Silicon carbide-tungsten carbide heterostructure composite material and preparation method thereof

Abstract

The invention provides a preparation method of a silicon carbide-tungsten carbide heterostructure composite material and the silicon carbide-tungsten carbide heterostructure composite material, and relates to the technical field of ceramic matrix composites.The preparation method comprises the steps that a polymer containing a carbon source and a silicon carbide precursor is dissolved in a solvent, and a precursor solution is formed; uniformly mixing tungsten powder with the precursor solution to obtain a mixed solution; performing vacuum drying on the mixed solution to remove a solvent in the mixed solution to obtain a dried mixture; the obtained dried mixture is subjected to high-temperature sintering, the silicon carbide-tungsten carbide heterostructure composite material is prepared, and tungsten carbide in the silicon carbide-tungsten carbide heterostructure composite material is evenly distributed in a silicon carbide matrix. The performance and preparation efficiency of the silicon carbide-tungsten carbide heterostructure composite material can be improved.

Description

Technical Field

[0001] This disclosure relates to the field of ceramic matrix composite technology, and more specifically, to a method for preparing a silicon carbide-tungsten carbide heterostructure composite material and the silicon carbide-tungsten carbide heterostructure composite material. Background Technology

[0002] SiC ceramics are a very important advanced structural and functional ceramic. Due to their unique atomic bonding and crystal structure, they possess excellent comprehensive properties such as high temperature strength, strong thermal shock resistance, corrosion resistance, and lightweight high strength, making them irreplaceable in extreme and harsh environments. However, they still have characteristics such as high brittleness, poor impact resistance, and high processing difficulty, which seriously limit their applications.

[0003] Tungsten carbide (WC), a typical transition metal carbide, is widely used in various fields due to its unique mechanical properties. The extremely strong covalent bonds between tungsten and carbon in tungsten carbide effectively hinder crystal plane slip, resulting in high melting point, high hardness, high elastic modulus, and high fracture toughness. This makes tungsten carbide an indispensable industrial material in machining and aerospace components. Introducing tungsten carbide (WC) as a reinforcing phase into a SiC matrix is ​​an effective way to improve its mechanical properties.

[0004] In related technologies, the forming and sintering methods of WC / SiC composite materials mainly include hot pressing sintering, pressureless sintering, and reaction sintering. Among them, hot pressing sintering has complex equipment and high cost, and can only produce parts with simple shapes; pressureless sintering has high sintering temperature and high energy consumption, and the high density of WC may cause uneven component distribution; reaction sintering often leaves free silicon in the sintered body, which may affect high-temperature performance, and requires precise control to avoid excessive reaction between WC and Si, making the process more difficult. Summary of the Invention

[0005] The purpose of this disclosure is to provide a method for preparing silicon carbide-tungsten carbide heterostructure composite materials and silicon carbide-tungsten carbide heterostructure composite materials, thereby overcoming, to at least a certain extent, the problems of uneven component distribution, high production cost, complex and difficult process, and poor performance caused by the limitations and defects of related technologies.

[0006] According to one aspect of this disclosure, a method for preparing a silicon carbide-tungsten carbide heterostructure composite material is provided, comprising: A polymer containing a carbon source and a silicon carbide precursor is dissolved in a solvent to form a precursor solution; Tungsten powder and precursor solution are uniformly mixed to obtain a mixed solution; The mixed solution is vacuum dried to remove the solvent, thus obtaining a dried mixture; The dried mixture was sintered at high temperature to prepare a silicon carbide-tungsten carbide heterostructure composite material, in which tungsten carbide was uniformly distributed in the silicon carbide matrix.

[0007] In one exemplary embodiment of this disclosure, the carbon source is selected from high-temperature pyrolysis products containing free carbon polymers, and the carbon source is selected from polycarbosilane.

[0008] In one exemplary embodiment of this disclosure, the solvent is an organic solvent with a concentration of 30wt%-60wt%.

[0009] In one exemplary embodiment of this disclosure, the organic solvent is selected from xylene.

