation of SiC preform coating: spray the SiC suspension prepared in step S1 to the surface of the substrate to form a SiC preform coating. Nitrogen is used as the main gas, heated to 100-150℃, the spraying stress is 1.5-2.5 MPa, and the spraying distance is 50-60 mm; the above suspension is sent into the system, and under the control of the mechanical arm, a porous SiC preform coating with a thickness of about 1 mm is deposited on the carbon ceramic substrate.

[0043] S3. Post-curing treatment: carried out in a protective atmosphere or air, the treatment temperature is 160-200℃, and the treatment time is 1-1.5 h, so that the coating obtains sufficient initial strength; specifically, the substrate with coating is put into an atmosphere furnace and heated at 200℃ for 1.5 h under nitrogen protection to further enhance the cohesive strength of the coating. The post-curing treatment also includes carbonization treatment, the carbonization treatment temperature is 600-700℃, and the carbonization time is 1 h. The purpose is to carbonize the organic matter attached to the surface of SiC and in the voids of the preform.

[0044] S4. Siliconizing treatment: the SiC preform coating after post-curing treatment is subjected to siliconizing treatment, the siliconizing temperature range is 1800-1900℃, and a dense SiC composite material is obtained. In this embodiment, solid siliconizing method is used, the sample is placed in a melting furnace, heated to 1900℃ under argon protection and kept for 2 h for siliconizing, and a dense SiC composite material is obtained.

[0045] Embodiment 3: This embodiment takes the preparation of flat plate-shaped SiC composite material as an example, and the preparation method comprises the following steps:

[0046] S1. Preparation of the suspension: SiC powder is mixed with a solvent, the ratio of SiC powder to solvent is 25%:75% by mass; SiC powder with an average particle size of 30-35 μm is taken as the solvent, a small amount of sodium dodecyl benzene sulfonate is added as a dispersant, wherein the amount of the dispersant is 1% of the SiC powder; a suspension is prepared, and it is uniformly and stably dispersed by ultrasonic dispersion for 3 h.

[0047] S2. Preparation of the SiC preform coating: the SiC suspension prepared in step S1 is sprayed onto the surface of the substrate to form a SiC preform coating. Nitrogen is used as the main gas, and the temperature is heated to 300-450°C, the spraying stress is 1.5-2.5 MPa, and the spraying distance is 50-60 mm; the above suspension is fed into the system, and under the control of the mechanical arm, a porous SiC preform coating with a thickness of about 1 mm is deposited on the carbon ceramic substrate.

[0048] S3. Post-curing treatment: carried out in a protective atmosphere or air, the treatment temperature is 100-150°C, and the treatment time is 6-8 h, so that the coating obtains sufficient initial strength; the substrate with the coating is placed in an atmosphere furnace and heat treated at 150°C for 6 h under nitrogen protection to further enhance the cohesive strength of the coating. The post-curing treatment also includes carbonization treatment, the carbonization treatment temperature is 800-900°C, and the carbonization time is 3 h. The purpose is to carbonize the organic matter attached to the surface of SiC and in the voids of the preform.

[0049] S4. Silicon infiltration treatment: the SiC preform coating after the post-curing treatment is subjected to silicon infiltration treatment, the silicon infiltration temperature range is 1600-1700°C. Specifically, the solid silicon infiltration method is used, and in this embodiment, the sample is placed in a melting furnace, heated to 1600°C under argon protection, and held for 4 h for silicon infiltration, to obtain a dense SiC composite material.

[0050] Comparative Example 1: The preparation method of this comparative example is similar to that of Example 3, but the cold spraying step is not used, and the SiC preform coating is prepared by scraping a 40 wt % solid content SiC slurry. Post-curing treatment: carried out in a protective atmosphere or air, the treatment temperature is 100-150°C, and the treatment time is 6-8 h, the carbonization treatment temperature is 800-900°C, and the carbonization time is 3 h. The purpose is to carbonize the organic matter attached to the surface of SiC and in the voids of the preform.