[0010] In one exemplary embodiment of this disclosure, the mass ratio of polymer to solvent is 0.3:1 to 1:1.

[0011] In one exemplary embodiment of this disclosure, the mass ratio of tungsten powder to precursor solution is 10wt%-30wt%.

[0012] In one exemplary embodiment of this disclosure, tungsten powder is uniformly mixed with a precursor solution to form a mixed solution, comprising: Tungsten powder and precursor solution are uniformly mixed by ultrasonic dispersion, and the ultrasonic dispersion time is 1-2 hours.

[0013] In one exemplary embodiment of this disclosure, vacuum drying of the mixed solution includes: The mixed solution was vacuum dried in a vacuum oven, with the vacuum level maintained below 4 kPa, the drying temperature at 60℃, and the drying time at 10-15 h.

[0014] In one exemplary embodiment of this disclosure, the high-temperature sintering atmosphere is an inert atmosphere, the high-temperature sintering temperature is 800-1300℃, and the holding time is 1-4 hours.

[0015] According to one aspect of this disclosure, a silicon carbide-tungsten carbide heterostructure composite material is provided, which is prepared according to the above-described method for preparing the silicon carbide-tungsten carbide heterostructure composite material.

[0016] In the technical solution provided in this disclosure, on the one hand, a polymer containing a carbon source and a silicon carbide precursor, a solvent, and tungsten powder are used as the main raw materials. A precursor solution is prepared by the polymer and solvent, and the tungsten powder is uniformly dispersed in the precursor solution by ultrasonic dispersion. After vacuum drying, a uniformly mixed dried mixture is obtained. Then, the dried mixture is subjected to high-temperature pyrolysis under an inert atmosphere. During the pyrolysis process, the tungsten powder and the free carbon generated from the polymer PCS undergo an in-situ carbonization reaction to obtain a silicon carbide-tungsten carbide ceramic matrix composite material. In the obtained material, SiC and tungsten carbide are tightly composited, forming a dispersed distribution structure of tungsten carbide in the SiC ceramic matrix. This achieves nanoscale uniform dispersion and clean interface bonding of tungsten carbide in the SiC matrix, avoiding the agglomeration problem of the added reinforcing phase. By controlling the molecular structure of PCS and the pyrolysis process, ceramic transformation can be achieved at a relatively low temperature. This facilitates the preparation of complex microstructures such as thin films, coatings, or fiber-reinforced composite materials, increasing the application range and improving the performance and reliability of ceramic materials. On the other hand, the process of this disclosure is simple and convenient, reduces energy consumption, improves feasibility, and increases preparation efficiency. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0018] Figure 1 The flowchart illustrates a method for preparing a silicon carbide-tungsten carbide heterostructure composite material according to an embodiment of the present disclosure.

[0019] Figure 2 This is a SEM image of the morphology of tungsten powder in an embodiment of this disclosure.

[0020] Figure 3 The image shows the X-ray diffraction (XRD) pattern of the silicon carbide-tungsten carbide composite material prepared in Example 3.

[0021] Figure 4 The image shows the SEM image of the morphology of the silicon carbide-tungsten carbide composite material prepared in Example 1.

[0022] Figure 5 The image shows the SEM image of the morphology of the silicon carbide-tungsten carbide composite material prepared in Example 2.

[0023] Figure 6 The image shows the SEM image of the morphology of the silicon carbide-tungsten carbide composite material prepared in Example 3.

[0024] Figure 7The image shows the surface scan result of energy dispersive spectroscopy (EDS) of the silicon carbide-tungsten carbide composite material prepared in Example 3.

[0025] Figure 8 This is an energy dispersive spectroscopy (EDS) spot scan image of the silicon carbide-tungsten carbide composite material prepared in Example 3.

[0026] Figure 9 This is a schematic diagram of the energy dispersive spectroscopy (EDS) surface scan results of the tungsten carbide-silicon carbide composite material prepared in a comparative proportion. Detailed Implementation

[0027] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided to make this disclosure more comprehensive and complete, and to fully convey the concept of the example embodiments to those skilled in the art. The described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a full understanding of embodiments of this disclosure. However, those skilled in the art will recognize that the technical solutions of this disclosure can be practiced with one or more of the specific details omitted, or other methods, components, apparatus, steps, etc., can be employed. In other instances, well-known technical solutions are not shown or described in detail to avoid obscuring various aspects of this disclosure.

[0028] The terms “a,” “an,” “the,” and “the” are used in this specification to indicate the presence of one or more elements / components, etc.; the terms “including” and “having” are used to indicate an open-ended inclusion and to mean that there may be other elements / components, etc., in addition to those listed; the terms “first” and “second” are used only as markings and are not a limitation on the number of objects.

[0029] Tungsten carbide (WC), a typical transition metal carbide, is widely used in various fields due to its unique mechanical properties. The extremely strong covalent bonds between tungsten and carbon in tungsten carbide effectively hinder crystal plane slip, resulting in high melting point, high hardness, high elastic modulus, and high fracture toughness. This makes tungsten carbide an indispensable industrial material in machining and aerospace components. Introducing tungsten carbide (WC) as a reinforcing phase into a SiC matrix is ​​an effective strategy to improve its mechanical properties. However, achieving uniform dispersion of WC and its good interfacial bonding with the matrix depends on the composite material preparation process.

[0030] Currently, the forming and sintering of WC / SiC composite materials mainly include hot pressing sintering, pressureless sintering, and reaction sintering. Hot pressing sintering, by applying pressure at high temperatures, can significantly reduce the sintering temperature and inhibit grain growth, resulting in high-density, fine-grained composite materials, thus effectively leveraging the reinforcing and toughening effects of WC. However, this process involves complex equipment, high costs, and can only produce parts with simple shapes. Pressureless sintering, while enabling mass production and suitable for complex-shaped products, has high sintering temperatures and high energy consumption, and the high density of WC may cause uneven component distribution. Reaction sintering, combined with advanced forming technologies such as gel casting, can achieve near-net-shape forming and produce extremely complex-shaped parts. However, free silicon often remains in the sintered body, which may affect high-temperature performance, and requires precise control to avoid excessive reaction between WC and Si.

[0031] Based on this, this disclosure provides a method for preparing a silicon carbide-tungsten carbide heterostructure composite material, used to prepare the silicon carbide-tungsten carbide heterostructure composite material. (Reference) Figure 1 As shown, the preparation method of this silicon carbide-tungsten carbide heterostructure composite material mainly includes the following steps: In step S110, the polymer containing a carbon source and a silicon carbide precursor is dissolved in a solvent to form a precursor solution; In step S120, tungsten powder and precursor solution are uniformly mixed to obtain a mixed solution; In step S130, the mixed solution is vacuum dried to remove the solvent from the mixed solution, thereby obtaining a dried mixture; In step S140, the obtained dried mixture is subjected to high-temperature sintering to prepare a silicon carbide-tungsten carbide heterostructure composite material, in which tungsten carbide is uniformly distributed in the silicon carbide matrix.

[0032] In this embodiment, a precursor solution formed from a polymer represented by polycarbosilane (PCS) is mixed with tungsten powder. Through crosslinking, molding, and high-temperature pyrolysis, the tungsten powder reacts in situ with the free carbon released from the pyrolysis of PCS to generate a WC reinforcing phase. This achieves nanoscale uniform distribution and clean interface bonding of WC in the SiC matrix, avoiding the agglomeration problem of the added reinforcing phase. By controlling the molecular structure of PCS and the pyrolysis process, ceramic transformation can be achieved at relatively low temperatures. There is no need for precise control of reaction conditions and process parameters to avoid excessive reaction between WC and Si, enhancing operability and facilitating the preparation of complex microstructures such as thin films, coatings, or fiber-reinforced composites. Furthermore, it improves the performance and reliability of ceramic matrix composites. In addition, it reduces the complexity of process equipment and preparation costs, lowers energy consumption, and improves preparation efficiency.