[0051] Silicon infiltration treatment: the SiC preform coating after the post-curing treatment is subjected to silicon infiltration treatment, the silicon infiltration temperature range is 1600-1700°C, to obtain a dense SiC composite material. The solid silicon infiltration method is used, and in this embodiment, the sample is placed in a melting furnace, heated to 1600°C under argon protection, and held for 4 h for silicon infiltration, to obtain a dense SiC composite material.

[0052] The SiC composite materials prepared in Examples 1-3 were detected to have high density (>95%) and good combination. The SiC coating prepared in Comparative Example 1 has a density of 70%-80%. The SiC composite material prepared in Comparative Example 1 does not reach the high level (>95%) of the Examples, which indicates that the different coating preparation methods have a significant impact on the performance of the final material.

[0053] The above is only an embodiment of the present application, and the present application is not limited to the field involved in this embodiment. The common knowledge of specific structures and properties in the scheme is not described in detail. It should be pointed out that for those skilled in the art, without departing from the content of the present application, a number of modifications and improvements can be made, which should also be considered as the protection scope of the present application, which will not affect the effect and practicality of the patent. The protection scope claimed in the present application should be subject to the content of its claims, and the specific implementation mode and the like recorded in the specification can be used to explain the content of the claims.

Claims

1. A method for preparing a SiC composite material based on cold spraying and siliconizing, characterized in that, SiC powder is prepared into a suspension, the suspension is deposited on a substrate by a cold gas dynamic spraying system to form a porous SiC preform coating layer; The preform coating layer is subjected to post-solidification treatment to improve its cohesive strength; finally, through silicon infiltration treatment, silicon reacts with carbon in the preform to generate new SiC phase and fill the pores, so as to obtain a SiC composite material component with high density and excellent performance; The method comprises the following steps: S1. Preparation of the suspension: SiC powder is mixed with a solvent, and the mass ratio of SiC powder to the solvent is 20%-40%: 60%-80%; the particle size of the SiC powder is 18-45 μm; S2. Preparation of the SiC preform coating layer: the SiC suspension prepared in step S1 is sprayed onto the surface of the substrate to form a SiC preform coating layer; S3. Post-solidification treatment: post-solidification treatment is carried out in a protective atmosphere or air, the treatment temperature is 40-200 ℃, and the treatment time is 0.5-12 h, so that the coating layer obtains sufficient initial strength; S4. Silicon infiltration treatment: the SiC preform coating layer after the post-solidification treatment is subjected to silicon infiltration treatment, the silicon infiltration temperature ranges from 1600 ℃ to 1900 ℃, and the silicon infiltration time is 2-4 h; a dense SiC composite material is obtained.

2. The method of claim 1, wherein the SiC composite material is prepared by cold spraying and siliconizing. The solvent comprises at least one of deionized water, isopropyl alcohol, and methylpyrrolidone.

3. The method of claim 1, wherein the SiC composite material is prepared by cold spraying and siliconizing. The suspension further comprises a dispersant, the dispersant is one of sodium dodecyl benzene sulfonate and polyetherimide, and the addition amount of the dispersant is 0.5%-3% of the addition amount of the SiC powder.

4. The method of claim 1, wherein the SiC composite material is prepared by cold spraying and siliconizing. The spraying and heating temperature of the SiC suspension is 100-600 ℃.

5. The method according to claim 4, wherein the SiC composite material is prepared by cold spraying and siliconizing. When the dispersant is added to the suspension, the post-solidification treatment further comprises carbonization treatment, the carbonization temperature is 600-900 ℃, and the carbonization time is 1-3 h.

6. The method for producing SiC composite material based on cold spraying and silicidation according to claim 1, characterized in that, The silicon infiltration treatment is silicon infiltration treatment using silicon powder as raw material in an inert gas atmosphere.

7. Use of a material prepared according to the method of claim 1-6, characterized in that, The SiC composite material is used for aerospace hot end components, nuclear reactor cladding materials, semiconductor equipment components, or wear-resistant devices. The SiC composite material is used for aerospace hot end components, nuclear reactor cladding materials, semiconductor equipment components, or wear-resistant devices.

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