[0033] Next, the preparation method of the silicon carbide-tungsten carbide heterostructure composite material in the embodiments of this disclosure will be described in detail.

[0034] In step S110, the polymer containing a carbon source and a silicon carbide precursor is dissolved in a solvent to form a precursor solution.

[0035] In this embodiment, the polymer can be a high molecular weight polymer, which includes a silicon carbide precursor and a carbon source, wherein the content of the carbon source is less than the content of silicon carbide. The polymer is pyrolyzed to generate silicon carbide and carbon, and in-situ doping is achieved through the carbon. The carbon source can be selected from high molecular weight polymers whose high-temperature pyrolysis products contain free carbon. For example, the carbon source can be selected from polycarbosilane (PCS), that is, the polymer containing a carbon source and a silicon carbide precursor can be a polycarbosilane.

[0036] Polymer precursors are widely used in ceramic matrix composites due to their structural designability and molding effect that is unmatched by traditional ceramic processes. Among them, polycarbosilane (PCS), a SiC ceramic precursor, refers to a polymer compound whose main chain or branches mainly contain Si and C atoms. After pyrolysis, it can yield ceramics containing SiC and free carbon. At lower pyrolysis temperatures, it mainly consists of an amorphous phase. As the pyrolysis temperature increases, the SiC grain size increases and the graphitization degree of free carbon increases.

[0037] The solvent can be an organic solvent, and when the solvent is an organic solvent, xylene can be used. The concentration of the solvent is 30wt%-60wt%.

[0038] The mass ratio of the carbon source polymer to the solvent can be 0.3:1 to 1:1, for example, 3:7, 4:6, or 5:5. The polymer containing the carbon source and silicon carbide precursor can be dissolved in the solvent to form a precursor solution. Here, we will use polycarbosilane as the carbon source and xylene as the solvent as an example. When the carbon source is polycarbosilane and the solvent is xylene, the polymer containing the carbon source and silicon carbide precursor is polycarbosilane. Polycarbosilane and xylene can be mixed at mass ratios of 3:7, 4:6, and 5:5 respectively to obtain a mixture. The mixture can then be ultrasonically dispersed in an ultrasonic disperser for 1-2 hours to obtain the precursor solution, which is the PCS / xylene solution.

[0039] In step S120, tungsten powder and precursor solution are uniformly mixed to obtain a mixed solution.

[0040] In this embodiment of the present disclosure, when tungsten powder is added to the prepared precursor solution to obtain a mixed solution, ultrasonic dispersion can be used to uniformly mix the tungsten powder and the precursor solution. The ultrasonic dispersion time is 1-2 hours to obtain a PCS / xylene solution containing tungsten powder as the mixed solution. The mass ratio of tungsten powder to precursor solution is 10wt%-30wt%.

[0041] In step S130, the mixed solution is vacuum dried to remove the solvent from the mixed solution, thereby obtaining a dried mixture.

[0042] In this embodiment of the disclosure, when drying the mixed solution, the mixed solution can be placed in a vacuum oven for vacuum drying. During the vacuum drying process, the vacuum degree of the vacuum oven is maintained below 4 kPa, the drying temperature is 60°C, and the drying time is 10-15 hours. Vacuum drying of the mixed solution refers to drying the solvent in the mixed solution to remove xylene solvent, thereby obtaining a dried mixture.

[0043] In step S140, the obtained dried mixture is subjected to high-temperature sintering to prepare a silicon carbide-tungsten carbide heterostructure composite material, in which tungsten carbide is uniformly distributed in the silicon carbide matrix.

[0044] In this embodiment, after obtaining the dried mixture, the dried tungsten powder and PCS mixture is ground and crushed, then placed in an alumina crucible for high-temperature sintering. The high-temperature sintering atmosphere is an inert atmosphere, such as argon. The high-temperature sintering temperature is 800-1300℃, and the holding time is 1-4 hours. After high-temperature sintering, polycarbosilane undergoes pyrolysis to generate amorphous SiC and free carbon. Simultaneously, the tungsten powder reacts in situ with the free carbon generated from the pyrolysis of polycarbosilane to generate WC, achieving in-situ production and uniform distribution of WC within the SiC ceramic matrix. A silicon carbide-tungsten carbide heterostructure composite material is obtained through in-situ reaction. In the prepared silicon carbide-tungsten carbide heterostructure composite material, tungsten carbide is uniformly distributed within the silicon carbide SiC ceramic matrix.

[0045] The technical solution in this embodiment firstly disperses tungsten powder uniformly in a polycarbosilane / xylene solution using ultrasonic dispersion. Vacuum drying yields a homogeneous mixture of tungsten powder and polycarbosilane. High-temperature sintering causes the polycarbosilane to decompose, generating amorphous SiC and free carbon. Simultaneously, the tungsten powder reacts in situ with the free carbon to generate WC, achieving in-situ production and uniform distribution of WC within the SiC ceramic matrix. Alternatively, tungsten powder is mixed with a PCS / xylene solution. After solution preparation, introduction of the reinforcing phase, vacuum drying, and high-temperature reaction, while the PCS decomposes at high temperature to generate SiC and free carbon, the free carbon reacts with the tungsten powder uniformly mixed within the PCS, generating a tungsten carbide reinforcing phase in situ within the SiC. The WC phase not only has a tight composite with the SiC matrix but also forms a dispersed distribution structure within the SiC, achieving uniform distribution of the tungsten carbide reinforcing phase within the silicon carbide ceramic matrix. This improves the performance of the composite material, and its unique structure provides a new strategy for the design of ceramic matrix composites.

[0046] Uniform mixing of tungsten powder and PCS is achieved by mixing tungsten powder with a PCS / xylene solution. Sintering this mixture allows for in-situ generation of tungsten carbide within a SiC matrix. The tungsten powder content in the PCS / xylene solution and the concentration of the PCS / xylene solution are controlled, thereby adjusting the tungsten carbide content in the SiC matrix, enabling flexible tungsten powder addition. This method can be applied to other polymers, such as polycarbosilanes, polysiloxanes, and polysilazanes, which contain free carbon, thus expanding its application range.

[0047] Next, the preparation method of the silicon carbide-tungsten carbide heterostructure composite material provided in this disclosure will be described in detail with reference to the embodiments.

[0048] Example 1

[0049] Step 1, Solution Preparation: Mix polycarbosilane and xylene at a mass ratio of 3:7 to obtain a mixture. Then, place the mixture in an ultrasonic disperser and ultrasonically disperse for 1 hour to obtain a 30wt% PCS / xylene solution, which will be used as the precursor solution.

[0050] Step 2, introducing filler: Using an ultrasonic dispersion process, 16g of tungsten powder is uniformly mixed into 50g of a 30 wt% PCS / xylene solution, and ultrasonically dispersed for 1 hour using an ultrasonic disperser. The tungsten powder and PCS / xylene solution are uniformly mixed to obtain a PCS / xylene solution containing tungsten powder as a mixed solution.

[0051] Step 3: Drying Treatment: The mixed solution is dried in a vacuum oven to remove xylene solvent. Specifically, the mixed solution is placed in a vacuum oven with the vacuum level maintained below 4 kPa and the oven temperature set at 65°C for 12 hours. After all the solvent in the mixed solution has evaporated, the PCS / tungsten powder composite material is obtained as the dried mixture.

[0052] Step 4, sintering treatment: The dried mixture of tungsten powder and PCS is ground and crushed and placed in a corundum crucible. It is then sintered at 800°C for 2 hours under an argon atmosphere to obtain a silicon carbide-tungsten carbide heterostructure composite material prepared by in-situ carbonization.

[0053] Example 2

[0054] Step 1, Solution Preparation: Mix polycarbosilane and xylene at a mass ratio of 4:6 to obtain a mixture. Place the mixture in an ultrasonic disperser and ultrasonically disperse for 1.5 hours to obtain a 40wt% PCS / xylene solution, which will be used as the precursor solution.

[0055] Step 2, introducing filler: Using an ultrasonic dispersion process, 14g of tungsten powder is uniformly mixed into 50g of a 40wt% PCS / xylene solution, and ultrasonically dispersed for 1.5 hours using an ultrasonic disperser. The tungsten powder and PCS / xylene solution are uniformly mixed to obtain a PCS / xylene solution containing tungsten powder as a mixed solution.

[0056] Step 3: Drying Treatment: The mixed solution is dried in a vacuum oven to remove xylene solvent. Specifically, the mixed solution is placed in a vacuum oven with the vacuum level maintained below 4 kPa and the oven temperature set at 65°C for 10 hours. After all the solvent in the mixed solution has evaporated, the PCS / tungsten powder composite material is obtained. This PCS / tungsten powder composite material is the dried mixture.

[0057] Step 4, sintering treatment: The dried mixture of tungsten powder and PCS is ground and crushed and placed in a corundum crucible. It is sintered at 1000℃ for 2 hours under argon atmosphere protection to obtain silicon carbide-tungsten carbide heterostructure composite material prepared by in-situ carbonization method.

[0058] Example 3

[0059] Step 1, Solution Preparation: Mix polycarbosilane and xylene at a mass ratio of 5:5 to obtain a mixture. Then, place the mixture in an ultrasonic disperser and ultrasonically disperse for 2 hours to obtain a 50wt% PCS / xylene solution, which will be used as the precursor solution.

[0060] Step 2, introducing filler: Using an ultrasonic dispersion process, 12g of tungsten powder is uniformly mixed into 50g of a 50wt% PCS / xylene solution, and ultrasonically dispersed for 2 hours using an ultrasonic disperser. The tungsten powder and PCS / xylene solution are uniformly mixed to obtain a PCS / xylene mixed solution containing tungsten powder as the mixed solution.

[0061] Step 3: Drying Treatment: The mixed solution is dried in a vacuum oven to remove xylene solvent. Specifically, the mixed solution is placed in a vacuum oven with the vacuum level maintained below 4 kPa and the oven temperature set at 65°C for 12 hours. After all the solvent in the mixed solution has evaporated, the PCS / tungsten powder composite material is obtained as the dried mixture.

[0062] Step 4, sintering treatment: The dried mixture of tungsten powder and PCS is ground and crushed and placed in a corundum crucible. It is sintered at 1100℃ for 2 hours under argon atmosphere protection to obtain silicon carbide-tungsten carbide heterostructure composite material prepared by in-situ carbonization method.

[0063] Comparative Example

[0064] Step 1: Mixing. Mix 20g of SiC powder and 10g of tungsten powder at a mass ratio of 2:1 and add to a ball mill jar for ball milling to obtain a mixed slurry. Zirconia grinding beads are used during the ball milling process, with alcohol as the dispersant. The ball-to-powder ratio is 3:1, the ball milling speed is 180 r / min, and the milling time is 6 hours.

[0065] Step 2: Vacuum Drying. The mixed slurry is dried in a vacuum oven to remove the alcohol dispersant solvent. The ball-milled mixed slurry is placed in a vacuum oven, with the vacuum level maintained below 3 kPa, and the oven temperature set at 65℃ for 12 hours. After all the alcohol solvent in the mixed solution has evaporated, SiC / tungsten powder composite powder is obtained.

[0066] Step 3: High-temperature reaction. The dried tungsten powder and the SiC / tungsten powder composite powder, represented by the SiC mixture, are placed in a box furnace and sintered at 1600℃ for 2 hours under an argon atmosphere to obtain the tungsten carbide in-situ reinforced silicon carbide ceramic matrix composite material.

[0067] After preparing the silicon carbide-tungsten carbide heterostructure composite material, the microstructure of the tungsten carbide-silicon carbide heterostructure composite materials obtained in Examples 1-3 and the comparative examples was observed. The phase composition of the tungsten carbide-silicon carbide heterostructure composite material was analyzed by XRD, and the elemental content of the phase was analyzed by EDS using surface scanning and point scanning.

[0068] Figure 2A schematic SEM image of tungsten powder is shown. From Figure 2 It can be seen that the tungsten powder used is a powder with a particle size of 50-100nm.

[0069] Figure 3 The X-ray diffraction (XRD) pattern of the prepared tungsten carbide-silicon carbide composite material is shown. Figure 3 It can be seen that there are obvious tungsten carbide characteristic peaks in the SiC matrix, proving that the technical solution in this embodiment successfully generated tungsten carbide phase in situ in the SiC matrix.

[0070] Figures 4-6 SEM images of the morphology of the tungsten carbide-silicon carbide composite materials prepared in Examples 1-3 are shown below. Figures 4-6 It can be seen that tungsten carbide is uniformly distributed in the SiC matrix.

[0071] Figure 7 The image shows the energy dispersive spectroscopy (EDS) surface scan results of the silicon carbide-tungsten carbide composite material prepared in Example 3. Figure 7 (a) shows the morphology of the SiC matrix with WC. Figure 7 (b) in the diagram shows the elemental distribution of C, Si, and W. Figure 7 (c) in the diagram represents the distribution of C element within the SiC matrix. Figure 7 (d) in the diagram represents the distribution of Si elements within the SiC matrix. Figure 7 In the diagram, (e) represents the distribution of W element within the SiC matrix. Table 1 shows the elemental composition of the silicon carbide-tungsten carbide composite material prepared in Example 3 using energy dispersive spectroscopy (EDS). Figure 7 As shown in Table 1, W is uniformly distributed within the SiC matrix.

[0072] Table 1

[0073] Figure 8 Table 2 shows the energy dispersive spectroscopy (EDS) spot scan results of the tungsten carbide-silicon carbide composite material prepared in Example 3. Table 2 is a schematic diagram of the elemental composition of the silicon carbide-tungsten carbide composite material prepared in Example 3 using EDS spot scans. Figure 8 As shown in Table 2, the compounds generated in situ within the SiC matrix contain tungsten and carbon elements.

[0074] Table 2

[0075] Figure 9 The above are the energy dispersive spectroscopy (EDS) surface scan results of the tungsten carbide-silicon carbide composite material prepared in the comparative example, where... Figure 9 (a) in the figure is a comparative example of the SiC matrix morphology. Figure 9(b) in the diagram shows the elemental distribution of C, Si, and W. Figure 9 (c) in the diagram represents the distribution of C element within the SiC matrix. Figure 9 (d) in the diagram represents the distribution of Si elements within the SiC matrix. Figure 9 (e) in the figure represents the distribution of W element in the SiC matrix. Table 3 shows the elemental composition of the tungsten carbide-silicon carbide composite material prepared in the comparative example by energy dispersive spectroscopy (EDS).

[0076] Table 3

[0077] Depend on Figure 9 (b) and Figure 9 As shown in (e) and Table 3, the W element distribution in the SiC matrix of the comparative example is not uniform. Furthermore, since the SiC ceramic powder does not contain free carbon, it is difficult to generate the WC reinforcing phase in situ within the SiC matrix using the preparation process of the comparative example.

[0078] In summary, the technical solution in this embodiment involves dissolving PCS in xylene, then uniformly dispersing tungsten powder in the PCS / xylene mixed solution to mix the tungsten powder with the PCS / xylene solution. After solution preparation, introduction of filler, vacuum drying, and high-temperature sintering, the PCS undergoes high-temperature pyrolysis to generate amorphous SiC and free carbon. Simultaneously, the free carbon generated from the pyrolysis reacts in situ with the tungsten powder uniformly mixed within the PCS, generating a tungsten carbide phase in situ within the SiC matrix. This tungsten carbide phase not only has a tight composite with the SiC matrix, but the resulting WC material forms a dispersed distribution structure within the SiC, ensuring uniform distribution of WC within the SiC matrix and effectively improving the performance of the ceramic material. This method facilitates the uniform distribution of tungsten carbide within the SiC matrix, making it easier to control the tungsten carbide content within the SiC matrix and improving operability. It is suitable for use in the field of ceramic matrix composites, expanding its application range. The preparation of tungsten carbide-silicon carbide ceramic matrix composites by means of mixing, ultrasonic dispersion, drying and high-temperature sintering simplifies the operation steps, reduces the preparation cost, improves feasibility and preparation efficiency, and enables mass production.

[0079] In this embodiment of the disclosure, a silicon carbide-tungsten carbide heterostructure composite material is also provided, which can be prepared according to the preparation method of silicon carbide-tungsten carbide heterostructure composite material in steps S110 to S140. This silicon carbide-tungsten carbide heterostructure composite material can achieve in-situ generation and uniform distribution of WC within the SiC ceramic matrix, thereby improving material properties.

[0080] Furthermore, the above figures are merely illustrative of the processes included in the method according to exemplary embodiments of this disclosure and are not intended to be limiting. It is readily understood that the processes shown in the above figures do not indicate or limit the temporal order of these processes. Additionally, it is readily understood that these processes may be executed synchronously or asynchronously, for example, in multiple modules.

[0081] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the appended claims.

[0082] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. A method for preparing a silicon carbide-tungsten carbide heterostructure composite material, characterized in that, include: A polymer containing a carbon source and a silicon carbide precursor is dissolved in a solvent to form a precursor solution; The tungsten powder is uniformly mixed with the precursor solution to obtain a mixed solution; The mixed solution is subjected to vacuum drying to remove the solvent from the mixed solution, thereby obtaining a dried mixture; The obtained dried mixture is subjected to high-temperature sintering to prepare a silicon carbide-tungsten carbide heterostructure composite material, wherein tungsten carbide is uniformly distributed in the silicon carbide matrix in the silicon carbide-tungsten carbide heterostructure composite material.

2. The method for preparing the silicon carbide-tungsten carbide heterostructure composite material according to claim 1, characterized in that, The carbon source is selected from high-temperature pyrolysis products containing free carbon polymers, and the carbon source is selected from polycarbosilane.

3. The method for preparing the silicon carbide-tungsten carbide heterostructure composite material according to claim 1, characterized in that, The solvent is an organic solvent, and the concentration of the solvent is 30wt%-60wt%.

4. The method for preparing the silicon carbide-tungsten carbide heterostructure composite material according to claim 3, characterized in that, The organic solvent is selected from xylene.

5. The method for preparing the silicon carbide-tungsten carbide heterostructure composite material according to claim 1, characterized in that, The mass ratio of the polymer to the solvent is 0.3:1 to 1:

1.

6. The method for preparing the silicon carbide-tungsten carbide heterostructure composite material according to claim 1, characterized in that, The mass ratio of the tungsten powder to the precursor solution is 10wt%-30wt%.

7. The method for preparing the silicon carbide-tungsten carbide heterostructure composite material according to claim 1, characterized in that, The step of uniformly mixing tungsten powder with the precursor solution to form a mixed solution includes: The tungsten powder and the precursor solution are uniformly mixed by ultrasonic dispersion, and the ultrasonic dispersion time is 1-2 hours.

8. The method for preparing the silicon carbide-tungsten carbide heterostructure composite material according to claim 1, characterized in that, The vacuum drying of the mixed solution includes: The mixed solution was vacuum dried in a vacuum oven, with the vacuum level maintained below 4 kPa, the drying temperature at 60°C, and the drying time at 10-15 h.

9. The method for preparing the silicon carbide-tungsten carbide heterostructure composite material according to claim 1, characterized in that, The high-temperature sintering atmosphere is an inert atmosphere, the high-temperature sintering temperature is 800-1300℃, and the holding time is 1-4 hours.

10. A silicon carbide-tungsten carbide heterostructure composite material, characterized in that, The silicon carbide-tungsten carbide heterostructure composite material is prepared by the method for preparing the silicon carbide-tungsten carbide heterostructure composite material according to any one of claims 1-9.

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